1、Lessons Learned Entry: 0205Lesson Info:a71 Lesson Number: 0205a71 Lesson Date: 1992-11-12a71 Submitting Organization: KSCa71 Submitted by: Lisa L. MusgraveSubject: Hardware Interface Module (HIM) Description of Driving Event: The External Tank (ET) hardware incorporates five categories of instrument
2、ation, sensors, and associated cabling, where the instrumentation data is recorded in the orbiter for transmittal to ground stations. The electrical system provides the propellant level, among other functions. The instrumentation is comprised of 38 sensors which control ullage temperature and pressu
3、re, liquid level, LH2 depletion, and vent valve position. During pre-launch propellant loading of the STS 51-L mission, a HIM failure caused a two hour, 20 minute delay while repairs were made. A HIM is used to interface the ET sensors with the launch control computer systems, where it is analyzed b
4、y systems engineers. The HIM failure resulted in the loss of all fire detection and hazardous gas measurements, which are required during propellant loading to provide adequate visibility of propellant leaks and fire.Lesson(s) Learned: The failure of a HIM during propellant loading caused a launch d
5、elay, resulting in the loss of all fire detection and hazardous gas measurements.Recommendation(s): Provide a back-up system or module to: (a) preclude the inability to monitor measurements taken during loading and (b) prevent propellant loading delays.Evidence of Recurrence Control Effectiveness: N
6、/AProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Documents Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Energetic Materials - Explosive/Propellant/Pyrotechnica71 Fire Protectiona71 Hazardous/Toxic Waste/MaterialsAdditional Info: Approval Info: a71 Approval Date: 1994-06-08a71 Approval Name: James G. Klinea71 Approval Organization: KSC/HEIa71 Approval Phone Number: 407-867-7614Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
