gandalf@pro-electric.cts.com (Ken Hollis) (06/04/91)
Greetings and Salutations: From: sw@cbnewsl.att.com (Stuart Warmink) >> WORK COMPLETED: >> - Installation of plugs instead of temperature transducers in the >> main propulsion system liquid hydrogen main engine inlets. Offi- >> cials determined that these transducers can be eliminated and >> still meet the launch commit criteria and flight rules. An >> analysis is continuing to determine if the liquid oxygen tempera- >> ture transducers can also be eliminated. >This seems kind of strange. Either the sensors are needed or they are not. >If they are not, why scrub the mission when they are faulty? (OK, so this >time they were cracked) If they are needed - presumably to guard against >dangerously high temperatures - then why fly without them? There are redundancies all over the vehicle. These temp ducers were used for data to determine LH2 & LOX temperature during all phases of load & launch. There are temp ducers on both the MPS (Main Propulsion System) & SSME (Space Shuttle Main Engine) side. The temp ducers removed are on the MPS side. The LH2 ducers are basically not used for the LCC (Launch Commit Criteria). The LOX transducers are used to determine the temperature of the LOX during final count (LOX Drainback time) to make sure that the LOX is in a specific temperature range (not too dense, not dense enough), however the temp ducers on the SSME could also be used for this. They also at this time are working on redesigning the temp ducers and are considering putting the LH2 temp ducers back in after the redesign. Ken Hollis Contact Ken Hollis through these paths: ProLine: gandalf@pro-electric ARPA: crash!pro-electric!gandalf@nosc.mil UUCP: crash!pro-electric!gandalf Internet: gandalf@pro-electric.cts.com