Satellites Collide In Orbit

DrEnter writes "According to this story on Yahoo, two communications satellites collided in orbit, resulting in two large clouds of debris. The new threat from these debris clouds hasn't been fully determined yet. From the article, 'The collision involved an Iridium commercial satellite, which was launched in 1997, and a Russian satellite launched in 1993 and believed to be nonfunctioning. Each satellite weighed well over 1,000 pounds.' This is the fifth spacecraft/satellite collision to occur in space, but the other four were all fairly minor by comparison."

Comments

When Satellites Collide!

[AJ Mexico]

Too bad orbital tracking didn't give enough warning for Iridium to get their bird out of the way. I guess no one is cross checking the orbits of all satellites? I know it is done for the shuttle and space station. (The space station *has* maneuvered to keep away from space junk.)

A good question....

[reality-bytes]

TFA says that they knew this would happen 'sooner or later' but doesn't mention anything specific.

The question is, did anyone have any specific knowledge of the likelihood of this specific collision prior to the event?

I'm assuming just now there wasn't orbital information of sufficient precision to predict this.

High Perigees LEOs Should be Reserved

[Baldrson]

This is a good example of why circular, indeed any high-perigee orbit should be reserved for applications like tether propulsion such as HASTOL Rotovators.

Low perigee orbits, orbits that dip into upper atmosphere, naturally decay to reentry. If collisions occur, the pieces will naturally decay to reentry.

Rotovators are highly valuable and actually need to operate in LEO to throw things out of LEO, both up and down -- and Rotovators are quite vulnerable to debris.

500 mile perigee is way to high. It is a nighmare orbit for debris proliferation.

Planetes

[Bonker]

Planetes is a japenese cartoon about this very subject, and other unpleasant realities of space travel including space-radiation induced cancer, the birth problems of people living on the moon, and the long delay involved in inter-planetary travel.

The main character, 'Hachimaki', is basically a space garbage collector.

Re:Was this really bound to happen?

[Zak3056]

Iridium Satellite should file a claim against the Russians.

Typically, when it comes to right of way, the less maneuverable vehicle has the right of way (for example, a balloon has the right of way over a glider, which has the right of way over an airship, which has the right of way over an airplane. Similar rules apply to seaborne vessels.) Taking at face value the summary's statement that the Russian satellite was non-functional, it was clearly the duty of the operators of the Iridium satellite to take action. If you want to talk claims/liability, I'd say that the Iridium folks are on the hook for huge damages--through negligence they've created a massive hazard to navigation that will be a problem for... what, centuries?

Re:5th collision??

[MichaelSmith]

How about the progress freighter which hit Mir because it had the incorrect mass information loaded?

Re:Was this really bound to happen?

[kelnos]

If you were told in advance that the satellite was going to fall into the exact location where your car was sitting, and that no one could change the satellite's trajectory because it was dead, and you nevertheless left your car there, then, yes, I'd say you're at fault.

Try fleshing out the analogy so it actually makes sense next time.

Ablation Cascade: This is how it starts

[computersareevil]

This is one way the theoretical Ablation Cascade could start. At least then we wouldn't have to worry about getting to the Moon. We couldn't.

Bummer if it happens before the Webb Space Telescope launches...

Risk adjusted net present value

[Baldrson]

The risk adjusted net present value of unicorns is basically 0 because the risk of their not existing is close to 1. Of genies, well that depends on your religion, but for the vast majority of folks making economic decisions with real money, its 0. Of "Rotovators" of the type linked to by you, it is probably higher than space elevators but lower than the HASTOL rotovator type I linked to by quite a lot because the HASTOL rotovator can be constructed with current materials and suborbital launch vehicles now going into commercial operation.

So a fair comparison has to compare the economies of a HASTOL rotovator, adjusted for the technological risk, to the difference between current high perigee LEO applications and modification of those applications to have perigees low enough to naturally reenter at about the same time the satellite is at the end of its projected useful life.

The trade-off is not nearly as clear as you make it out to be, and with the value of getting things to and from space being essentially "halfway to anywhere", it is pretty clear that you've got a lot weaker case than you apparently think.

Re:First collision

[jd]

Some of the early proposals for satellite phones would have put enough in orbit that if any two had collided, the rest would have smashed into the debris field, again resulting in a complete block to launch.

Remember, one of the early space shuttles was hit by a fleck of paint in orbit. The impact nearly smashed a hole through the windshield. A fragment the size of a dried pea would not necessarily be visible from ground stations on Earth but might easily be expected to punch through any space vehicle in its path, along with anyone inside.

Re:First collision

[TheTurtlesMoves]

That was in fact my friends house. It was in New Zealand Auckland. It took me a while to believe her.

Re:First collision

[zeropointburn]

not to break into a perfectly good argument, but why not do it this way?

An object does not need to be ferromagnetic to acquire a STATIC charge. Lob a stream of electrons into the debris field, and some of them will stick... to ANYTHING. The objects will develop a static, negative charge.

The objects with their newfound negative charge will now repel each other. The force is not likely to be large, but it does not have to be. The debris field will scatter over time, and even small destabilizations of their orbits will lead to a large divergence in position over successive orbits.

Now on your launch vehicle, you have two options. Maintain a static, negative charge on the nose; this will force further scattering and prevent impact with material within a certain range of relative velocities. Maintain a magnetic field extending in front of the vehicle; this will induce motion in the charged debris, forcing it out of the way. This also has a limit on the maximum relative velocities of the vehicle and the debris.

It may be more effective to use positive ions instead of electrons. In that case, you reverse the charge on the cone. The magnetic method would not require changes. All of this works under the inverse square law, so the force of the effect increases as ship and debris get closer.