Satellite Debris Forces ISS Crew Into Rescue Craft

Muad'Dave writes "CNN is reporting that the crew of the International Space Station was forced to take refuge from a possible collision of the ISS with a piece of space debris Thursday. From the article: 'Floating debris from a satellite forced the crew of the international space station to retreat to a safety capsule Thursday, according to a NASA news release. .. The debris was too close for the space station to move out of the way, so the station's three crew members were temporarily evacuated to a the station's Soyuz TMA-13 capsule, NASA said.'" Update: 03/12 18:42 GMT by T : The original story incorrectly said the ISS had 18 crew members. Luckily for the three in the Soyuz, that was a mistake.

Comments

Opportunity is perfect

[WindBourne]

Now is the time for private investors to step forward with solutions. For example a small craft to grab and safely drop items (lower their speeds at the right time ) could take down items that are 30 CM and bigger. Perhaps, system for taking down whole sats. Keep in mind that working sats have to maneuver around them, which is a lose in energy. No doubt countries or even insurance companies would pay for this.

Re:Opportunity is perfect

[geekoid]

What if you used an ion drive and a fuel system for quick maneuvering. Maybe soemthing that can dock with the Space Station for refueling?

This is starting to get silly...

[NoNeeeed]

At some point all those agencies (government and private) who have put that junk up there are going to have to get together and find a solution. That includes all the private sat operators who have left stuff up there as well as the national space agencies.

At the moment everyone seems to be saying, "well, it's not *all* my mess, so I'm not cleaning it up". At some point this is going to start impacting (literally) everyone involved with space. We've already lost a few satellites, how many more do we need to lose before people get off their arses and find a proper solution.

You could probably work out the approximate proportions of the total problem were caused by each agency/company, so divide the bill up accordingly.

Of course, anyone who has watched engineers divide up the bill in a restaurant will know that probably isn't as easy as it sounds...

Note The Source

[DynaSoar]

The debris wasn't from a smashed satellite, either from collision with another or blasted by a missile. It was their own trash, "a piece of a satellite rocket motor left behind by an earlier space shuttle mission". The chances of something from an entirely different orbit impacting a craft are still infinitesimal. To quote the philosopher Adams "Space is big. Really big. You wouldn't believe how mind-boggling big it is." Compare to broken junk floating around even near Earth orbit is that big.

Re:Note The Source

[rlseaman]

The chances of something from an entirely different orbit impacting a craft are still infinitesimal.

Much more likely than infinitesimal. As someone else commented, this has already happened. You must not have been watching the news lately.

The odds are either identically zero if the orbits do not intersect, or are small but significant if they do intersect. Orbits are not static and basically are never perfect closed ellipses, so there is a fair amount of fuzziness about whether two close orbits do or do not intersect. And, of course, every pair of orbits (about the same primary) cross twice on opposite sides of the planet - the two questions to ask are 1) whether they cross at the same altitude, and 2) whether the two objects are at the crossing at the same time.

Since an object in LEO completes about 15 orbits per day and each orbit crosses ALL others twice per orbit, there are many opportunities daily for collision. Most close passes are quite distant. Even if the two objects are near the particular crossing point the altitude may differ. Do the math, however, and you will find that there are several passages of two large objects within a few kilometers every single day. The odds of an actual collision then just scale as the volumes of the spacecraft divided by the volume of a unit cube. Wait long enough and they are guaranteed to collide.

All else being equal, the odds are about even that two large objects (spacecraft sized or so) will collide once per decade. There are hundreds of such orbiting objects, of course, so the odds for a specific satellite are something like once per a few millennia - for a collision with a similarly sized object. The odds are correspondingly larger for a collision between a spacecraft and the much more numerous pieces of small orbital debris.

Re:More accurate early warning

[rjmx]

Trouble with that idea is that it'll only detect objects in almost exactly the same orbit as the ISS. And if they are in the same orbit, their velocities will be almost identical (Kepler's third law, correct?), and so the object will probably never catch the ISS (and if it did, their relative velocities would be quite low).

From the differences in velocity mentioned in the space.com article, I'd guess that the debris is moving in a much more elliptical orbit than the ISS is. Makes it lots harder to detect.

Re:Soyuz is invincible.

[shadowbearer]

  According to an article I just read*, that piece of junk was estimated to be about five inches in diameter and traveling at a relative velocity (to the ISS) of about 22,000 mph. That's almost ten kilometers a second**.

  If that had hit the Soyuz, it would have went in one side and out the other likely without even slowing down much, vaporizing a significant chunk of the hull - think white-hot metal shrapnel and shredded astronauts.

  Look at what happens to an armored tank when a depleted uranium shell hits it at a much slower velocity. At the velocities we're talking about here, even a pebble can cause a lot of destruction; a five inch piece of debris likely weighing at least a kg has an effect like a large artillery shell. Remember the flake of paint that put an inch diameter pit into the shuttle's windshield all those years ago?

  The only effective armor against something like this is a meter or so of rock.

* http://www.usatoday.com/tech/science/space/2009-03-12-space-station_N.htm

**Google: 22000 mph in meters per second = 9834.88 meters per second.

SB

Re:Soyuz is invincible.

[shadowbearer]

  Considering the size/mass and velocity of this object - and I agree it'd be nice to have more info :) - I doubt the orientation would have made much difference.

  The other modules would have absorbed some of the kinetic energy - perhaps all of it if the object , whatever it was, was fragile enough to have disintegrated when it hit them. But if it was a very solid piece - like, say, a fuel pump - it probably would go completely thru them, too.

  Even with the modules on either side that still leaves a lot of open sky :(

  It *will* happen, eventually. That satellite that was impacted recently had a lot smaller cross-section than ISS does. I'm actually rather surprised that the ISS hasn't been holed by something smaller yet.

Cheers,
SB

Re:Lasers

[Neanderthal Ninny]

The USSR had Polyus, which never made it to orbit, which had a self-defense cannon and a blinding laser. http://www.astronautix.com/craft/polyus.htm
However if don't incinerate the target, then you are left with more debris that you may run into. They need a space "refuse" service which will remove
debris, old satellites, and other stuff. Maybe all space faring countries can contribute to an fund that will allow an creation of this organization so that some private or public organization will do this job.

Re:Debris Details

[Anonymous Coward]

Not that CNN is authoritative, but... they reported "The 9-millimeter (1/3-inch) chunk of metal came from a satellite rocket motor that had been used on an earlier space mission, NASA said." USA today is the only source I've seen that has described it as 5 inches.

So maybe somebody can track things much smaller than 10cm in LEO.