AAE450 Spring Attitude Control – Arbitrary Payload Christine Troy Assistant Project Manager Webmaster Lunar Descent Attitude Control Analysis Design Alternative Evaluation Arbitrary Payload Integration Manager Christine Troy Attitude

AAE450 Spring Problem  Size of attitude control system increases with increased mass in low lunar orbit (LLO)  Previous analysis simply assumed linear scale up of mass from 10 kg case  More detailed analysis required –Number of thrusters to counteract thrust offset –Mass and cost of thrusters –Mass and cost of required propellant  Analysis showed 14N H2O2 thrusters used in 10 kg case unsuitable for arbitrary payload ( thrusters required) Christine Troy Attitude

AAE450 Spring  Recommendation: Use 355 N H2O2 thrusters for attitude control on arbitrary payload regardless of launch vehicle (4-60 thrusters required)  Allocate 2% of wet lander mass for attitude control for arbitrary payload Christine Troy Attitude Launch Vehicle Total Attitude Control Mass (kg) Cost (Thousand $) Attitude Prop Mass (kg) Dnepr Falcon Falcon 9H Ares V

AAE450 Spring Christine Troy Attitude

AAE450 Spring Christine Troy Attitude

AAE450 Spring Christine Troy Attitude Launch Vehicle Attitude Control Mass (kg) Cost (Thousand $) Number Thrusters Dnepr Falcon Falcon 9H Ares V First number in each cell is when 14N H2O2 thrusters are used. - Second number in each cell is when 400N hydrazine thrusters are used. - Third number in each cell is when 355N H2O2 thrusters are used.

AAE450 Spring References  Rauschenbakh, Boris, Michael Ovchinnikov, and Susan McKenna- Lawlor. Essential Spaceflight Dynamics and Magnetospherics. Dordrecht, The Netherlands: Kluwer Academic Publishers,  Monopropellant Hydrazine Thrusters. Astrium Space Propulsion. 21 Jan hrusters.html  Hydrazine. Astronautix. 4 March  Propellant Grade Hydrogen Peroxide. Peroxide Propulsion. 4 March  H202 Monoprop Thruster. General Kinetics, Inc. 4 March pdf Christine Troy Attitude