meetings - Space Flight Mechanics Committee

Feb 13, 2013 Kauai Salon 3
SESSION 23: SMALL-BODY MISSIONS
Chair: Dr. Ryan Park, Jet Propulsion Laboratory
13:30 AAS Classification of Distant Earth-Return Trajectories for Near-Earth Asteroid
13-408 Mission Applications
Nicholas Bradley, The University of Texas at Austin; Cesar Ocampo, The University
of Texas at Austin
A classification is presented that categorizes free-return trajectories in the Earth-Sun
rotating frame that begin and end near the Earth with no intermediate velocity adjustments.
Candidate trajectories and trajectory families are searched to determine possible orbits to
rendezvous with near-Earth asteroids. Determination of trajectory families is accomplished
via a numerical search technique, which uses a constrained zero-cost optimization
algorithm. Hundreds of candidate trajectories are found, satisfying constraints at Earth and
escape energy conditions. The trajectories are classified as periodic and non-periodic, and
further subdivided as Earth-leading, Earth-trailing, in-plane, and out-of-plane.
13:50 AAS Trajectories to Nab a NEA (Near-Earth Asteroid)
13-409 Damon Landau, NASA / Caltech JPL; John Dankanich, AeroDank, Inc.; Nathan
Strange, NASA / Caltech JPL; Julie Bellerose, Carnegie Mellon University SV /
NASA ARC; Pedro Llanos, University of Southern California; Marco Tantardini,
The Planetary Society
In 2010 and 2011 NASA and KISS sponsored studies to investigate the feasibility of
identifying, capturing, and returning an entire (albeit small) NEA to the vicinity of Earth,
and concluded that a 40kW solar electric propulsion system launched on an Atlas551
provided sufficient propulsion to control an asteroids trajectory. Once secured by the
spacecraft, a NEA with a naturally close encounter with Earth is nudged over a few years to
target a lunar gravity assist, capturing the object into Earth orbit. With further use of solar
perturbations, up to 3,600,000kg of NEA could enter in high-lunar orbit.
14:10 AAS Design, Dynamics and Stability of the OSIRIS-REx Sun-Terminator Orbits
13-411 Daniel Scheeres, University of Colorado; Brian Sutter, Lockheed-Martin
OSIRIS-REx is a NASA asteroid sample return mission that launches in 2016 and visits
asteroid 1999 RQ36. To support its main goal of surface sampling, the spacecraft must orbit
in close proximity to the asteroid to estimate accurate models of the asteroid’s shape,
gravity field and spin state. To do this it is essential that the spacecraft reside in an orbit that
is relatively close to the asteroid and which is stable enough to not require trajectory control
maneuvers for periods up to a few weeks. This paper with discuss the dynamics, design and
implementation of these orbits.
14:30 AAS Electric Propulsion Alternatives for the OSIRIS-REx Mission
13-412 Kamesh Sankaran, Whitworth University; Christopher Grochowski, Whitworth
23 rd AAS / AIAA Space Flight Mechanics Meeting Page 85