AAE450 Spring 2009 Final Lander Volume and Mass 10kg, 100g, Arbitrary March 12, 2009 Lunar Descent Phase Group [Ryan Nelson] [STRC] 1

AAE450 Spring 2009 Final Lander Dimensions and Volume (All Cases) 2 10kg100gArbitrary Height 1.1 m 1.0 m 2.0 m Top Diameter 1.0 m 2.4 m Bottom Diameter 1.3 m 3.6 m Total Volume m m m 3 Arbitrary Volume based on max diameter of payload fairing Height Scaled from 100g case Need for additional thrusters cause 1.1m height on 10kg

AAE450 Spring 2009 Final Frame Mass (All Cases)  100g –Mass of Frame = kg  10kg –Mass of Frame = kg  Arbitrary –Mass of Frame = kg Arbitrary Case Scaled from 100g No need for added structure to support extra 2 thrusters Thrusters for hop have no effect on volume constraints 3

AAE450 Spring 2009 Key Drivers in Lander Frame Size  H2O2 Tank Radius –0.53 m for 10kg –0.5 m for 100g  Pressure Tank Radius –0.4 m 10kg –0.38 m for 100g  Nozzle (Only constraint for Leg size) –0.325 m both cases –This leaves m ground clearance  Main Chamber Height –0.438 m for 10kg –0.293m for 100g – m into Lander for 2 added thrusters on 10kg case  Solar Panel –needs m 2 area for both cases –Top diameter must be 1 m  Payload Size (Only 100g) –Approx 0.35m 3 X 0.35m 3 X 0.35m 3 4

AAE450 Spring 2009 Explanation behind Lander Frame Masses  Volume and total mass upon touchdown drivers in overall frame mass –Larger volume means more material and more mass –Larger mass on touchdown means individual frame components must be thicker to support larger loads –Code from last weeks presentation used in iterative process 5

AAE450 Spring 2009 Calculations for Thruster Angle on 10kg case  Center of Mass code used to find line of action for thrust –Center of Mass found to be m from bottom of Lander at Touchdown  Chamber of thrusters oriented perpendicular to Lander floor –Only the nozzle is tilted to fire through CM  5 cm between main chamber and thruster chamber  5.75 cm of the chamber is exposed (hangs out of Lander floor) 6

AAE450 Spring 2009 Calculations for Thruster Angle on 10kg case (Cont.)  Optimal angle of action = 32.26°  Clearance from bottom of Lander = 2.68 cm 7

AAE450 Spring 2009 Center of Mass Code  Allows for easy CM calculation as individual components of Lander change. 8