1. Space Grant Symposium Presentation
Saturday – April 19th, 2008
Joseph Farrell – U of A

2. 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

3. 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

4. Lunar Surface Return Mission
Focus of Analysis
Image taken from the Boomerang Report
Joseph Farrell

5. 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

6. 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

7. 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

8. 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

9. Thruster Configuration – Cont.
Joseph Farrell

10. 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

11. Thruster Configuration – Cont.
Configuration 3 chosen to be optimum configuration – 2 Down, 2 Lateral Divert Thrusters, 8 ACS Thrusters on deck.
Joseph Farrell

12. 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