1、Lessons Learned Entry: 0558Lesson Info:a71 Lesson Number: 0558a71 Lesson Date: 1997-07-17a71 Submitting Organization: JPLa71 Submitted by: C. Guernsey/D. OberhettingerSubject: Migration and Differential Draw Between Multiple Propellant Tanks (1997) Abstract: Use of multiple tanks for a given propell
2、ant can introduce the potential for propellant transfer between tanks and cause unexpected shifts in spacecraft inertial properties and/or reduction of useable propellant. Where a propellant is stored in multiple tanks, design an appropriate set of pyro valves and latch valves to control propellant
3、migration and differential draw.Description of Driving Event: Serious drawbacks have emerged from the propulsion subsystem design on a series of geosyncronous satellites impacting the on-orbit lifespan of a recent mission. The design uses four separate tanks for the hydrazine load, with a separate c
4、heck valve for each tank in the pressurization system. Following each orbit-raising maneuver, and until the final burn, this results in propellant transfer from those tanks with check valves having the highest reseat pressures to the tanks with check valves having the lowest. Since orbit raising on
5、this specific mission was done while spinning, this moved the spacecraft spin axis closer to the fuller tanks, which may have resulted in yet further propellant transfer. Differential heating or cooling of the tanks can add to the propellant migration problem.In addition to changing spacecraft dynam
6、ics, this transfer of mass may limit the spacecrafts on-orbit life because pressurant gas instead of propellant will be drawn from the first tank to be depleted, leading to early engine shutdown.For interplanetary spacecraft with a similar configuration, such as the Mars 98 lander, propellant transf
7、er or differential draw during cruise may cause dynamic imbalance and/or reduction of useable propellant.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Additional Keyword(s): Bipropellant Propulsion SystemsLesson(s) Learned: Use of multiple tanks fo
8、r a given propellant can introduce the potential for propellant transfer between tanks and cause unexpected shifts in spacecraft inertial properties and/or reduction of useable propellant.Recommendation(s): Where a propellant is stored in multiple tanks, design an appropriate set of pyro valves and
9、latch valves to control propellant migration and differential draw.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): N/AAdditional Info: Approval Info: a71 Approval Date: 1997-08-07a71 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-,-,-
