1、Lessons Learned Entry: 0877Lesson Info:a71 Lesson Number: 0877a71 Lesson Date: 2000-03-06a71 Submitting Organization: JSCa71 Submitted by: Larry GreggSubject: Testing of Environmental Conditions to Be Experienced During Operations Description of Driving Event: On May 28, 1993, a NASA astronaut suffe
2、red frostbite on eight fingers during manned thermal-vacuum (MTV) testing in Chamber B, Building 32, at JSC. This test was the second portion of a two-part test designed to evaluate the extravehicular activity (EVA) hand tool functionality and flight crew operations for the Hubble Space Telescope Fi
3、rst Servicing Mission. The actual test lasted 6 hours in the thermal-vacuum chamber with the suited astronaut repeatedly operating a large number of hand tools and hardware at temperatures as low as 140F. At the conclusion of the test, upon removal of his extravehicular mobility unit (EMU) gloves, t
4、he astronaut noted to the test director that his hands appeared frostbitten.During this test, the astronaut had reported that his hands were cold and that he was experiencing pain. This report was not made in a way that indicated any concern or alarm, and it went undetected by the test team. Astrona
5、uts routinely note experiencing cold during MTV and some hand pain is also a normally experienced due to the effort required to function in the pressurized suit gloves. The astronaut never again indicated during the run that he was experiencing pain or cold in his hands. As the test continued, the a
6、stronaut operated virtually all of the flight tools, most of them repeatedly. Temperature of the tools and other items was consistently measured via thermocouples at between -113F and -131F. Furthermore, these tools required hand however, they concentrated on hardware malfunctions and did not thorou
7、ghly assess hazards associated with the unique human factors in this test run, nor adequately consider operational hazards. The EMU-specific hazard analysis also did not adequately address hazards associated with exposure to extreme cold. It was Provided by IHSNot for ResaleNo reproduction or networ
8、king permitted without license from IHS-,-,-also noted during the investigation that certain of the tools did not operate properly, or had not undergone any type of thermal of vacuum testing prior to the MTV tests. Additionally, the thermal effects of these tools on the astronauts hands were not a d
9、esign consideration. Nothing had been done to reduce thermal conductivity of the hand tools, and most had bare metal surfaces. There was also a lack of specific test data on thermal effects within the EMU gloves. Tests had been done on maximum allowable temperatures for short/light exposure, and on
10、warmer temperatures for longer exposures; but it is difficult to extrapolate from these to actual temperatures, grasp pressures, length (of time) of grasp and cumulative effects. These factors are also affected by a number of variables in EMU sizing and individual astronaut options.Lesson(s) Learned
11、: Testing of operational hardware must simulate actual hardware environmental operating conditions as closely as possible.Recommendation(s): Specific testing of environmental conditions (emulating as closely as possible those which are to be to be experienced during actual testing and/or operations)
12、 should be undertaken and the results factored into design and operations analysis prior to any test or operation.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): a71 Exploration Systemsa71 Sciencea71 Space Operationsa71 Aeronautics ResearchAdd
13、itional Key Phrase(s): a71 Configuration Managementa71 Emergency Preparednessa71 Flight OperationsProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-a71 Ground Operationsa71 Industrial Operationsa71 Payloadsa71 Personal Protective Equipmenta71 Policy &
14、Planninga71 Range Operationsa71 Research & Developmenta71 Risk Management/Assessmenta71 Safety & Mission Assurancea71 Spacecrafta71 Test Articlea71 Test Facilitya71 Test & VerificationAdditional Info: Approval Info: a71 Approval Date: 2000-04-11a71 Approval Name: Eric Raynora71 Approval Organization: QSa71 Approval Phone Number: 202-358-4738Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
