ISS Orbit-Raising Attempt Fails

hpulley writes "ITAR-TASS reports that the Progress cargo ship currently docked at the ISS attempted an orbit raising burn this morning but the engine failed three minutes into the firing. Further burns are cancelled until they figure out the problem and meanwhile, the station continues to lose approximately a kilometer of altitude every week, with the rate increasing as the orbit decays. At present, the schedule says the next Progress, 20P, will be launched on December 21st, nearly 9 weeks from now. Normally the shuttle would also raise the orbit of ISS but it is not scheduled to launch until May 3rd at the earliest. Nominally the ISS orbits at 358km but if it drops to 300km, it may decay in a matter of days. It was down to 340km already on October 13th."

Comments

Eh, well, it's a matter of scale

[Julian Morrison]

Nine months might sound like a long while. But consider the lead times for rockets. Can an unscheduled mission be planned, built, prepped, tested, rubberstamped and shot into orbit inside nine months?

I trust the Russians on this.

[bogaboga]

These Russians have years of experience in the field. Heck, they had MIR for 15 years. That is, 3 times the time it was intendd to last. Sad that we as Americans can only sit and observe at least for now. Even aftr pumping billions into our space program, I will not be suuprised if things just do not work for us.

Skylab

[OrangeTide]

Will the same thing happen to ISS that happened to Skylab? A series of incidents (generally involving funding) that results in the space station sinking below a level that it could be lifted out.

Of course there are people in ISS, so it's perhaps a bit too early to wonder if funding would be delayed long enough for ISS to fall to Earth.

Solution?

[waterlogged]

So why haven't they put that tether experiment on the ISS that the shuttle ran a number of years ago. Basically it was able to turn orbital motion into electricity or electicity to motion. Next trip take them up a tether and a bunch of solar cell and Fagetaboutit.

Please explain for me

[joeslugg]

IANARocketScientist, and for those other readers who aren't can someone please explain:

Why don't they have ISS in a higher orbit that won't decay as fast/often? And again, pardon my ignorance, but my (un)common sense tells me if they are at a high enough orbit, it shouldn't decay as readily - too high and you have the opposite problem of drifting farther away from Earth.

In other words, rather than having to make orbit adjustments so often, isn't it possible to push it to a high enough orbit that won't require a tweak for a longer period of time?

TIA for n00b-enlightenment.

ION Power!

[MythoBeast]

It occurs to me that station-keeping engines would be an excellent application for ion engines. They don't have the power to push the thing into orbit, but certainly they could be built with enough thrust to counter the atmospheric drag at those altitudes. While it would take a bit of effort to bring the engines up on the rockets, it would probably be more than compensated by being able to shuttle up a small load of xenon every now and then instead of all of the fuel necessary to boost it back into its original orbit.

Maybe it's just convenient to have it ride lower every now and again, but I can't imagine that the fuel saved by the lower orbit compensates for having to push it back up there again. I haven't done the math, but it's possible that ion engines would allow it to stay at a lower altitude indefinitely, since there's no danger of decay.

And while we're at it, maybe we could design these things with just a tad bit of aerodynamic considerations. Ok, I'm truly talking out my backside right now, but it's fun to think about how to avoid this kind of thing.