REG NASA-LLIS-0906-2000 Lessons Learned AMSU-B EMI EMC System Level Testing.pdf

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1、Lessons Learned Entry: 0906Lesson Info:a71 Lesson Number: 0906a71 Lesson Date: 2000-01-01a71 Submitting Organization: GSFCa71 Submitted by: Donald CrosbySubject: AMSU-B EMI/EMC System Level Testing Description of Driving Event: After the launch of the NOAA-15 spacecraft, an EMI/EMC interference affe

2、cting science data was noted in the Advanced Microwave Sounding Unit (AMSU)-B data. This interference was subsequently attributed to the SAR and S band transmitters and was due to inadequate AMSU-B shielding. The problem was aggravated by a malfunction in the spacecraft antenna. Fortunately, the AMS

3、U-B data was recoverable on the ground through additional data manipulation and processing.Lesson(s) Learned: 1. The key lesson here is not a new one. Ground testing should be done in the same configuration in which you will fly. The normal on-orbit operating mode for AMSU-B is scanning. However, du

4、ring much of the spacecraft level EMI/EMC testing on the NOAA-K spacecraft, the AMSU-B instrument was tested in a non-scanning mode due to a ground test, antenna bearing operating time restriction. Even though there were restrictions on the ground operating time of the instrument in the scan mode, m

5、ore time could have been allocated for EMI/EMC system level testing. It is important to test all flight hardware in as near flight conditions as possible to avoid on-orbit surprises.2. The second lesson here is to carefully and thoroughly review all of your test data. In reviewing the spacecraft lev

6、el EMI/EMC data again after the flight anomaly was noted, it was discovered that during the times the instrument was scanning, interference was visible in the data. The instrument was also tested by itself before delivery to the spacecraft and interference should have been detected there also.3. The

7、 third lesson is that in the design of space flight hardware, care must be taken to assure that whenever possible, hardware can be adequately tested on the ground before launch. In the case of AMSU-B, the manufacturer of the instrument was concerned that bearing lubricant would degrade through oxida

8、tion while operating at ambient pressure. They therefore Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-imposed a ground test operating time limit on the instrument. Other lubricants and/or designs were available that would have eliminated this cons

9、traint.Recommendation(s): See Lessons Learned.Evidence of Recurrence Control Effectiveness: Fortunately, the AMSU-B NOAA-K data was correctable, through ground data processing, down to the normal noise level limitation. The FM 2 and FM 3 units, which were still on the ground, were physically modifie

10、d to include more shielding for radiated emissions. Subsequently, they were retested for radiation susceptibility and demonstrated performance nearly at the noise limit. Any remaining noise effects will be correctable through ground processing.Documents Related to Lesson: N/AMission Directorate(s):

11、a71 Exploration Systemsa71 Sciencea71 Space Operationsa71 Aeronautics ResearchAdditional Key Phrase(s): a71 Hardwarea71 Test & VerificationAdditional Info: Approval Info: a71 Approval Date: 2000-09-18a71 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-,-,-