Assessment of hypersonic separation dynamics for drag modulation systems at mars

Michelle N. McClary, Zachary R. Putnam

Research output: Chapter in Book/Report/Conference proceedingConference contribution


This paper presents an analysis of the hypersonic separation dynamics for a planetary entry vehicle and a deployable drag area that is jettisoned during planetary entry. The first portion of the paper identifies separation times for a range of vehicle parameters and flight conditions which includes vehicle size, drag area size, and jettison velocity. For a given entry trajectory, minimum separation time corresponds to a jettison event at maximum dynamic pressure. Results show that vehicles with a larger initial ballistic coefficients require less time to achieve a separation distance of one drag area aft radius, in addition to a smaller range of possible separation times. Analysis is performed in the second portion of this paper to determine if recontact occurs between the two bodies after jettison. Results indicate recontact is most likely to occur at jettison conditions with low dynamic pressures, large angles of attack, and angle of attack rates, and with small differences in ballistic coefficient between the entry vehicle and drag area. Sensitivity analysis is performed to determine which conditions are most important to the success of the jettison event. Results show that the difference in ballistic coefficient between entry vehicle and drag area is the most influential parameter in determining the recontact-free jettison envelope. This envelope can be manipulated through moving the drag area center of gravity off of the axis of symmetry. Overall, results indicate a successful jettison, with no recontact, is possible and likely for typical blunt body spherecone entry trajectories and attitude dynamics. The chance of recontact can be minimized by jettisoning the drag area closer to maximum dynamic pressure.

Original languageEnglish (US)
Title of host publicationAIAA Scitech 2021 Forum
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
Number of pages26
ISBN (Print)9781624106095
StatePublished - 2021
EventAIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2021 - Virtual, Online
Duration: Jan 11 2021Jan 15 2021

Publication series

NameAIAA Scitech 2021 Forum


ConferenceAIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2021
CityVirtual, Online

ASJC Scopus subject areas

  • Aerospace Engineering


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