1、Lessons Learned Entry: 0380Lesson Info:a71 Lesson Number: 0380a71 Lesson Date: 1995-02-01a71 Submitting Organization: JPLa71 Submitted by: B. LarmanSubject: Inadequate Knowledge of Spacecraft Tape Recorder Tape Position Abstract: For Voyager and Viking, tape position error accumulation on the onboar
2、d spacecraft tape recorder required arduous workarounds to reset the position indicator. Specifically, up/down counters should be used in all bidirectional divide by stages whenever accurate position information is needed.Description of Driving Event: The Viking and Voyager onboard tape recorders co
3、ntain a mechanism to provide knowledge, via downlink telemetry, of the position of the tape. The project can also command the tape to a desired position by uplink telemetry. The design is such that an intolerable amount of error accumulates during normal use requiring an arduous workaround involving
4、 periodic interruption in use to reset the position indicator at a known tape position (i.e. beginning of tape).Additional Keyword(s): Positioning DevicesLesson(s) Learned: Tape position error accumulation on an onboard spacecraft tape recorder can require arduous workarounds to reset the position i
5、ndicator.Recommendation(s): The capability to both observe and control movable elements to an appropriate precision (e.g. tape position, platform position, boom position, etc.) Without the possibility of significant error buildup through normal use should be incorporated into the basic spacecraft sy
6、stem design. Specifically, up/down counters should be used in all bidirectional divide by stages whenever accurate position Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-information is needed.Evidence of Recurrence Control Effectiveness: N/ADocumen
7、ts Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 SpacecraftAdditional Info: Approval Info: a71 Approval Date: 1985-12-18a71 Approval Name: Carol Dumaina71 Approval Organization: 125-204a71 Approval Phone Number: 818-354-8242Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
