1、Lessons Learned Entry: 0876Lesson Info:a71 Lesson Number: 0876a71 Lesson Date: 2000-03-06a71 Submitting Organization: JSCa71 Submitted by: Larry GreggSubject: Recognition and Communication of Hazards During Operational Testing Description of Driving Event: On May 28, 1993, a NASA astronaut suffered
2、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 First
3、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, the a
4、stronaut 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. Astronauts
5、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 astro
6、naut 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 thoroughly
7、 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 networking
8、 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 desig
9、n 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 warm
10、er 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: Lo
11、w hazard awareness by test team members, test subjects, and those performing hazard analyses can result in injury, especially where equipment is perceived to be “safe“.Recommendation(s): Those performing hazardous test operations should be specifically trained to recognize, report, and properly resp
12、ond to all credible hazard situations. They should be sensitized to the possibility of these circumstances and remain alert to early symptoms. Specific terms for describing symptoms should be clearly defined before the test, and proper reactions developed and, where necessary, practiced. Those perfo
13、rming hazard analysis should be similarly trained on the possibility of all credible hazards, and should ensure designs consider appropriate mitigation.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): a71 Exploration Systemsa71 Space Operations
14、a71 Aeronautics ResearchAdditional Key Phrase(s): a71 Cryogenic SystemsProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-a71 Emergency Preparednessa71 Environmenta71 Extra-Vehicular Activitya71 Flight Equipmenta71 Ground Equipmenta71 Hardwarea71 Hazard
15、ous/Toxic Waste/Materialsa71 Human Factorsa71 Human Resources & Educationa71 Medicala71 Parts Materials & Processesa71 Personal Protective Equipmenta71 Policy & Planninga71 Research & Developmenta71 Safety & Mission Assurancea71 Test Articlea71 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-,-,-
