국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Aspects of Parking Orbit Selection in a Manned Mars Mission
저자	Prasun N. Desai, Robert D. Braun and Richard W. Powell
Keyword	Mars parking orbits; Manned mars mission; Nonspherical gravitational effects
URL	http://techreports.larc.nasa.gov/ltrs/PDF/tp3256.pdf
보고서번호	NASA TP-3256
발행년도	1992
출처	NASA Langley Research Center
ABSTRACT	For any round-trip Mars mission, the selection of a parking orbit at Mars must consider the precession caused by the oblateness of the planet. This precession will affect the departure condition for Earth return and, therefore, the initial mass required in low Earth orbit (LEO). In this investigation, which considers precession effects, minimum initial LEO masses were obtained for parking orbits characterized by having near-equatorial inclinations, high eccentricities, and three-dimensional departure burns (i.e., a burn with an in-plane and an out-of-plane velocity increment component). However, because near-equatorial inclination orbits have poor planetary coverage characteristics, they are not desirable from a science viewpoint. To enhance the potential for satisfying science requirements along with landing site accessibility, a penalty in the initial LEO mass is required. This study shows that there are a set of orbits characterized by low to moderate eccentricities (e=0.2 to 0.5) and nonequatorial inclinations (i=70 degrees to 140 degrees) that reduce this initial LEO mass penalty. Therefore, careful selection of a parking orbit at Mars can enhance the potential for satisfying science requirements with minimal mass penalties.