1、Lessons Learned Entry: 1118Lesson Info:a71 Lesson Number: 1118a71 Lesson Date: 1999-02-01a71 Submitting Organization: HQa71 Submitted by: David M. LengyelSubject: International Space Station (ISS) Program/Extravehicular Activity (EVA)/Radiation Exposure Description of Driving Event: Increasing Extra
2、vehicular Mobility Unit (EMU) Shielding to Reduce Crew Radiation ExposureLesson(s) Learned: The greatest potential for overexposure of the crew to ionizing radiation exists during EVA operations. Furthermore, the magnitude of any overexposure cannot be predicted using current models.Recommendation(s
3、): NASA should determine the most effective method of increasing EMU shielding without adversely affecting operability and then implement that shielding for the EMUs.Evidence of Recurrence Control Effectiveness: NASA concurs with the ASAP recommendation. Efforts are in work to both minimize radiatio
4、n exposure and to obtain data relative to increased EMU shielding. Efforts to minimize EVA doses include coordination to minimize the South Atlantic anomaly passes between the Space Radiation Analysis Group, Medical Operations, EVA Office, and Flight Director. Monitoring of EVA doses on ISS will inc
5、lude the use of crew dosimeters and the external vehicle charge particle detector systems (EVCPDS). Developing active dosimeters to be worn inside the EMU that would augment the EVCPDS as a warning system and improve the monitoring of crew doses is being considered.A proposal to deploy an external t
6、issue equivalent proportional counter prior to EVCPDS deployment on ISS Increment 8A that would provide improved EVA dose enhancement warning Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-capability is being developed. JSC in collaboration with the
7、 Lawrence Berkeley National Laboratory is assessing ways to measure the shielding capacity of the EMU and the Russian Orlan suit using proton and electron exposure facilities at Loma Linda University. These measurements would support a study of the effectiveness of increasing EMU shielding. In addit
8、ion, the development of an electron belt enhancement model and improved solar particle event forecasting and Earth geomagnetic field models that would provide large improvements in predictive capabilities for the occurrence of enhanced EVA doses is being considered.Documents Related to Lesson: N/AMi
9、ssion Directorate(s): a71 Exploration Systemsa71 Space Operationsa71 Aeronautics ResearchAdditional Key Phrase(s): a71 Aerospace Safety Advisory Panela71 Extra-Vehicular Activitya71 Flight Equipmenta71 Hazardous/Toxic Waste/Materialsa71 Medicala71 Research & Developmenta71 Safety & Mission AssuranceAdditional Info: Approval Info: a71 Approval Date: 2002-02-12a71 Approval Name: Bill Loewya71 Approval Organization: HQa71 Approval Phone Number: 202-358-0528Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
