Design of optimal cyclers using solar sails

Ongoing interest in establishing a base on Mars has spurred a need for regular and repeated visits to the red planet using a cycling shuttle to transport supplies, equipment and to retrieve surface samples. This thesis presents an approach to designing an optimal heliocentric cycling orbit, or cycler, using solar sa ils. Results show that solar sails can be used to significantly reduce s Và at Mars and Earth. For example, using a reasonably high performance solar sail, a VM̲ars Và = 2.5 km/s is possible at every synodic period using a two-dimensional orbit model. Lower performance sails were also modeled resulting in paths that behaved more like a ballistic Aldrin cycler with higher Và s. Double rendezvous missions were explored where the spacecraft must match the velocities of both Earth and Mars, offering promising trajectories for Mars sample return missions. The solutions to these missions, although not necessarily cyclers, show that using a sail to rendezvous with and remain near Mars for an optimal amount of time will minimize the total transit time between Earth and Mars. General -purpose dynamic optimization software, DIDO, is used to solve the optimal control problem using a pseudospectral method using both two - and three-dimensional elliptic orbit models.http://archive.org/details/designofoptimalc109453260Lieutenant Commander, United States NavyApproved for public release; distribution is unlimited