Net successfully snares space debris | Hacker News Reader

Net successfully snares space debris

surrey.ac.uk

47 pointsEwanToo33 comments

Wikipedia has more information about the experiments it is performing: https://en.wikipedia.org/wiki/RemoveDEBRIS

Note that it caught a 'fake' piece of space debris that it launched specifically for this experiment. I'm curious how it would fare when trying to snag a real chunk moving at higher relative velocities.

I also had no idea it had a harpoon on it!

Here is a good mission simulation: https://www.youtube.com/watch?v=7CEH9V9psKY

I feel oddly letdown that the harpoon won't be fired at a free floating object.

I am glad that they are testing a drag sail. It would be nice to require these in future LEO objects if they prove successful.

In the early plans the harpoon was launched at a moving target. But in addition to the complexity and the risk associated with that, this prevented having a close-up look at the target after the operation. A harpoon for debris removal is only useful if it does not create too many debris and you cannot really assess how many were generated if the harpoon and it's target are floating away.

I concur with you in the drag sail. So many LEO projects are planning on using propulsion for deorbiting, which requires having a fairly working spacecraft. Drag sails or other deployables do not require a lot of power, are completely passive once deployed, and make the object even more trackable.

Most people don't realize that any space debris removal tool is actually considered a weapon, so it's kinda hard to deploy them for real production usage.

What? It's only a 'weapon' if you intentionally de-orbit debris with a real chance of hitting something of value. We have a hard time calculating where current space junk will de-orbit because we don't control any variables. With this thing, we would control enough variables to calculate when/where the space junk will impact the earth (assuming it doesn't burn up..), with sufficient accuracy that we could (for example) always hit the middle of the Pacific.

> It's only a 'weapon' if you intentionally de-orbit debris with a real chance of hitting something of value.

A weapon is a weapon even before it is used in anger.

> A weapon is a weapon even before it is used in anger.

Only if you use an incredibly loose definition of 'weapon'. I suppose you think hammers, shoestrings, pebbles, carrots, and and a rotting fish are all weapons too, since they could cause damage if used in anger?

> > A weapon is a weapon even before it is used in anger.

> Only if you use an incredibly loose definition of 'weapon'.

No, by the standard definition. A gun is a weapon even before you shoot someone with it, it doesn't transform from a non-weapon to a weapon when that happens.

Based on the standard definition of weapon:

https://en.m.wikipedia.org/wiki/Weapon

A firearm is not a weapon it is an armament. An armament only becomes a weapon when it is used to inflict harm.

I don't think that matches the common understanding of "weapon" in English. A sword, spear, gun, etc., is considered a weapon whether or not it is actually used.

An object not normally regarded as a weapon -- a walking-stick, perhaps, or a kitchen knife -- might become a weapon by virtue of its use as one. But military arms are inherently weapons, whether in use or not.

That's not what the link you posted says.

Your link starts with: "A weapon, arm or armament is any device that can be used with intent to inflict damage or harm." Which is means a bat is a weapon even if it's never used in anger.

Posting a link that directly contradicts your argument is not an effective means of supporting it.

Well, it can be if your audience doesn't actually follow the link, but that trick is more effective with references in hardcopy where there is non-trivial effort involved in checking references.

So we're all perpetually carrying around weapons, by virtue of having hands/legs/clothing/cellphone batteries/bags/etc?

In a sense, yes absolutely. OTOH in another sense this is clearly ridiculous. I suspect this ambiguity is irreducible.

Whether something "is a weapon" is about the intent of the maker or the wielder.

Fun little tangent:

https://www.quora.com/Do-martial-artists-have-to-register-th...

"Only if you use an incredibly loose definition of 'weapon'."

You're looking at things through the lens of a ground-dweller, where by default, all high-energy events diffuse their energy through the environment in a matter of moments. Even nuclear explosions or asteroid impacts will diffuse in relatively short periods of time. Thus, it is an exception to encounter a configuration of matter that can deliver the sort of concentrated energy and/or mass meant to hurt somebody, and we can assume that they are deliberately created by an intelligence, place such exceptional objects into exceptional cognitive categories and create special laws for them, and so on.

In space, there is no such energy diffusion. Anything put into orbit is going much faster than all but the fastest bullets and are much larger to boot, and thus put any firearms you've ever seen to shame. If it's in orbit, and it's still useful which implies it has the ability to maneuver, it's a weapon. It may also be other things, but it is certainly a weapon; everything could be used at the very least to threaten something else. (Think chess here; even threats have real impact.)

Even if you can't agree with that, it doesn't matter, because everybody involved with space does and will continue to act accordingly.

(The signed agreements not to militarize space are quite pointless, really, and I doubt there's a single signatory to any such agreement that is actually abiding by it even if we stipulate for the sake of argument that a "mere satellite" isn't a weapon despite the manifest untruth of such a stipulation.)

I think this comment is being downvoted unreasonably.

Regardless of the (im-)morality of weaponizing space I'm fairly certain the only binding treaty signed by the space powers addressing weapons in space was The Outer Space Treaty of '66. That only banned nuclear or other weapons of mass destruction.

As far as the definition of weapon; popular opinion isn't germain if we're discussing a legal matter, only the legal definition and how loose it might be. In the past few decades the US, Russia, and China have all shot down a satellite with missles from Earth, and generated more space junk in the process I might add. If that didn't run afoul of a treaty I don't see how this project could.

Alright then, what physical object isn't a weapon then? A brick is a weapon, a chair, a hand even.

We've just redefined everything as a "weapon", not sure if that is useful. Though, I think we are slightly more afraid than before, which might be the intended goal here.

Hi, sorry, I should've elaborated. I was referring to US Munitions List:

https://www.ecfr.gov/cgi-bin/text-idx?node=pt22.1.121#se22.1...

> *(2) Autonomously detect and track moving ground, airborne, missile, or space objects other than celestial bodies, in real-time using imaging, infrared, radar, or laser systems;

and maybe other points around it are also applicable.

What if you intentionally de-orbit a critical piece of infrastructure?

It could indirectly cause bodily harm, e.g. cause autonomous cars suddenly lose GPS lock and crash into things.

I get your point, but in particular GPS satellites are not in LEO.

GPS is quite redundant. Losing one satellite should not cause crashes. Actually a car that responds to GPS outages by crashing will not be very useful e.g. in tunnels or among tall buildings.

Right this could be used to snare other things like, say, satellites. Or maybe pop a net in the way of missiles.

Very useful technology, even if it's only ever used to clean up garbage.

Could you not use any satellite with propulsion to produce the exact same result, ie crash into debris or other satellites and push them into earth?

You can use a lot of missiles to destroy any spacecraft easily, while creating a big mess. But this is not really true for the deorbiting part: satellites are not planned for high velocity impact. So either you have a low velocity impact but you delta-v is not high enough to change significantly the orbit of the debris, or you go full speed into it, and explode everything into thousands of small debris, with very random orbit.

The net is just a technique to catch a debris. After it is caught, you have many different ways of deorbiting: either the net has a solar sail and deploy it, or it has a small propulsion system and uses it, or if you hook the net to your de-orbiter, you can use the tether as a sling to release the debris in a shorter life orbit while your de-orbiter is raised to another orbit where it can find its next debris (the most promising system, but the sling part will be quite difficult to master)

On the one hand, yes of course anything that can remove space debris could be used to remove space non-debris, and so is in some sense a weapon. On the other hand, space debris can also be used to remove space non-debris (i.e. collisions), and the more of it there is up there the more likely it is to happen, so the idea of space being all safe is more or less already gone. Cars are weapons, not only in the theoretical sense, but also in the sense that they have been used to kill people. It didn't prevent us from making and deploying cars. If there's enough space debris to be a problem, I guarantee you there will be space debris removal tools, in real production usage.

No, I'm talking about official certifications and export controls. Cars are not certified as weapons. Space debris removal satellites are. I heard that even if your satellite is capable of just taking a picture of another satellite -- expect problems with military during pre-launch approval paperwork with FCC, and also during satellite operations (e.g. every single image from any satellite is classified by default, and must pass a de-classification process).

EDIT: googled relevant documentation: US Munitions List: https://www.ecfr.gov/cgi-bin/text-idx?node=pt22.1.121#se22.1...

> *(2) Autonomously detect and track moving ground, airborne, missile, or space objects other than celestial bodies, in real-time using imaging, infrared, radar, or laser systems;

and maybe other points around it are also applicable.

Seems like an important and potentially lucrative project but I'm a bit worried about its future - what happens after Brexit?

It's lead by a British team, but many of the components are made on the continent, and it looks like half the funding came from the EU...

Well there was a South African university involved in the consortium, so EU membership was not apparently mandatory for this. But regardless, as long as the results of the experiment are available, then both the EU and the UK (and perhaps other friendly governments such as Japan, U.S., etc.) could benefit from the knowledge gained.

EU membership played a key role in this project though. The consortium would not have had the same funding from the European Commission if the UK was outside EU.

If SpaceX's BFR is a success, I hope it is used to launch a huge number of space debris removal satellites.

Reply on news.ycombinator.com