Re: ISS Service Module Thruster Test Fails -- first story on line

Derek Lyons wrote:
Chris Bennetts <benetsc2000@xxxxxxxxxxxx> wrote:
The backup solution is Progress.


Incorrect. Progress is the primary system - the integral thrusters
are the backups.

You're right. I guess further backups would include reboosts by shuttle, ATV, or Soyuz, and the station could be evacuated if none of those were available in the months before the station reentered.

Just remember that Mir was in the same situation for almost all of its life.


Just remember - the O-rings never *completely* failed.

Just remember - even though the specs say 'no foam impingement', it
never has actually caused serious damage.

As Jim himself has said on numerous occasions, 'getting away with
something does not mean it was safe'.

Derek, those are bad comparisons. Compared to those two cases, losing reboost engines on the station gives you much longer to respond (several months rather than minutes/seconds), and does not lead to the loss of the crew (short of Soyuz failing, and not being able to launch another Soyuz or shuttle on a rescue mission).

The loss of the reboost engines is a concerning thing. The cause of the failure needs to be identified so that any related problems can be mitigated against. But this is *not* anything like the problems that caused the loss of Challenger or Columbia.

--Chris
.

Relevant Pages