Space Sails Could Bring Used Rockets Back To Earth

GordonCopestake writes "An article from New Scientist proposes that all new spacecraft have sails attached to bring them back to earth — a measure that would reduce the amount of garbage in space. From the article: 'The risk to spacecraft from a collision with space debris could be reduced by equipping launchers with a gossamer-thin "sail." The idea is to deploy the sail after the rocket has released its payload to amplify the drag of the last vestiges of the atmosphere, and so force the rocket out of orbit.'" Wired has a related story about the risks faced by the space shuttles as they share orbits with tons of drifting space debris. "... in the 54 missions from STS-50 through STS-114, space junk and meteoroids hit shuttle windows 1,634 times necessitating 92 window replacements. In addition, the shuttle's radiator was hit 317 times, actually causing holes in the radiator's facesheet 53 times."

Comments

And the old junk?

[JorDan Clock]

This might be helpful for rockets launched in 4 or 5 years (Which I think is a very generous estimate on how long something like this would take to be adopted even close to universally.) it doesn't address the issue of all the stuff already up there. How long will the majority of the debris in orbit remain? How effective are these sails when they themselves are punctured by debris? It's a great plan for keeping things from getting worse, but as I understand, a lot of things up there that are in danger of causing damage will be up for quite some time.

Re:And the old junk?

[Profane MuthaFucka]

The debris in low orbits where the Shuttle operates will return within just a few years. Higher than that means it stays up longer.

If an object is orbiting twice as high as the shuttle, about 500 miles, it'll stay up roughly a couple centuries. Just a bit higher than that and you're measuring orbital lifetimes in millennia.

Re:And the old junk?

[rcw-home]

Do you know how much of a difference the size of the debris makes?

Densities of materials vary widely, but as a rule of thumb, mass increases with the cube of an object's size, but drag only increases with the square.

Woah

[Idiomatick]

Those numbers are frigging huge compared to what I thought. 300 measurable hits per mission is crazy. And it will only get worse. I don't think sails are the solution. We need a way to clean it up. (While i liked PlanetES I don't think doing it by hand is very viable)

Re:Woah

[Anonymous Coward]

The 317 hits were over 54 missions. ~6 hits per mission.

Actually, it might, for the larger stuff

[WindBourne]

this might be where Private Enterprise wants to step forward and work on getting a space ship to approach a used up sat, and attack a sail to it to force it down the gravity well. With small control units on the sail, this could be really useful. That same tech would be needed for remote servicing of sats anyway, if private enterprise wants to take that on. As to who would pay, well, I would guess that whoever owns the sat would find it cheaper to pay 5-10 million to de-orbit a sat than deal with lawsuits. For the small to medium size, well that will require a totally different approach.

Shoot em up?

[powerslave12r]

Well, with the kind of weapons tech being developed (electric eye with lasers?), it shouldn't be a big deal burning down these debris. The problem would be allowing (or acknowledging that *anyone* has) that kinda weaponry up there.

Re:Proud to be White

[Jurily]

Now that you mention it... Maybe we should try launching politicians up there to collect the debris. Or bankers.

Can we build something cheap enough to launch them all?

Hit or Miss or Hit

[DynaSoar]

"For the final stage of an Ariane 5 launcher, the conical sail would need to have an area of about 350 square metres and be supported by an inflatable mast 12 metres long."

And the expected time to reentry is 25 years.

Good luck on keeping something inflated in space for 25 years. And that's not even considering the probability that the the mast, and the much higher probability that the large sail, will be hit by orbiting debris during that time and torn to shreds

Re:Hit or Miss or Hit

[camperdave]

Good luck on keeping something inflated in space for 25 years.

Inflate it with a plastic foam resin that hardens into a "solid" mast.

Re:Moon or obiting junkyard

[Rakishi]

Space is not earth.

Moving things in space and keeping them from crashing into the atmosphere requires energy. Energy means fuel and fuel means you need to pay to send it up. Docking objects in space requires complex electronics which means even more mass to send up.

Recycling requires a highly advanced and complex industrial base which doesn't exist in space. If it did then you wouldn't need the junk since you can mine your own raw materials.

Bad idea

[bigsteve@dstc]

If you blow up an old booster ... or satellite ... you only make the space junk problem worse. Instead of 1 large lump of junk that is easy to track and (with luck) avoid, you end up with thousands of smaller lumps, each of which would damage or destroy a satellite.

Making solar sails

[Kim0]

Here is my idea for making an extra light solar sail:

http://kim.oyhus.no/Solar_sail.html

Kim0

Re:Getting bombarded by our own crap

[NotQuiteReal]

The universe is mocking us for not thinking ahead. Again.

Don't anthropomorphise the universe. It doesn't like it. All kidding aside, I am not sure that you said anything. Do you only want to put small things into orbit? Or are you saying we should make sure "what goes up, must come down?"

I think you are saying adding the sails would make the debris bigger, and thus even more of a problem.

Maybe you should have just said "the road to hell is paved with good intentions" and left it at that.

Re:Choke

[julesh]

Please, go back to YouTube. Your peers there are missing you.

I pray he never learns the word 'sheeple'.

Such a Waste

[32771]

I think that any mass in orbit is far more valuable there than back on earth. It still has all the energy the owner has paid for by launching it in the first place, and at ~$1000 per kg in LEO that is nothing to sneeze at. I think the solar sails should be used to cart the stuff into a higher orbit where the parts can be stored with less effort.

The problem is that whatever we sent up is not built for reusability it would seem. Without a decent plan to produce something from space junk I guess nobody is going to worry about where the hardware in orbit goes beyond its eol, it has paid for the launch costs already why worry about much costlier manufacturing in orbit. Then it is also safer to just drop the stuff. This proposal is more of the same shortsighted thinking however. We will continuously put stuff into orbit, why let it decay back to earth if there could be a continuous reuse of material in orbit? Something goes up nothing comes down!

The space junk problem could finally lead to better planning for the future. Somebody could come up with an in orbit manufacturing and launch facility which buys the energy + material value of your satellite/booster. Its main bussiness would be in orbit manfacturing and launch of hardware with a certain orbit.

I would venture a guess and say that we already have the technology to make this work today. So it is time to check whether this could become a viable business model.