1、Lessons Learned Entry: 1402Lesson Info:a71 Lesson Number: 1402a71 Lesson Date: 2004-05-10a71 Submitting Organization: GSFCa71 Submitted by: David LeckroneSubject: NASA Engineering and Safety Center Consultation on Mars Exploration Rover Entry, Descent and Landing Abstract: Engineering sensors includ
2、ed on board the Spirit and Opportunity Mars Exploration Rovers were inadequate to allow an unambiguous physical reconstruction of vehicle performance during the critical entry, descent and landing phase. Suitable sensors to measure pressure, temperature and/or other key variables of the local enviro
3、nment, should be included on future landed missions.Description of Driving Event: Mars Exploration Rover Spirit successfully landed on January 4, 2004. Prior to the scheduled landing of the twin Rover, Opportunity, on January 25, an Entry, Descent and Landing (EDL) team at JPL carried out a reconstr
4、uction of the EDL performance of Spirit in order to determine if any “lessons learned“ could be used to modify the planned EDL sequence for Opportunity in order to improve its chances for a successful landing on Mars. An independent EDL “Red Team“ oversaw and assessed the work of the MER Project Rec
5、onstruction Team, to assure that the reconstruction was the best that could be done. The NASA Engineering and Safety Center (NESC) sent two EDL experts as independent participants on the “Red Team“. Both Spirit and Opportunity deviated from their expected trajectory profiles/timelines. An important
6、conclusion drawn by the “Red Team“ and strongly endorsed by the NESC experts states, “Relative to atmospheric reconstruction, it is suggested that the Project was remiss in not flying pressure and temperature sensors for use during terminal descent and on the ground. Such sensors, with a likely mass
7、 of hundreds of grams, would have allowed separation of the density and drag coefficient error sources, something for which the Reconstruction Team could only speculate. It is suggested that these sensors be added to the EDL reconstruction requirements of future landed systems.“Lesson(s) Learned: Pr
8、ovided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Future planetary missions should include instrumentation to assess entry performance and adequately characterize the environment encountered during entry, descent, and landing.Recommendation(s): The engin
9、eering instrumentation of future landed planetary missions should include sensors to adequately monitor the local environment during terminal descent and on the ground, to allow accurate reconstruction of the physical factors pertinent to vehicle EDL performance. This rule should be administered and
10、 enforced by the appropriate safety and mission assurance and science program authorities at NASA Headquarters and at the relevent field centers. Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): a71 ScienceAdditional Key Phrase(s): a71 Flight O
11、perationsa71 Hardwarea71 Program and Project Managementa71 Risk Management/Assessmenta71 Safety & Mission Assurancea71 SpacecraftAdditional Info: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Approval Info: a71 Approval Date: 2004-05-20a71 Approval Name: Al Galloa71 Approval Organization: GSFCa71 Approval Phone Number: 301-286-3756Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
