1、Public Lessons Learned Entry: 2298 Lesson Info: Lesson Number: 2298 Lesson Date: 2007-7-20 Submitting Organization: MSFC Submitted by: Jerry Owens Subject: Identification of True Environmental Bounds of Heritage Hardware Abstract: The use of heritage hardware that has been flown previously in simila
2、r or more demanding orbits does not mean that this hardware is necessarily suitable to the mission for which it is being considered. The design of the overall system in which it is to be used is a very important consideration. Description of Driving Event: The filter wheel design used in the X-Ray T
3、elescope (XRT) had been used successfully on previous missions, but other considerations resulted in the part of XRT in which the filter wheel resides being operated in the lower part of its temperature range. After launch of Hinode, it was soon learned that the design had never been used in this te
4、mperature range. Furthermore, the design and construction of the heritage subsystem was that of another company. When problems were experienced on-orbit, there was little, or no, in-house experience and knowledge relating to this design and its vagaries, and the subcontractor was reluctant to share
5、information or spend time assisting in troubleshooting and problem solving. Lesson(s) Learned: Use of heritage hardware requires very careful consideration of its verification program in addition to consideration of the environment in which it was previously flown as compared to the environment it m
6、ay experience in the mission for which it is being considered. Recommendation(s): Be very careful to not only assure that heritage hardware is to be used in a similar or less demanding space environment, but also assure that adequate testing is done to assure operation over the range of environments
7、 that may be encountered including off-nominal environments. Also, be careful not to accept as legitimate heritage hardware any subsystem that has been developed for another mission that has not yet flown. Evidence of Recurrence Control Effectiveness: N/A Documents Related to Lesson: N/A Mission Dir
8、ectorate(s): Science Additional Key Phrase(s): Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Systems Engineering and Analysis.Level II/III requirements definition Systems Engineering and Analysis.Engineering design and project processes and standar
9、ds Missions and Systems Requirements Definition.Requirements critical to costing and cost credibility Missions and Systems Requirements Definition.Level 0/1 Requirements Missions and Systems Requirements Definition.Configuration control and data management Program Management.Risk management Program
10、Management.International partner coordination Program Management.Contractor relationships Program Management.Configuration and data management Program Management.Acquisition / procurement strategy and planning Systems Engineering and Analysis.Mission and systems trade studies Integration and Testing
11、 Manufacturing and Assembly Engineering Design (Phase C/D).Spacecraft and Spacecraft Instruments Systems Engineering and Analysis.Planning of requirements verification processes Additional Info: Project: Hinode/Solar-B Approval Info: Approval Date: 2011-11-30 Approval Name: mbell Approval Organization: HQ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
