On orbital garbage disposal efforts

[Zor]

Having watched a Few episodes of Planetes which is pretty damn hard as far a sci-fi is concerned, i got thinking about the problems of space junk.

There is a lot of old satelites and other such rubbish in orbit and even small peices of said rubbish flying at 8 kilometers per second can make it a massive nagivational hazard if it is just left to accumulate. As such, would it make sense to have it have clean up efforts to dispose of it before it becomes to much of a problem?

Zor

[Forum Troll]

Do this.

"One laser facility could remove all of the one-to-ten centimeter debris in three years or less."

[Ariphaos]

The laser broom seems to be the de facto solution. The only argument against that I've seen is the power requirements. As if putting up nets would be 'cheaper'.

[Forum Troll]

The laser broom seems to be the de facto solution. The only argument against that I've seen is the power requirements. As if putting up nets would be 'cheaper'.

Yes.

Seeing some comments in a "Satellites Collide Over Siberia" thread, it's apparently easy to overestimate laser requirements.

Yet laser cleanup is easier than it could seem:

1. It takes only a slight velocity change to deorbit low-earth-orbit junk, as directly canceling the bulk of its orbital velocity is unnecessary, only several percent or less of that total velocity. Since it is already in a low orbit, its resulting new lower perigee will then intersect traces of the uppermost atmosphere, so the atmosphere will take care of it over time.

2. Laser ablation is decently efficient at changing velocity, as it works in the same manner as laser boosted rockets, not dependent on the near-zero momentum of the laser beam itself but on the far greater recoil of plasma thrown out by the impacting laser pulses.

As the USAF laser expert said in the past post's link, the cost of "eliminating debris in orbits up to 800 km in altitude within 3 years of operation would not exceed $200 million."

NASA could pay for the significant but still fairly moderate cost, yet understandably so far has hesitated to spend an amount equivalent to having to cut another mission from its budget to pay for it. The Tragedy of the Commons applies for the average corporation.

The 1cm to 10cm range is the main goal to eliminate. Debris smaller than that is practical to shield against. An object bigger than 10cm is typically more than 1000 times the mass of a 1cm object and thus correspondingly far less common. The very biggest objects are few enough in number that they can be avoided, like the ISS has done minor thruster burns, when tracking confirmed such were needed.

The fact that a debris-clearing laser can also be used as a weapon against satellites has historically been an occasional objection to the idea, for the international politics of the matter, though alternately it is a side advantage depending on your perspective.

[dragon]

The laser broom seems to be the de facto solution. The only argument against that I've seen is the power requirements. As if putting up nets would be 'cheaper'.

The energy requirement will depend where you place the laser. If its ground based you'll need more power to get based the effects of the atmosphere but hook the laser up to a nuclear power plant and should be enough power. Or you could build it in a orbital satellite that uses solar panels. It might take longer between shoots as the solar panels would take longer to charge the laser.

[Sky Captain]

The laser broom seems to be the de facto solution. The only argument against that I've seen is the power requirements. As if putting up nets would be 'cheaper'.

The energy requirement will depend where you place the laser. If its ground based you'll need more power to get based the effects of the atmosphere but hook the laser up to a nuclear power plant and should be enough power. Or you could build it in a orbital satellite that uses solar panels. It might take longer between shoots as the solar panels would take longer to charge the laser.

IMHO putting the thing on the ground, preferably on some high mountain to minimize atmospheric interference would be much more cost effective than launching the laser facility in space. Cost of the electricity to run the laser would be trivial compared to the capital cost of the laser and maintenance. Besides putting the laser in space means that if something breaks down your laser becomes a billion dollar piece of scrap. Not to mention laser that powerful would be too big to fit in a rocket.

[Fingolfin_Noldor]

IMHO putting the thing on the ground, preferably on some high mountain to minimize atmospheric interference would be much more cost effective than launching the laser facility in space. Cost of the electricity to run the laser would be trivial compared to the capital cost of the laser and maintenance. Besides putting the laser in space means that if something breaks down your laser becomes a billion dollar piece of scrap. Not to mention laser that powerful would be too big to fit in a rocket.

I have a feeling that the diplomatic furore in deploying such a laser which could also be instantaneously turned into a weapon might prevent it from ever working.

But that aside, getting such a laser up and working might be a mountain of work and I'm not sure how far they have gotten with lasers of this sort.

[Kelp]

I instantly thought of Dr. Evil using such laser to threaten to punch a hole in the ozone and hold the world ransom for $1,000,000.

I don't see it being an international politic problem if it a joint project like the ISS. Otherwise, everyone can just build one, if they want to, and share the cost of orbital cleanup. If any one country should attempt to use it as an anti-satellite weapon, then it will be treated as a valid military target and promptly eat a laser guided bunker buster or something.

[Fingolfin_Noldor]

I instantly thought of Dr. Evil using such laser to threaten to punch a hole in the ozone and hold the world ransom for $1,000,000.

I don't see it being an international politic problem if it a joint project like the ISS. Otherwise, everyone can just build one, if they want to, and share the cost of orbital cleanup. If any one country should attempt to use it as an anti-satellite weapon, then it will be treated as a valid military target and promptly eat a laser guided bunker buster or something.

Erm, no. If anyone uses it as a weapon, it be next surrounded by a ring of anti-air defences, along with patrol craft.

And if it s a joint project, you can be rest assured it'd take forever to decide where to put the laser.

[Ariphaos]

The energy requirement will depend where you place the laser. If its ground based you'll need more power to get based the effects of the atmosphere but hook the laser up to a nuclear power plant and should be enough power. Or you could build it in a orbital satellite that uses solar panels. It might take longer between shoots as the solar panels would take longer to charge the laser.

If you put it in space you also need to do heat dissipation.

[TheLostVikings]

As someone said in the already mentioned "Satellites Collide Over Siberia" thread, you could team up the ground based laser with a mirror in orbit for added effect.

As an added benefit you can have the laser beam be pretty wide when it hit the targeting satellite before focusing it down to pinprick accuracy. And since the final focusing phase takes place above the atmosphere it removes annoying stuff like atmospheric diffraction etc.

Powering your laser with a honking big nuclear plant, and having plenty of available heat sinks nearby makes ground based ones much easier to build. Not to mention not having to lift all that stuff into orbit in the first place.

[Sky Captain]

IMHO putting the thing on the ground, preferably on some high mountain to minimize atmospheric interference would be much more cost effective than launching the laser facility in space. Cost of the electricity to run the laser would be trivial compared to the capital cost of the laser and maintenance. Besides putting the laser in space means that if something breaks down your laser becomes a billion dollar piece of scrap. Not to mention laser that powerful would be too big to fit in a rocket.

I have a feeling that the diplomatic furore in deploying such a laser which could also be instantaneously turned into a weapon might prevent it from ever working.

But that aside, getting such a laser up and working might be a mountain of work and I'm not sure how far they have gotten with lasers of this sort.

I think to overcome diplomatic obstacles it would need to orbit become so full of junk that it begins to cause junk chain reaction destroying nearly every satellite and practically sealing off access to space.

[Sea Skimmer]

The laser broom seems to be the de facto solution. The only argument against that I've seen is the power requirements. As if putting up nets would be 'cheaper'.

The real argument against it is politics, since despite the fact that China, the US and Russia all already have military lasers in service that can destroy spacecraft a persistent notion exists that we must ‘avoid a space weapons arms race’. Any kind of laser for clearing debris is a by default an ASAT device, and the high refire rate needed for the job would make it especially potent.

I' figure once nations realize that ABM projects also lead to easy creation of ASAT weapons, and high power lasers become more common in general, the political arguments will fade away and the US and Europe will build and jointly operate two or three debris destructors.