Preliminary Design of Multiple Gravity-Assist Trajectories
M. Vasile, P. De Pascale
2006
Journal of Spacecraft and Rockets
2006) Preliminary design of multiple gravity-assist trajectories. Journal of Spacecraft and Rockets, 43 (4). pp. 794-805. ISSN 0022-4650 Strathprints is designed to allow users to access the research output of the University of Strathclyde. AIAA Member. ϕ Dq = subdomain fitness ψ Dq = subdomain qualification index ω Dq = subdomain density I. Introduction HE access to high ∆v targets in the Solar System has been made possible by the enabling concept of gravity assist, 1,2 through which many
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... ons with challenging objectives were successfully accomplished with significant reductions in launch energy and in transfer time. Past missions, like Mariner 3 10, Voyager 4 1 and 2, Pioneer 10 and 11 and more recent missions like Galileo, 5 Ulysses and Cassini 6 made extensively use of gravity-assist maneuvers; future missions to completely or partially unexplored planets, such as Mercury 7,8 or Pluto, 9,10 will be possible thanks to gravity-assist maneuvers. The availability of new propulsion systems, such as low-thrust engines, while widening the possibility of flights in the Solar System, has not diminished the importance of gravity-assist maneuvers. This is true at least for two different reasons: many missions will still resort to pure ballistic trajectories using only impulsive corrections; optimal gravity-assist sequences are important in the design of low-thrust gravity-assist trajectories 7 . Multiple gravity-assist trajectories have been extensively investigated over the last forty years, and their preliminary design has been approached mainly relying on the experience of mission analysts and following simplifying assumptions in unison with systematic searches or some simple analysis tools such as the Tisserand's graph. 1,10 This graphical tool, however, turns out to be unsuitable for the investigation of transfers to asteroids and comets with highly eccentric or inclined orbits, and for the analysis of transfer options that require additional corrective maneuvers, performed by either high-thrust or low-thrust engines. On the other hand, since at the early stage of the design of a space mission a number of different options is generally required, it would be desirable to automatically generate many optimal or nearly optimal solutions over the range of the design parameters (escape velocity, launch date, time of flight, etc...), accurately enough to allow a correct trade-off analysis. This could translate into the need for an exhaustive characterization of highly complex solution domains deriving from sophisticated trajectory models. Recently, different attempts have been carried out toward the definition of automatic design tools, although so far most of these tools have been based on systematic search engines. An example is represented by the automatic T tool for the investigation of multiple gravity-assist transfers, called STOUR, originally developed by JPL 5 and subsequently enhanced by Longuski et al. at Purdue university. 11, 12, 13, 14 This tool has been extensively used for the preliminary investigation of interplanetary trajectories to Jupiter and Pluto, 11,12 for the design of the tour of Jovian moons 15 and for Earth-Mars cycling trajectories. 16 It should be noted that such a systematic search methodology although theoretically complete, could require long computational times, in order to identify all the suitable options. Although completeness is a desirable property of
doi:10.2514/1.17413
fatcat:f6ujog4svva7zg2dfy7zv3wkoi