By: Josh Lukasak Attitude Group Lead Lunar Descent Phase Manager Final Slides By: Josh Lukasak Attitude Group Lead Lunar Descent Phase Manager

Necessity of Attitude Control The above animation shows how attitude control is employed for main engine offset. Attitude Control is an important facet of all mission phases Lunar Injection: The space craft must be oriented in a fashion such that the solar panels and communication satellites are properly pointed. Lunar Descent: The space craft must be oriented in a fashion such that on touchdown the Lander legs can rest gently on the lunar surface. Additionally attitude control thrusters can be used for translational motion.

Lander Final Attitude Masses Device 100g Payload 10kg Payload Large Payload Attitude Determination 7.1 kg Thrusters Inert 1.08 kg 10.92 kg Piping 2.57 kg 2 kg 6.56 kg Attitude Prop 3.57 kg 5.53 kg 81.26 kg The above Table gives all the final attitude control masses for the Lunar Descent Vehicle. These masses are for all three payload cases.

Initial Hopper Analysis for Large Payload The hopper design for the 10 kg payload cases has considerable savings. Lander/Rover total system mass of 278 kg Hopper total system mass of 262.7 kg Reduction in two COM systems, one on the Lander and one on the rover, totaling over $200,000. The most viable use for the hopper design seemed to be in the Falcon 9 large payload case. Initial Scale Up Considerations for the Falcon 9 Falcon 9 Hopper Payload 897kg Falcon 9 Rover Payload 1197kg Falcon 9 Rover Size 300kg

Attitude Propellant Calculations M=r x F M is the induced moment F is the force or thrust r is the radius from the force to the center of mass m is the time averaged mass g is the gravitation constant of 9.80665 m/s^2 Isp is the specific impulse of Monopropellant Hydrogen Peroxide L is the distance from the thruster to the center of mass