Illustrative NASA Low Earth Orbit spacecraft subsystems design-for-demise trade-offs, analyses and limitations

Abstract

An uncontrolled re-entry mission that completely ablates would comply with stipulated NASA Earth atmosphere re-entry requirements without requiring an integrated provision for controlled re-entry. Consequently, such a mission design implies a relatively simpler and cheaper option. Moreover, mission unavailability risk due to a controlled re-entry subsystem failure is essentially eliminated, which would improve mission on-orbit reliability and robustness. We propose a generic critical parts identification plan that is followed by methods of designing spacecraft parts for demise. To demonstrate the exhaustive analyses and design of spacecraft parts for demise, we consider representative parts from the propulsion and power subsystems – propellant tank and batteries respectively. On-orbit performance and practical design threshold considered provide intuition into the design-for-demise limitations of investigated parts. Further, the tank proposed here is not only demisable, but is also seen to exhibit superior on-orbit performance compared to a similar monolithic titanium tank.