A low-thrust two-burn orbit transfer from Earth to Mars with a swingby of Venus. Thrust direction was chosen to maximize the payload at Mars arrival, with gravitational perturbations from the planetary bodies. SOCS created the resulting sparse nonlinear programming problem after five mesh refinement iterations involved 9206 variables, with 8666 constraints and was computed in less than 1400 seconds on a Sun Sparc20. Details of the problem are described in the paper, "Optimal Interplanetary Orbit Transfers by Direct Transcription," John T. Betts, The Journal of the Astronautical Sciences, Vol. 42, No. 3, July-September 1994, pp 247-268.