meetings - Space Flight Mechanics Committee

Feb 13, 2013 Kauai Salon 1
SESSION 21: RENDEZVOUS AND FORMATION FLYING
Chair: Dr. Ossama Abdelkhalik, Michigan Technological University
13:30 AAS Optimal Formation Keeping near a General Keplerian Orbit under Nonlinear
13-389 Perturbations
Kwangwon Lee, Yonsei University; Chandeok Park, Yonsei University; Sang-Young
Park, Yonsei University; Daniel Scheeres, University of Colorado
This study presents a new semi-analytic approach to optimal spacecraft formation keeping
by employing generating functions which appear in the theory of Hamiltonian systems. An
appropriate generating function allows us to assign the costate as an explicit function of its
associated states, and to consider any desired tracking trajectories by simple algebraic
substitutions. This analytic nature is highly favorable, as it is often necessary to analyze
many different boundary conditions and operational time spans for a variety of desired
tracking trajectories. Numerical results demonstrate that the accommodation of higher-order
nonlinearities results in more accurate tracking property.
13:50 AAS Orbit Trajectory Design for the Boeing Commercial Crew Transportation
13-390 System
Tom Mulder, Boeing
Under a Space Act Agreement with NASA, Boeing is developing a transportation system
that delivers crew and cargo to the International Space Station and future Bigelow Space
Complex. The launch vehicle and Boeing spacecraft will be capable of both automated (no
human interaction) and autonomous (no ground assistance) flight from lift-off to docking
and undocking to landing. Orbit and entry trajectory design is derived from techniques
proven on Apollo-Skylab, Space Shuttle, and Orbital Express missions; mixed with new
algorithms Boeing developed internally and for other programs. This paper describes orbit
trajectory design for the CST-100 mission.
14:10 AAS Minimum Time Rendezvous using Differential Drag
13-391 Matthew Harris, The University of Texas at Austin; David Hull, The University of
Texas at Austin; Behcet Acikmese, The University of Texas at Austin
This paper presents a numerical scheme to solve the minimum time rendezvous problem of
two spacecraft using differential drag. In light of the linear time invariant dynamics,
existence and uniqueness of the minimum time control problem is guaranteed. The
nonlinear programming problem is converted to a sequence of linear programming
problems with guaranteed convergence to the global minimum. The linear programs appear
as part of a line search for the final time on a bounded interval. Conservative lower and
upper bounds for the final time are derived, and comparisons with other methods regarding
computation time and flight time are made.
23 rd AAS / AIAA Space Flight Mechanics Meeting Page 79