1、Lessons Learned Entry: 0377Lesson Info:a71 Lesson Number: 0377a71 Lesson Date: 1995-01-31a71 Submitting Organization: JPLa71 Submitted by: B. Wagoner / J.A. BryantSubject: Performance Decrease due to Propulsion Thruster Plume Impingement on the Voyager Spacecraft Abstract: A 21% shortfall in Voyager
2、s velocity change was suspected to be due to exhaust plume impingement. Due to the complexity of spacecraft/thruster configurations, additional care must be taken in the development and utilization of spacecraft and plume models. Analysis should be conducted on early and final designs.Description of
3、 Driving Event: The initial Voyager Spacecraft Trajectory Correction Maneuver (TCM) delivered approximately 21 percent less velocity change than had been predicted. Since the spacecraft telemetry indicated that pointing accuracy, thruster performance, and spacecraft equipment all were normal, it was
4、 suspected that the degradation was due to exhaust plume impingement effects.Subsequent analysis indicated that pre-flight models underestimated the effects of plume impingement due to over-simplified geometry models and inadequate characterization of rarefied gas dynamics flow fields.Reference(s):
5、PFR #41003.Lesson(s) Learned: Rocket engine plume effects can vary dramatically as a function of thruster type, location, and operating conditions, and interaction of plumes with the spacecraft structure and/or other subsystems can have a substantial impact on spacecraft performance.Provided by IHSN
6、ot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Recommendation(s): 1. Due to the complexity of spacecraft/thruster configurations, additional care must be taken in the development and utilization of spacecraft and plume models.2. Analysis should be conducted on earl
7、y and final designs, as part of the normal design team activity.Evidence of Recurrence Control Effectiveness: JPL has referenced this lesson learned as additional rationale and guidance supporting Paragraph 4.2.2.6 (“Mechanical Configuration/Systems Design: Configuration- Plume Impingement”) in the
8、Jet Propulsion Laboratory standard “Design, Verification/Validation and Operations Principles for Flight Systems (Design Principles),” JPL Document D-17868, Rev. 3, December 11, 2006.Documents Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Flight Equipmenta71 SpacecraftAdditional Info: Approval Info: a71 Approval Date: 1988-09-22a71 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-,-,-
