Engineering-Oriented Optimization Design of Entry Interface for Manned Lunar Return Mission
- Paper number
IAC-11,A3,2.P,17,x10743
- Author
Dr. Hong-xin Shen, National University of Defense Technology, China
- Coauthor
Dr. Hai-yang Li, National University of Defense Technology, China
- Coauthor
Dr. Qi-bo Peng, National University of Defense Technology, China
- Year
2011
- Abstract
A simple determining algorithm of Earth entry interface (EI) conditions for lunar return mission with landing a preselected location is developed. To achieve the desired landing site, the trans-Earth injection maneuver must place the spacecraft on its final approach to Earth while targeting appropriate EI state (velocity, flight path angle, latitude, longitude or time, and azimuth are included). Prior design implies fixed EI condition, however, the EI state imposed by the desired landing location still has much room to choose for economizing fuel or flight time consumption. This algorithm includes four stages with the objective to meet practical engineering constraints. First, EI altitude is arbitrarily defined to be 400,000ft, entry range and corridor are computed by permitting the trajectory to be safely designed within desired heat rate, heat load and g-load constraints. Second, EI longitude and azimuth are computed with restriction of reentry-tracking condition. Third, EI latitude is determined by limiting on allowable declination of the moon. EI velocity magnitude is determined as a function of flight time and Moon-to-Earth distance. Moreover, to permit landing within a 4-hour period following sunrise, the launch window from the moon described by lunar phase is available. Finally, with application of the relationship of lunar antipode, perigee, entry interface and landing location, the generating procedure of lunar return EI conditions can be implemented by spherical trigonometry. Some examples are presented to substantiate the efficiency of this algorithm, the results indicate that the algorithm ensures the entry constraints are met in addition to optimized fuel and flight time consumption.
- Abstract document
- Manuscript document
(absent)