hckrnws

Paper: https://iris.cnr.it/retrieve/3c9394c7-a04f-431a-976d-cdc65af...

> China launched 21 of the 26 hazardous new rocket bodies over the last 21 months, each averaging more than 4 metric tons (8,800 pounds). Two more came from US launchers, one from Russia, one from India, and one from Iran

What are the American ones?

> most of the rockets used for Guowang and Thousand Sails launches have left their upper stages in orbit

Are they in the same orbit as the satellites? If so, China is effectively mining their own constellations.

(Side note: Ars is usually much better at citing its sources. This is terribly written by their standards.)

US rocketry has a tradition of making second stages dispose of themselves after their work is done. AFAIK no regulatory body enforces this - but launch providers usually do it anyway.

A common way to do that is to perform an extra burn and tip the second stage's orbit into the atmosphere - so that it burns up in a controlled manner. That's what's done on Starlink launches - the most common type of US launch.

Other countries may choose not to do that, because the second stage has to be designed to allow for those extra burns, and the fuel used cuts straight into the performance margins.

> Are they in the same orbit as the satellites?

Not exactly. Most larger satellites nowadays carry their own fuel and engines, and perform orbital adjustments and station-keeping. Which has a way of putting distance between them and the second stages. They might end up in the same orbital plane, but not the same orbit.

For some satellite types, the second stage only gets the satellite to a transfer orbit - and the satellite itself gets to the deployment orbit from there under its own power.

> US rocketry has a tradition of making second stages dispose of themselves after their work is done. AFAIK no regulatory body enforces this - but launch providers usually do it anyway.

The FCC individually licenses every launch, and explicitly cares about collision risk. I'm not sure if there's a specific rule about when second stages must be deorbitted, but I'm pretty sure that if a launch provider intended to leave a second stage in a crowded orbit the FCC would cause trouble for them.

Also even if/when there isn't an actual regulation, it is to your benefit to act as if there is one and keep things "clean enough". If things never reach the point of regulators getting interested you can choose how to follow the intent and ensure regulations you hate don't get in. (once regulations you need to spend money on lobbyists to capture and write the regulation, cheaper to not get that far in the first place)

Of course the above is a game of prisoners dilemma. You are risking others defecting first. In the current situation there doesn't seem to be much cost if you are last to defect (since regulations will come in just a few rounds). In other situations there can be great gain in defecting first.

If you're in this situation, you can guide how that regulation is created though so that whatever your current situation is can be the cutoff levels in the regulations.

True but others also have input. This can help or hurt you depending on what they want and relative powers between them.

do those others make matching contributions to election campaigns?

The FCC deals with the comms for a rocket launch, but I think its the FAA that deals with the actual rocket stuff you are talking about.

Edit: I stand corrected!

The FAA does have licenses over launch and they are trying to impose rules for upper stages of launch vehicles [0]. The FAA said they would complete these regulations in 2025 [1], but I haven't seen something saying they have gone in to effect yet.

The FCC does deal with disposal requirements for US satellites that are launched. In order to secure a license from the FCC you have to prove that your satellite will meet the latest guideline that it will be disposed of (either de-orbit for LEO, or moved to disposal orbit for higher orbits) within 5 years after mission complete [2]. Unfortunately this doesn't seem to apply to upper stages for some reason even though I would say that it is an orbit object that gets licensed and would "complete the mission" after deploying the satellites and have to abide by the 5 year rule.

[0] https://www.faa.gov/newsroom/faa-proposed-rule-would-reduce-...

[1] https://spacenews.com/faa-to-complete-orbital-debris-upper-s...

[2] https://www.fcc.gov/space/faq-orbital-debris

It is the FCC[1]. The FAA is only concerned about the launch and de-orbiting as it passes through airspace, and doesn't regulate what happens between, including whether object de-orbit at all. It is odd for the FCC to have this responsibility. They kind of picked it up by default since they were the only agency regulating operations in space in any way, and we had ratified treaties that needed to be enforced, without creating an agency to enforce them.

Edit: The FAA is also proposing orbital debris rules that were supposed to be finalized this year, but aren't released yet[2]. This whole area is a mess, and really needs congress to set clear responsibilities.

[1] https://www.fcc.gov/space/orbital-debris

[2] https://spacenews.com/faa-to-complete-orbital-debris-upper-s...

For the actual current rules about collisions and debris broadly see: https://www.ecfr.gov/current/title-47/chapter-I/subchapter-B...

> Are they in the same orbit as the satellites? If so, China is effectively mining their own constellations

This is LEO, so it's everyone's orbits. And in any case the big worry about space junk is not so much that it takes out one or one thousand existing satellites - which China could replace - but that it makes the orbits unusable by future spacecraft.

> which China could replace - but that it makes the orbits unusable by future spacecraft

The point is that having junk in your own orbits is an interesting self goal. It opens the window to hybrid war strikes, for example.

The junk being in everyone's orbits means it isn't particularly useful for the purposes of warfare though. If major spacefaring powers want to take out adversary satellites they have the capabilities to do it in a more targeted manner to various levels of deniability without background junk adding anything to the equation.

> junk being in everyone's orbits

It takes a lot of energy to change orbital planes. Debris tend to stay in constrained orbits (usually their original ones). If the upper stages are in the birds’ orbits (which is a big if), the debris will all tend to stay there.

> they have the capabilities to do it in a more targeted manner

But not plausibly deniable. My point is China is leaving the front door open to shenanigans by leaving high-energy mass next to its birds. (If, again, it is.)

Orbits can intersect and naturally decay, at different rates according to different drag coefficients, that's why large pieces of debris require periodic avoidance manoeuvres as they cross others' paths, and the less predictable movements of debris from an actual collision would be a nightmare for years. Which means your space warfare strategy probably doesn't involve causing collisions unless you've contingency planned for losing your own assets.

I don't see any plausibly deniable scenario involving apparent spent rocket stages suddenly reanimating in militarily useful way. c.f. routine electronic warfare jamming. Even a "malfunctioning satellite" would have more deniability, and certainly equal ability to threaten others' space assets.

I think this one fits here:

"Never attribute to malice that which is adequately explained by stupidity."

In rocket science, is the bar for stupidity really really high, or really really low?

Sounds like an excuse for how stupidly the Trump administration is acting, but it's actually an extremely toxic combination of malice plus stupidity. You don't have to be smart to be malicious. Occam's razor says "why not both?"

I think there are only two US rocket stages in LEO that were launched in the past 21 months:

1. 2024-125H — Firefly Alpha FLTA005 Stage 2, launching demo cubesats for NASA

2. 2025-077C — Orbital Minotaur IV (8) Stage 4 (Orion 38), launching a few spy satellites

Fun fact: the first stage of the latter rocket was manufactured in 1966.

> the first stage of the [Minotaur IV] was manufactured in 1966.

Was it? Minotaurs repurposed components of Peacekeeper missiles. Development of the SR118 first stage motor—reused as the first stage on Minotaur IV—didn’t start until 1978. [1, pg16]

[1]: https://ntrs.nasa.gov/api/citations/20120016230/downloads/20...

Oops, you're right. I read that factoid [1] while searching for information about the 2025-077C, but it was about a different 2021 launch.

[1]: https://spaceflightnow.com/2021/06/15/three-nro-satellites-l...

> What are the American ones? One of them is the second Vulcan Centaur flight[2]. IIRC an SRB nozzle failed, and the other stages had to make up the missing thrust, which didn't leave enough for a deorbit burn.

[1] https://www.n2yo.com/satellite/?s=61448

I know I read about another over the last year, but can't remember of the top of my head.

I think that Centaur was sent into solar orbit.

For rocket bodies, no.

In 2022, the FCC adopted a “5-Year Rule” requiring that satellites in low Earth orbit (below ~2,000 km) be disposed of (deorbited or moved to a safe disposal orbit) “as soon as practicable but no later than five years after mission completion.”

It used to be 25 years but less stringent and more of a guideline. This is problematic for CubeSats that are already on tight budgets and some are requiring redesign like AMSAT’s

agreed on the side note. The headline itself must be miles away from their own old-standards.

This reminded me to go look up what Japan was doing with their space junk net. Turns out it failed to deploy in 2017, and nothing has really been done with the idea since. :|

https://www.sciencedirect.com/science/article/abs/pii/S00945...

There's definitely a "tragedy of the commons" vibe to all of this. No one wants to bear the cost, and everyone assumes someone else will eventually clean it up. Meanwhile, space gets more crowded and fragile

It's kind of like how the Rhino was endangered in Africa, until ownership was allowed. Who owns orbits?

I'm not sure if this would be practical. I wonder if a laser fired from a higher orbit at the debris as it approaches over the earth horizon would slow it down, and gradually push it to lower orbits and eventually reenter. This could possibly work for the small stuff anyway.

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Imagine if humanity ending is not because we cannot exit the planet that we have destroyed for a better one, but because we’ve also polluted earths orbit so much that it becomes impossible to escape.

No point - the universe is too large to think we could get to a better planet even in the best case of it being close to us. Light years are not small and the energy needed to reach them too large. A generational ship is the only hope and we have no reason to think we can make one that will survive the trip.

The above is a consequence of physics and not an opinion. Even if we discover "new physics" it still needs to fit all the data we have and so that is unlikely to help.

I still don't get how people are so fixed on planets - is it because of Star Trek or Star Wars or in general being more consumable for the average human ? Even just the Solar system has resources and energy to build artificial habitats for trilions of people, based just on current and near term technology scaled up & robust in space infrastructure. It's just about getting to it and the necessary time and resource investments to get things running.

We have no clue how to create artificial gravity. Current human space missions of found lots of negative effects on humans in space that are because of lack of gravity. there are a number of other problems they are researching with no reason to think they can be solved except via gravity.

Also your space station suffers the same lifetime issues of a generation ship: it will decay over time, so you still are dependent on earth (or at least a planet) to provide resources.

If we're talking space colonies that house large numbers of people wouldn't they be large enough to spin for artificial gravity?

Yeah, just spin it - like Oneil Island 3 or similar (Stanfort Torus, etc.): https://en.wikipedia.org/wiki/O%27Neill_cylinder

That's a 1975 design using quite conservative 1950s tech - lots of bulk steel and aluminium with unprocessed Lunar regolith for shielding.

There's some calculation around that say you can't make usably-large habitats by plugging them in a tether and spinning them... so people almost universally decided that you can't make usably-large habitats that spin.

I guess that's the nature of internet arguments.

I'm interested in spin gravity but I've never heard of this before. Where can I find these calculations?

I don't remember where you can find it.

But that tether will have to lift the entire weight of your ship, plus a share of its own weight. The longer you make it, the heavier it will be, and you get a problem similar to a space elevator, and before you get to city-sized, it seems to require exotic materials already.

The choice of materials impose a maximum size for any design that rotates as a whole.

Maybe. Is that good enough or not is an open question. Also is it feasible or is the engineering too difficult for some reason?

I always thought the scenes in Wall-E showing the space ships colliding with all the space junk were horribly unrealistic. They should show the space ships exploding and all the humans and bots perishing.

Even with a full on Kessler syndrome scenario happening the risk to an object moving through LEO, (rather than attempting to stay there) is minimal.

And if we've got hypothetical indistinguishable-from-magic tech to reach and colonise faraway planets, we'll have mastered the relatively trivial problem of clearing LEO

Even if a few would manage to escape a dying world, billions would perish. "Humanity" will have been lost anyways.

Currently yes, but let’s imagine we have a few hundred years to plan our escape.

The people in charge will spend the time and resources ensuring their comfort and security, they won’t ensure that normal people are saved.

The elites will send their art collection to space before the poor

Heh, there's a story to be written there about a spaceship carrying art crewed by LLMs. "Full self-flying", said the salesman CEO.

It'd also be interesting if what gets sent to space is an SQL database which most important table has the columns account_owner, account_balance..

Let's call it the B ark.

Why waste time writing dystopian fiction when you can just let reality happen?

> The same basic technologies needed for space debris cleanup—rendezvous and docking systems, robotic arms, and onboard automation—could be used to latch on to an adversary's satellite.

And here we have the basic requisite military-industrial pitch to develop this dual-use tech and git er done.

Yep, definitely already on people's minds: "China’s use of its SJ-21 to remove a GEO satellite that had been shedding debris to a very high graveyard orbit in January 2022 has been repeatedly used as evidence that they can threaten other on-orbit satellites" [0]

[0] https://spacenews.com/chinese-on-orbit-servicing-and-debris-...

If it’s anything like the SLS it’ll cost 100 times as much and take 3 times longer than if was outsourced to the private sector.

Boeing was the prime contractor for the SLS core stage and upper stages, and Northrop Grumman builds the solid rocket boosters. The entire rocket was outsourced to private industry.

The military does not use or want the sls. They have been notable (and vocal) early users of commercial lift.

I can't find the source, but one reason why SpaceX can reduce costs more than NASA, is that SpaceX is allowed to fail. NASA has to underpromise and overdeliver on everything. Else it will result in budget cuts for not meeting targets or wasting money. Having such constraints, results in much higher costs. If NASA could "fail-fast" without fear of cuts, it would look very different.

Another point is that NASA also works as a job program for a lot of states.

Don't forget the cost of oversight either. Someone, somewhere, slacked off while on a government job, so now we need someone to watch everyone work, and we need someone to watch them watch them work, and then we need a council to decide on team 1 and team 2's efficacy in case they slacked off ever, and then we need a division to determine that the council is doing their job as well!

Commercial crew was a call for the private sector to fly astronauts to the ISS. 2 private companies were selected, one is flying currently, the other? Still trying to get there.

If this second provider was a NASA project everyone would be screaming how much of a waste it is. Conclusion? Space remains hard.

The private industry incentive must be in rubbish removed though rather than expensive, overuning and overbudget contracts for useless space providers like Northrop & Boeing (who are having the floor mopped with them by SpaceX).

Planetes is a great anime on the topic of space junk, recommended.

> The European Space Agency's Envisat satellite launched in 2002 and failed in 2012. It is the second-most hazardous object in the Top 50 list.

As a European, I would be happy if ESA planned a mission to deorbit Envisat. Besides making the orbit safer, I'm thrilled by the engineering challenge of capturing a large uncontrolled spacecraft.

There was a mission planned, but it was cancelled in 2018.

https://en.wikipedia.org/wiki/E.Deorbit

What would it cost to deorbit those rogue and derelict 50 safely and with intentional consensus, maybe as a post-orbital insertion deployment secondary mission?

When will it be safe and cost-efficient to - instead of deorbiting toward Earth's atmosphere - Capture and Haul and Rendezvous and gently Land orbital scrap on non-earth locations like the Moon or Mars or a thrust-retrofitted asteroid for later processing?

Would ISS be more useful as an oxygen tank in earth-moon orbit than in Earth's atmosphere and ocean?

It's not going to be cost-efficient to move to the moon unless and until there is commercial demand for scrap material on the moon and equipment to process it. A lot of delta-v is needed to transport stuff to the moon. On the other hand stuff in LEO naturally deorbits with a certain timeframe and can be accelerated with a small nudge, a dragsail or possibly even laser ablation, and it's really not very far to go if you decide to actively deorbit it.

You'll likely get recycling in orbit (where the spacecraft are) before the moon (which has abundant aluminium anyway) first, so the compromise would be shifting debris in LEO to storage orbits with longer decay times

Tethers.inc thought they had a plan but their test tether cooked itself considerably faster than they expected and they sort of fell off the media radar after that.

Just get the space debris section on the case https://en.wikipedia.org/wiki/Planetes

Maybe once in-space manufacturing and refueling become reality, scrap recycling will make more sense beyond Earth

Do we really want to start junking up the moon?

Having a pile of junk ready when you want to start a permanent base sounds like it could be useful.

Please explain that to my wife in reference to my collections in the garage.

"It might be useful some day"

If it's iron or aluminium, someone probably will pay silly (Earth) money for it on the Moon during early colonisation, but maybe not right at the start when there's no bandwidth it facilities for recycling scrap. Right up until the bigger regolith smelters come online.

The box of pre-loved Beanie Babies, perhaps also quite valuable: who knows how much hydrocarbons will be worth in early lunar colonies. Carbon isn't especially abundant in regolith (compared to silicon, aluminium, iron, etc) and has to be baked out as gases. Though I still doubt you'd have takers if the shipping isn't included...

Hydrogen moreso!

Oxygen is usually plentiful in various minerals, but hydrogen tends to get blown into space if there isn't a reactive atmosphere to recapture it.

Yes indeed. Apparently some of the carbon will come along with hydrogen as methane when you bake it out of the rock. Separating straight to carbon and hydrogen is a hassle, though, as the carbon clogs the catalyst.

Perhaps crashing a carbonaceous asteroid into the moon or disassembling in orbit and landing the results may work?

Thank you for inspiring my next project. I shall do all in my power to relocate the contents of my garage to the lunar surface.

Does anybody have Tom Mueller's phone number?

Best I can do is this very old card I found for a Mr von Braun, I think it is. It's in a very, um, spiky font.

That will do. I don't need reusability, and London makes for a decent Plan B target.

The amount of tools needed to process that junk and make newly usable stuff would be huge and not worth it. Not even talking about the energy needed to take the junk there and land it safely. The article is talking about rocket bodies mostly: they don't have that much useful material.

Of course.

If Starship achieves full and “rapid” reusability then it seems like it would be a lot more feasible to collect and deorbit space junk.

Most of the list is rocket bodies which are quite large, and rendezvous is already challenging when everybody is collaborating, rendezvous with a tumbling uncontrolled giant piece of junk is even more difficult.

Astroscale is working on that in collaboration with various space agencies, they're currently planning a mission (ADRAS-J2) to connect to an uncontrolled rocket body and deorbit it circa 2027: https://arstechnica.com/space/2025/02/astroscale-aced-the-wo...

Theoretically, a cheap option is to modify Starlink with enlarged argon tanks to rendezvous and "shepherd" large debris into lower orbits. Add LiDAR (DragonEye) and "Push Me Pull You" argon thrusters and it can exert a gentle push even when the debris object is uncontrolled and tumbling.

I'm somewhat surprised SpaceX hasn't tackled this problem yet. Even including just one StarCleaner every 2-3 Starlink launches could make a huge difference.

SpaceX even has the perfect test satellite. RatSat was their first successful launch in 2008, and it's barely decayed despite saying it would only last five to ten years.

https://forum.nasaspaceflight.com/index.php?topic=44753.0

And to answer the cost question, Astroscale is charging $8-100 million [0] per LEO junk removal mission (small numbers for small failed comms sats, big numbers for a spent upper stage).

The objects in the article are all at the bigger end. Presumably Aeroscale have started with a technically easier mission than some of the 50 in the article, but they will also eventually benefit from economies of scale. So you can estimate the cost to remove the 50 bodies in the single digit billions.

[0] https://www.kratosspace.com/constellations/articles/astrosca...

Starship launch costs are hypothetical, but pundits are estimating one to two hundred dollars per kg, or about ten million per launch. This would shave a significant amount off the cost of launching something big enough to de-orbit a large target, like an upper stage. Still, even if you spitball a figure like 20 million for each removal that’s still a billion dollars in total.

"Is charging" for an activity which is wreathed in hypotheticals. Surely it's "proposes charging"?

No, it's signed two contracts already according to the link.

I'm sure the contracts are more complicated than "this amount of money for this job" but the price, at least, is not hypothetical.

Starship lowers launch costs. One can launch more Astroscales with Starship.

It’s not necessary. But it helps turn what is currently research curiosity into something someone can fund at scale.

That tumbling should be conveniently predictable in absence of aerodynamics, but then even the best prediction would leave you with a tough nut to crack. I guess trying to solve that problem could be very helpful as a reality check to reign in any space mining fantasies?

You can deorbit things by pushing them "up" from Earth which lowers their perigee on the other side of the orbit.

A ground based high energy laser could ablate material from Earth which would provide propellant mass and incrementally knock objects into deorbiting trajectories.

And what happens to the ablated material? One large stage that is easily tracked via radar is preferable to tens or hundreds of milimetre size chunks that could potentially flake off while ablating the surface of a rocket stage or derelict satellite.

Ablation turns the material into individual molecules.

Yes, when done perfectly in a lab. Under less than ideal conditions, temperature gradients cause cracks and then flakes are released and expelled.

Drag brings those flakes to the ground.

Flakes of solid material are typically far more than dense than structures made of the same material. Therefore flakes' orbital lifetimes are likely longer than structures made of the same materials.

Pushing "up" on an orbiting body causes no change to the altitude at the other side of the orbit (that is, 180 degrees around the orbit). However, it does raise the orbital altitude 90 degrees ahead, and lowers it 270 degrees ahead.

Tangential, but if you're interested in orbital debris and anime, I warmly recommend Planetes. It's a "hard sci-fi" anime partially about how fantastic, and at the same time mundane, space can be.

Boyan Slat could expand the plastic collection to space.

In future it would of course probably be technically easiest to attach a deorbit package (tether for example) to satellites at launch...

This sounds like a classic 80/20 rule (change the numbers to your liking). This applies to many things. Notable examples are the majority of misinformation on social media coming from a few people and a relatively small number of words getting you most of the way there when learning a language

It's like the universe is sneakily efficient in some areas, if we're willing to look for the leverage points

It's just a hit piece playing with statistics.

How convenient that the key culprits are Russia (and the scary Soviet Union) and China.

Especially when Trump wants to take on China while handing off The Ukraine to Europe.

The list would most likely look very similar if you did top 20, 30, 40, or whatever cutoff you want. China is especially bad with many videos easily available on youtube of them just dumping entire stages on random villages in their own country.

> How convenient that the key culprits are Russia (and the scary Soviet Union) and China

Uh, it’s widely known that the Soviets before and Chinese now abandon rocket bodies in orbit.

Maybe so. I'm just fascinated by the convenient propaganda of the West. And I point it out to observe the reaction online. It's consistent across Reddit, Slashdot and here: US good, RoW bad.

There's only a few major space players. The US is bound to be well ahead in several ways and well behind in several other ways. The level of "convenience" here is like rolling a particular number on a 6 sided die. It would be weird if it didn't happen often.

whoa, your comment got whiter than germany in forties, how did you do it

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nah, reddit is king, HN has been garbage for years

How is it that the US can put thousands of objects into LEO, but somehow they have no collision risk?

They actively move to avoid collisions rather than tumbling uncontrollably.

SpaxeX does clean work.

yes they do!

though what has not been brought up is the several ways that everything space x is flying, can be bricked simultaneously, so there failure modes present unique risks

To give an earnest answer, SpaceX deorbits its second stages, and the vast majority of those thousands of satellites are Starlinks which are in a quite low orbit (naturally decaying) and are intentionally deorbited when they reach EOL.

Space is big, man.

A 50% reduction isn't really a useful metric.

What, does it reduce the risk from 0.001% chance to 0.0005%?

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After some thinking, I've concluded that I'd actually like if there was a large collision that resulted in a chain reaction and took out most of the military and commercial satellites. It's obviously needed, in order for people to reassess their priorities, and whether additional garbage will be left with every mission.

(if we're imagining, without damage to ISS and scientific projects, of course)

Maybe we shouldn't wish widespread harm on society to force them to "reassess their priorities" and engage in civilized dialogue instead.

If you find yourself rooting for the system to burn, it’s usually a sign the analysis stopped one layer too soon.

It’s tempting to think a big crash would finally wake people up, but that’s not how it works. When things fall apart, folks just rebuild the same broken setup, only shakier. Look at the Internet. It was supposed to change everything. And it did! Except we just ended up mostly reinventing the same old power structures we had before, just with different players. (There are some really good exceptions tho!)

The real move is to figure out what makes people change and get them to do to, before it all goes up in flames.

What priorities do you have in mind here? Let's say all commercial satellites explode: A bunch of people have to change internet or TV provider and a few percent of them are stuck without for a while. It gets harder to make calls in certain areas. Our maps update somewhat less often. What does that accomplish? What's being reassessed at the large scale?