Space Grant Symposium Presentation Saturday – April 19th, 2008 Joseph Farrell – U of A
Background Information Junior in Aerospace Engineering at University of Arizona Location of internship – Raytheon Missile Systems Project Title – “Robotic Lander Design and Development” Mentor – Jim Head (with assistance from Raytheon Engineers, and UA Faculty/Students) Joseph Farrell
General Tasks/Analysis Completed Analysis of a Lunar Surface Return (LSR) report and excel spreadsheet (‘06-’07 Space Grant Report). Review of the Boomerang Report (NASA). Analysis of Lander thruster configurations. Other Tasks: Organization and summarization of the Goddard Space Flight Center Program Listing. Basic Matlab proficiency. Preliminary Honeycomb Analysis (See Chris Rogers’ presentation). Joseph Farrell
Lunar Surface Return Mission Focus of Analysis Image taken from the Boomerang Report Joseph Farrell
LSR – Cont. LSR Report details a round-trip mission to the moon to collect a payload of moon material and bring it back to Earth. “Boomerang” Report details a functionally similar mission. Tasked with making the spreadsheet “close” Enough Net Delta V available for both the ascent and landing stages Positive lift margin for the launch stage Goal was to optimize the spreadsheet to function with the parameters of the “Boomerang” Report. Joseph Farrell
LSR – Cont. Analysis parameters: - Fixed Launch Vehicle - Landing Stage Between 1-4 pairs of fuel tanks Variable SRM Engine (Star # ATK Motor) - Lunar Ascent Stage (LAV) 2 Stage Launch Stage 1 – Variable SRM Engine (Star # ATK Motor) Stage 2 – Variable SRM Engine (Star # ATK Motor) Joseph Farrell
LSR – Cont. Ultimately concluded that spreadsheet can not ‘close’. “Boomerang” assumptions include the Lunar Lander providing delta V for landing and ascent. LSR Report / Spreadsheet lacks this assumption. Joseph Farrell
Thruster Configuration Analysis Presented with four potential thruster configurations for landing a Planetary Lander with a vertical delta V=250m/s: Configuration 1: 4 Divert Thrusters, 8 ACS Thrusters on deck. Configuration 2: 4 Divert Thrusters, 6 ACS Thrusters on poles. Configuration 3: 2 Lateral and 2 Downward Divert Thrusters , 8 ACS Thrusters on deck. Configuration 4: 2 Lateral and 2 Downward Divert Thrusters, 6 ACS Thrusters on poles. Joseph Farrell
Thruster Configuration – Cont. Joseph Farrell
Thruster Configuration – Cont. Task was to judge/analyze different configurations based on (only a few listed): - Braking Time - Fuel usage - Correction time for 10ms Divert misfire - Ability to compensate for C.G. drift - Misfires about the X, Y, and Z axes - More… Horizontal Vertical Error bars compensate for C.G. Drift Joseph Farrell
Thruster Configuration – Cont. Configuration 3 chosen to be optimum configuration – 2 Down, 2 Lateral Divert Thrusters, 8 ACS Thrusters on deck. Joseph Farrell
Conclusion Overall, my experience at Raytheon has been a very positive one. Gained valuable insight into team-work and solitary analysis. Better understanding of the practical work that goes with the title of an “engineer”. Thanks!! Joseph Farrell