Venus Aerocapture Assessment
Ye Lu ([email protected]), Athul P. G., Sarag J. Saikia, and James Cutts
Sincere gratitude to VEXAG for generous travel support!
15th Venus Exploration Assessment Group (VEXAG) Meeting NASA Reports, Mission and Technology Studies Applied Physics Laboratory, Laurel, Maryland.
November 14-16, 2017 What is Aerocapture? • Orbit insertion maneuver that uses aerodynamic drag to decelerate and get into orbit
1 Control authority - Corridor Width • Uncertainties in – Guidance and navigation – Atmosphere knowledge – Density & wind – Aerodynamic properties • Control is required – Aerodynamic lift – Example: MSL
• Corridor Width – A measure of the control authority
2 Venus Aerocapture Studies
• 2005 Parametric Study of Venus Aerocapture [Craig & Lyne]
– Considered interplanetary arrival V∞ from 4-10 km/s • 2006 NASA aerocapture studies on Venus
– Based on a single interplanetary trajectory, i.e., V∞ = 2.88km/s – Provided reference design for aerocapture vehicle
• This study – a framework to assess aerocapture – Vehicle ballistic coefficients – Vehicle Lift-to-Drag (L/D) ratio – V-infinity from interplanetary trajectory
3 Framework
Interplanetary Trajectory Arrival Velocity Control Authority
V¥
Aerodynamic Vehicle Design Heating Ballistic Coefficients
b = mCA( D ) Peak Deceleration Lift-to-Drag Ratio L/D
4 Thermal Protection System (TPS)
Peak heat rate Total Heat Load Stagnation Pressure
TPS Mass Fraction TPS material TPS%= 0.091´ Heat Load0.51575
Peak heat rate Material Manufacturability W/cm2 PICA >1400 Yes HEEET ~7,000 [Tested] Yes Reduced Carbon ~25,000 ??? Phenolic
5 Parameter Space
Parameters Range
Arrival V∞ 0 – 30 km/s b = mCA( D ) Rigid aeroshell Lift-to-Drag Ratio, L/D 0 – 0.4 Viking: ~60 kg/m2 MSL: 140 kg/m2 Ballistic Coefficients, β 50 and 500 kg/m2 Apollo: 50-500 kg/m2 Entry altitude 180 km
Target orbit Circular of 400 km
6 Feasibility - β=50 kg/m2 Feasible Region
PICA Limit
25% TPS mass
50g Limit
1 deg corridor Width
Infeasible due to insufficient control authority
Propulsive Limit ΔV=3.5 km/s 10 11 14 18 22 27 32 Entry Velocity at 180 km, km/s 7 Feasibility - β=50 kg/m2 Feasible Region
PICA Limit
25% TPS mass
50g Limit
Cassini Galileo & MESSENGER 10 11 14 18 22 27 32 Entry Velocity at 180 km, km/s 8 Feasibility - β=50 kg/m2 Feasible Region Reduced CP 50% TPS mass
100g Limit
1 deg corridor Width
insufficient control authority
10 11 14 18 22 27 32 Entry Velocity at 180 km, km/s 9 Feasibility - β=500 kg/m2 Feasible Region
Reduced CP
50% TPS mass
50g Limit 1 deg corridor Width
insufficient control authority
10 11 14 18 22 27 32 Entry Velocity at 180 km, km/s 10 Aerocapture Vehicle Design ADEPT MSL
0.24
Apollo >0.20
Viking I & II (1976)
>0.30 0.18 Low L/D 0 0.2 0.4 0.6 Lift-to-Drag Ratio, L/D
Source: Lockwood et al.(2006), Edquist et al.(2007), and Ethiraj et.al 11 Conclusion • For ride-along small satellite options, or secondary payload, aerocapture is not an enhancing technology, it is indeed an enabling technology as it allows for arrival velocities at which propulsive orbit insertion is not a viable option • This work allows for a faster decision turn-around for determining feasibility of SIMPLEx missions - decision is turned to mission designer (interplanetary trajectory)
12 Reference
Lockwood, M. K., Edquist, K. T., Starr, B. R., Hollis, B. R., Hrinda, G. A., Bailey, R. W., Hall, J. L., Spilker, T. R., Noca, M. A., Kongo, N. O., Haw, R. J., Justus, C. G., Duvall, A. L., Keller, V. W., Sutton, K., and Dyke, R. E., “Aerocapture Systems Analysis for a Neptune Mission,” Tech. Rep. NASA/TM-2006-214300, 2006. Cerimele, C. J., Robertson, E. A., Sostaric, R. R., Campbell, C. H., Robinson, P., Matz, D. A., Johnson, B. J., Stachowiak, S. J., Garcia, J. A., Bowles, J. V., Kinney, D. J., and Theisinger, J. E., “A Rigid Mid Lift-to-Drag Ratio Approach to Human Mars Entry, Descent, and Landing,” AIAA Guidance, Navigation, and Control Conference, Grapevine, Texas: AIAA2017-1898, 2017. Edquist, K. T., Hollis, B. R., Dyakonov, A. A., Laub, B., Wright, M. J., Rivellini, T. P., Slimko, E. M., and Willcockson, W. H., “Mars science laboratory entry capsule aerothermodynamics and thermal protection system,” IEEE Aerospace Conference Proceedings, 2007. Venkatapathy, E., Hamm, K., Fernandez, I., Arnold, J., Kinney, D., Laub, B., Makino, A., McGuire, M., Peterson, K., Prabhu, D., Empey, D., Dupzyk, I., Huynh, L., Hajela, P., Gage, P., Howard, A., and Andrews, D., “Adaptive Deployable Entry and Placement Technology (ADEPT): A Feasibility Study for Human Missions to Mars,” 21st AIAA Aerodynamic Decelerator Systems Technology Conference and Seminar, Dublin, Ireland: AIAA 2011-2608, , pp. 1–22. Craig, S., and Lyne, J. E., “Parametric Study of Aerocapture for Missions to Venus,” Journal of Spacecraft and Rockets, vol. 42, 2005, pp. 1035–1038. Sutton, K., and Graves, R. a., A General Stagnation-Point Convective-Heating Equation for Arbitrary Gas Mixtures, NASA-TR-R- 376, November, 1971. Page, W. A., and Woodward, H. T., “Radiative and Convective Heating During Venus Entry,” AIAA Journal, Vol. 10, No. 10, 1972, pp. 1379–1381. Kolawa, E., Balint, T., Birur, G., Bolotin, G., Brandon, E., Castillo, L. Del, Garrett, H., Hall, J., Johnson, M., Jones, J., Jun, I., Manvi, R., Mojarradi, M., Mossessian, A., Patel, J., Pauken, M., Peterson, C., Surampudi, R., Schone, H., Whitacre, J., Martinez, E., Venkapath, R., Laud, B., and Neudeck, P., Extreme Environments Technologies for Future Space Science Missions, 2007.
13 Thanks for your attention!
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