Ph.D. Thesis Proposal

By

David J. Blette

(Advisor: Prof. Robert D. Braun)

SUPERSONIC DESCENT STAGING AERODYNAMIC

AND PERFORMANCE ANALYSIS

3:00 PM, Friday, January 27, 2017

Weber Space Science and Technology Building

Collaborative Design Environment (CoDE) Auditorium

ABSTRACT:

Entry, Descent, and Landing (EDL) technologies used since the 1960’s Viking missions to Mars have reached their practical limits with the landing of the 1-t Mars Science Laboratory (MSL). Supersonic Retropropulsion (SRP) is one potential enabling technology to extend Mars EDL capability to human-class landed payloads (~20-40 t). To utilize SRP for human Mars missions, it is necessary to perform supersonic descent vehicle staging to transform an entry vehicle from its hypersonic configuration to a configuration that enables the use of SRP. Descent vehicle reconfigurations require the ejection of the vehicle aeroshell as debris during supersonic flight. The ejected debris present risk to catastrophically recontact the primary descent vehicle during and after ejection. The flight dynamics of the ejected debris are exacerbated by supersonic interference aerodynamics between the primary descent vehicle and the ejected debris. The development of strategies to understand and mitigate debris recontact risk during supersonic descent vehicle reconfigurations is paramount to the advancement of the technology readiness level of SRP and therefore to enabling human missions to Mars.

Supersonic descent vehicle staging has not been performed and published research in the field is non-existent. This investigation is the first assessment of supersonic descent staging aerodynamic and performance analysis. An analysis methodology is put forth to enable rapid, high-level assessment of performance metrics for proposed candidate vehicle reconfiguration architectures. Far-field debris flight envelopes are investigated to determine probable bounds on debris scatter. A 3-step, sequential approximation approach is developed to model interference aerodynamics between ejected debris and a primary vehicle. In order to reduce the number of computationally expensive interference aerodynamic data points required during a supersonic descent vehicle reconfiguration analysis, response surface methods are used to model the difference between isolated and interference aerodynamics.

COMMITTEE MEMBERS:

Dr. Robert D. Braun (Advisor)

Dr. Mark F. Costello

Dr. Brian German

Dr. Charles Campbell, NASA Johnson Space Center

Mr. Devin Kipp, Jet Propulsion Laboratory