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Atmospheric Entry Studies for Venus Missions: 45 Sphere-Cone Rigid Aeroshells and Ballistic EntriesThe present study considers direct ballistic entries into the atmosphere of Venus using a 45deg sphere-cone rigid aeroshell, a legacy shape that has been used successfully in the past in the Pioneer Venus Multiprobe Mission. For a number of entry mass and heatshield diameter combinations (i.e., various ballistic coefficients) and entry velocities, the trajectory space in terms of entry flight path angles between skip out and -30deg is explored with a 3DoF trajectory code, TRAJ. From these trajectories, the viable entry flight path angle space is determined through the use of mechanical and thermal performance limits on the thermal protection material and science payload; the thermal protection material of choice is entry-grade carbon phenolic, for which a material thermal response model is available. For mechanical performance, a 200 g limit is placed on the peak deceleration load experienced by the science instruments, and 10 bar is assumed as the pressure limit for entry-grade carbon-phenolic material. For thermal performance, inflection points in the total heat load distribution are used as cut off criteria. Analysis of the results shows the existence of a range of critical ballistic coefficients beyond which the steepest possible entries are determined by the pressure limit of the material rather than the deceleration load limit.
Document ID
20130010987
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Prabhu, Dinesh K.
(Engineering Research and Consulting, Inc. Moffett Field, CA, United States)
Spilker, Thomas R.
(Solar System Science and Exploration Monrovia, CA, United States)
Allen, Gary A., Jr.
(Engineering Research and Consulting, Inc. Moffett Field, CA, United States)
Hwang, Helen H.
(NASA Ames Research Center Moffett Field, CA, United States)
Cappuccio, Gelsomina
(NASA Ames Research Center Moffett Field, CA, United States)
Moses, Robert W.
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
August 27, 2013
Publication Date
March 2, 2013
Subject Category
Spacecraft Design, Testing And Performance
Report/Patent Number
ARC-E-DAA-TN7270
Report Number: ARC-E-DAA-TN7270
Meeting Information
Meeting: IEEE Aerospace Conference
Location: Big Sky, MT
Country: United States
Start Date: March 2, 2013
End Date: March 9, 2013
Sponsors: Institute of Electrical and Electronics Engineers
Funding Number(s)
CONTRACT_GRANT: NNA10DE12C
Distribution Limits
Public
Copyright
Public Use Permitted.
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