NASA

RFK Jr.’s health department calls Nature “junk science,” cancels subscriptions

doe, health, NASA, Nature, NIH, USDA / Mike M. / July 2, 2025

The move comes after HHS Secretary and anti-vaccine activist Robert F. Kennedy Jr. said on a May 27 podcast that prestigious medical journals are “corrupt.”

“We’re probably going to stop publishing in the Lancet, New England Journal of Medicine, JAMA, and those other journals because they’re all corrupt,” he said. He accused the journals collectively of being a “vessel for pharmaceutical propaganda.” He went on to say that “unless these journals change dramatically,” the federal government would “stop NIH scientists from publishing there” and create “in-house” journals instead.

Kennedy’s criticism largely stems from his belief that modern medicine and mainstream science are part of a global conspiracy to generate pharmaceutical profits. Kennedy is a germ-theory denier who believes people can maintain their health not by relying on evidence-based medicine, such as vaccines, but by clean living and eating—a loose concept called “terrain theory.”

Access to top scientific and medical journals is essential for federal scientists to keep up to date with their fields and publicize high-impact results. One NIH employee added to Nature news that it “suppresses our scientific freedom, to pursue information where it is present.”

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Ars reflects on Apollo 13 turning 30

Apollo13, culture, Entertainment, film anniversaries, films, NASA, Science, space history, Staff source, Universal Pictures / 9u50fv / June 29, 2025

Ron Howard’s 1995 love letter to NASA’s Apollo program takes a few historical liberties but it still inspires awe.

Credit: Universal Pictures

This year marks the 30th anniversary of the 1995 Oscar-winning film, Apollo 13, director Ron Howard’s masterful love letter to NASA’s Apollo program in general and the eponymous space mission in particular. So we’re taking the opportunity to revisit this riveting homage to American science, ingenuity, and daring.

(Spoilers below.)

Apollo 13 is a fictional retelling of the aborted 1970 lunar mission that became a “successful failure” for NASA because all three astronauts made it back to Earth alive against some pretty steep odds. The film opens with astronaut Jim Lovell (Tom Hanks) hosting a watch party in July 1969 for Neil Armstrong’s historic first walk on the Moon. He is slated to command the Apollo 14 mission, and is ecstatic when he and his crew—Ken Mattingly (Gary Sinise) and Fred Haise (Bill Paxton)—are bumped to Apollo 13 instead. His wife, Marilyn (Kathleen Quinlan) is more superstitious and hence less thrilled: “It had to be 13.” To which her pragmatic husband replies, “It comes after 12.”

A few days before launch, Mattingly is grounded because he was exposed to the measles and replaced with backup Jack Swigert (Kevin Bacon), who is the only one happy about the situation. But Lovell and Haise rebound from the disappointment and the launch goes off without a hitch. The public, alas, just isn’t interested in what they think has become routine. But the mission is about to become anything but that.

During a maintenance task to stir the oxygen tanks, an electrical short causes one of the tanks to explode, with the other rapidly venting its oxygen into space. The crew has less than an hour to evacuate the command module Odyssey into the lunar module Aquarius, using it as a lifeboat. There is no longer any chance of landing on the Moon; the new mission is to keep the astronauts alive long enough to figure out how to bring them safely home. That means overcoming interpersonal tensions, freezing conditions, dwindling rations, and unhealthy CO2 levels, among other challenges, as well as taking on a pulse-pounding manual course correction with no navigational computer. (Spoiler alert: they make it!)

The Apollo 13 crew: Jim Lovell (Tom Hanks), Jack Swigert (Kevin Bacon), and Fred Haise (Bill Paxton). Universal Pictures

The film is loosely based on Lovell’s 1994 memoir, Lost Moon. While Lovell initially hoped Kevin Costner would portray him, Howard ultimately cast Hanks in the role, in part because the latter already had extensive knowledge of the Apollo program and space history. Hanks, Paxton, and Bacon all went to US Space Camp to prepare for their roles, participating in astronaut training exercises and flying on the infamous “Vomit Comet” (the KC-135) to experience simulated weightlessness. Howard ultimately shot most of the weightless scenes aboard the KC-135 since recreating those conditions on a soundstage and with CGI would have been prohibitively expensive.

In fact, Howard didn’t rely on archival mission footage at all, insisting on shooting his own footage. That meant constructing realistic spacecraft interiors—incorporating some original Apollo materials—and reproducing exactly the pressure suits worn by astronauts. (The actors, once locked in, breathed air pumped into the suits just like the original Apollo astronauts.) The Mission Control set at Universal Studios was so realistic that one NASA consultant kept looking for the elevator when he left each day, only to remember he was on a movie set.

The launch sequence was filmed using miniature models augmented with digital image stitching. Ditto for the splashdown, in which actual parachutes and a prop capsule were tossed out of a helicopter to shoot the scene. Only the exhaust from the attitude control thrusters was generated with CGI. A failed attempt at using CGI for the in-space urine dump was scrapped in favor of just spraying droplets from an Evian bottle.

It all paid off in the end. Apollo 13 premiered on June 30, 1995, to critical acclaim and racked up over $355 million globally at the box office. It was nominated for nine Oscars and won two—Best Film Editing and Best Sound—although it lost Best Picture to another Hanks film, Forrest Gump. (We can’t quite believe it either.) And the film has stood the test of time, capturing the essence of America’s early space program for posterity. A few Ars staffers shared their thoughts on Apollo 13‘s enduring legacy.

Failure should be an option

White Team Flight Director Gene Krantz (Ed Harris) insists, “We are not losing those men!” Universal Pictures

The tagline for Apollo 13 is “Failure is not an option.” But this is a bit of Hollywood magic. It turns out that NASA Flight Director Gene Kranz never said the line during the actual Apollo 13 mission to the Moon, or the subsequent efforts to save the crew.

Instead the line was conceived after the script writers, Al Reinert and Bill Broyles, interviewed Kranz at his home Texas, south of Johnson Space Center. They were so taken by the notion it became synonymous with the film and with Kranz himself, one of NASA most storied flight directors. He has lived with the line in the decades since, and embraced it by using it as the title of his autobiography. Ever since then the public has associated the idea that NASA would never accept failure with the space agency.

Of course it is great that the public believes so strongly in NASA. But this also turned out to be a millstone around the agency’s neck. This is not really the fault of Kranz. However, as the public became unaccepting of failure, so did Congress, and NASA’s large programs became intolerant of failure. This is one of the reasons why the timeline and cost of NASA’s rockets and spacecraft and interplanetary missions have ballooned. There are so many people looking for things that could possibly go wrong, the people actually trying to build hardware and fly missions are swamped by requirements.

This is why companies like SpaceX, with an iterative design methodology that accepts some level of failure in order to go more quickly, have thrived. They have moved faster, and at significantly less cost, than the government. I asked Kranz about this a few years ago, the idea that NASA (and its Congressional paymasters) should probably be a little more tolerant of failure.

“Space involves risk, and I think that’s the one thing about Elon Musk and all the various space entrepreneurs: they’re willing to risk their future in order to accomplish the objective that they have decided on,” he told me. “I think we as a nation have to learn that, as an important part of this, to step forward and accept risk.”

—Eric Berger

The perfect gateway drug

“Gentlemen, that’s not good enough.” Universal Pictures

Technically I am a child of the ’60s (early Gen-X), but I was far too young to grasp the significance of the Apollo 11 moon landing in 1969, or just how impressive NASA’s achievement really was. The adults made us sit around the TV in our PJs and seemed very excited about the grainy picture. That’s it. That’s all I remember. My conscious knowledge of space exploration was more influenced by Star Wars and the 1986 Challenger explosion. So going to see Apollo 13 in 1995 as a young science writer was a revelation. I walked out of the theater practically vibrating with excitement, turned to my friends and exclaimed, “Oh my god, we went to the Moon in a souped-up Buick!”

Apollo 13 makes space exploration visceral, makes the audience feel like they are right there in the capsule with the crew battling the odds to get back home. It perfectly conveys the huge risks and stalwart courage of everyone involved in the face of unimaginable pressure. Nerds are the heroes and physics and math are critical: I love the scene where Lovell has to calculate gimbal conversions by hand and asks mission control to check his work. A line of men with slide rules feverishly make their own calculations and one-by-one give the thumbs up.

Then there’s the pragmatic ingenuity of the engineers who had to come up with a way to fit square air filters into a round hole using nothing but items already onboard the spacecraft. There’s a reason I rewatch Apollo 13 every couple of years when I’m in the mood for a “let’s work the problem, people” pick-me-up. (Shoutout to Lovell’s mother, Blanche—played by Howard’s mother, the late Jean Speegle Howard—and her classic line: “If they could get a washing machine to fly, my Jimmy could land it.”)

Naturally, Howard had to sacrifice some historical accuracy in the name of artistic license, sparking the inevitable disgruntled griping among hardcore space nerds. For instance, the mission’s original commander, Alan Shepard, wasn’t grounded because of an ear infection but by Meniere’s disease (an inner ear issue that can cause dizziness). Mission control didn’t order the shutdown of the fuel cells; they were already dead. Swigert and Haise didn’t really argue about who was to blame for the accident. And the film ignores the critical role of Flight Director Glynn Lunney and his Black Team (among others), choosing to focus on Kranz’s White Team to keep the story streamlined.

Look, I get it: nobody wants to see a topic they’re passionate about misrepresented in a movie. But there’s no question that thanks to Howard’s narrative instincts, the film continues to resonate with the general public in ways that a by-the-book docudrama obsessing over the tiniest technical details never could.

In the grand scheme of things, that matters far more than whether Lovell really said, “Houston, we have a problem” in those exact words. If you want the public to support space exploration and—crucially—for Congress to fund it, you need to spark their imaginations and invite them to share in the dream. Apollo 13 is the perfect gateway drug for future space fans, who might find themselves also vibrating with excitement afterward, so inspired by the film that they decide they want to learn more—say, by watching the 12-part Emmy-winning docuseries From the Earth to the Moon that Howard and Hanks co-produced (which is historically accurate). And who knows? They might even decide they want to be space explorers themselves one day.

—Jennifer Ouellette

A common touchstone

Lift-off! Universal Pictures

My relationship with Apollo 13 is somewhat different from most folks: I volunteer as a docent at Space Center Houston, the visitor’s center for Houston’s Johnson Space Center. Specifically, I’m an interpretive guide for the center’s Saturn V exhibit—the only one of the three remaining Saturn V exhibits in the world composed of tip-to-tip of flight stages.

I reference Apollo 13 constantly during guide shifts because it’s a common touchstone that I can count on most folks visiting SCH to have seen, and it visually explicates so many of the more technical aspects of the Apollo program. If I’m explaining that the near-avalanche of white stuff one sees falling off of a Saturn V at launch is actually ice (the rocket’s cryogenic fuels are fantastically cold, and the launch pad at Florida is usually warm and humid, so ice forms on the rocket’s outer skin over the liquid oxygen and liquid hydrogen tanks as it sits on the pad), I reference the launch scene in the movie. If I’m explaining the transposition and docking maneuver by which the Apollo command module docked with and extracted the lunar module from its little garage, I reference the T&D scene in the movie.

Questions about breathing and carbon dioxide? Movie scene. The well-known tension between the astronaut corps and the flight surgeons? Movie scene. And the list goes on. It’s the most amazing reference material I could possibly have.

The film has its detractors, of course, and most geeks wanting to take issue with it will fire shots at the film’s historical accuracy. (Apollo EECOM Sy Liebergot, played in the film by director Ron Howard’s brother Clint, griped once to me that the movie had the audacity to depict the Apollo spacecraft’s trans-lunar injection burn as occurring with the Moon visible in the windows instead of on the far side of the planet—an apparently unforgivable astronavigational sin.) The movie amps up the drama in all respects, adds dialog no astronaut or controller would say, mashes people together into composite characters, compresses or expands the timelines of many of the events in the mission, shows many of those same events happening out of order, and puts people (like Gary Sinise’s Ken Mattingly) in places and roles they were never in.

All these things are true—but they’re also necessary additions in order to get one’s hands around a messy historical event (an event, like all events, that was basically just a whole bunch of stuff all happening at the same time) and fit it into a three-act structure that preserves the important things and that non-technical non-astronaut audiences can follow and understand. And the film succeeds brilliantly, telling a tale that both honors the historicity and technical details of the mission, and that also continues to function as a powerful interpretive tool that teaches people even 35 years after release.

Is every button pressed in the right way? No. Does it bug the crap out of me every time Kevin Bacon answers Tom Hanks’ “How’s the alignment?” question by nonsensically saying “GDC align” and pressing the GDC align button, which is neither what Lovell was asking nor the proper procedure to get the answer Lovell was looking for? Yes. But’s also pure competence porn—an amazing love letter to the space program and the 400,000 men and women who put humans on the Moon.

And like Lovell says: “It’s not a miracle. We just decided to go.”

—Lee Hutchinson

Jennifer is a senior writer at Ars Technica with a particular focus on where science meets culture, covering everything from physics and related interdisciplinary topics to her favorite films and TV series. Jennifer lives in Baltimore with her spouse, physicist Sean M. Carroll, and their two cats, Ariel and Caliban.

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Rocket Report: SpaceX’s dustup on the border; Northrop has a nozzle problem

launch, NASA, rocket report, Science, Space, spacex / Shannon Garcia / June 27, 2025

NASA has finally test-fired the first of its new $100 million SLS rocket engines.

Backdropped by an offshore thunderstorm, a SpaceX Falcon 9 booster stands on its landing pad at Cape Canaveral after returning to Earth from a mission launching four astronauts to the International Space Station early Wednesday. Credit: SpaceX

Welcome to Edition 7.50 of the Rocket Report! We’re nearly halfway through the year, and it seems like a good time to look back on the past six months. What has been most surprising to me in the world of rockets? First, I didn’t expect SpaceX to have this much trouble with Starship Version 2. Growing pains are normal for new rockets, but I expected the next big hurdles for SpaceX to clear with Starship to be catching the ship from orbit and orbital refueling, not completing a successful launch. The state of Blue Origin’s New Glenn program is a little surprising to me. New Glenn’s first launch in January went remarkably well, beating the odds for a new rocket. Now, production delays are pushing back the next New Glenn flights. The flight of Honda’s reusable rocket hopper also came out of nowhere a few weeks ago.

As always, we welcome reader submissions. If you don’t want to miss an issue, please subscribe using the box below (the form will not appear on AMP-enabled versions of the site). Each report will include information on small-, medium-, and heavy-lift rockets, as well as a quick look ahead at the next three launches on the calendar.

Isar raises 150 million euros. German space startup Isar Aerospace has obtained 150 million euros ($175 million) in funding from an American investment company, Reuters reports. The company, which specializes in satellite launch services, signed an agreement for a convertible bond with Eldridge Industries, it said. Isar says it will use the funding to expand its launch service offerings. Isar’s main product is the Spectrum rocket, a two-stage vehicle designed to loft up to a metric ton (2,200 pounds) of payload mass to low-Earth orbit. Spectrum flew for the first time in March, but it failed moments after liftoff and fell back to the ground near its launch pad. Still, Isar became the first in a new crop of European launch startups to launch a rocket theoretically capable of reaching orbit.

Flush with cash … Isar is leading in another metric, too. The Munich-based company has now raised more than 550 million euros ($642 million) from venture capital investors and government-backed funds. This far exceeds the fundraising achievements of any other European launch startup. But the money will only go so far before Isar must prove it can successfully launch a rocket into orbit. Company officials have said they aim to launch the second Spectrum rocket before the end of this year. (submitted by EllPeaTea)

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Rocket Lab aiming for record turnaround. Rocket Lab demonstrated a notable degree of flexibility this week. Two light-class Electron rockets were nearing launch readiness at the company’s privately owned spaceport in New Zealand, but one of the missions encountered a technical problem, and Rocket Lab scrubbed a launch attempt Tuesday. The spaceport has two launch pads next to one another, so while technicians worked to fix that problem, Rocket Lab slotted in another Electron rocket to lift off from the pad next door. That mission, carrying a quartet of small commercial signals intelligence satellites for HawkEye 360, successfully launched Thursday.

Giving it another go … A couple of hours after that launch, Rocket Lab announced it was ready to try again with the mission it had grounded earlier in the week. “Can’t get enough of Electron missions? How about another one tomorrow? With our 67th mission complete, we’ve scheduled our next launch from LC-1 in less than 48 hours—Electron’s fastest turnaround from the same launch site yet!” Rocket Lab hasn’t disclosed what satellite is flying on this mission, citing the customer’s preference to remain anonymous for now.

You guessed it! Baguette One will launch from France. French rocket builder HyPrSpace will launch its Baguette One demonstrator from a missile testing site in mainland France, after signing an agreement with the country’s defense procurement agency, European Spaceflight reports. HyPrSpace was founded in 2019 to begin designing an orbital-class rocket named Orbital Baguette 1 (OB-1). The Baguette One vehicle is a subscale, single-stage suborbital demonstrator to prove out technologies for the larger satellite launcher, mainly its hybrid propulsion system.

Sovereign launch … HyPrSpace’s Baguette One will stand roughly 10 meters (30 feet) tall and will be capable of carrying payloads of up to 300 kilograms (660 pounds) to suborbital space. It is scheduled to launch next year from a French missile testing site in the south of France. “Gaining access to this dual-use launch pad in mainland France is a major achievement after many years of work on our hybrid propulsion technology,” said Sylvain Bataillard, director general of HyPrSpace. “It’s a unique opportunity for HyPrSpace and marks a decisive turning point. We’re eager to launch Baguette One and to play a key role in building a more sovereign, more sustainable, and boldly innovative European dual-use space industry.” (submitted by EllPeaTea)

Firefly moves closer to launching from Sweden. An agreement between the United States and Sweden brings Firefly Aerospace one step closer to launching its Alpha rocket from a Swedish spaceport, Space News reports. The two countries signed a technology safeguards agreement (TSA) at a June 20 ceremony at the Swedish embassy in Washington, DC. The TSA allows the export of American rockets to Sweden for launches there, putting in place measures to protect launch vehicle technology.

A special relationship … The US government has signed launch-related safeguard agreements with only a handful of countries, such as Australia, the United Kingdom, and now Sweden. Rocket exports are subject to strict controls because of the potential military applications of that technology. Firefly currently launches its Alpha rocket from Vandenberg Space Force Base, California, and is building a launch site at Wallops Island, Virginia. Firefly also has a lease for a launch pad at Cape Canaveral, Florida, although the company is prioritizing other sites. Then, last year, Firefly announced an agreement with the Swedish Space Corporation to launch Alpha from Esrange Space Center as soon as 2026. (submitted by EllPeaTea)

Amazon is running strong out of the gate. For the second time in two months, United Launch Alliance sent a batch of 27 broadband Internet satellites into orbit for Amazon on Monday morning, Ars reports. This was the second launch of a full load of operational satellites for Amazon’s Project Kuiper, a network envisioned to become a competitor to SpaceX’s Starlink. Just like the last flight on April 28, an Atlas V rocket lifted off from Cape Canaveral, Florida, and delivered Amazon’s satellites into an on-target orbit roughly 280 miles (450 kilometers) above Earth.

Time to put up or shut up … After lengthy production delays at Amazon’s satellite factory, the retail giant is finally churning out Kuiper satellites at scale. Amazon has already shipped the third batch of Kuiper satellites to Florida to prepare for launch on a SpaceX Falcon 9 rocket next month. ULA won the lion’s share of Amazon’s multibillion-dollar launch contract in 2022, committing to up to 38 Vulcan launches for Kuiper and nine Atlas V flights. Three of those Atlas Vs have now launched. Amazon also reserved 18 launches on Europe’s Ariane 6 rocket, and at least 12 on Blue Origin’s New Glenn. Vulcan, Ariane 6, and New Glenn have only flown one or two times, and Amazon is asking them to quickly ramp up their cadence to deliver 3,232 Kuiper satellites to orbit in the next few years. The handful of Falcon 9s and Atlas Vs that Amazon has on contract are the only rockets in the bunch with a proven track record. With Kuiper satellites now regularly shipping out of the factory, any blame for future delays may shift from Amazon to the relatively unproven rockets it has chosen to launch them.

Falcon 9 launches with four commercial astronauts. Retired astronaut Peggy Whitson, America’s most experienced space flier, and three rookie crewmates from India, Poland, and Hungary blasted off on a privately financed flight to the International Space Station early Wednesday, CBS News reports. This is the fourth non-government mission mounted by Houston-based Axiom Space. The four commercial astronauts rocketed into orbit on a SpaceX Falcon 9 launcher from NASA’s Kennedy Space Center in Florida, and their Dragon capsule docked at the space station Thursday to kick off a two-week stay.

A brand-new Dragon … The Crew Dragon spacecraft flown on this mission, serial number C213, is the fifth and final addition to SpaceX’s fleet of astronaut ferry ships built for NASA trips to the space station and for privately funded commercial missions to low-Earth orbit. Moments after reaching orbit Wednesday, Whitson revealed the name of the new spacecraft: Crew Dragon Grace. “We had an incredible ride uphill, and now we’d like to set our course for the International Space Station aboard the newest member of the Dragon fleet, our spacecraft named Grace. … Grace reminds us that spaceflight is not just a feat of engineering, but an act of goodwill to the benefit of every human everywhere.”

How soon until Ariane 6 is flying regularly? It’ll take several years for Arianespace to ramp up the launch cadence of Europe’s new Ariane 6 rocket, Space News reports. David Cavaillolès, chief executive of Arianespace, addressed questions at the Paris Air Show about how quickly Arianespace can reach its target of launching 10 Ariane 6 rockets per year. “We need to go to 10 launches per year for Ariane 6 as soon as possible,” he said. “It’s twice as more as for Ariane 5, so it’s a big industrial change.” Two Ariane 6 rockets have launched so far, and a third mission is on track to lift off in August. Arianespace’s CEO reiterated earlier plans to conduct four more Ariane 6 launches through the end of this year, including the first flight of the more powerful Ariane 64 variant with four solid rocket boosters.

Not a heavy lift … Arianespace’s target flight rate of 10 Ariane 6 rockets per year is modest compared to other established companies with similarly sized launch vehicles. United Launch Alliance is seeking to launch as many as 25 Vulcan rockets per year. Blue Origin’s New Glenn is designed to eventually fly often, although the company hasn’t released a target launch cadence. SpaceX, meanwhile, aims to launch up to 170 Falcon 9 rockets this year. But European governments are perhaps more committed than ever to maintaining a sovereign launch capability for the continent, so Ariane 6 isn’t going away. Arianespace has sold more than 30 Ariane 6 launches, primarily to European institutional customers and Amazon.

SLS booster blows its nozzle. NASA and Northrop Grumman test-fired a new solid rocket booster in Utah on Thursday, and it didn’t go exactly according to plan, Ars reports. This booster features a new design that NASA would use to power Space Launch System rockets, beginning with the ninth mission, or Artemis IX. The motor tested on Thursday isn’t flight-worthy. It’s a test unit that engineers will use to learn about the rocket’s performance. It turns out they did learn something, but perhaps not what they wanted. About 1 minute and 40 seconds into the booster’s burn, a fiery plume emerged from the motor’s structure just above its nozzle. Moments later, the nozzle violently disintegrated. The booster kept firing until it ran out of pre-packed solid propellant.

A questionable future … NASA’s Space Launch System appears to have a finite shelf life. The Trump administration wants to cancel it after just three launches, while the preliminary text of a bill making its way through Congress would extend it to five flights. But chances are low the Space Launch System will make it to nine flights, and if it does, it’s questionable if it would reach that point before 2040. The SLS rocket is a core piece of NASA’s plan to return US astronauts to the Moon under the Artemis program, but the White House seeks to cancel the program in favor of cheaper commercial alternatives.

NASA conducts a low-key RS-25 engine test. The booster ground test on Thursday was the second time in less than a week that NASA test-fired new propulsion hardware for the Space Launch System. Last Friday, June 20, NASA ignited a new RS-25 engine on a test stand at Stennis Space Center in Mississippi. The hydrogen-fueled engine is the first of its kind to be manufactured since the end of the space shuttle program. This particular RS-25 engine is assigned to power the fifth launch of the SLS rocket, a mission known as Artemis V, that may end up never flying. While NASA typically livestreams engine tests at Stennis, the agency didn’t publicize this event ahead of time.

It has been 10 years … The SLS rocket was designed to recycle leftover parts from the space shuttle program, but NASA will run out of RS-25 engines after the rocket’s fourth flight and will exhaust its inventory of solid rocket booster casings after the eighth flight. Recognizing that shuttle-era parts will eventually run out, NASA signed a contract with Aerojet Rocketdyne (now L3Harris) to set the stage for the production of new RS-25 engines in 2015. NASA later ordered an initial batch of six RS-25 engines from Aerojet, then added 18 more to the order in 2020, at a price of about $100 million per engine. Finally, a brand-new flight-worthy RS-25 engine has fired up on a test stand. If the Trump administration gets its way, these engines will never fly. Maybe that’s fine, but after so long with so much taxpayer investment, last week’s test milestone is worth publicizing, if not celebrating.

SpaceX finds itself in a dustup on the border. President Claudia Sheinbaum of Mexico is considering taking legal action after one of SpaceX’s giant Starship rockets disintegrated in a giant fireball earlier this month as it was being fueled for a test-firing of its engines, The New York Times reports. No one was injured in the explosion, which rained debris on the beaches of the northern Mexican state of Tamaulipas. The conflagration occurred at a test site SpaceX operates a few miles away from the Starship launch pad. This test facility is located next to the Rio Grande River, just a few hundred feet from Mexico. The power of the blast sent wreckage flying across the river into Mexican territory.

Collision course …“We are reviewing everything related to the launching of rockets that are very close to our border,” Sheinbaum said at a news conference Wednesday. If SpaceX violated any international laws, she added, “we will file any necessary claims.” Sheinbaum’s leftist party holds enormous sway around Mexico, and the Times reports she was responding to calls to take action against SpaceX amid a growing outcry among scientists, regional officials, and environmental activists over the impact that the company’s operations are having on Mexican ecosystems. SpaceX, on the other hand, said its efforts to recover debris from the Starship explosion have been “hindered by unauthorized parties trespassing on private property.” SpaceX said it requested assistance from the government of Mexico in the recovery and added that it offered its own resources to help with the cleanup.

Next three launches

June 28: Falcon 9 | Starlink 10-34 | Cape Canaveral Space Force Station, Florida | 04: 26 UTC

June 28: Electron | “Symphony in the Stars” | Māhia Peninsula, New Zealand | 06: 45 UTC

June 28: H-IIA | GOSAT-GW | Tanegashima Space Center, Japan | 16: 33 UTC

Stephen Clark is a space reporter at Ars Technica, covering private space companies and the world’s space agencies. Stephen writes about the nexus of technology, science, policy, and business on and off the planet.

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NASA tested a new SLS booster that may never fly, and the end of it blew off

artemis, human spaceflight, L3Harris, launch, NASA, Northrop Grumman, Science, Space, space launch system / DJ Henderson / June 27, 2025

NASA didn’t want to say much about one of the tests, and the other one lost its nozzle.

An uncontained plume of exhaust appeared near the nozzle of an SLS solid rocket booster moments before its nozzle was destroyed during a test-firing Thursday. Credit: NASA

NASA’s Space Launch System appears to have a finite shelf life. The Trump administration wants to cancel it after just three launches, while the preliminary text of a bill making its way through Congress would extend it to five flights.

But chances are low the Space Launch System will make it to nine flights, and if it does, it’s questionable that it would reach that point before 2040. The SLS rocket is a core piece of NASA’s plan to return US astronauts to the Moon under the Artemis program, but the White House seeks to cancel the program in favor of cheaper commercial alternatives.

For the second time in less than a week, NASA test-fired new propulsion hardware Thursday that the agency would need to keep SLS alive. Last Friday, a new liquid-fueled RS-25 engine ignited on a test stand at NASA’s Stennis Space Center in Mississippi. The hydrogen-fueled engine is the first of its kind to be manufactured since the end of the Space Shuttle program. This particular RS-25 engine is assigned to power the fifth flight of the SLS rocket, a mission known as Artemis V.

Then, on Thursday of this week, NASA and Northrop Grumman test-fired a new solid rocket booster in Utah. This booster features a new design that NASA would use to power SLS rockets beginning with the ninth mission, or Artemis IX. The motor tested on Thursday isn’t flight-worthy. It’s a test unit that engineers will use to gather data on the rocket’s performance.

While the engine test in Mississippi apparently went according to plan, the ground firing of the new solid rocket booster didn’t go quite as smoothly. Less than two minutes into the burn, the motor’s exhaust nozzle violently shattered into countless shards of debris. You can watch the moment in the YouTube video below.

At the start of the program nearly 15 years ago, NASA and its backers in Congress pitched the SLS rocket as the powerhouse behind a new era of deep space exploration. The Space Launch System, they said, would have the advantage of recycling old space shuttle engines and boosters, fast-tracking the new rocket’s path to the launch pad for less money than the cost of an all-new vehicle.

That didn’t pan out. Each Artemis mission costs $4.2 billion per flight, and that’s with shuttle-era engines and boosters that NASA and its contractors already have in their inventories. NASA’s 16 leftover shuttle main engines are enough for the first four SLS flights. NASA has leftover parts for eight pairs of solid rocket boosters.

It has been 10 years

Recognizing that shuttle-era parts will eventually run out, NASA signed a contract with Aerojet Rocketdyne to set the stage for the production of new RS-25 engines in 2015. NASA later ordered an initial batch of six RS-25 engines from Aerojet, then added 18 more to the order in 2020, at a price of about $100 million per engine. NASA and its contractor aim to reduce the cost to $70 million per engine, but even that figure is many times the cost of engines of comparable size and power: Blue Origin’s BE-4 and SpaceX’s Raptor.

Finally, NASA test-fired a new flight-rated RS-25 engine for the first time last week at Stennis Space Center. The agency has often provided a livestream of its engine tests at Stennis, but it didn’t offer the public any live video. And this particular test was a pretty big deal. L3Harris, which acquired Aerojet Rocketdyne in 2023, has finally reactivated the RS-25 production line after a decade and billions of dollars of funding.

In fact, NASA made no public statement about the RS-25 test until Monday, and the agency didn’t mention its assignment to fly on the Artemis V mission. If the Trump administration gets its way, the engine will never fly. Maybe that’s fine, but after so long with so much taxpayer investment, this is a milestone worth publicizing, if not celebrating.

L3Harris issued a press release Tuesday confirming the engine’s planned use on the fifth SLS mission. The engine completed a 500-second acceptance test, throttling up to 111 percent of rated thrust, demonstrating more power than engines that flew on the space shuttle or on the first SLS launch in 2022.

A new RS-25 engine, No. 20001, was installed on its test stand in Mississippi earlier this year. Credit: NASA

“This successful acceptance test shows that we’ve been able to replicate the RS-25’s performance and reliability, while incorporating modern manufacturing techniques and upgraded components such as the main combustion chamber, nozzle, and pogo accumulator assembly,” said Kristin Houston, president of space propulsion and power systems at Aerojet Rocketdyne, L3Harris. “Our propulsion technology is key to ensuring the United States leads in lunar exploration, creates a sustained presence on the Moon and does not cede this strategic frontier to other nations.”

The test-firing last Friday came a few days before the 50th anniversary of the first space shuttle main engine test at Stennis on June 24, 1975. That engine carried the serial number 0001. The new RS-25 engine is designated No. 20001.

Watch out

NASA followed last week’s low-key engine test with the test-firing of a solid-fueled booster at Northrop Grumman’s rocket test site in Promontory, Utah, on Thursday. Held in place on its side, the booster produced 3.9 million pounds of thrust, outclassing the power output of the existing boosters assigned to the first eight SLS missions.

Unlike the RS-25 firing at Stennis, NASA chose to broadcast the booster test. Everything appeared to go well until 1 minute and 40 seconds into the burn, when a fiery plume of super-hot exhaust appeared to burn through part of the booster’s structure just above the nozzle. Moments later, the nozzle disintegrated.

Solid rocket boosters can’t be turned off after ignition, and for better or worse, the motor continued firing until it ran out of propellant about 30 seconds later. The rocket sparked a fire in the hills overlooking the test stand.

This was the first test-firing of the Booster Obsolescence and Life Extension (BOLE) program, which aims to develop a higher-performance solid rocket booster for SLS missions. NASA awarded Northrop Grumman a $3.2 billion contract in 2021 to produce boosters with existing shuttle parts for five SLS missions (Artemis IV-VIII), and design, develop, and test a new booster design for Artemis IX.

The boosters produce more than 75 percent of the thrust required to propel the SLS rocket off the launch pad with NASA’s crewed Orion spacecraft on top. Four RS-25 engines power the core stage, collectively generating more than 2 million pounds of thrust.

Northrop Grumman calls the new booster “the largest and most powerful segmented solid rocket motor ever built for human spaceflight.”

One of the most significant changes with the BOLE booster design is that it replaces shuttle-era steel cases with carbon-fiber composite cases. Northrop says the new cases are lighter and stronger. It also replaces the booster’s hydraulic thrust vector control steering system with an electronic system. The propellant packed inside the booster is also different, using a mix that Northrop packs inside its commercial rocket motors instead of the recipe used for the space shuttle.

Northrop Grumman has had a tough time with rocket nozzles in recent years. In 2019, a test motor for the company’s now-canceled Omega rocket lost its nozzle during a test-firing in Utah. Then, last year, a smaller Northrop-made booster flying on United Launch Alliance’s Vulcan rocket lost its nozzle in flight. Vulcan’s guidance system and main engines corrected for the problem, and the rocket still achieved its planned orbit.

NASA tested a new SLS booster that may never fly, and the end of it blew off Read More »

During a town hall Wednesday, NASA officials on stage looked like hostages

Donald Trump, janet petro, NASA, nasa budget, Science, Space, space policy, space science / Shannon Garcia / June 26, 2025

A Trump appointee suggests NASA may not have a new administrator until next year.

NASA press secretary Bethany Stevens, acting administrator Janet Petro, chief of staff Brian Hughes, associate administrator Vanessa Wyche, and deputy associate administrator Casey Swails held a town hall with NASA employees Wednesday. Credit: NASA

The four people at the helm of America’s space agency held a town hall meeting with employees Wednesday, fielding questions about downsizing, layoffs, and proposed budget cuts that threaten to undermine NASA’s mission and prestige.

Janet Petro, NASA’s acting administrator, addressed questions from an auditorium at NASA Headquarters in Washington, DC. She was joined by Brian Hughes, the agency’s chief of staff, a political appointee who was formerly a Florida-based consultant active in city politics and in Donald Trump’s 2024 presidential campaign. Two other senior career managers, Vanessa Wyche and Casey Swails, were also on the stage.

They tried to put a positive spin on the situation at NASA. Petro, Wyche, and Swails are civil servants, not Trump loyalists. None of them looked like they wanted to be there. The town hall was not publicized outside of NASA ahead of time, but live video of the event was available—unadvertised—on an obscure NASA streaming website. The video has since been removed.

8 percent down

NASA’s employees are feeling the pain after the White House proposed a budget cut of nearly 25 percent in fiscal year 2026, which begins October 1. The budget request would slash NASA’s topline budget by nearly 25 percent, from $24.8 billion to $18.8 billion. Adjusted for inflation, this would be the smallest NASA budget since 1961, when the first American launched into space.

“The NASA brand is really strong still, and we have a lot of exciting missions ahead of us,” Petro said. “So, I know it’s a hard time that we’re going to be navigating, but again, you have my commitment that I’m here and I will share all of the information that I have when I get it.”

It’s true that NASA employees, along with industry officials and scientists who regularly work with the agency, are navigating through what would most generously be described as a period of great uncertainty. The perception among NASA’s workforce is far darker. “NASA is f—ed,” one current leader in the agency told Ars a few weeks ago, soon after President Trump rescinded his nomination of billionaire businessman and commercial astronaut Jared Isaacman to be the agency’s next administrator.

Janet Petro, NASA’s acting administrator, is seen in 2020 at Kennedy Space Center in Florida. Credit: NASA/Kim Shiflett

Before the White House released its detailed budget proposal in May, NASA and other federal agencies were already scrambling to respond to the Trump administration’s directives to shrink the size of the government. While NASA escaped the mass layoffs of probationary employees that affected other departments, the space agency offered buyouts and incentives for civil servants to retire early or voluntarily leave their posts.

About 900 NASA employees signed up for the first round of the government’s “deferred resignation” program. Casey Swails, NASA’s deputy associate administrator, said Wednesday that number is now up to 1,500 after NASA announced another chance for employees to take the government’s deferred resignation offer. This represents about 8 percent of NASA’s workforce, and the window for employees to apply runs until July 25.

One takeaway from Wednesday’s town hall is that at least some NASA leaders want to motivate more employees to resign voluntarily. Hughes said a “major reason” for luring workers to leave the agency is to avoid “being in a spot where we have to do the involuntary options.”

Rumors of these more significant layoffs, or reductions in force, have hung over NASA for several months. If that happens, workers may not get the incentives the government is offering today to those who leave the agency on their own. Swails said NASA isn’t currently planning any such layoff, although she left the door open for the situation to change: “We’re doing everything we can to avoid going down that path.”

Ultimately, it will depend on how many employees NASA can get to resign on their own. If it’s not enough, layoffs may still be an option.

Many questions, few answers

Nearly all of the questions employees addressed to NASA leadership Wednesday were submitted anonymously, and in writing: When might Trump nominate someone for NASA administrator to take Isaacman’s place? Will any of NASA’s 10 field centers be closed? What is NASA going to do about Trump’s budget proposal, particularly its impact on science missions?

Their responses to these questions, in order: Probably not any time soon, maybe, and nothing.

The Trump administration selected Petro, an engineer and former Army helicopter pilot, to become acting head of NASA on Inauguration Day in January. Bill Nelson, who served as a Florida senator until 2019, resigned the NASA administrator job when former President Biden left the White House.

Petro was previously director of NASA’s Kennedy Space Center since 2021, and before that, she was deputy director of the Florida spaceport for 14 years. She leapfrogged NASA’s top civil servant, associate administrator Jim Free, to become acting administrator in January. Free retired from the agency in February. Before the presidential election last year, Free advocated for the next administration to stay the course with NASA’s Artemis program.

But that’s not what the Trump administration wants to do. The White House seeks to cancel the Space Launch System rocket and Orion spacecraft, both core elements of the Artemis program to return astronauts to the Moon after two more flights. Under the new plan, NASA would procure commercial transportation to ferry crews to the Moon and Mars in a similar way to how the agency buys rides for its astronauts to the International Space Station in low-Earth orbit.

NASA’s Curiosity rover captured images to create this selfie mosaic on the surface of Mars in 2015. If implemented as written, the Trump budget proposal would mark the first time in 30 years that NASA does not have a Mars lander in development. The agency would instead turn to commercial companies to demonstrate they can deliver payloads, and eventually humans, to the red planet.

The Trump administration’s statements on space policy have emphasized the longer-term goal of human missions to Mars. The White House’s plans for what NASA will do at the Moon after the Artemis program’s first landing are still undefined.

Petro has kept a low profile since becoming NASA’s temporary chief executive five months ago. If Trump moved forward with Isaacman’s nomination, he would likely be NASA administrator today. The Senate was a few days away from confirming Isaacman when Trump pulled his nomination, apparently for political reasons. The White House withdrew the nomination the day after Elon Musk, who backed Isaacman to take the top job at NASA, left the Trump administration.

Who’s running NASA?

Now, Petro could serve out the year as NASA’s acting administrator. Petro is well-regarded at Kennedy Space Center, where she was a fixture in the center’s headquarters building for nearly 20 years. But she lacks a political constituency in the Trump administration and isn’t empowered to make major policy decisions. The budget cuts proposed for NASA came from the White House’s Office of Management and Budget, not from within the agency itself.

President Trump has the reins on the process to select the next NASA administrator. Trump named Isaacman for the office in December, more than a month before his inauguration, and the earliest any incoming president has nominated a NASA administrator. Musk had close ties to Trump then, and a human mission to Mars got a mention in Trump’s inauguration speech.

But space issues seem to have fallen far down Trump’s list of priorities. Hughes, who got his job at NASA in part due to his political connections, suggested it might be a while before Trump gets around to selecting another NASA administrator nominee.

“I think the best guess would tell you that it’s hard to imagine it happening before the next six months, and could perhaps go longer than that into the eight- or nine-month range, but that’s purely speculation,” Hughes said, foreseeing impediments such as the large number of other pending nominations for posts across the federal government and high-priority negotiations with Congress over the federal budget.

Congress is also expected to go on recess in August, so the earliest a NASA nominee might get a confirmation hearing is this fall. Then, the Senate must vote to confirm the nominee before they can take office.

The timeline of Isaacman’s nomination for NASA administrator is instructive. Trump nominated Isaacman in December, and his confirmation hearing was in April. He was on the cusp of a confirmation vote in early June when Trump withdrew his nomination on May 31.

As NASA awaits a leader with political backing, Petro said the agency is undergoing an overhaul to make it “leaner and more agile.” This is likely to result in office closures, and Hughes indicated NASA might end up shuttering entire field centers.

“To the specific question, will they be closed or consolidated? I don’t think we’re there yet to answer that question, but it is actively a part of the conversation we’re having as we go step-by-step through this,” Hughes said.

What can $4 billion buy you?

While Trump’s budget proposal includes robust funding for human space exploration, it’s a different story for most of the rest of NASA. The agency’s science budget would be cut in half to approximately $3.9 billion. NASA’s technology development division would also be reduced by 50 percent.

If the White House gets its way, NASA would scale back research on the International Space Station and cancel numerous robotic missions in development or already in space. The agency would terminate missions currently exploring Jupiter, on the way to study an asteroid, and approaching interstellar space. It would shut down the largest X-ray space telescope ever built and the only one in its class likely to be operating for the next 10 years.

“There’s a lot of science that can still be done with $4 billion,” Petro said. “How we do science, and how we do partnerships, may change in the future to sort of multiply what we’re doing.”

These partnerships might include asking academic institutions or wealthy benefactors to pitch in money to fund science projects at NASA. The agency might also invite commercial companies to play bigger roles in NASA robotic missions, which are typically owned by the government.

This view of Jupiter’s turbulent atmosphere from NASA’s Juno spacecraft includes several of the planet’s southern jet streams. Juno is one of the missions currently in space that NASA would shut down under Trump’s budget request. Credit: NASA

One employee asked what NASA could do to secure more funding in the president’s budget request. But that ship has sailed. The options now available to NASA’s leadership are to support the budget proposal, stay silent, or leave. NASA is an executive agency and part of the Trump administration, and the White House’s budget request is NASA’s, too.

“It’s not our job to advocate, but let’s try to look at this in a positive way,” Petro said. “We’ve still got a lot of money. Let’s see how much mission we can do.”

Ultimately, it’s up to Congress to appropriate funding for NASA and other parts of the government. Lawmakers haven’t signaled where they might land on NASA’s budget, but Sen. Ted Cruz (R-Texas), who is influential on space-related matters, released the text of a proposed bill a few weeks ago that would restore funding for the International Space Station and forego cancellation of the Space Launch System rocket, among other things. But Cruz did not have much to say about adding more money for NASA’s science programs.

NASA’s senior leaders acknowledged on Wednesday that the pain of the agency’s downsizing will extend far beyond its walls.

“Eighty-five percent of our budget goes out the door to contractors,” Petro said. “So, with a reduced budget, absolutely, our contractors will also be impacted. In fact, they’re probably the bigger driver that will be impacted.”

It’s clearly a turbulent time for America’s space agency, and NASA employees have another month to decide if they want to be part of it.

“I know there’s a lot to consider,” Swails said. “There’s a lot that people are thinking about. I would encourage you to talk it out. Tap into your support systems. Talk to your spouse, your partner, your friend, your financial advisor, whomever you consider those trusted advisors for you.”

This sounds like hollow advice, but it seems like it’s all NASA’s workers can do. The Trump administration isn’t waiting for Congress to finalize the budget for 2026. The downsizing is here.

During a town hall Wednesday, NASA officials on stage looked like hostages Read More »

Psyche keeps its date with an asteroid, but now it’s running in backup mode

asteroid, jet propulsion laboratory, Maxar, NASA, psyche, Science, solar system, Space, valves / Shannon Garcia / June 22, 2025

The spacecraft, built by Maxar Space Systems, will operate its electric thrusters for the equivalent of three months between now and November to keep the mission on track for arrival at asteroid Psyche in 2029.

“Through comprehensive testing and analysis, the team narrowed down the potential causes to a valve that may have malfunctioned in the primary line,” NASA said in a statement Friday. “The switch to the identical backup propellant line in late May restored full functionality to the propulsion system.”

The next waypoint on Psyche’s voyage will be a flyby of Mars in May 2026. Officials expect Psyche to keep that date, which is critical for using Mars’ gravity to slingshot the spacecraft deeper into the Solar System, eventually reaching the asteroid belt about four years from now.

NASA’s Psyche spacecraft takes a spiral path to the asteroid Psyche, as depicted in this graphic that shows the path from above the plane of the planets, labeled with key milestones of the prime mission. Credit: NASA/JPL-Caltech

At Psyche, the spacecraft will enter orbit and progressively move closer to the asteroid, using a suite of sensors to map its surface, measure its shape, mass, and gravity field, and determine its elemental composition. Observations through telescopes suggest Psyche is roughly 140 miles (226 kilometers) in diameter, or about the width of Massachusetts. But it’s likely not spherical in shape. Scientists describe its shape as more akin to a potato.

Potatoes come in lots of shapes, and researchers won’t know exactly what Psyche looks like until NASA’s asteroid explorer arrives in 2029. Psyche will be the first metallic, or M-type, asteroid visited by any spacecraft, and scientists are eager to study an object that’s largely made of metals—probably iron, nickel, and perhaps some rarer elements— instead of rocky minerals.

With the Psyche spacecraft’s plasma thrusters back in action, these goals of NASA’s billion-dollar science mission remain achievable.

“The mission team’s dedication and systematic approach to this investigation exemplifies the best of NASA engineering,” said Bob Mase, Psyche project manager at JPL, in a statement. “Their thorough diagnosis and recovery, using the backup system, demonstrates the value of robust spacecraft design and exceptional teamwork.”

But there’s still a lingering concern whatever problem caused the valve to malfunction in the primary fuel line might also eventually affect the same kind of valve in the backup line.

“We are doing a lot of good proactive work around that possible issue,” wrote Lindy Elkins-Tanton, Psyche’s principal investigator at Arizona State University, in a post on X.

Psyche keeps its date with an asteroid, but now it’s running in backup mode Read More »

Rocket Report: New delay for Europe’s reusable rocket; SpaceX moves in at SLC-37

blue origin, european space agency, falcon 9, launch, NASA, new glenn, rocket report, Science, Space, spacex, starship, united launch alliance / Mike M. / June 13, 2025

Canada is the only G7 nation without a launch program. Quebec wants to do something about that.

This graphic illustrates the elliptical shape of a geosynchronous transfer orbit in green, and the circular shape of a geosynchronous orbit in blue. In a first, SpaceX recently de-orbited a Falcon 9 upper stage from GTO after deploying a communications satellite. Credit: European Space Agency

Welcome to Edition 7.48 of the Rocket Report! The shock of last week’s public spat between President Donald Trump and SpaceX founder Elon Musk has worn off, and Musk expressed regret for some of his comments going after Trump on social media. Musk also backtracked from his threat to begin decommissioning the Dragon spacecraft, currently the only way for the US government to send people to the International Space Station. Nevertheless, there are many people who think Musk’s attachment to Trump could end up putting the US space program at risk, and I’m not convinced that danger has passed.

Quebec invests in small launch company. The government of Quebec will invest CA$10 million ($7.3 million) into a Montreal-area company that is developing a system to launch small satellites into space, The Canadian Press reports. Quebec Premier François Legault announced the investment into Reaction Dynamics at the company’s facility in Longueuil, a Montreal suburb. The province’s economy minister, Christine Fréchette, said the investment will allow the company to begin launching microsatellites into orbit from Canada as early as 2027.

Joining its peers … Canada is the only G7 nation without a domestic satellite launch capability, whether it’s through an independent national or commercial program or through membership in the European Space Agency, which funds its own rockets. The Canadian Space Agency has long eschewed any significant spending on developing a Canadian satellite launcher, and a handful of commercial launch startups in Canada haven’t gotten very far. Reaction Dynamics was founded in 2017 by Bachar Elzein, formerly a researcher in multiphase and reactive flows at École Polytechnique de Montréal, where he specialized in propulsion and combustion dynamics. Reaction Dynamic plans to launch its first suborbital rocket later this year, before attempting an orbital flight with its Aurora rocket as soon as 2027. (submitted by Joey S-IVB)

Sign Me Up!

Another year, another delay for Themis. The European Space Agency’s Themis program has suffered another setback, with the inaugural flight of its reusable booster demonstrator now all but certain to slip to 2026, European Spaceflight reports. It has been nearly six years since the European Space Agency kicked off the Themis program to develop and mature key technologies for future reusable rocket stages. Themis is analogous to SpaceX’s Grasshopper reusable rocket prototype tested more than a decade ago, with progressively higher hop tests to demonstrate vertical takeoff and vertical landing techniques. When the program started, an initial hop test of the first Themis demonstrator was expected to take place in 2022.

Tethered to terra firma … ArianeGroup, which manufactures Europe’s Ariane rockets, is leading the Themis program under contract to ESA, which recently committed an additional 230 million euros ($266 million) to the effort. This money is slated to go toward the development of a single-engine variant of the Themis program, continued development of the rocket’s methane-fueled engine, and upgrades to a test stand at ArianeGroup’s propulsion facility in Vernon, France. Two months ago, an official update on the Themis program suggested the first Themis launch campaign would begin before the end of the year. Citing sources close to the program, European Spaceflight reports the first Themis integration tests at the Esrange Space Center in Sweden are now almost certain to slip from late 2025 to 2026.

French startup tests a novel rocket engine. While Europe’s large government-backed rocket initiatives face delays, the continent’s space industry startups are moving forward on their own. One of these companies, a French startup named Alpha Impulsion, recently completed a short test-firing of an autophage rocket engine, European Spaceflight reports. These aren’t your normal rocket engines that burn conventional kerosene, methane, or hydrogen fuel. An autophage engine literally consumes itself as it burns, using heat from the combustion process to melt its plastic fuselage and feed the molten plastic into the combustion chamber in a controlled manner. Alpha Impulsion called the May 27 ground firing a successful test of the “largest autophage rocket engine in the world.”

So, why hasn’t this been done before? … The concept of a self-consuming rocket engine sounds like an idea that’s so crazy it just might work. But the idea remained conceptual from when it was first patented in 1938 until an autophage engine was fired in a controlled manner for the first time in 2018. The autophage design offers several advantages, including its relative simplicity compared to the complex plumbing of liquid and hybrid rockets. But there are serious challenges associated with autophage engines, including how to feed molten fuel into the combustion chamber and how to scale it up to be large enough to fly on a viable rocket. (submitted by trimeta and EllPeaTea)

Rocket trouble delays launch of private crew mission. A propellant leak in a Falcon 9 booster delayed the launch of a fourth Axiom Space private astronaut mission to the International Space Station this week, Space News reports. SpaceX announced the delay Tuesday, saying it needed more time to fix a liquid oxygen leak found in the Falcon 9 booster during inspections following a static-fire test Sunday. “Once complete–and pending Range availability–we will share a new launch date,” the company stated. The Ax-4 mission will ferry four commercial astronauts, led by retired NASA commander Peggy Whitson, aboard a Dragon spacecraft to the ISS for an approximately 14-day stay. Whitson will be joined by crewmates from India, Poland, and Hungary.

Another problem, too … While SpaceX engineers worked on resolving the propellant leak on the ground, a leak of another kind in orbit forced officials to order a longer delay to the Ax-4 mission. In a statement Thursday, NASA said it is working with the Russian space agency to understand a “new pressure signature” in the space station’s Russian service module. For several years, ground teams have monitored a slow air leak in the aft part of the service module, and NASA officials have identified it as a safety risk. NASA’s statement on the matter was vague, only saying that cosmonauts on the station recently inspected the module’s interior surfaces and sealed additional “areas of interest.” The segment is now holding pressure, according to NASA. (submitted by EllPeaTea)

SpaceX tries something new with Falcon 9. With nearly 500 launches under its belt, SpaceX’s Falcon 9 rocket isn’t often up to new tricks. But the company tried something new following a launch on June 7 with a radio broadcasting satellite for SiriusXM. The Falcon 9’s upper stage placed the SXM-10 satellite into an elongated, high-altitude transfer orbit, as is typical for payloads destined to operate in geosynchronous orbit more than 22,000 miles (nearly 36,000 kilometers) over the equator. When a rocket releases a satellite in this type of high-energy orbit, the upper stage has usually burned almost all of its propellant, leaving little fuel to steer itself back into Earth’s atmosphere for a destructive reentry. This means these upper stages often remain in space for decades, becoming a piece of space junk that transits across the orbits of many other satellites.

Now, a solution … SpaceX usually deorbits rockets after they deploy payloads like Starlink satellites into low-Earth orbit, but deorbiting a rocket from a much higher geosynchronous transfer orbit is a different matter. “Last week, SpaceX successfully completed a controlled deorbit of the SiriusXM-10 upper stage after GTO payload deployment,” wrote Jon Edwards, SpaceX’s vice president of Falcon and Dragon programs. “While we routinely do controlled deorbits for LEO stages (e.g., Starlink), deorbiting from GTO is extremely difficult due to the high energy needed to alter the orbit, making this a rare and remarkable first for us. This was only made possible due to the hard work and brilliance of the Falcon GNC (guidance, navigation, and control) team and exemplifies SpaceX’s commitment to leading in both space exploration and public safety.”

New Glenn gets a tentative launch date. Five months have passed since Blue Origin’s New Glenn rocket made its mostly successful debut in January. At one point, the company targeted “late spring” for the second launch of the rocket. However, on Monday, Blue Origin’s CEO, Dave Limp, acknowledged on social media that the rocket’s next flight will now no longer take place until at least August 15, Ars reports. Although he did not say so, this may well be the only other New Glenn launch this year. The mission, with an undesignated payload, will be named “Never Tell Me the Odds,” due to the attempt to land the booster. “One of our key mission objectives will be to land and recover the booster,” Limp wrote. “This will take a little bit of luck and a lot of excellent execution. We’re on track to produce eight GS2s [second stages] this year, and the one we’ll fly on this second mission was hot-fired in April.”

Falling short … Before 2025 began, Limp set expectations alongside Blue Origin founder Jeff Bezos: New Glenn would launch eight times this year. That’s not going to happen. It’s common for launch companies to take a while ramping up the flight rate for a new rocket, but Bezos told Ars in January that his priority for Blue Origin this year was to hit a higher cadence with New Glenn. Elon Musk’s rift with President Donald Trump could open a pathway for Blue Origin to capture more government business if the New Glenn rocket is able to establish a reliable track record. Meanwhile, Limp told Blue Origin employees last month that Jarrett Jones, the manager running the New Glenn program, is taking a sabbatical. Although it appears Jones’ leave may have been planned, the timing is curious.

Making way for Starship at Cape Canaveral. The US Air Force is moving closer to authorizing SpaceX to move into one of the largest launch pads at Cape Canaveral Space Force Station in Florida, with plans to use the facility for up to 76 launches of the company’s Starship rocket each year, Ars reports. A draft Environmental Impact Statement (EIS) released by the Department of the Air Force, which includes the Space Force, found SpaceX’s planned use of Space Launch Complex 37 (SLC-37) at Cape Canaveral would have no significant negative impacts on local environmental, historical, social, and cultural interests. The Air Force also found SpaceX’s plans at SLC-37 will have no significant impact on the company’s competitors in the launch industry.

Bringing the rumble … SLC-37 was the previous home to United Launch Alliance’s Delta IV rocket, which last flew from the site in April 2024, a couple of months after the military announced SpaceX was interested in using the launch pad. While it doesn’t have a lease for full use of the launch site, SpaceX has secured a “right of limited entry” from the Space Force to begin preparatory work. This included the explosive demolition of the launch pad’s Delta IV-era service towers and lightning masts Thursday, clearing the way for eventual construction of two Starship launch towers inside the perimeter of SLC-37. The new Starship launch towers at SLC-37 will join other properties in SpaceX’s Starship empire, including nearby Launch Complex 39A at NASA’s Kennedy Space Center, and SpaceX’s privately owned facility at Starbase, Texas.

Preps continue for Starship Flight 10. Meanwhile, at Starbase, SpaceX is moving forward with preparations for the next Starship test flight, which could happen as soon as next month following three consecutive flights that fell short of expectations. This next launch will be the 10th full-scale test flight of Starship. Last Friday, June 6, SpaceX test-fired the massive Super Heavy booster designated to launch on Flight 10. All 33 of its Raptor engines ignited on the launch pad in South Texas. This is a new Super Heavy booster. On Flight 9 last month, SpaceX flew a reused Super Heavy booster that launched and was recovered on a flight in January.

FAA signs off on SpaceX investigation … The Federal Aviation Administration said Thursday it has closed the investigation into Starship Flight 8 in March, which spun out of control minutes after liftoff, showering debris along a corridor of ocean near the Bahamas and the Turks and Caicos Islands. “The FAA oversaw and accepted the findings of the SpaceX-led investigation,” an agency spokesperson said. “The final mishap report cites the probable root cause for the loss of the Starship vehicle as a hardware failure in one of the Raptor engines that resulted in inadvertent propellant mixing and ignition. SpaceX identified eight corrective actions to prevent a reoccurrence of the event.” SpaceX implemented the corrective actions prior to Flight 9 last month, when Starship progressed further into its mission before starting to tumble in space. It eventually reentered the atmosphere over the Indian Ocean. The FAA has mandated a fresh investigation into Flight 9, and that inquiry remains open.

Next three launches

June 13: Falcon 9 | Starlink 12-26 | Cape Canaveral Space Force Station, Florida | 15: 21 UTC

June 14: Long March 2D | Unknown Payload | Jiuquan Satellite Launch Center, China | 07: 55 UTC

June 16: Atlas V | Project Kuiper KA-02| Cape Canaveral Space Force Station, Florida | 17: 25 UTC

Rocket Report: New delay for Europe’s reusable rocket; SpaceX moves in at SLC-37 Read More »

Isaacman’s bold plan for NASA: Nuclear ships, seven-crew Dragons, accelerated Artemis

isaacman, Mars, NASA, nuclear spaceships, Space / Shannon Garcia / June 13, 2025

Needs a Super Administrator

“I was very disappointed, especially because it was so close to confirmation.”

Jared Isaacman speaks at the Spacepower Conference in Orlando, Florida. Credit: John Kraus

Nearly two weeks have passed since Jared Isaacman received a fateful, brief phone call from two officials in President Trump’s Office of Personnel Management. In those few seconds, the trajectory of his life over the next three and a half years changed dramatically.

The president, the callers said, wanted to go in a different direction for NASA’s administrator. At the time, Isaacman was within days of a final vote on the floor of the US Senate and assured of bipartisan support. He had run the gauntlet of six months of vetting, interviews, and a committee hearing. He expected to be sworn in within a week. And then, it was all gone.

“I was very disappointed, especially because it was so close to confirmation and I think we had a good plan to implement,” Isaacman told Ars on Wednesday.

Isaacman’s nomination was pulled for political reasons. As SpaceX founder and one-time President Trump confidant Elon Musk made his exit from the White House, key officials who felt trampled on by Musk took their revenge. They knifed a political appointment, Isaacman, who shared Musk’s passion for extending humanity’s reach to Mars. The dismissal was part of a chain of events that ultimately led to a break in the relationship between Trump and Musk, igniting a war of words.

When I spoke with Isaacman this week, I didn’t want to rehash the political melee. I preferred to talk about his plan. After all, he had six months to look under the hood of NASA, identify the problems that were holding the space agency back, and release its potential in this new era of spaceflight.

A man with a plan

“It shouldn’t be a surprise, the organizational structure is very heavy with management and leadership,” Isaacman said. “Lots of senior leadership with long meetings, who have their deputies, who have their chiefs of staff, who have deputy chiefs of staff and associate deputies. It is not just a NASA problem; across government, there are principal, deputy, assistant-to-the-deputy roles. It makes it very hard to have a culture of ownership and urgent decision-making.”

Isaacman said his plan, a blueprint of more than 100 pages detailing various actions to modernize NASA and make it more efficient, would have started with the bureaucracy. “It was going to be hard to get the big, exciting stuff done without a reorganization, a rebuild, including cultural rebuilding, and an aggressive, hungry, mission-first culture,” he said.

One of his first steps would have been to attempt to accelerate the timeline for the Artemis II mission, which is scheduled to fly four astronauts around the Moon in April 2026. He planned to bring in “strike” teams of engineers to help move Artemis and other programs forward. Isaacman wanted to see the Artemis II vehicle on the pad later this summer, with the goal of launching in December of this year, echoing the historic launch of Apollo 8 in December 1968.

Isaacman also sought to reverse the space agency’s decision to cut utilization of the International Space Station due to budget issues.

“Instead of the current thinking, three crew members every eight months to manage the budget, I wanted to go seven crew members every four months,” he said. “I was even going to pay for one of the missions, if need be, to just get more people up there, more cracks at science, and try and figure out the orbital economy, or else life will be very hard on the commercial LEO destinations.”

As part of this, he would have pushed for certification of SpaceX’s Dragon spacecraft to carry seven astronauts—which was in the vehicle’s baseline design—instead of the current four. This would have allowed NASA to fly more professional astronauts, but also payload specialists like the agency used to do during the Space Shuttle program. Essentially, NASA experts of certain experiments would fly and conduct their own research.

“I wanted to bring back the Payload Specialist program and open it up to the NASA workforce,” he said. “Because things are pretty difficult right now, and I wanted to get people excited and reward the best.”

He also planned to seek goodwill by donating his salary as administrator to Space Camp at the US Space & Rocket Center in Huntsville, Alabama, for scholarships to inspire the next generation of explorers.

Nuclear spaceships

Isaacman’s signature issue was going to be a full-bore push into nuclear electric propulsion, which he views as essential for the sustainable exploration of the Solar System by humans. Nuclear electric propulsion converts heat from a fission reactor to electrical power, like a power plant on Earth, and then uses this energy to produce thrust by accelerating an ionized propellant, such as xenon. Nuclear propulsion requires significantly less fuel than chemical propulsion, and it opens up more launch windows to Mars and other destinations.

“We would have gone right to a 100-kilowatt test vehicle that we would send somewhere inspiring with some great cameras,” he said. “Then we are going right to megawatt class, inside of four years, something you could dock a human-rated spaceship to, or drag a telescope to a Lagrange point and then return, big stuff like that. The goal was to get America underway in space on nuclear power.”

Another key element of this plan is that it would give some of NASA’s field centers, including Marshall Space Flight Center, important work to do after the cancellation of the Space Launch System rocket.

“Pivoting to nuclear spaceships, in my mind, was just the right thing to do for the SLS states, even if it’s not the right locations or the right people. There is a lot of dollars there that those states don’t want to let go of,” he said. “When you speak to those senators, if you give them another kind of bar to grab onto, they can get excited about what comes next. And imagine an SLS-caliber budget going into building, literally, nuclear orbiters that could do all sorts of things. That’s directionally correct, right?”

What direction NASA takes now is unclear, but the loss of Isaacman is acute. The agency’s acting administrator, Janet Petro, is largely taking direction from the White House Office of Management and Budget and has no independence. A confirmed administrator is now months away. The lights at the historic space agency get a little dimmer each day as a result.

Considering politics

As for what he plans to do now that he suddenly has time on his hands—Isaacman stepped down as chief executive of Shift4, the financial payments company he founded, to become NASA administrator—Isaacman is weighing his options.

“I’m sure a lot of supporters in the space community would love to hear me say that I’m done with politics, but I’m not sure that’s the case,” he said. “I want to serve our country, give back, and make a difference. I don’t know what, but I will find something.”

What his role in politics would be, Isaacman, who has described himself as a moderate, Republican-leaning voter, is unsure. However, he wants to help bridge a nation that is riven by partisan politics. “I think if you don’t have more moderates and better communicators try to pull us closer together, we’re just going to keep moving farther apart,” he said. “And that just doesn’t seem like it’s in any way good for the country.”

Eric Berger is the senior space editor at Ars Technica, covering everything from astronomy to private space to NASA policy, and author of two books: Liftoff, about the rise of SpaceX; and Reentry, on the development of the Falcon 9 rocket and Dragon. A certified meteorologist, Eric lives in Houston.

Isaacman’s bold plan for NASA: Nuclear ships, seven-crew Dragons, accelerated Artemis Read More »

5 things in Trump’s budget that won’t make NASA great again

budget, Donald Trump, NASA, Science, solar system, Space, space policy, space science / Kelly Newman / June 11, 2025

If signed into law as written, the White House’s proposal to slash nearly 25 percent from NASA’s budget would have some dire consequences.

It would cut the agency’s budget from $24.8 billion to $18.8 billion. Adjusted for inflation, this would be the smallest NASA budget since 1961, when the first American launched into space.

The proposed funding plan would halve NASA’s funding for robotic science missions and technology development next year, scale back research on the International Space Station, turn off spacecraft already exploring the Solar System, and cancel NASA’s Space Launch System rocket and Orion spacecraft after two more missions in favor of procuring lower-cost commercial transportation to the Moon and Mars.

The SLS rocket and Orion spacecraft have been targets for proponents of commercial spaceflight for several years. They are single-use, and their costs are exorbitant, with Moon missions on SLS and Orion projected to cost more than $4 billion per flight. That price raises questions about whether these vehicles will ever be able to support a lunar space station or Moon base where astronauts can routinely rotate in and out on long-term expeditions, like researchers do in Antarctica today.

Reusable rockets and spaceships offer a better long-term solution, but they won’t be ready to ferry people to the Moon for a while longer. The Trump administration proposes flying SLS and Orion two more times on NASA’s Artemis II and Artemis III missions, then retiring the vehicles. Artemis II’s rocket is currently being assembled at Kennedy Space Center in Florida for liftoff next year, carrying a crew of four around the far side of the Moon. Artemis III would follow with the first attempt to land humans on the Moon since 1972.

The cuts are far from law

Every part of Trump’s budget proposal for fiscal year 2026 remains tentative. Lawmakers in each house of Congress will write their own budget bills, which must go to the White House for Trump’s signature. A Senate bill released last week includes language that would claw back funding for SLS and Orion to support the Artemis IV and Artemis V missions.

5 things in Trump’s budget that won’t make NASA great again Read More »

Senate response to White House budget for NASA: Keep SLS, nix science

budget, NASA, Senate, Space / DJ Henderson / June 6, 2025

This legislation, the committee said in a messaging document, “Dedicates almost $10 billion to win the new space race with China and ensure America dominates space. Makes targeted, critical investments in Mars-forward technology, Artemis Missions and Moon to Mars program, and the International Space Station.”

The reality is that it signals that Republicans in the US Senate are not particularly interested in sending humans to Mars, probably are OK with the majority of cuts to science programs at NASA, and want to keep the status quo on Artemis, including the Space Launch System rocket.

Where things go from here

It is difficult to forecast where US space policy will go from here. The very public breakup between President Trump and SpaceX founder Elon Musk on Thursday significantly complicates the equation. At one point, Trump and Musk were both championing sending humans to Mars, but Musk is gone from the administration, and Trump may abandon that idea due to their rift.

For what it’s worth, a political appointee in NASA Communications said on Thursday that the president’s vision for space—Trump spoke of landing humans on Mars frequently during his campaign speeches—will continue to be implemented.

“NASA will continue to execute upon the President’s vision for the future of space,” NASA’s press secretary, Bethany Stevens, said on X. “We will continue to work with our industry partners to ensure the President’s objectives in space are met.”

Congress, it seems, may be heading in a different direction.

Senate response to White House budget for NASA: Keep SLS, nix science Read More »

Jared Isaacman speaks out, and it’s clear that NASA lost a visionary leader

jared isaacman, NASA, Space / DJ Henderson / June 5, 2025

“There’s enough hardware now to fly a couple of missions and make sure you beat China back to the Moon,” he said. “But you can’t be stuck on this forever. This is literally the equivalency, by the way, of taking P-51 Mustangs [a fighter aircraft] from World War II and using them in Desert Storm, because we got to keep the plants open. And that obviously makes no logical sense whatsoever.”

On his de-nomination

Isaacman said he is, politically, a moderate, although he leans right. He supports Trump’s desire to cut alleged waste and fraud from the US government, and that is what he intended to do at NASA. He also did not blame Trump for his departure, saying that a president makes a thousand decisions a day, often with a few seconds of information.

He also said he enjoyed the Senate confirmation process, which allowed him to candidly discuss his positions on NASA with individual US senators.

As for why he was removed, Isaacman said the following: “I had a pretty good idea, I don’t think the timing was much of a coincidence,” he said. “Obviously, there was more than one departure that was covered on that day.”

The phone call to Isaacman saying his nomination was being pulled came the same day that SpaceX founder Elon Musk left his position as a special advisor to the president. Musk had been supportive of Isaacman’s nomination. However, in his time running the Department of Government Efficiency, Musk had made enemies within the US government.

“There were some people who had some axes to grind, and I was a good, visible target,” Isaacman said. “I want to be overwhelmingly clear: I don’t fault the president.”

Although Isaacman did not name anyone, multiple sources have told Ars that it was Sergio Gor, an official in the White House Presidential Personnel Office, who moved against Isaacman after Musk left the White House. Gor was irked by Musk’s failure to consult him and other personnel officials on some decisions.

As a result of what appears to be political pettiness, NASA lost a visionary leader who had the potential to lead the space agency into the middle of the 21st century at a time when an aging agency needs to modernize. If you listen to him, losing that potential in such a way is downright painful. It’s a damn shame.

Jared Isaacman speaks out, and it’s clear that NASA lost a visionary leader Read More »

Some parts of Trump’s proposed budget for NASA are literally draconian

darpa, DRACO, NASA, nasa budget, nuclear thermal propulsion, Science, Space, White House / Kelly Newman / June 3, 2025

“That’s exactly the kind of thing that NASA should be concentrating its resources on.”

Artist’s illustration of the DRACO nuclear rocket engine in space. Credit: Lockheed Martin

New details of the Trump administration’s plans for NASA, released Friday, revealed the White House’s desire to end the development of an experimental nuclear thermal rocket engine that could have shown a new way of exploring the Solar System.

Trump’s NASA budget request is rife with spending cuts. Overall, the White House proposes reducing NASA’s budget by about 24 percent, from $24.8 billion this year to $18.8 billion in fiscal year 2026. In previous stories, Ars has covered many of the programs impacted by the proposed cuts, which would cancel the Space Launch System rocket and Orion spacecraft and terminate numerous robotic science missions, including the Mars Sample Return, probes to Venus, and future space telescopes.

Instead, the leftover funding for NASA’s human exploration program would go toward supporting commercial projects to land on the Moon and Mars.

NASA’s initiatives to pioneer next-generation space technologies are also hit hard in the White House’s budget proposal. If the Trump administration gets its way, NASA’s Space Technology Mission Directorate, or STMD, will see its budget cut nearly in half, from $1.1 billion to $568 million.

Trump’s budget request isn’t final. Both Republican-controlled houses of Congress will write their own versions of the NASA budget, which must be reconciled before going to the White House for President Trump’s signature.

“The budget reduces Space Technology by approximately half, including eliminating failing space propulsion projects,” the White House wrote in an initial overview of the NASA budget request released May 2. “The reductions also scale back or eliminate technology projects that are not needed by NASA or are better suited to private sector research and development.”

Breathing fire

Last week, the White House and NASA put a finer point on these “failing space propulsion projects.”

“This budget provides no funding for Nuclear Thermal Propulsion and Nuclear Electric Propulsion projects,” officials wrote in a technical supplement released Friday detailing Trump’s NASA budget proposal. “These efforts are costly investments, would take many years to develop, and have not been identified as the propulsion mode for deep space missions. The nuclear propulsion projects are terminated to achieve cost savings and because there are other nearer-term propulsion alternatives for Mars transit.”

Foremost among these cuts, the White House proposes to end NASA’s participation in the Demonstration Rocket for Agile Cislunar Operations (DRACO) project. NASA said this proposal “reflects the decision by our partner to cancel” the DRACO mission, which would have demonstrated a nuclear thermal rocket engine in space for the first time.

NASA’s partner on the DRACO mission was the Defense Advanced Research Projects Agency, or DARPA, the Pentagon’s research and development arm. A DARPA spokesperson confirmed the agency was closing out the project.

“DARPA has completed the agency’s involvement in the Demonstration Rocket for Agile Cislunar Orbit (DRACO) program and is transitioning its knowledge to our DRACO mission partner, the National Aeronautics and Space Administration (NASA), and to other potential DOD programs,” the spokesperson said in a response to written questions.

A nuclear rocket engine, which was to be part of NASA’s aborted NERVA program, is tested at Jackass Flats, Nevada, in 1967. Credit: Corbis via Getty Images)

Less than two years ago, NASA and DARPA announced plans to move forward with the roughly $500 million DRACO project, targeting a launch into Earth orbit aboard a traditional chemical rocket in 2027. “With the help of this new technology, astronauts could journey to and from deep space faster than ever, a major capability to prepare for crewed missions to Mars,” former NASA administrator Bill Nelson said at the time.

The DRACO mission would have consisted of several elements, including a nuclear reactor to rapidly heat up super-cold liquid hydrogen fuel stored in an insulated tank onboard the spacecraft. Temperatures inside the engine would reach nearly 5,000° Fahrenheit, boiling the hydrogen and driving the resulting gas through a nozzle, generating thrust. From the outside, the spacecraft’s design looks a lot like the upper stage of a traditional rocket. However, theoretically, a nuclear thermal rocket engine like DRACO’s would offer twice the efficiency of the highest-performing conventional rocket engines. That translates to significantly less fuel that a mission to Mars would have to carry across the Solar System.

Essentially, a nuclear thermal rocket engine combines the high-thrust capability of a chemical engine with some of the fuel efficiency benefits of low-thrust solar-electric engines. With DRACO, engineers sought hard data to verify their understanding of nuclear propulsion and wanted to make sure the nuclear engine’s challenging design actually worked. DRACO would have used high-assay low-enriched uranium to power its nuclear reactor.

Nuclear electric propulsion uses an onboard nuclear reactor to power plasma thrusters that create thrust by accelerating an ionized gas, like xenon, through a magnetic field. Nuclear electric propulsion would provide another leap in engine efficiency beyond the capabilities of a system like DRACO and may ultimately offer the most attractive option for enduring deep space transportation.

NASA led the development of DRACO’s nuclear rocket engine, while DARPA was responsible for the overall spacecraft design, operations, and the thorny problem of securing regulatory approval to launch a nuclear reactor into orbit. The reactor on DRACO would have launched in “cold” mode before activating in space, reducing the risk to people on the ground in the event of a launch accident. The Space Force agreed to pay for DRACO’s launch on a United Launch Alliance Vulcan rocket.

DARPA and NASA selected Lockheed Martin as the lead contractor for the DRACO spacecraft in 2023. BWX Technologies, a leader in the US nuclear industry, won the contract to develop the mission’s reactor.

“We received the notice from DARPA that it ended the DRACO program,” a Lockheed Martin spokesperson said. “While we’re disappointed with the decision, it doesn’t change our vision of how nuclear power influences how we will explore and operate in the vastness of space.”

Mired in the lab

More than 60 years have passed since a US-built nuclear reactor launched into orbit. Aviation Week reported in January that one problem facing DRACO engineers involved questions about how to safely test the nuclear thermal engine on the ground while adhering to nuclear safety protocols.

“We’re bringing two things together—space mission assurance and nuclear safety—and there’s a fair amount of complexity,” said Matthew Sambora, a DRACO program manager at DARPA, in an interview with Aviation Week. At the time, DARPA and NASA had already given up on a 2027 launch to concentrate on developing a prototype engine using helium as a propellant before moving on to an operational engine with more energetic liquid hydrogen fuel, Aviation Week reported.

Greg Meholic, an engineer at the Aerospace Corporation, highlighted the shortfall in ground testing capability in a presentation last year. Nuclear thermal propulsion testing “requires that engine exhaust be scrubbed of radiologics before being released,” he wrote. This requirement “could result in substantially large, prohibitively expensive facilities that take years to build and qualify.”

These safety protocols weren’t as stringent when NASA and the Air Force first pursued nuclear propulsion in the 1960s. Now, the first serious 21st-century effort to fly a nuclear rocket engine in space is grinding to a halt.

“Given that our near-term human exploration and science needs do not require nuclear propulsion, current demonstration projects will end,” wrote Janet Petro, NASA’s acting administrator, in a letter accompanying the Trump administration’s budget release last week.

This figure illustrates the major elements of a typical nuclear thermal rocket engine. Credit: NASA/Glenn Research Center

NASA’s 2024 budget allocated $117 million for nuclear propulsion work, an increase from $91 million the previous year. Congress added more funding for NASA’s nuclear propulsion programs over the Biden administration’s proposed budget in recent years, signaling support on Capitol Hill that may save at least some nuclear propulsion initiatives next year.

It’s true that nuclear propulsion isn’t required for any NASA missions currently on the books. Today’s rockets are good at hurling cargo and people off planet Earth, but once a spacecraft arrives in orbit, there are several ways to propel it toward more distant destinations.

NASA’s existing architecture for sending astronauts to the Moon uses the SLS rocket and Orion spacecraft, both of which are proposed for cancellation and look a lot like the vehicles NASA used to fly astronauts to the Moon more than 50 years ago. SpaceX’s reusable Starship, designed with an eye toward settling Mars, uses conventional chemical propulsion, with methane and liquid oxygen propellants that SpaceX one day hopes to generate on the surface of the Red Planet.

So NASA, SpaceX, and other companies don’t need nuclear propulsion to beat China back to the Moon or put the first human footprints on Mars. But there’s a broad consensus that in the long run, nuclear rockets offer a better way of moving around the Solar System.

The military’s motive for funding nuclear thermal propulsion was its potential for becoming a more efficient means of maneuvering around the Earth. Many of the military’s most important spacecraft are limited by fuel, and the Space Force is investigating orbital refueling and novel propulsion methods to extend the lifespan of satellites.

NASA’s nuclear power program is not finished. The Trump administration’s budget proposal calls for continued funding for the agency’s fission surface power program, with the goal of fielding a nuclear reactor that could power a base on the surface of the Moon or Mars. Lockheed and BWXT, the contractors involved in the DRACO mission, are part of the fission surface power program.

There is some funding in the White House’s budget request for tech demos using other methods of in-space propulsion. NASA would continue funding experiments in long-term storage and transfer of cryogenic propellants like liquid methane, liquid hydrogen, and liquid oxygen. These joint projects between NASA and industry could pave the way for orbital refueling and orbiting propellant depots, aligning with the direction of companies like SpaceX, Blue Origin, and United Launch Alliance.

But many scientists and engineers believe nuclear propulsion offers the only realistic path for a sustainable campaign ferrying people between the Earth and Mars. A report commissioned by NASA and the National Academies concluded in 2021 that an aggressive tech-development program could advance nuclear thermal propulsion enough for a human expedition to Mars in 2039. The prospects for nuclear electric propulsion were murkier.

This would have required NASA to substantially increase its budget for nuclear propulsion immediately, likely by an order of magnitude beyond the agency’s baseline funding level, or to an amount exceeding $1 billion per year, said Bobby Braun, co-chair of the National Academies report, in a 2021 interview with Ars. That didn’t happen.

Going nuclear

The interplanetary transportation architectures envisioned by NASA and SpaceX will, at least initially, primarily use chemical propulsion for the cruise between Earth and Mars.

Kurt Polzin, chief engineer of NASA’s space nuclear propulsion projects, said significant technical hurdles stand in the way of any propulsion system selected to power heavy cargo and humans to Mars.

“Anybody who says that they’ve solved the problem, you don’t know that because you don’t have enough data,” Polzin said last week at the Humans to the Moon and Mars Summit in Washington.

“We know that to do a Mars mission with a Starship, you need lots of refuelings at Earth, you need lots of refuelings at Mars, which you have to send in advance,” Polzin said. “You either need to send that propellant in advance or send a bunch of material and hardware to the surface to be set up and robotically make your propellant in situ while you’re there.”

Elon Musk’s SpaceX is betting on chemical propulsion for round-trip flights to Mars with its Starship rocket. This will require assembly of propellant-generation plants on the Martian surface. Credit: SpaceX

Last week, SpaceX founder Elon Musk outlined how the company plans to land its first Starships on Mars. His roadmap includes more than 100 cargo flights to deliver equipment to produce methane and liquid oxygen propellants on the surface of Mars. This is necessary for any Starship to launch off the Red Planet and return to Earth.

“You can start to see that this starts to become a Rube Goldberg way to do Mars,” Polzin said. “Will I say it can’t work? No, but will I say that it’s really, really difficult and challenging. Are there a lot of miracles to make it work? Absolutely. So the notion that SpaceX has solved Mars or is going to do Mars with Starship, I would challenge that on its face. I don’t think the analysis and the data bear that out.”

Engineers know how methane-fueled rocket engines perform in space. Scientists have created liquid oxygen and liquid methane since the late 1800s. Scaling up a propellant plant on Mars to produce thousands of tons of cryogenic liquids is another matter. In the long run, this might be a suitable solution for Musk’s vision of creating a city on Mars, but it comes with immense startup costs and risks. Still, nuclear propulsion is an entirely untested technology as well.

“The thing with nuclear is there are challenges to making it work, too,” Polzin said. “However, all of my challenges get solved here at Earth and in low-Earth orbit before I leave. Nuclear is nice. It has a higher specific impulse, especially when we’re talking about nuclear thermal propulsion. It has high thrust, which means it will get our astronauts there and back quickly, but I can carry all the fuel I need to get back with me, so I don’t need to do any complicated refueling at Mars. I can return without having to make propellant or send any pre-positioned propellant to get back.”

The tug of war over nuclear propulsion is nothing new. The Air Force started a program to develop reactors for nuclear thermal rockets at the height of the Cold War. NASA took over the Air Force’s role a few years later, and the project proceeded into the next phase, called the Nuclear Engine for Rocket Vehicle Application (NERVA). President Richard Nixon ultimately canceled the NERVA project in 1973 after the government had spent $1.4 billion on it, equivalent to about $10 billion in today’s dollars. Despite nearly two decades of work, NERVA never flew in space.

Doing the hard things

The Pentagon and NASA studied several more nuclear thermal and nuclear electric propulsion initiatives before DRACO. Today, there’s a nascent commercial business case for compact nuclear reactors beyond just the government. But there’s scant commercial interest in mounting a full-scale nuclear propulsion demonstration solely with private funding.

Fred Kennedy, co-founder and CEO of a space nuclear power company called Dark Fission, said most venture capital investors lack the appetite to wait for financial returns in nuclear propulsion that they may see in 15 or 20 years.

“It’s a truism: Space is hard,” said Kennedy, a former DARPA program manager. “Nuclear turns out to be hard for reasons we can all understand. So space-nuclear is hard-squared, folks. As a result, you give this to your average associate at a VC firm and they get scared quick. They see the moles all over your face, and they run away screaming.”

But commercial launch costs are coming down. With sustained government investment and streamlined regulations, “this is the best chance we’ve had in a long time” to get a nuclear propulsion system into space, Kennedy said.

Technicians prepare a nozzle for a prototype nuclear thermal rocket engine in 1964. Credit: NASA

“I think, right now, we’re in this transitional period where companies like mine are going have to rely on some government largesse, as well as hopefully both commercial partnerships and honest private investment,” Kennedy said. “Three years ago, I would have told you I thought I could have done the whole thing with private investment, but three years have turned my hair white.”

Those who share Kennedy’s view thought they were getting an ally in the Trump administration. Jared Isaacman, the billionaire commercial astronaut Trump nominated to become the next NASA administrator, promised to prioritize nuclear propulsion in his tenure as head of the nation’s space agency.

During his Senate confirmation hearing in April, Isaacman said NASA should turn over management of heavy-lift rockets, human-rated spacecraft, and other projects to commercial industry. This change, he said, would allow NASA to focus on the “near-impossible challenges that no company, organization, or agency anywhere in the world would be able to undertake.”

The example Isaacman gave in his confirmation hearing was nuclear propulsion. “That’s something that no company would ever embark upon,” he told lawmakers. “There is no obvious economic return. There are regulatory challenges. That’s exactly the kind of thing that NASA should be concentrating its resources on.”

But the White House suddenly announced on Saturday that it was withdrawing Isaacman’s nomination days before the Senate was expected to confirm him for the NASA post. While there’s no indication that Trump’s withdrawal of Isaacman had anything to do with any specific part of the White House’s funding plan, his removal leaves NASA without an advocate for nuclear propulsion and a number of other projects falling under the White House’s budget ax.

Some parts of Trump’s proposed budget for NASA are literally draconian Read More »