ISS Service Module Thruster Test Fails

Details developing

Burn automatically aborted pre-ignition.

Uh, isn't anyone interested in this 'non-event'?

"Jim Oberg" wrote
Details developing

Uh, isn't anyone interested in this 'non-event'?

Well, I was just trying to remember what propulsion on the station was
and was not working. Though I guess I was thinking of reboost
engines, and "thruster" could mean either that or attitude control.

I guess in a nutshell, I'm too ignorant, both in terms of background
and in terms of this latest event, to know whether to be interested or
not.

"Jim Oberg" wrote:

"Jim Oberg" wrote
Details developing

Uh, isn't anyone interested in this 'non-event'?

Uh, yes. But some of us do try and avoid uninformed speculation.

If you were expecting a chorus a 'do tell Jim, do tell' - you should
know better.

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

MSNBC COSMIC LOG//. April 19, 2006 | 6 p.m. ET

http://www.msnbc.msn.com/id/12359455/#060419b
Space station test fizzles: Today was supposed to mark the first time in
six years that the engines were fired up on the international space
station's Zvezda service module. The test firing was aimed at raising the
orbital outpost's altitude by about half a mile (700 meters) - and also
finding out whether the engines still worked.

NBC News space analyst James Oberg was watching the test closely, and
reported that the firing was aborted because one of the valves on one of the
engines failed to open. Fortunately, the non-firing is basically a
"non-event," and there are no immediate plans to try the test again, Oberg
quoted NASA spokesman Rob Navias as saying.

The station will still be in an acceptable orbit for next week's
scheduled rendezvous with a Progress cargo ship, even without the engine
firing, Oberg said.

"Even if the engines never work, they are only a backup to propulsion
capability usually provided by visiting vehicles docked to the aft port," he
explained in an e-mail. "The loss of these engines has no impact on station
operations - the Russians were just curious if they would work after so
long, and they have their answer."

Jim Oberg wrote:

"Even if the engines never work, they are only a backup to propulsion
capability usually provided by visiting vehicles docked to the aft port," he
explained in an e-mail. "The loss of these engines has no impact on station
operations - the Russians were just curious if they would work after so
long, and they have their answer."

Losing a backup system has always got to be a Bad Thing (although Mir
spent nearly its entire life in the same situation, but for a different
reason).

It makes you wonder what other long-term dormant systems no longer work.
The failure of P6's array extension/retraction system would be extremely
bad, for example.

--Chris

Gene Cash wrote in :

Chris Bennetts writes:

It makes you wonder what other long-term dormant systems no longer
work. The failure of P6's array extension/retraction system would be
extremely bad, for example.

Why would that be? I can't think of any reason to need to retract the
arrays, or how it could become a problem.

P6 was originally intended to be installed at the far port end of the
truss. To provide more power for the US segment during the assembly
sequence, the sequence was modified to launch P6 early and mount it to the
Z1 truss at the center of the station.

Once assembly of the truss resumes, the P6 arrays would interfere with the
rotation of the arrays on the P3/P4 and S3/S4 truss segments, so the arrays
must be retracted until P6 can be relocated to its permanent position on
the port end, then re-extended.

--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

"Jim Oberg" wrote:

NBC News space analyst James Oberg was watching the test closely, and
reported that the firing was aborted because one of the valves on one of the
engines failed to open. Fortunately, the non-firing is basically a
"non-event," and there are no immediate plans to try the test again, Oberg
quoted NASA spokesman Rob Navias as saying.

All-singing all-dancing, just a different tune and a different set of
steps.

The station will still be in an acceptable orbit for next week's
scheduled rendezvous with a Progress cargo ship, even without the engine
firing, Oberg said.

"Even if the engines never work, they are only a backup to propulsion
capability usually provided by visiting vehicles docked to the aft port," he
explained in an e-mail. "The loss of these engines has no impact on station
operations - the Russians were just curious if they would work after so
long, and they have their answer."

Ah, right. It's *OK* for backups to be faulty - we'll never need them
after all.

Ask the shades of the crew of the USS Thresher what they think of
that.

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

John Doe wrote:

Question is whether those are field replaceable/repairable,

It depends on the exact nature of the problem, but I think it's
unlikely. Anything more than the most superficial repair work would mean
dealing with hardware that has been contaminated with hydrazine and
N2O4, both very nasty chemicals. Better to leave the problem unsolved
than to try fixing it if either of those are involved.

and if Russia has any plans to provide a new backup solution since
they knew from the outset that those engines wouldn't last for the
whole station lifetime.

The backup solution is Progress. Just remember that Mir was in the same
situation for almost all of its life[1].


[1] Kvant-1 was in the way of the base block's engines.

--Chris