Hi, my name is Justin Graupman and I am a senior in Aerospace Engineering and will be graduating in May of 2012. My favorite area of study inside the aerospace curriculum has always been atrodynamics. Undergraduate research has not only allowed me study something I love, but has also allowed me gain something I lack going into graduation; professional experience. The ISGC New Base Program through Iowa State’s Asteroid Deflection Research Center has allowed me to acquire valuable experience in information gathering and project planning as well as working in a team research environment. In the future, I hope to carry this experience into a professional aerospace work setting that values the skillset I have gained through this program.
The topic I chose to study for this research cycle is gravity assist trajectories to Near Earth Objects (NEO). By the end of the semester I hope to have a working computer code that simulates a gravity assist trajectory to a NEO. A NEO is any object, such as an asteroid, that has an orbit which brings it within close proximity to Earth. The gravity assist is a maneuver in which a spacecraft or satellite passes behind a flyby planet in order to steal momentum from it and thus increase its own heliocentric velocity. This increase in heliocentric velocity allows the satellite to reach locations in our solar system that it would otherwise be unable to reach.
I plan to accomplish this using ephemeris data from NASA’s horizons database and direct integration of Newton’s Law of Gravitation equations. Using Newton’s Law of Gravitation will give me much more flexibility in mission planning and allow me to use an ion propulsion system. However, given time constraints and an issue I am currently having with the code for my propagator, I may default back to a lambert solver and a two impulse burn maneuver. In the near future I hope to be able to fix the issue with my propagator and get to the point where I can simulate a gravity assist maneuver. After that I can start picking targets and begin the mission planning process.
Final Paper: Gravity Assist Preliminary Research
Final Fortran 90 Code: GRAVITY_ASSIST_PROGRAM