Hacker News Reader

Comment by JumpCrisscross | Hacker News Reader

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.)

View on HN

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.

Reply on news.ycombinator.com