Astronauts Throw Trash Into Space

MattSparkes writes "The International Space Station is home to an increasing amount of unwanted goods, and NASA has just approved a policy where these could be thrown out of the door into space. 'Tools and other gear have accidentally floated away during spacewalks. But NASA has shied away from intentionally jettisoning gear off the ISS in the past because of the threat of space junk hitting the station or other spacecraft.' The loosening of the rules on this comes just as Russian cosmonaut Mikhail Tyurin is about to take a space walk where he will hit a golf ball from the ISS in a promotional stunt for a golf company."

Comments

Pigs in space

[BadAnalogyGuy]

It starts with a piece of trash and quickly turns into a terrible neighborhood. Next thing you know, it'll be the International Space Crackhouse.

I told you we shouldn't have let those Russians in.

Re:Pigs in space

[Sporkinum]

International Space Crackhouse.

Ground control to Major Tom....

Randomly dump their trash would be stupid

[aadvancedGIR]

and criminal.

They could pack their trash and, with minimal thrust, send it on a quick reentry path in which it will burn in higher atmosphere a few days or weeks later. On the other hand, if they just dump things at random, they may be their own victims mounthes to years later.

Re:Randomly dump their trash would be stupid

[Noryungi]

They could pack their trash and, with minimal thrust, send it on a quick reentry path in which it will burn in higher atmosphere a few days or weeks later.

Exactly, there is no reason not to incinerate their trash. I can't believe this is 2006, people have been going into space for more than 40 years now, and they still are throwing trash overboard even though they know the danger. Stupid, stupid, stupid.

Re:Randomly dump their trash would be stupid

[SysKoll]

They could pack their trash and, with minimal thrust, send it on a quick reentry path in which it will burn in higher atmosphere a few days or weeks later.

Yeah, because see, all these rocket scientists, they are well known for bein' stoopid. Ain't that a shame to pollute them purty stars.

SARCASM_MODE=OFF

If all you needed to deorbit something thrown from the ISS was a "small amount of thrust", don't you think that atmospheric drag would have already deorbitted the ISS itself?

In order to deorbit something, you need a very considerable amount of thrust, with an engine and propellant brought up from Earth at enormous cost. Left to its own device, a low-density object such as a bag of trash is going to slowly lose altitude due to atmospheric drag, then burn. No need for propellants. Good old air envelope does the trick.

As for reusing it, I'm afraid that a sizeable fraction of the trash is, er, astronaut dung. I doubt the reuse value of human waste is very high in space, until we have complete hydroponic gardens.

there is no reason not to incinerate their trash.

Incinerate? Whaaa?? Look, this is space, ok? Having a simple combustion chamber working in space would be a major, major physics achievement. There is no convection, so flames don't behave as expected. There are whole experiments studying a simple candle flame in space.

Never mind the fact that you'd need oxygen and fuel, brought from Earth at enormous cost, to burn wet waste.

The only way to incinerate things in space practically would be with a electric plasma arc, which in turn would requires a really large energy input. So until the ISS flies several isotope generators, there will be no such thing.

Remember, these decisions are made by people who actually know what's going on. The only problem is that they obviously don't communicate their reasons, since Slashdot readers -- Slashdot readers! -- feel compelled to call them stupid.

Re:Randomly dump their trash would be stupid

[SirCyn]

IANARS!
Having an astronaut literally throw a typical size bag of trash toward the Earth would be sufficient acceleration (or deceleration depending on your point of view) to cause it to burn up within a couple weeks. And better yet it would instantly be in a non-intersecting orbit with the ISS.

In the past they haven't done this because it will cause the ISS to be accelerated into a higher orbit. The difference would be minimal, but certainly measurable. The ISS is not very well equipped to deal with such problems (remember that it is technically falling all the time normally). Apparently NASA has decided that this effect is minimal enough that it would not be detrimental to the ISS orbit.

Re:Randomly dump their trash would be stupid

[Mindwarp]

Actually, no. If an astronaut were to throw a bag of trash 'downwards' towards the Earth then its orbital velocity relative to the space station would increase (since it is moving into a lower orbit) so it would start to overtake the space station below it. As the orbital velocity increases it would start to again climb to a higher orbit, passing above the space station in front of it. As it gained a higher orbit than the space station its orbital velocity relative to the ISS would drop, causing the trash to drop to a lower orbit. In summary, if you throw anything out of the ISS down towards the Earth it will in fact pull a complete loop and end up impacting the top of the ISS.

There is only one safe direction to throw anything out of an orbiting spacecraft - backwards, in the opposite direction of your orbit. By doing this you reduce the orbital velocity of the object relative to your spacecraft thereby guaranteeing that the object will enter a lower orbit from which it is guaranteed not to climb. At this point atmospheric drag will continue to degrade the objects orbit until it eventually burns up.

Re:Randomly dump their trash would be stupid

[RingDev]

hope he doesn't slice it!

-Rick

Re:Randomly dump their trash would be stupid

[roystgnr]

Wait a minute. What you are saying seems to defy common sense.

Yup, orbital mechanics will do that. It starts with "if you want to go faster, slow down" and just gets weirder from there.

In space, if you throw an object, it will continue in that direction until resistance is met.

Only if its orbital velocity is negligable compared to the velocity you throw it at; otherwise it's direction will change constantly under the influence of gravity.

So, if the space station is 220 to 250 miles out in orbit and you throw or eject a package of trash toward the earth at 20 miles per hour (that seems reasonably simple). The package would travel 220 to 250 miles in 11 to 12.5 hours. It would be incinerated well before that. Am I missing something? Is there some principle of physics that would cause it's descent to slow as it's orbit decreased? It seems to me, that it would speed up if anything.

If you throw your trash toward the Earth at 20 miles per hour, the trash won't be moving at 20 miles per hour, it will still be moving at approximately 11,000 miles per hour; its velocity will just have changed direction by about a tenth of a degree. Its new orbit will now be slightly elliptical, but it still won't be elliptical enough to intersect thick atmosphere.

You're right that the trash will speed up as it gets closer to Earth... and as it speeds up, the centrifugal force required to keep it moving closer to Earth increases, gravity can't keep up, and the trash moves outwards again.

Method of keeping altitude

[Frans Faase]

What about installing a device to eject garbage in the direction of the earth, so that they will be burned in the atmosphere as this would also help the ISS to maintain altitude. I realize that the effect would be minimal, but yet all small things might help. Anyway ejecting materials towards is always better than just let them float away.

Re:Method of keeping altitude

[elvum]

The ISS needs boosting into a higher orbit periodically to avoid burning up anyway, so any rubbish they eject will burn up eventually. Ejecting rubbish in the direction of earth wouldn't help though - read up on the counter-intuitive nature of orbital mechanics :-)

I'd sell the trash...

[Takuryu]

... after all, one man's trash is another man's treasure (if you believe that saying). I know of a number of people who would pay what I consider to be a fair sum of money just to own something that had been _in space_.

Joking aside, how hard would it be to double-bag a few trash bags and keep the trash outside until a convenient "recovery" mission could come around?

Why doesn't ISS have an extensible trash module?

[Morgaine]

Quite apart from the obvious dangers involved in dumping trash into orbit ...

ISS trash isn't actually trash --- it's extremely valuable material (and mass) that has been boosted into LEO at very high cost.

They should attach an extensible trash module to the ISS, and place all their "trash" (which simply means stuff that they cannot currently use) into the containers through appropriate hatches.

(And I bet space contractors would love to bid for such a project too.)

Not only would you reduce the risk to future flights this way, but you would also provide useful materials for the future. *AND* you'd be seen to be environmentally sensitive, which is no bad thing.

Clarke, "Islands in the Sky" 1952

[dpbsmith]

Pigs. Litterbugs. Someone ought to fine them $500. What can you say?

But... after all... one of the pivotal episodes in Arthur C. Clarke's 1952 novel "Islands in the Sky" concerns an orbital spacecraft which is alarmed by the presence of a large, unidentified spacecraft, approach closely enough to identify it, and sees that it's covered in radiation symbols. In the novel, it turns out that the AEC had, at one time, had the bright idea of disposing of radioactive waste by shooting it into space, and this is a stray canister of high-level radioactive waste. So I guess it could be worse.

And "throwing away" (such an aptly descriptive phrase: just toss the waste a discrete distance from the dwelling) seems to be a basic part of human nature. In Owen Wister's novel, "The Virginian," set in Wyoming between 1874 and 1890, the narrator and his companions partake of "Sardines... and potted chicken, and devilled ham," and muses:

"But portable ready-made food plays of necessity a great part in the opening of a new country. These picnic pots and cans were the first of her trophies that Civilization dropped upon Wyoming's virgin soil. The cow-boy is now gone to worlds invisible; the wind has blown away the white ashes of his camp-fires; but the empty sardine box lies rusting over the face of the Western earth."