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The military’s squad of satellite trackers is now routinely going on alert


“I hope this blows your mind because it blows my mind.”

A Long March 3B rocket carrying a new Chinese Beidou navigation satellite lifts off from the Xichang Satellite Launch Center on May 17, 2023. Credit: VCG/VCG via Getty Images

This is Part 2 of our interview with Col. Raj Agrawal, the former commander of the Space Force’s Space Mission Delta 2.

If it seems like there’s a satellite launch almost every day, the numbers will back you up.

The US Space Force’s Mission Delta 2 is a unit that reports to Space Operations Command, with the job of sorting out the nearly 50,000 trackable objects humans have launched into orbit.

Dozens of satellites are being launched each week, primarily by SpaceX to continue deploying the Starlink broadband network. The US military has advance notice of these launches—most of them originate from Space Force property—and knows exactly where they’re going and what they’re doing.

That’s usually not the case when China or Russia (and occasionally Iran or North Korea) launches something into orbit. With rare exceptions, like human spaceflight missions, Chinese and Russian officials don’t publish any specifics about what their rockets are carrying or what altitude they’re going to.

That creates a problem for military operators tasked with monitoring traffic in orbit and breeds anxiety among US forces responsible for making sure potential adversaries don’t gain an edge in space. Will this launch deploy something that can destroy or disable a US satellite? Will this new satellite have a new capability to surveil allied forces on the ground or at sea?

Of course, this is precisely the point of keeping launch details under wraps. The US government doesn’t publish orbital data on its most sensitive satellites, such as spy craft collecting intelligence on foreign governments.

But you can’t hide in low-Earth orbit, a region extending hundreds of miles into space. Col. Raj Agrawal, who commanded Mission Delta 2 until earlier this month, knows this all too well. Agrawal handed over command to Col. Barry Croker as planned after a two-year tour of duty at Mission Delta 2.

Col. Raj Agrawal, then-Mission Delta 2 commander, delivers remarks to audience members during the Mission Delta 2 redesignation ceremony in Colorado Springs, Colorado, on October 31, 2024. Credit: US Space Force

Some space enthusiasts have made a hobby of tracking US and foreign military satellites as they fly overhead, stringing together a series of observations over time to create fairly precise estimates of an object’s altitude and inclination.

Commercial companies are also getting in on the game of space domain awareness. But most are based in the United States or allied nations and have close partnerships with the US government. Therefore, they only release information on satellites owned by China and Russia. This is how Ars learned of interesting maneuvers underway with a Chinese refueling satellite and suspected Russian satellite killers.

Theoretically, there’s nothing to stop a Chinese company, for example, from taking a similar tack on revealing classified maneuvers conducted by US military satellites.

The Space Force has an array of sensors scattered around the world to detect and track satellites and space debris. The 18th and 19th Space Defense Squadrons, which were both under Agrawal’s command at Mission Delta 2, are the units responsible for this work.

Preparing for the worst

One of the most dynamic times in the life of a Space Force satellite tracker is when China or Russia launches something new, according to Agrawal. His command pulls together open source information, such as airspace and maritime warning notices, to know when a launch might be scheduled.

This is not unlike how outside observers, like hobbyist trackers and space reporters, get a heads-up that something is about to happen. These notices tell you when a launch might occur, where it will take off from, and which direction it will go. What’s different for the Space Force is access to top-secret intelligence that might clue military officials in on what the rocket is actually carrying. China, in particular, often declares that its satellites are experimental, when Western analysts believe they are designed to support military activities.

That’s when US forces swing into action. Sometimes, military forces go on alert. Commanders develop plans to detect, track, and target the objects associated with a new launch, just in case they are “hostile,” Agrawal said.

We asked Agrawal to take us through the process his team uses to prepare for and respond to one of these unannounced, or “non-cooperative,” launches. This portion of our interview is published below, lightly edited for brevity and clarity.

Ars: Let’s say there’s a Russian or Chinese launch. How do you find out there’s a launch coming? Do you watch for NOTAMs (Notices to Airmen), like I do, and try to go from there?

Agrawal: I think the conversation starts the same way that it probably starts with you and any other technology-interested American. We begin with what’s available. We certainly have insight through intelligence means to be able to get ahead of some of that, but we’re using a lot of the same sources to refine our understanding of what may happen, and then we have access to other intel.

The good thing is that the Space Force is a part of the Intelligence Community. We’re plugged into an entire Intelligence Community focused on anything that might be of national security interest. So we’re able to get ahead. Maybe we can narrow down NOTAMs; maybe we can anticipate behavior. Maybe we have other activities going on in other domains or on the Internet, the cyber domain, and so on, that begin to tip off activity.

Certainly, we’ve begun to understand patterns of behavior. But no matter what, it’s not the same level of understanding as those who just cooperate and work together as allies and friends. And if there’s a launch that does occur, we’re not communicating with that launch control center. We’re certainly not communicating with the folks that are determining whether or not the launch will be safe, if it’ll be nominal, how many payloads are going to deploy, where they’re going to deploy to.

I certainly understand why a nation might feel that they want to protect that. But when you’re fielding into LEO [low-Earth orbit] in particular, you’re not really going to hide there. You’re really just creating uncertainty, and now we’re having to deal with that uncertainty. We eventually know where everything is, but in that meantime, you’re creating a lot of risk for all the other nations and organizations that have fielded capability in LEO as well.

Find, fix, track, target

Ars: Can you take me through what it’s like for you and your team during one of these launches? When one comes to your attention, through a NOTAM or something else, how do you prepare for it? What are you looking for as you get ready for it? How often are you surprised by something with one of these launches?

Agrawal: Those are good questions. Some of it, I’ll be more philosophical on, and others I can be specific on. But on a routine basis, our formation is briefed on all of the launches we’re aware of, to varying degrees, with the varying levels of confidence, and at what classifications have we derived that information.

In fact, we also have a weekly briefing where we go into depth on how we have planned against some of what we believe to be potentially higher threats. How many organizations are involved in that mission plan? Those mission plans are done at a very tactical level by captains and NCOs [non-commissioned officers] that are part of the combat squadrons that are most often presented to US Space Command…

That integrated mission planning involves not just Mission Delta 2 forces but also presented forces by our intelligence delta [Space Force units are called deltas], by our missile warning and missile tracking delta, by our SATCOM [satellite communications] delta, and so on—from what we think is on the launch pad, what we think might be deployed, what those capabilities are. But also what might be held at risk as a result of those deployments, not just in terms of maneuver but also what might these even experimental—advertised “experimental”—capabilities be capable of, and what harm might be caused, and how do we mission-plan against those potential unprofessional or hostile behaviors?

As you can imagine, that’s a very sophisticated mission plan for some of these launches based on what we know about them. Certainly, I can’t, in this environment, confirm or deny any of the specific launches… because I get access to more fidelity and more confidence on those launches, the timing and what’s on them, but the precursor for the vast majority of all these launches is that mission plan.

That happens at a very tactical level. That is now posturing the force. And it’s a joint force. It’s not just us, Space Force forces, but it’s other services’ capabilities as well that are posturing to respond to that. And the truth is that we even have partners, other nations, other agencies, intel agencies, that have capability that have now postured against some of these launches to now be committed to understanding, did we anticipate this properly? Did we not?

And then, what are our branch plans in case it behaves in a way that we didn’t anticipate? How do we react to it? What do we need to task, posture, notify, and so on to then get observations, find, fix, track, target? So we’re fulfilling the preponderance of what we call the kill chain, for what we consider to be a non-cooperative launch, with a hope that it behaves peacefully but anticipating that it’ll behave in a way that’s unprofessional or hostile… We have multiple chat rooms at multiple classifications that are communicating in terms of “All right, is it launching the way we expected it to, or did it deviate? If it deviated, whose forces are now at risk as a result of that?”

A spectator takes photos before the launch of the Long March 7A rocket carrying the ChinaSat 3B satellite from the Wenchang Space Launch Site in China on May 20, 2025. Credit: Meng Zhongde/VCG via Getty Images

Now, we even have down to the fidelity of what forces on the ground or on the ocean may not have capability… because of maneuvers or protective measures that the US Space Force has to take in order to deviate from its mission because of that behavior. The conversation, the way it was five years ago and the way it is today, is very, very different in terms of just a launch because now that launch, in many cases, is presenting a risk to the joint force.

We’re acting like a joint force. So that Marine, that sailor, that special operator on the ground who was expecting that capability now is notified in advance of losing that capability, and we have measures in place to mitigate those outages. And if not, then we let them know that “Hey, you’re not going to have the space capability for some period of time. We’ll let you know when we’re back. You have to go back to legacy operations for some period of time until we’re back into nominal configuration.”

I hope this blows your mind because it blows my mind in the way that we now do even just launch processing. It’s very different than what we used to do.

Ars: So you’re communicating as a team in advance of a launch and communicating down to the tactical level, saying that this launch is happening, this is what it may be doing, so watch out?

Agrawal: Yeah. It’s not as simple as a ballistic missile warning attack, where it’s duck and cover. Now, it’s “Hey, we’ve anticipated the things that could occur that could affect your ability to do your mission as a result of this particular launch with its expected payload, and what we believe it may do.” So it’s not just a general warning. It’s a very scoped warning.

As that launch continues, we’re able to then communicate more specifically on which forces may lose what, at what time, and for how long. And it’s getting better and better as the rest of the US Space Force, as they present capability trained to that level of understanding as well… We train this together. We operate together and we communicate together so that the tactical user—sometimes it’s us at US Space Force, but many times it’s somebody on the surface of the Earth that has to understand how their environment, their capability, has changed as a result of what’s happening in, to, and from space.

Ars: The types of launches where you don’t know exactly what’s coming are getting more common now. Is it normal for you to be on this alert posture for all of the launches out of China or Russia?

Agrawal: Yeah. You see it now. The launch manifest is just ridiculous, never mind the ones we know about. The ones that we have to reach out into the intelligence world and learn about, that’s getting ridiculous, too. We don’t have to have this whole machine postured this way for cooperative launches. So the amount of energy we’re expending for a non-cooperative launch is immense. We can do it. We can keep doing it, but you’re just putting us on alert… and you’re putting us in a position where we’re getting ready for bad behavior with the entire general force, as opposed to a cooperative launch, where we can anticipate. If there’s an anomaly, we can anticipate those and work through them. But we’re working through it with friends, and we’re communicating.

We’re not having to put tactical warfighters on alert every time … but for those payloads that we have more concern about. But still, it’s a very different approach, and that’s why we are actively working with as many nations as possible in Mission Delta 2 to get folks to sign on with Space Command’s space situational awareness sharing agreements, to go at space operations as friends, as allies, as partners, working together. So that way, we’re not posturing for something higher-end as a result of the launch, but we’re doing this together. So, with every nation we can, we’re getting out there—South America, Africa, every nation that will meet with us, we want to meet with them and help them get on the path with US Space Command to share data, to work as friends, and use space responsibly.”

A Long March 3B carrier rocket carrying the Shijian 21 satellite lifts off from the Xichang Satellite Launch Center on October 24, 2021. Credit: Li Jieyi/VCG via Getty Images

Ars: How long does it take you to sort out and get a track on all of the objects for an uncooperative launch?

Agrawal: That question is a tough one to answer. We can move very, very quickly, but there are times when we have made a determination of what we think something is, what it is and where it’s going, and intent; there might be some lag to get it into a public catalog due to a number of factors, to include decisions being made by combatant commanders, because, again, our primary objective is not the public-facing catalog. The primary objective is, do we have a risk or not?

If we have a risk, let’s understand, let’s figure out to what degree do we think we have to manage this within the Department of Defense. And to what degree do we believe, “Oh, no, this can go in the public catalog. This is a predictable elset (element set)”? What we focus on with (the public catalog) are things that help with predictability, with spaceflight safety, with security, spaceflight security. So you sometimes might see a lag there, but that’s because we’re wrestling with the security aspect of the degree to which we need to manage this internally before we believe it’s predictable. But once we believe it’s predictable, we put it in the catalog, and we put it on space-track.org. There’s some nuance in there that isn’t relative to technology or process but more on national security.

On the flip side, what used to take hours and days is now getting down to seconds and minutes. We’ve overhauled—not 100 percent, but to a large degree—and got high-speed satellite communications from sensors to the centers of SDA (Space Domain Awareness) processing. We’re getting higher-end processing. We’re now duplicating the ability to process, duplicating that capability across multiple units. So what used to just be human labor intensive, and also kind of dial-up speed of transmission, we’ve now gone to high-speed transport. You’re seeing a lot of innovation occur, and a lot of data fusion occur, that’s getting us to seconds and minutes.

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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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Ars spoke with the military’s chief orbital traffic cop—here’s what we learned


“We have some 2,000 or 2,200 objects that I call the ‘red order of battle.'”

Col. Raj Agrawal participates in a change of command ceremony to mark his departure from Mission Delta 2 at Peterson Space Force Base, Colorado. Col. Barry Croker became the new commander of Mission Delta 2 on July 3.

For two years, Col. Raj Agrawal commanded the US military unit responsible for tracking nearly 50,000 human-made objects whipping through space. In this role, he was keeper of the orbital catalog and led teams tasked with discerning whether other countries’ satellites, mainly China and Russia, are peaceful or present a military threat to US forces.

This job is becoming more important as the Space Force prepares for the possibility of orbital warfare.

Ars visited with Agrawal in the final weeks of his two-year tour of duty as commander of Mission Delta 2, a military unit at Peterson Space Force Base, Colorado. Mission Delta 2 collects and fuses data from a network of sensors “to identify, characterize, and exploit opportunities and mitigate vulnerabilities” in orbit, according to a Space Force fact sheet.

This involves operating radars and telescopes, analyzing intelligence information, and “mapping the geocentric space terrain” to “deliver a combat-ready common operational picture” to military commanders. Agrawal’s job has long existed in one form or another, but the job description is different today. Instead of just keeping up with where things are in space—a job challenging enough—military officials now wrestle with distinguishing which objects might have a nefarious purpose.

From teacher to commander

Agrawal’s time at Mission Delta 2 ended on July 3. His next assignment will be as Space Force chair at the National Defense University. This marks a return to education for Agrawal, who served as a Texas schoolteacher for eight years before receiving his commission as an Air Force officer in 2001.

“Teaching is, I think, at the heart of everything I do,” Agrawal said. 

He taught music and math at Trimble Technical High School, an inner city vocational school in Fort Worth. “Most of my students were in broken homes and unfortunate circumstances,” Agrawal said. “I went to church with those kids and those families, and a lot of times, I was the one bringing them home and taking them to school. What was [satisfying] about that was a lot of those students ended up living very fulfilling lives.”

Agrawal felt a calling for higher service and signed up to join the Air Force. Given his background in music, he initially auditioned for and was accepted into the Air Force Band. But someone urged him to apply for Officer Candidate School, and Agrawal got in. “I ended up on a very different path.”

Agrawal was initially accepted into the ICBM career field, but that changed after the September 11 attacks. “That was a time with anyone with a name like mine had a hard time,” he said. “It took a little bit of time to get my security clearance.”

Instead, the Air Force assigned him to work in space operations. Agrawal quickly became an instructor in space situational awareness, did a tour at the National Reconnaissance Office, then found himself working at the Pentagon in 2019 as the Defense Department prepared to set up the Space Force as a new military service. Agrawal was tasked with leading a team of 100 people to draft the first Space Force budget.

Then, he received the call to report to Peterson Space Force Base to take command of what is now Mission Delta 2, the inheritor of decades of Air Force experience cataloging everything in orbit down to the size of a softball. The catalog was stable and predictable, lingering below 10,000 trackable objects until 2007. That’s when China tested an anti-satellite missile, shattering an old Chinese spacecraft into more than 3,500 pieces large enough to be routinely detected by the US military’s Space Surveillance Network.

This graph from the European Space Agency shows the growing number of trackable objects in orbit. Credit: European Space Agency

Two years later, an Iridium communications satellite collided with a defunct Russian spacecraft, adding thousands more debris fragments to low-Earth orbit. A rapid uptick in the pace of launches since then has added to the problem, further congesting busy orbital traffic lanes a hundred miles above the Earth. Today, the orbital catalog numbers roughly 48,000 objects.

“This compiled data, known as the space catalog, is distributed across the military, intelligence community, commercial space entities, and to the public, free of charge,” officials wrote in a fact sheet describing Mission Delta 2’s role at Space Operations Command. Deltas are Space Force military units roughly equivalent to a wing or group command in the Air Force.

The room where it happens

The good news is that the US military is getting better at tracking things in space. A network of modern radars and telescopes on the ground and in space can now spot objects as small as a golf ball. Space is big, but these objects routinely pass close to one another. At speeds of nearly 5 miles per second, an impact will be catastrophic.

But there’s a new problem. Today, the US military must not only screen for accidental collisions but also guard against an attack on US satellites in orbit. Space is militarized, a fact illustrated by growing fleets of satellites—primarily American, Chinese, and Russian—capable of approaching another country’s assets in orbit, and in some cases, disable or destroy them. This has raised fears at the Pentagon that an adversary could take out US satellites critical for missile warning, navigation, and communications, with severe consequences impacting military operations and daily civilian life.

This new reality compelled the creation of the Space Force in 2019, beginning a yearslong process of migrating existing Air Force units into the new service. Now, the Pentagon is posturing for orbital warfare by investing in new technologies and reorganizing the military’s command structure.

Today, the Space Force is responsible for predicting when objects in orbit will come close to one another. This is called a conjunction in the parlance of orbital mechanics. The US military routinely issues conjunction warnings to commercial and foreign satellite operators to give them an opportunity to move their satellites out of harm’s way. These notices also go to NASA if there’s a chance of a close call with the International Space Station (ISS).

The first Trump administration approved a new policy to transfer responsibility for these collision warnings to the Department of Commerce, allowing the military to focus on national security objectives.

But the White House’s budget request for next year would cancel the Commerce Department’s initiative to take over collision warnings. Our discussion with Agrawal occurred before the details of the White House budget were made public last month, and his comments reflect official Space Force policy at the time of the interview. “In uniform, we align to policy,” Agrawal wrote on his LinkedIn account. “We inform policy decisions, but once they’re made, we align our support accordingly.”

US Space Force officials show the 18th Space Defense Squadron’s operations floor to officials from the German Space Situational Awareness Centre during an “Operator Exchange” event at Vandenberg Space Force Base, California, on April 7, 2022. Credit: US Space Force/Tech. Sgt. Luke Kitterman

Since our interview, analysts have also noticed an uptick in interesting Russian activity in space and tracked a suspected Chinese satellite refueling mission in geosynchronous orbit.

Let’s rewind the tape to 2007, the time of China’s game-changing anti-satellite test. Gen. Chance Saltzman, today the Space Force’s Chief of Space Operations, was a lieutenant colonel in command of the Air Force’s 614th Space Operations Squadron at the time. He was on duty when Air Force operators first realized China had tested an anti-satellite missile. Saltzman has called the moment a “pivot point” in space operations. “For those of us that are neck-deep in the business, we did have to think differently from that day on,” Saltzman said in 2023.

Agrawal was in the room, too. “I was on the crew that needed to count the pieces,” he told Ars. “I didn’t know the significance of what was happening until after many years, but the Chinese had clearly changed the nature of the space environment.”

The 2007 anti-satellite test also clearly changed the trajectory of Agrawal’s career. We present part of our discussion with Agrawal below, and we’ll share the rest of the conversation tomorrow. The text has been lightly edited for brevity and clarity.

Ars: The Space Force’s role in monitoring activities in space has changed a lot in the last few years. Can you tell me about these changes, and what’s the difference between what you used to call Space Situational Awareness, and what is now called Space Domain Awareness?

Agrawal: We just finished our fifth year as a Space Force, so as a result of standing up a military service focused on space, we shifted our activities to focus on what the joint force requires for combat space power. We’ve been doing space operations for going on seven decades. I think a lot of folks think that it was a rebranding, as opposed to a different focus for space operations, and it couldn’t be further from the truth. Compared to Space Domain Awareness (SDA), Space Situational Awareness (SSA) is kind of the knowledge we produce with all these sensors, and anybody can do space situational awareness. You have academia doing that. You’ve got commercial, international partners, and so on. But Space Domain Awareness, Gen. [John “Jay”] Raymond coined the term a couple years before we stood up the Space Force, and he was trying to get after, how do we create a domain focused on operational outcomes? That’s all we could say at the time. We couldn’t say war-fighting domain at the time because of the way of our policy, but our policy shifted to being able to talk about space as a place where, not that we want to wage war, but that we can achieve objectives, and do that with military objectives in mind.

We used to talk about detect, characterize, attribute, predict. And then Gen. [Chance] Saltzman added target onto the construct for Space Domain Awareness, so that we’re very much in the conversation of what it means to do a space-enabled attack and being able to achieve objectives in, from, and to space, and using Space Domain Awareness as a vehicle to do those things. So, with Mission Delta 2, what he did is he took the sustainment part of acquisition, software development, cyber defense, intelligence related to Space Domain Awareness, and then all the things that we were doing in Space Domain Awareness already, put all that together under one command … and called us Mission Delta 2. So, the 18th Space Defense Squadron … that used to kind of be the center of the world for Space Domain Awareness, maybe the only unit that you could say was really doing SDA, where everyone else was kind of doing SSA. When I came into command a couple years ago, and we face now a real threat to having space superiority in the space domain, I disaggregated what we were doing just in the 18th and spread out through a couple of other units … So, that way everyone’s got kind of majors and minors, but we can quickly move a mission in case we get tested in terms of cyber defense or other kinds of vulnerabilities.

This multi-exposure image depicts a satellite-filled sky over Alberta. Credit: Alan Dyer/VWPics/Universal Images Group via Getty Images

We can’t see the space domain, so it’s not like the air domain and sea domain and land domain, where you can kind of see where everything is, and you might have radars, but ultimately it’s a human that’s verifying whether or not a target or a threat is where it is. For the space domain, we’re doing all that through radars, telescopes, and computers, so the reality we create for everyone is essentially their reality. So, if there’s a gap, if there’s a delay, if there are some signs that we can’t see, that reality is what is created by us, and that is effectively the reality for everyone else, even if there is some other version of reality in space. So, we’re getting better and better at fielding capability to see the complexity, the number of objects, and then translating that into what’s useful for us—because we don’t need to see everything all the time—but what’s useful for us for military operations to achieve military objectives, and so we’ve shifted our focus just to that.

We’re trying to get to where commercial spaceflight safety is managed by the Office of Space Commerce, so they’re training side by side with us to kind of offload that mission and take that on. We’re doing up to a million notifications a day for conjunction assessments, sometimes as low as 600,000. But last year, we did 263 million conjunction notifications. So, we want to get to where the authorities are rightly lined, where civil or commercial notifications are done by an organization that’s not focused on joint war-fighting, and we focus on the things that we want to focus on.

Ars: Thank you for that overview. It helps me see the canvas for everything else we’re going to talk about. So, today, you’re not only tracking new satellites coming over the horizon from a recent launch or watching out for possible collisions, you’re now trying to see where things are going in space and maybe even try to determine intent, right?

Agrawal: Yeah, so the integrated mission delta has helped us have intel analysts and professionals as part of our formation. Their mission is SDA as much as ours is, but they’re using an intel lens. They’re looking at predictive intelligence, right? I don’t want to give away tradecraft, but what they’re focused on is not necessarily where a thing is. It used to be that all we cared about was position and vector, right? As long as you knew an object’s position and the direction they were going, you knew their orbit. You had predictive understanding of what their element set would be, and you only had to do sampling to get a sense of … Is it kind of where we thought it was going to be? … If it was far enough off of its element set, then we would put more energy, more sampling of that particular object, and then effectively re-catalog it.

Now, it’s a different model. We’re looking at state vectors, and we’re looking at anticipatory modeling, where we have some 2,000 or 2,200 objects that I call the “red order of battle”—that are high-interest objects that we anticipate will do things that are not predicted, that are not element set in nature, but that will follow some type of national interest. So, our intel apparatus gets after what things could potentially be a risk, and what things to continue to understand better, and what things we have to be ready to hold at risk. All of that’s happening through all the organizations, certainly within this delta, but in partnership and in support of other capabilities and deltas that are getting after their parts of space superiority.

Hostile or friendly?

Ars: Can you give some examples of these red order of battle objects?

Agrawal: I think you know about Shijian-20 (a “tech demo” satellite that has evaded inspection by US satellites) and Shijian-24C (which the Space Force says demonstrated “dogfighting” in space), things that are advertised as scientific in nature, but clearly demonstrate capability that is not friendly, and certainly are behaving in ways that are unprofessional. In any other domain, we would consider them hostile, but in space, we try to be a lot more nuanced in terms of how we characterize behavior, but still, when something’s behaving in a way that isn’t pre-planned, isn’t pre-coordinated, and potentially causes hazard, harm, or contest with friendly forces, we now get in a situation where we have to talk about is that behavior hostile or not? Is that escalatory or not? Space Command is charged with those authorities, so they work through the legal apparatus in terms of what the definition of a hostile act is and when something behaves in a way that we consider to be of national security interest.

We present all the capability to be able to do all that, and we have to be as cognizant on the service side as the combatant commanders are, so that our intel analysts are informing the forces and the training resources to be able to anticipate the behavior. We’re not simply recognizing it when it happens, but studying nations in the way they behave in all the other domains, in the way that they set policy, in the way that they challenge norms in other international arenas like the UN and various treaties, and so on. The biggest predictor, for us, of hazardous behaviors is when nations don’t coordinate with the international community on activities that are going to occur—launches, maneuvers, and fielding of large constellations, megaconstellations.

A stack of Starlink satellites in space right before deployment

Starlink satellites. Credit: Starlink

There are nearly 8,000 Starlink satellites in orbit today. SpaceX adds dozens of satellites to the constellation each week. Credit: SpaceX

As you know, we work very closely with Starlink, and they’re very, very responsible. They coordinate and flight plan. They use the kind of things that other constellations are starting to use … changes in those elsets (element sets), for lack of a better term, state vectors, we’re on top of that. We’re pre-coordinating that. We’re doing that weeks or months in advance. We’re doing that in real-time in cooperation with these organizations to make sure that space remains safe, secure, accessible, profitable even, for industry. When you have nations, where they’re launching over their population, where they’re creating uncertainty for the rest of the world, there’s nothing else we can do with it other than treat that as potentially hostile behavior. So, it does take a lot more of our resources, a lot more of our interest, and it puts [us] in a situation where we’re posturing the whole joint force to have to deal with that kind of uncertainty, as opposed to cooperative launches with international partners, with allies, with commercial, civil, and academia, where we’re doing that as friends, and we’re doing that in cooperation. If something goes wrong, we’re handling that as friends, and we’re not having to involve the rest of the security apparatus to get after that problem.

Ars: You mentioned that SpaceX shares Starlink orbit information with your team. Is it the same story with Amazon for the Kuiper constellation?

Agrawal: Yeah, it is. The good thing is that all the US and allied commercial entities, so far, have been super cooperative with Mission Delta 2 in particular, to be able to plan out, to talk about challenges, to even change the way they do business, learning more about what we are asking of them in order to be safe. The Office of Space Commerce, obviously, is now in that conversation as well. They’re learning that trade and ideally taking on more of that responsibility. Certainly, the evolution of technology has helped quite a bit, where you have launches that are self-monitored, that are able to maintain their own safety, as opposed to requiring an entire apparatus of what was the US Air Force often having to expend a tremendous amount of resources to provide for the safety of any launch. Now, technology has gotten to a point where a lot of that is self-monitored, self-reported, and you’ll see commercial entities blow up their own rockets no matter what’s onboard if they see that it’s going to cause harm to a population, and so on. So, yeah, we’re getting a lot of cooperation from other nations, allies, partners, close friends that are also sharing and cooperating in the interest of making sure that space remains sustainable and secure.

“We’ve made ourselves responsible”

Ars: One of the great ironies is that after you figure out the positions and tracks of Chinese or Russian satellites or constellations, you’re giving that data right back to them in the form of conjunction and collision notices, right?

Agrawal: We’ve made ourselves responsible. I don’t know that there’s any organization holding us accountable to that. We believe it’s in our interests, in the US’s interests, to provide for a safe, accessible, secure space domain. So, whatever we can do to help other nations also be safe, we’re doing it certainly for their sake, but we’re doing it as much for our sake, too. We want the space domain to be safe and predictable. We do have an apparatus set up in partnership with the State Department, and with a tremendous amount of oversight from the State Department, and through US Space Command to provide for spaceflight safety notifications to China and Russia. We send notes directly to offices within those nations. Most of the time they don’t respond. Russia, I don’t recall, hasn’t responded at all in the past couple of years. China has responded a couple of times to those notifications. And we hope that, through small measures like that, we can demonstrate our commitment to getting to a predictable and safe space environment.

A model of a Chinese satellite refueling spacecraft on display during the 13th China International Aviation and Aerospace Exhibition on October 1, 2021, in Zhuhai, Guangdong Province of China. Credit: Photo by VCG/VCG via Getty Images

Ars:  What does China say in response to these notices?

Agrawal: Most of the time it’s copy or acknowledged. I can only recall two instances where they’ve responded. But we did see some hope earlier this year and last year, where they wanted to open up technical exchanges with us and some of their [experts] to talk about spaceflight safety, and what measures they could take to open up those kinds of conversations, and what they could do to get a more secure, safer pace of operations. That, at some point, got delayed because of the holiday that they were going through, and then those conversations just halted, or at least progress on getting those conversations going halted. But we hope that there’ll be an opportunity again in the future where they will open up those doors again and have those kinds of conversations because, again, transparency will get us to a place where we can be predictable, and we can all benefit from orbital regimes, as opposed to using them exploitively. LEO is just one of those places where you’re not going to hide activity there, so you just are creating risk, uncertainty, and potential escalation by launching into LEO and not communicating throughout that whole process.

Ars:  Do you have any numbers on how many of these conjunction notices go to China and Russia? I’m just trying to get an idea of what proportion go to potential adversaries.

Agrawal: A lot. I don’t know the degree of how many thousands go to them, but on a regular basis, I’m dealing with debris notifications from Russian and Chinese ASAT (anti-satellite) testing. That has put the ISS at risk a number of times. We’ve had maneuvers occur in recent history as a result of Chinese rocket body debris. Debris can’t maneuver, and unfortunately, we’ve gotten into situations with particularly those two nations that talk about wanting to have safer operations, but continue to conduct debris-causing tests. We’re going to be dealing with that for generations, and we are going to have to design capability to maneuver around those debris clouds as just a function of operating in space. So, we’ve got to get to a point where we’re not doing that kind of testing in orbit.

Ars: Would it be accurate to say you send these notices to China and Russia daily?

Agrawal: Yeah, absolutely. That’s accurate. These debris clouds are in LEO, so as you can imagine, as those debris clouds go around the Earth every 90 minutes, we’re dealing with conjunctions. There are some parts of orbits that are just unusable as a result of that unsafe ASAT test.

Photo of Stephen Clark

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.

Ars spoke with the military’s chief orbital traffic cop—here’s what we learned Read More »

nearly-everyone-opposes-trump’s-plan-to-kill-space-traffic-control-program

Nearly everyone opposes Trump’s plan to kill space traffic control program

The trade organizations count the largest Western commercial satellite operators among their members: SpaceX, Amazon, Eutelsat OneWeb, Planet Labs, Iridium, SES, Intelsat, and Spire. These are the companies with the most at stake in the debate over the future of space traffic coordination. Industry sources told Ars that some companies are concerned a catastrophic collision in low-Earth orbit might trigger a wave of burdensome regulations, an outcome they would like to avoid.

“Without funding for space traffic coordination, US commercial and government satellite operators would face greater risksputting critical missions in harm’s way, raising the cost of doing business, and potentially driving US industry to relocate overseas,” the industry groups warned.

Members of the 18th Space Defense Combat Squadron observe orbital data at Vandenberg Space Force Base, California, on October 4, 2024. Credit: US Space Force/David Dozoretz

The military currently performs the spaceflight safety mission, providing up to a million collision warnings per day to give satellite operators a heads-up that their spacecraft will encounter another object as they speed around the Earth at nearly 5 miles per second. A collision at those velocities would endanger numerous other satellites, including the International Space Station. This happened in 2009 with the accidental collision of a functional commercial communications satellite and a defunct Russian spacecraft, adding more than 2,000 pieces of debris to busy orbital traffic lanes.

Ideally, the Space Force issues its warnings in time for a satellite operator to maneuver their spacecraft out of the path of a potential collision. Satellite operators might also have more precise information on the location of their spacecraft and determine that they don’t need to perform any collision avoidance maneuver.

The military’s Space Surveillance Network (SSN) tracks more than 47,000 objects in orbit. Most of these objects are orbital debris, but there’s a growing number of active spacecraft as many operators—mainly SpaceX, Amazon, the Space Force, and Chinadeploy megaconstellations with hundreds to thousands of satellites.

The Satellite Industry Association reports that nearly 2,700 satellites were launched into Earth orbit last year, bringing the total number of active satellites to 11,539, a threefold increase over the number of operating spacecraft in 2020.

Under strain

Space Force officials are eager to exit the business of warning third-party satellite operators, including rivals such as Russia and China, of possible collisions in orbit. The military would prefer to focus on managing ever-growing threats from satellites, an intensive effort that requires continual monitoring as other nations’ increasingly sophisticated spacecraft maneuver from one orbit to another.

Nearly everyone opposes Trump’s plan to kill space traffic control program Read More »

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A Soviet-era spacecraft built to land on Venus is falling to Earth instead

Kosmos 482, a Soviet-era spacecraft shrouded in Cold War secrecy, will reenter the Earth’s atmosphere in the next few days after misfiring on a journey to Venus more than 50 years ago.

On average, a piece of space junk the size of Kosmos 482, with a mass of about a half-ton, falls into the atmosphere about once per week. What’s different this time is that Kosmos 482 was designed to land on Venus, with a titanium heat shield built to withstand scorching temperatures, and structures engineered to survive atmospheric pressures nearly 100 times higher than Earth’s.

So, there’s a good chance the spacecraft will survive the extreme forces it encounters during its plunge through the atmosphere. Typically, space debris breaks apart and burns up during reentry, with only a small fraction of material reaching the Earth’s surface. The European Space Agency, one of several institutions that track space debris, says Kosmos 482 is “highly likely” to reach Earth’s surface in one piece.

Fickle forecasts

The Kosmos 482 spacecraft launched from the Baikonur Cosmodrome, now part of Kazakhstan, aboard a Molniya rocket on March 31, 1972. A short time later, the rocket’s upper stage was supposed to propel the probe out of Earth orbit on an interplanetary journey toward Venus, where it would have become the third mission to land on the second planet from the Sun.

But the rocket failed, rendering it unable to escape the gravitational grip of Earth. The spacecraft separated into several pieces, and Russian engineers gave up on the mission. The main section of the Venus probe reentered the atmosphere in 1981, but for 53 years, the 3.3-foot-diameter (1-meter) segment of the spacecraft that was supposed to land on Venus remained in orbit around the Earth, its trajectory influenced only by the tenuous uppermost layers of the atmosphere.

The mission was part of the Soviet Union’s Venera program, which achieved the first soft landing of a spacecraft on another planet with the Venera 7 mission in 1970, and followed up with another successful landing with Venera 8 in 1972. Because it failed, Soviet officials gave the next mission, which would have become Venera 9, a non-descriptive name: Kosmos 482.

A Soviet-era spacecraft built to land on Venus is falling to Earth instead Read More »

astroscale-aced-the-world’s-first-rendezvous-with-a-piece-of-space-junk

Astroscale aced the world’s first rendezvous with a piece of space junk

Astroscale’s US subsidiary won a $25.5 million contract from the US Space Force in 2023 to build a satellite refueler that can hop around geostationary orbit. Like the ADRAS-J mission, this project is a public-private partnership, with Astroscale committing $12 million of its own money. In January, the Japanese government selected Astroscale for a contract worth up to $80 million to demonstrate chemical refueling in low-Earth orbit.

The latest win for Astroscale came Thursday, when the Japanese Ministry of Defense awarded the company a contract to develop a prototype satellite that could fly in geostationary orbit and collect information on other objects in the domain for Japan’s military and intelligence agencies.

“We are very bullish on the prospects for defense-related business,” said Nobu Matsuyama, Astroscale’s chief financial officer.

Astroscale’s other projects include a life extension mission for an unidentified customer in geostationary orbit, providing a similar service as Northrop Grumman’s Mission Extension Vehicle (MEV).

So, can Astroscale really do all of this? In an era of a militarized final frontier, it’s easy to see the usefulness of sidling up next to a “non-cooperative” satellite—whether it’s to refuel it, repair it, de-orbit it, inspect it, or (gasp!) disable it. Astroscale’s demonstration with ADRAS-J showed it can safely operate near another object in space without navigation aids, which is foundational to any of these applications.

So far, governments are driving demand for this kind of work.

Astroscale raised nearly $400 million in venture capital funding before going public on the Tokyo Stock Exchange last June. After quickly spiking to nearly $1 billion, the company’s market valuation has dropped to about $540 million as of Thursday. Astroscale has around 590 full-time employees across all its operating locations.

Matsuyama said Astroscale’s total backlog is valued at about 38.9 billion yen, or $260 million. The company is still in a ramp-up phase, reporting operating losses on its balance sheet and steep research and development spending that Matsuyama said should max out this year.

“We are the only company that has proved RPO technology for non-cooperative objects, like debris, in space,” Okada said last month.

“In simple terms, this means approach and capture of objects,” Okada continued. “This capability did not exist before us, but one’s mastering of this technology enables you to provide not only debris removal service, but also orbit correction, refueling, inspection, observation, and eventually repair and reuse services.”

Astroscale aced the world’s first rendezvous with a piece of space junk Read More »

space-command-chief-says-dialogue-with-china-is-too-often-a-one-way-street

Space Command chief says dialogue with China is too often a one-way street

Gen. Stephen Whiting, commander of US Space Command, speaks earlier this year at Peterson Space Force Base, Colorado.

Enlarge / Gen. Stephen Whiting, commander of US Space Command, speaks earlier this year at Peterson Space Force Base, Colorado.

The head of US Space Command said Wednesday he would like to see more transparency from the Chinese government on space debris, especially as one of China’s newer rockets has shown a propensity for breaking apart and littering low-Earth orbit with hundreds of pieces of space junk.

Gen. Stephen Whiting, commander of US Space Command, said he’s observed some improvement in the dialogue between US and Chinese military officials this year. But the disintegration of the upper stage from a Long March 6A rocket earlier this month showed China could do more to prevent the creation of space debris, and communicate openly about it when it happens.

The Chinese government acknowledged the breakup of the Long March 6A rocket’s upper stage in a statement by its Ministry of Foreign Affairs on August 14, more than a week after the rocket’s launch August 6 with the first batch of 18 Internet satellites for a megaconstellation of thousands of spacecraft analogous to SpaceX’s Starlink network.

Space Command reported it detected more than 300 objects associated with the breakup of the upper stage in orbit, and LeoLabs, a commercial space situational awareness company, said its radars detected at least 700 objects attributed to the Chinese rocket.

“I hope the next time there’s a rocket like that, that leaves a lot of debris, that it’s not our sensors that are the first to detect that, but we’re getting communications to help us understand that, just like we communicate with others,” Whiting said at an event hosted by the Mitchell Institute marking the fifth anniversary of the reestablishment of Space Command.

Whiting said he didn’t have any technical details about why the Long March 6A rocket’s upper stage broke apart, but it happened after the rocket deployed all of its payloads. “They had already released the satellites at that point, and it seems like the mission was overall successful, but all this debris gets left in orbit,” he said. “We certainly don’t want to see that kind of debris.”

Due regard

The Space Force’s 18th Space Defense Squadron, located at Vandenberg Space Force Base in California, is responsible for tracking objects in Earth orbit, maintaining a catalog of all satellites and space junk, and monitoring for potential collisions between spacecraft or debris. Space Command regularly issues warnings of conjunctions, or close approaches, between objects to commercial companies and foreign governments.

“For decades now, the United States has so cared about the space domain that we have made available the vast majority of tracking data that we have, for free, for the world,” Whiting said. “Every day, we screen every active satellite against all that debris, and we provide notifications out to everyone, including the Chinese and Russians.

“People sometimes ask, ‘Well, why do you do that?’ Well, it’s because we don’t want satellites to run into pieces of debris and create more debris. So we think it’s really important, and we have a set of responsible behaviors that we follow each and every day. We provide these notifications to the Chinese,” Whiting said.

The Commerce Department plans to take over some of the military’s role in space traffic management, but Space Command will maintain its own catalog and will remain responsible for working with foreign militaries on space debris matters, according to Whiting.

Space Command chief says dialogue with China is too often a one-way street Read More »

there-are-2,000-plus-dead-rockets-in-orbit—here’s-a-rare-view-of-one

There are 2,000-plus dead rockets in orbit—here’s a rare view of one

Astroscale's ADRAS-J spacecraft captured these views of the H-IIA rocket upper stage on July 15.

Enlarge / Astroscale’s ADRAS-J spacecraft captured these views of the H-IIA rocket upper stage on July 15.

There are more than 2,000 mostly intact dead rockets circling the Earth, but until this year, no one ever launched a satellite to go see what one looked like after many years of tumbling around the planet.

In February, a Japanese company named Astroscale sent a small satellite into low-Earth orbit on top of a Rocket Lab launcher. A couple of months later, Astroscale’s ADRAS-J (Active Debris Removal by Astroscale-Japan) spacecraft completed its pursuit of a Japanese rocket stuck in orbit for more than 15 years.

ADRAS-J photographed the upper stage of an H-IIA rocket from a range of several hundred meters and then backed away. This was the first publicly released image of space debris captured from another spacecraft using rendezvous and proximity operations.

Since then, Astroscale has pulled off more complex maneuvers around the H-IIA upper stage, which hasn’t been controlled since it deployed a Japanese climate research satellite in January 2009. Astroscale attempted to complete a 360-degree fly-around of the H-IIA rocket last month, but the spacecraft triggered an autonomous abort one-third through the maneuver after detecting an attitude anomaly.

ADRAS-J flew away from the H-IIA rocket for several weeks. After engineers determined the cause of the glitch that triggered the abort, ADRAS-J fired thrusters to approach the upper stage again this month. The ADRAS-J spacecraft is about the size of a kitchen oven, while the H-IIA rocket it’s visiting is nearly the size of a city bus.

Astroscale’s satellite completed two fly-around maneuvers of the H-IIA upper stage on July 15 and 16, examining all sides of the rocket as it soared more than 350 miles (560 kilometers) above the planet. Engineers also wanted to measure the upper stage’s spin rate and spin axis. At first glance, the upper stage appears remarkably similar to the way it looked when it launched. Despite exposure to the harsh conditions of space, the rocket’s outer skin remains covered in orange foam insulation, and the engine nozzle still shines as if it were new.

ADRAS-J autonomously maneuvered around the rocket at a distance of about 50 meters (164 feet), using navigation data from a light detection and ranging sensor and Astroscale’s custom-developed guidance algorithms to control its position as the vehicles moved around Earth at nearly 4.7 miles per second (7.6 kilometers per second). This is the crux of the challenge for ADRAS-J because the rocket is unpowered and unable to hold position. The upper stage also lacks laser reflectors and targets that would aid an approaching spacecraft.

This is a first

These types of complex maneuvers, known as rendezvous and proximity operations (RPO), are common for crew and cargo spacecraft around the International Space Station. Other commercial satellites have demonstrated formation-flying and even docking with a spacecraft that wasn’t designed to connect with another vehicle in orbit.

Military satellites from the United States, Russia, and China also have RPO capabilities, but as far as we know, these spacecraft have only maneuvered in ultra-close range around so-called “cooperative” objects designed to receive them. In 2003, the Air Force Research Laboratory launched a small satellite named XSS-10 to inspect the upper stage of a Delta II rocket in orbit, but it had a head start. XSS-10 maneuvered around the same rocket that deployed it, rather than pursuing a separate target.

There are 2,000-plus dead rockets in orbit—here’s a rare view of one Read More »

nasa-and-spacex-misjudged-the-risks-from-reentering-space-junk

NASA and SpaceX misjudged the risks from reentering space junk

A European ATV cargo freighter reenters the atmosphere over the Pacific Ocean in 2013.

Enlarge / A European ATV cargo freighter reenters the atmosphere over the Pacific Ocean in 2013.

Since the beginning of the year, landowners have discovered several pieces of space junk traced to missions supporting the International Space Station. On all of these occasions, engineers expected none of the disposable hardware would survive the scorching heat of reentry and make it to Earth’s surface.

These incidents highlight an urgency for more research into what happens when a spacecraft makes an uncontrolled reentry into the atmosphere, according to engineers from the Aerospace Corporation, a federally funded research center based in El Segundo, California. More stuff is getting launched into space than ever before, and the trend will continue as companies deploy more satellite constellations and field heavier rockets.

“The biggest immediate need now is just to do some more work to really understand this whole process and to be in a position to be ready to accommodate new materials, new operational approaches as they happen more quickly,” said Marlon Sorge, executive director of Aerospace’s Center for Orbital and Reentry Debris Studies. “Clearly, that’s the direction that spaceflight is going.”

Ideally, a satellite or rocket body at the end of its life could be guided to a controlled reentry into the atmosphere over a remote part of the ocean. But this is often cost-prohibitive because it would require carrying extra fuel for the de-orbit maneuvers, and in many cases, a spacecraft doesn’t have any rocket thrusters at all.

In March, a fragment from a battery pack jettisoned from the space station punched a hole in the roof of a Florida home, a rare instance of terrestrial property damage attributed to a piece of space junk. In May, a 90-pound chunk of a SpaceX Dragon spacecraft that departed the International Space Station fell on the property of a “glamping” resort in North Carolina. At the same time, a homeowner in a nearby town found a smaller piece of material that also appeared to be from the same Dragon mission.

These events followed the discovery in April of another nearly 90-pound piece of debris from a Dragon capsule on a farm in the Canadian province of Saskatchewan. NASA and SpaceX later determined the debris fell from orbit in February, and earlier this month, SpaceX employees came to the farm to retrieve the wreckage, according to CBC.

Pieces of a Dragon spacecraft also fell over Colorado last year, and a farmer in Australia found debris from a Dragon capsule on his land in 2022.

NASA and SpaceX misjudged the risks from reentering space junk Read More »

family-whose-roof-was-damaged-by-space-debris-files-claims-against-nasa

Family whose roof was damaged by space debris files claims against NASA

The piece of debris that fell through Alejandro Otero's roof (right) came from a support bracket jettisoned from the International Space Station.

The piece of debris that fell through Alejandro Otero’s roof (right) came from a support bracket jettisoned from the International Space Station.

The owner of a home in southwestern Florida has formally submitted a claim to NASA for damages caused by a chunk of space debris that fell through his roof in March.

The legal case is unprecedented—no one has evidently made such a claim against NASA before. How the space agency responds will set a precedent, and that may be important in a world where there is ever more activity in orbit, with space debris and vehicles increasingly making uncontrolled reentries through Earth’s atmosphere.

Alejandro Otero, owner of the Naples, Florida, home struck by the debris, was not home when part of a battery pack from the International Space Station crashed through his home on March 8. His son Daniel, 19, was home but escaped injury. NASA has confirmed the 1.6-pound object, made of the metal alloy Inconel, was part of a battery pack jettisoned from the space station in 2021.

An attorney for the Otero family, Mica Nguyen Worthy, told Ars that she has asked NASA for “in excess of $80,000” for non-insured property damage loss, business interruption damages, emotional and mental anguish damages, and the costs for assistance from third parties.

“We intentionally kept it very reasonable because we did not want it to appear to NASA that my clients are seeking a windfall,” Worthy said.

The family has not filed a lawsuit against NASA, at least not yet. Worthy said she has been having productive conversations with NASA legal representatives. She said the Otero family wants to be made whole for their losses, but also to establish a precedent for future victims. “This is truly the first legal claim that is being submitted for recovery for damages related to space debris,” Worthy said. “How NASA responds will, in my view, be foundational for how future claims are handled. This is really changing the legal landscape.”

Who, exactly, is liable for space debris?

If space debris from another country—say, a Chinese or Russian rocket upper stage—were to strike a family in the United States, the victims would be entitled to compensation under the Space Liability Convention agreed to by space powers half a century ago. Under this treaty, a launching state is “absolutely” liable to pay compensation for damage caused by its space objects on the surface of the Earth or to aircraft, and liable for damage due to its faults in space. In an international situation, NASA or some other US government agency would negotiate on the victim’s behalf for compensation.

However, in this case the debris came from the International Space Station: an old battery pack that NASA was responsible for. NASA completed a multi-year upgrade of the space station’s power system in 2020 by installing a final set of new lithium-ion batteries to replace aging nickel-hydrogen batteries that were reaching end-of-life. During a spacewalk, this battery pack was mounted on a cargo pallet launched by Japan.

Officials originally planned to place pallets of the old batteries inside a series of Japanese supply freighters for controlled, destructive reentries over the ocean. But due to a series of delays, the final cargo pallet of old batteries missed its ride back to Earth, so NASA jettisoned the batteries to make an unguided reentry. NASA incorrectly believed the batteries would completely burn up during the return through the atmosphere.

This cylindrical object, a few inches in size, fell through the roof of Alejandro Otero's home in Florida in March.

Enlarge / This cylindrical object, a few inches in size, fell through the roof of Alejandro Otero’s home in Florida in March.

Because this case falls outside the Space Liability Convention, there is no mechanism for a US citizen to seek claims from the US government for damage from space debris. So the Otero family is making a first-ever claim under the Federal Torts Claim Act for falling space debris. This torts act allows someone to sue the US government if there has been negligence. In this case, the negligence could be that NASA miscalculated about the survival of enough debris to damage property on Earth.

NASA provided a form to the Otero family to submit a claim, which Worthy said they did at the end of May. NASA now has six months to review the claim. The space agency has several options. Legally, it could recompense the Otero family up to $25,000 for each of its claims based on the Federal Torts Claim Act (see legal code). If the agency seeks to pay full restitution, it would require approval from the US attorney general. Finally, NASA could refuse the claims or make an unacceptable settlement offer—in which case the Otero family could file a federal lawsuit in Florida.

Ars has sought comment from NASA about the claims made and will update this story when we receive one.

Family whose roof was damaged by space debris files claims against NASA Read More »

trash-from-the-international-space-station-may-have-hit-a-house-in-florida

Trash from the International Space Station may have hit a house in Florida

This cylindrical object, a few inches in size, fell through the roof of Alejandro Otero's home in Florida last month.

Enlarge / This cylindrical object, a few inches in size, fell through the roof of Alejandro Otero’s home in Florida last month.

A few weeks ago, something from the heavens came crashing through the roof of Alejandro Otero’s home, and NASA is on the case.

In all likelihood, this nearly two-pound object came from the International Space Station. Otero said it tore through the roof and both floors of his two-story house in Naples, Florida.

Otero wasn’t home at the time, but his son was there. A Nest home security camera captured the sound of the crash at 2: 34 pm local time (19: 34 UTC) on March 8. That’s an important piece of information because it is a close match for the time—2: 29 pm EST (19: 29 UTC)—that US Space Command recorded the reentry of a piece of space debris from the space station. At that time, the object was on a path over the Gulf of Mexico, heading toward southwest Florida.

This space junk consisted of depleted batteries from the ISS, attached to a cargo pallet that was originally supposed to come back to Earth in a controlled manner. But a series of delays meant this cargo pallet missed its ride back to Earth, so NASA jettisoned the batteries from the space station in 2021 to head for an unguided reentry.

Otero’s likely encounter with space debris was first reported by WINK News, the CBS affiliate for southwest Florida. Since then, NASA has recovered the debris from the homeowner, according to Josh Finch, an agency spokesperson.

Engineers at NASA’s Kennedy Space Center will analyze the object “as soon as possible to determine its origin,” Finch told Ars. “More information will be available once the analysis is complete.”

Ars reported on this reentry when it happened on March 8, noting that most of the material from the batteries and the cargo carrier would have likely burned up as they plunged through the atmosphere. Temperatures would have reached several thousand degrees, vaporizing most of the material before it could reach the ground.

The entire pallet, including the nine disused batteries from the space station’s power system, had a mass of more than 2.6 metric tons (5,800 pounds), according to NASA. Size-wise, it was about twice as tall as a standard kitchen refrigerator. It’s important to note that objects of this mass, or larger, regularly fall to Earth on guided trajectories, but they’re usually failed satellites or spent rocket stages left in orbit after completing their missions.

In a post on X, Otero said he is waiting for communication from “the responsible agencies” to resolve the cost of damages to his home.

Hello. Looks like one of those pieces missed Ft Myers and landed in my house in Naples.

Tore through the roof and went thru 2 floors. Almost his my son.

Can you please assist with getting NASA to connect with me? I’ve left messages and emails without a response. pic.twitter.com/Yi29f3EwyV

— Alejandro Otero (@Alejandro0tero) March 15, 2024

If the object is owned by NASA, Otero or his insurance company could make a claim against the federal government under the Federal Tort Claims Act, according to Michelle Hanlon, executive director of the Center for Air and Space Law at the University of Mississippi.

“It gets more interesting if this material is discovered to be not originally from the United States,” she told Ars. “If it is a human-made space object which was launched into space by another country, which caused damage on Earth, that country would be absolutely liable to the homeowner for the damage caused.”

This could be an issue in this case. The batteries were owned by NASA, but they were attached to a pallet structure launched by Japan’s space agency.

Trash from the International Space Station may have hit a house in Florida Read More »

a-hunk-of-junk-from-the-international-space-station-hurtles-back-to-earth

A hunk of junk from the International Space Station hurtles back to Earth

In March 2021, the International Space Station's robotic arm released a cargo pallet with nine expended batteries.

Enlarge / In March 2021, the International Space Station’s robotic arm released a cargo pallet with nine expended batteries.

NASA

A bundle of depleted batteries from the International Space Station careened around Earth for almost three years before falling out of orbit and plunging back into the atmosphere Friday. Most of the trash likely burned up during reentry, but it’s possible some fragments may have reached Earth’s surface intact.

Larger pieces of space junk regularly fall to Earth on unguided trajectories, but they’re usually derelict satellites or spent rocket stages. This involved a pallet of batteries from the space station with a mass of more than 2.6 metric tons (5,800 pounds). NASA intentionally sent the space junk on a path toward an unguided reentry.

Naturally self-cleaning

Sandra Jones, a NASA spokesperson, said the agency “conducted a thorough debris analysis assessment on the pallet and has determined it will harmlessly reenter the Earth’s atmosphere.” This was, by far, the most massive object ever tossed overboard from the International Space Station.

The batteries reentered the atmosphere at 2: 29 pm EST (1929 UTC), according to US Space Command. At that time, the pallet would have been flying between Mexico and Cuba. “We do not expect any portion to have survived reentry,” Jones told Ars.

The European Space Agency (ESA) also monitored the trajectory of the battery pallet. In a statement this week, the ESA said the risk of a person being hit by a piece of the pallet was “very low” but said “some parts may reach the ground.” Jonathan McDowell, an astrophysicist who closely tracks spaceflight activity, estimated about 500 kilograms (1,100 pounds) of debris would hit the Earth’s surface.

“The general rule of thumb is that 20 to 40 percent of the mass of a large object will reach the ground, though it depends on the design of the object,” the Aerospace Corporation says.

A dead ESA satellite reentered the atmosphere in a similar uncontrolled manner February 21. At 2.3 metric tons, this satellite was similar in mass to the discarded battery pallet. ESA, which has positioned itself as a global leader in space sustainability, set up a website that provided daily tracking updates on the satellite’s deteriorating orbit.

This map shows the track of the unguided cargo pallet around the Earth over the course of six hours Friday. It reentered the atmosphere near Cuba on southwest-to-northeast heading.

Enlarge / This map shows the track of the unguided cargo pallet around the Earth over the course of six hours Friday. It reentered the atmosphere near Cuba on southwest-to-northeast heading.

As NASA and ESA officials have said, the risk of injury or death from a spacecraft reentry is quite low. Falling space debris has never killed anyone. According to ESA, the risk of a person getting hit by a piece of space junk is about 65,000 times lower than the risk of being struck by lightning.

This circumstance is unique in the type and origin of the space debris, which is why NASA purposely cast it away on an uncontrolled trajectory back to Earth.

The space station’s robotic arm released the battery cargo pallet on March 11, 2021. Since then, the batteries have been adrift in orbit, circling the planet about every 90 minutes. Over a span of months and years, low-Earth orbit is self-cleaning thanks to the influence of aerodynamic drag. The resistance of rarefied air molecules in low-Earth orbit gradually slowed the pallet’s velocity until, finally, gravity pulled it back into the atmosphere Friday.

The cargo pallet, which launched inside a Japanese HTV cargo ship in 2020, carried six new lithium-ion batteries to the International Space Station. The station’s two-armed Dextre robot, assisted by astronauts on spacewalks, swapped out aging nickel-hydrogen batteries for the upgraded units. Nine of the old batteries were installed on the HTV cargo pallet before its release from the station’s robotic arm.

A hunk of junk from the International Space Station hurtles back to Earth Read More »

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Before snagging a chunk of space junk, Astroscale must first catch up to one

This artist's illustration released by Astroscale shows the ADRAS-J spacecraft (left) approaching the defunct upper stage from a Japanese H-IIA rocket.

Enlarge / This artist’s illustration released by Astroscale shows the ADRAS-J spacecraft (left) approaching the defunct upper stage from a Japanese H-IIA rocket.

Astroscale, a well-capitalized Japanese startup, is preparing a small satellite to do something that has never been done in space.

This new spacecraft, delivered into orbit Sunday by Rocket Lab, will approach a defunct upper stage from a Japanese H-IIA rocket that has been circling Earth for more than 15 years. Over the next few months, the satellite will try to move within arm’s reach of the rocket, taking pictures and performing complicated maneuvers to move around the bus-size H-IIA upper stage as it moves around the planet at nearly 5 miles per second (7.6 km/s).

These maneuvers are complex, but they’re nothing new for spacecraft visiting the International Space Station. Military satellites from the United States, Russia, and China also have capabilities for rendezvous and proximity operations (RPO), but as far as we know, these spacecraft have only maneuvered in ultra-close range around so-called “cooperative” objects designed to receive them.

The difference here is the H-IIA rocket is uncontrolled, likely spinning and in a slow tumble, and was never designed to accommodate any visitors. Japan left it in orbit in January 2009 following the launch of a climate monitoring satellite and didn’t look back.

That was the case, at least, until a few years ago, when the Japan Aerospace Exploration Agency (JAXA) partnered with Astroscale in a public-private partnership to demonstrate capabilities the private sector could use to eventually remove large pieces of space debris littering low-Earth orbit. The same robotic technologies could also apply to satellite servicing or refueling missions.

“We are putting this debris removal by robotic technology as one of our main technology development areas because safely approaching an object, and also observing the object and capturing the object, is basically a common technology for any on-orbit servicing,” said Eddie Kato, president and managing director of Astroscale Japan.

In hot pursuit

This mission is called ADRAS-J, short for Active Debris Removal by Astroscale-Japan. “This mission entails the first ever approach of actual space debris and will be a monumental step toward a more sustainable future in space,” Mike Lindsay, Astroscale’s chief technology officer, posted on X.

The ADRAS-J spacecraft, built in-house at Astroscale’s Tokyo headquarters, is about the size of a kitchen oven and weighs roughly 330 pounds (150 kilograms) fully fueled. The satellite launched from New Zealand at 9: 52 am EST (1452 UTC) Sunday aboard an Electron rocket provided by Rocket Lab. About an hour after liftoff, ADRAS-J deployed from the Electron’s kick stage into an on-target polar orbit reaching an altitude of 370 miles (600 kilometers) at its highest point.

The liftoff from Rocket Lab’s spaceport in New Zealand was timed to allow ADRAS-J to launch into the same orbital plane as its objective—the H-IIA upper stage. Astroscale reported the spacecraft was healthy after Sunday’s launch. In a pre-launch interview, Kato said ADRAS-J will begin its pursuit of the spent H-IIA rocket in a couple of weeks, once ground teams complete initial checkouts of the spacecraft.

ADRAS-J will fire thrusters to match orbits with the H-IIA rocket, and as soon as next month, it could be flying within about 300 feet (100 meters) of the abandoned upper stage. Astroscale engineers will initially rely on ground-based tracking data to pinpoint the H-IIA’s location in space. Once in closer range, ADRAS-J will use visible and infrared cameras, along with laser ranging sensors, to transition to relative navigation mode. These sensors will measure the distance, closing rate, and orientation of the upper stage.

Astroscale officials view the switch from relying on ground tracking data to onboard relative navigation sensors as a crucial moment for the ADRAS-J mission. ADRAS-J will circle the rocket to assess its spin rate, spin axis, and the condition of its structure. This is the crux of the challenge for ADRAS-J because the rocket is unpowered and therefore unable to hold position. The upper stage also lacks laser reflectors and targets that would aid an approaching spacecraft.

This will mark the conclusion of the JAXA-supported portion of the ADRAS-J mission. If everything is working as planned, the spacecraft could move closer to the rocket to further validate Astroscale’s sensor suite and automated navigation and guidance algorithms. This will allow the company’s engineers to gather data for a proposed follow-on mission to actually go up and grab onto the same H-IIA upper stage and remove it from orbit.

“We are targeting to go closer, maybe 1 to 2 meters away from the object. Why? Because the next mission will be to really capture the H-IIA launch vehicle,” Kato told Ars last week. “In order to safely approach to a range where a robotic arm is able to be extended, it’s probably like 1.5 to 2 meters away from the object. We want to demonstrate up to that point through this ADRAS-J mission. Then on the next mission, called ADRAS-J2, we are actually equipping the robotic arm and capturing the H-IIA launch vehicle.”

Before snagging a chunk of space junk, Astroscale must first catch up to one Read More »