Watching NASA TV a few minutes ago I heard something that really got my attention. All of us space geeks on this list probably know that during a shuttle launch the SMEs light first and then there is a few seconds delay before they light the SRBs. What I did not know is that after they light the SMEs but BEFORE they light the SRBs the explosive bolts that hold the whole shuttle stack in place on the ground are detonated. Made me wonder what would happen if the SRBs did not light. The guy conducting the briefing must have guessed people were wondering that as he quickly noted they are very confident the SRBs will light. Patrick
Joe Bauman wrote:
So Patrick, what did they say about the sensor? Thanks, Joe
It was a replay of last Tuesday's pre-launch briefing so the sensor was not mentioned. There was supposed to be a new one today that was billed as being held "not before 5:30 EDT" but as of now it still has not aired. But I saw in the article I quoted in today's issue of News, there apparently is talk of launching with only 3 sensors. Patrick
Don't worry Patrick, you're talking about a 4 sensor, daylight launch only, space agency. There are probably backup bolts somewhere. Quoting Patrick Wiggins <paw@trilobyte.net>:
Watching NASA TV a few minutes ago I heard something that really got my attention.
All of us space geeks on this list probably know that during a shuttle launch the SMEs light first and then there is a few seconds delay before they light the SRBs.
What I did not know is that after they light the SMEs but BEFORE they light the SRBs the explosive bolts that hold the whole shuttle stack in place on the ground are detonated.
Made me wonder what would happen if the SRBs did not light. The guy conducting the briefing must have guessed people were wondering that as he quickly noted they are very confident the SRBs will light.
Patrick
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diveboss@xmission.com wrote:
Don't worry Patrick, you're talking about a 4 sensor, daylight launch only, space agency. There are probably backup bolts somewhere.
Talk about redundancy... Watching an interview on NASA TV this evening I learned that the four H2 sensors are themselves part of a backup system that will only be used if something else goes wrong after launch that requires a non-standard climb to orbit. So if there's a normal climb out none of the 4 H2 sensors will ever be used. One has to wonder if maybe one can put too much redundancy in a system. Patrick
participants (3)
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diveboss＠xmission.com -
Joe Bauman -
Patrick Wiggins