A Bit of a Worry

From The Australian :

A Russian space transport ship failed to fully raise the orbit of the International Space Station in preparation for next month's docking of a supply ship, a Russian news agency reported.

Alexander Kireyev, head of the ballistic coordination group at Russia's Mission Control outside Moscow, said the docked Progress transport ship was supposed to raise the orbiting station by about 4.5km, but the ship's engines were not strong enough.

"Eight approach and attitude engines of Progress M-50 that is docked to the ISS were turned on at 17:12 Moscow time and worked for 549 seconds as was planned," Kireyev was quoted as saying by ITAR-Tass.

"However, the thrust they generated was not as big as was expected."

He said the station was raised by only 2.7km, but that it would still be enough to allow a new transport ship, scheduled to be launched from the Baikonur cosmodrome in Kazakhstan on December 23, to dock.

No need to panic.

The station, which is now orbiting about 358km above the earth, has dropped about 7km in the past two weeks due to strong magnetic storms.

OK, now we can panic. Or rather, start to get concerned. A few more months like that, and there will be all sorts of problems with attitude control, due to the increased resistance from the not-quite-as-near-as-it-was-to-vacuum near-vacuum. The ISS will start to slow down faster, leading to a lower orbit, leading to more resistance, leading to... well, it will Skylab in, eventually. Not for a while though.

7 km drop in 2 weeks is a bit of a worry though. Especially if someone's slipped up with the calculations, and a Progress can only claw back less than half of that.