1、Lessons Learned Entry: 1119Lesson Info:a71 Lesson Number: 1119a71 Lesson Date: 1999-02-01a71 Submitting Organization: HQa71 Submitted by: David M. LengyelSubject: International Space Station (ISS) Program/Extravehicular Activity (EVA)/EMU-Orlan Suit Description of Driving Event: Extravehicular Mobil
2、ity Unit (EMU) and Orlan Suit CriterionLesson(s) Learned: EVA ground rule 4.3.2.12, “No Simultaneous EMU/Orlan ISS Extravehicular Activity,“ is constraining and reduces flexibility.Recommendation(s): NASA should reexamine this ground rule and consider a criterion for selecting either an EMU or the O
3、rlan suit for a particular EVA based on the specific requirements of the EVA or the specific crewmembers performing the EVA.Evidence of Recurrence Control Effectiveness: NASA concurs with the intent of ASAP recommendation. Current mission planning requires one-fault tolerance for both EVA hardware a
4、nd personnel. Additionally, all EVA crewmembers (a minimum of three will be onboard the vehicle) will be trained to operate in both the U.S. EMU and Russian Orlan. Therefore, for example, a crewmember planning to perform an EVA in the EMU would have the following fault tolerance capability: 1) prima
5、ry EMU; 2) backup EMU; then 3) Orlan. Fault tolerance alone precludes the need to plan for a simultaneous EMU/Orlan EVA; however, the primary rationale for not planning for this is the safety risks associated with two different suit procedures/parameters during a single EVA.Primary spacesuit monitor
6、ing responsibility will reside with the country responsible for the Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-development of the hardware (i.e., Russians will have primary responsibility for the Orlan and Americans for the EMU).Therefore, if bo
7、th the Orlan and EMU were in use during a single EVA, a shared responsibility for monitoring spacesuit performance exists. If an emergency occurs, there are increased safety risks that result from the shared responsibilities. Based on the increased safety risks and given the fault tolerance capabili
8、ty defined above, NASA does not believe it is prudent to plan for the option to use both the EMU and Orlan simultaneously.Documents Related to Lesson: N/AMission Directorate(s): a71 Space Operationsa71 Exploration SystemsAdditional Key Phrase(s): a71 Aerospace Safety Advisory Panela71 Extra-Vehicula
9、r Activitya71 Flight Equipmenta71 Policy & Planninga71 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-,-,-
