low-level-sensor flight shutdown -- happened once already, but when?

I recall that there's been at least one actual
shuttle launch where a low-level sensor triggered
shutdown earlier than scheduled -- but nobody seems
to have any record of this at NASA. Does anyone
else recall which flight this was?

I'm remembering it was an ISS mission, and the
shutdown was within a few tenths of a second of the nominal one,
so there was not any significant orbital impact and the mission
proceded as planned.

Jim Oberg wrote:
I recall that there's been at least one actual
shuttle launch where a low-level sensor triggered
shutdown earlier than scheduled -- but nobody seems
to have any record of this at NASA. Does anyone
else recall which flight this was?

I'm remembering it was an ISS mission, and the
shutdown was within a few tenths of a second of the nominal one,
so there was not any significant orbital impact and the mission
proceded as planned.

I don't recall such an instance after launch, but NASA must have access
to sensor validation software now:

http://www.techbriefs.com/spinoff/spinoff1997/ps3.html

When you see a WCDT and a FRF, you'll know Griffen is serious about
launching another space shuttle. Until then, it looks like more of the
same -- crooked politics to shut down the shuttle, with the influence
and support of Lockheed lobbyists.

Challenger's Ghost

In sci.space.shuttle Jim Oberg wrote:
I recall that there's been at least one actual
shuttle launch where a low-level sensor triggered
shutdown earlier than scheduled -- but nobody seems
to have any record of this at NASA. Does anyone
else recall which flight this was?

I'm not sure what the reason was, but 51-F, Challenger's last successful
mission had a premature engine shutdown resulting in an ATO. The mission was
still able to be carried out in the lower orbit.

http://www-pao.ksc.nasa.gov/kscpao/chron/sts51-f.htm

On Thu, 14 Jul 2005 13:45:57 +0000, Sham Gardner wrote:

In sci.space.shuttle Jim Oberg wrote:
I recall that there's been at least one actual
shuttle launch where a low-level sensor triggered
shutdown earlier than scheduled -- but nobody seems
to have any record of this at NASA. Does anyone
else recall which flight this was?

I'm not sure what the reason was, but 51-F, Challenger's last successful
mission had a premature engine shutdown resulting in an ATO. The mission was
still able to be carried out in the lower orbit.

http://www-pao.ksc.nasa.gov/kscpao/chron/sts51-f.htm

I was Guidance Support in the MCC backroom on that one.

Also, I think he's thinking of another mission.

There was a mission were a plug in one of the combustion chamber injectors
came out during the flight. On it's way out of the engine, it hit the
engine bell putting a hole in the cooling tubes. This caused a hydrogen
leak in the nozzle. The engine controller then adjusted the mixture ratio
oxygen rich and a low level shutdown (low on oxydyzer) occured right
around MECO.

--
Craig Fink
Courtesy E-Mail Welcome @

There was a mission were a plug in one of the combustion chamber injectors
came out during the flight. On it's way out of the engine, it hit the
engine bell putting a hole in the cooling tubes. This caused a hydrogen
leak in the nozzle. The engine controller then adjusted the mixture ratio
oxygen rich and a low level shutdown (low on oxydyzer) occured right
around MECO.


That was STS-93, Eileen's first mission as commander...but that one did not
go to ISS, and there was no engine shut down...

--
--------------

Jacques :-)

www.spacepatches.info

Jim - I forwarded your question to the ascent FDO for that flight and
got this response:

Yeah, he probably is thinking of STS-93. It was Eileen's first CDR
flight...We shutdown .15 seconds early resulting in the 15fps
underspeed. No real impact on-orbit. All low level sensors flashed
dry resulting in the shutdown. It was caused by a combination of being
on the low side of the tanking estimate and the nozzle leak.

BP


Jim Oberg wrote:

I recall that there's been at least one actual
shuttle launch where a low-level sensor triggered
shutdown earlier than scheduled -- but nobody seems
to have any record of this at NASA. Does anyone
else recall which flight this was?

I'm remembering it was an ISS mission, and the
shutdown was within a few tenths of a second of the nominal one,
so there was not any significant orbital impact and the mission
proceded as planned.

"Jacques van Oene" wrote
That was STS-93, Eileen's first mission as commander...but that one did
not
go to ISS, and there was no engine shut down...

My ISS-association meme looks to have been a brainfart.

"Brian Perry" wrote in message
news5vBe.1731$LG4.1358@trnddc04...
Jim - I forwarded your question to the ascent FDO for that flight and
got this response:

Yeah, he probably is thinking of STS-93. It was Eileen's first CDR
flight...We shutdown .15 seconds early resulting in the 15fps
underspeed. No real impact on-orbit. All low level sensors flashed
dry resulting in the shutdown. It was caused by a combination of being
on the low side of the tanking estimate and the nozzle leak.

thanks, that's the one -- but i'm hearing theere may have been others,
earlier...

"Jim Oberg" ) writes:
"Brian Perry" wrote in message
news5vBe.1731$LG4.1358@trnddc04...
Jim - I forwarded your question to the ascent FDO for that flight and
got this response:

Yeah, he probably is thinking of STS-93. It was Eileen's first CDR
flight...We shutdown .15 seconds early resulting in the 15fps
underspeed. No real impact on-orbit. All low level sensors flashed
dry resulting in the shutdown. It was caused by a combination of being
on the low side of the tanking estimate and the nozzle leak.

More details on this aspect of STS-93 can be found in Jenkins, 3rd
edition, pages 316-317.

thanks, that's the one -- but i'm hearing theere may have been others,
earlier...

Andre

--
" I'm a man... But, I can change... If I have to... I guess. "
The Man Prayer, Red Green.

"Jim Oberg" wrote:

I recall that there's been at least one actual
shuttle launch where a low-level sensor triggered
shutdown earlier than scheduled -- but nobody seems
to have any record of this at NASA. Does anyone
else recall which flight this was?

Jim;

AIUI, the scrub yesterday was because the sensors were failing 'wet' -
I.E. they would never send the low level alarm, allowing the systems
to run dry.

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

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