Title :
Implications of wind-assisted aerial navigation for Titan mission planning and science exploration
Author :
Elfes, A. ; Reh, K. ; Beauchamp, P. ; Fathpour, N. ; Blackmore, L. ; Newman, C. ; Kuwata, Y. ; Wolf, M. ; Assad, C.
Author_Institution :
Jet Propulsion Lab., California Inst. of Technol., Pasadena, CA, USA
Abstract :
The recent Titan Saturn System Mission (TSSM) proposal incorporates a montgolfiere (hot air balloon) as part of its architecture. Standard montgolfiere balloons generate lift through heating of the atmospheric gases inside the envelope, and use a vent valve for altitude control. A Titan aerobot (robotic aerial vehicle) would have to use radioisotope thermoelectric generators (RTGs) for electric power, and the excess heat generated can be used to provide thermal lift for a montgolfiere. A hybrid montgolfiere design could have propellers mounted on the gondola to generate horizontal thrust; in spite of the unfavorable aerodynamic drag caused by the shape of the balloon, a limited amount of lateral controllability could be achieved. In planning an aerial mission at Titan, it is extremely important to assess how the moon-wide wind field can be used to extend the navigation capabilities of an aerobot and thereby enhance the scientific return of the mission. In this paper we explore what guidance, navigation and control capabilities can be achieved by a vehicle that uses the Titan wind field. The control planning approach is based on passive wind field riding. The aerobot would use vertical control to select wind layers that would lead it towards a predefined science target, adding horizontal propulsion if available. The work presented in this paper is based on aerodynamic models that characterize balloon performance at Titan, and on TitanWRF (Weather Research and Forecasting), a model that incorporates heat convection, circulation, radiation, Titan haze properties, Saturn´s tidal forcing, and other planetary phenomena. Our results show that a simple unpropelled montgolfiere without horizontal actuation will be able to reach a broad array of science targets within the constraints of the wind field. The study also indicates that even a small amount of horizontal thrust allows the balloon to reach any area of interest on Titan, and to do so in a fraction of the time needed- - by the unpropelled balloon. The results show that using the Titan wind field allows an aerobot to significantly extend its scientific reach, and that a montgolfiere (unpropelled or propelled) is a highly desirable architecture that can very significantly enhance the scientific return of a future Titan mission.
Keywords :
aerodynamics; aerospace instrumentation; balloons; navigation; planetary satellites; propellers; robots; space research; space vehicles; thermoelectric conversion; Saturn tidal forcing; TSSM proposal; Titan Saturn System Mission; Titan aerobot; Titan haze properties; Titan mission planning; TitanWRF; Weather Research and Forecasting; aerodynamic drag; altitude control; atmospheric gases; circulation; gondola; guidance; heat convection; horizontal thrust; hot air balloon; hybrid montgolfiere design; lateral controllability; montgolfiere balloons; moon-wide wind field; propellers; radiation; radioisotope thermoelectric generators; robotic aerial vehicle; thermal lift; vent valve; wind field riding; wind-assisted aerial navigation; Aerodynamics; Navigation; Power generation; Predictive models; Proposals; Propulsion; Saturn; Vehicles; Weather forecasting; Wind;
Conference_Titel :
Aerospace Conference, 2010 IEEE
Conference_Location :
Big Sky, MT
Print_ISBN :
978-1-4244-3887-7
Electronic_ISBN :
1095-323X
DOI :
10.1109/AERO.2010.5446995