AAE450 Senior Spacecraft Design Maguire,1 Dan Maguire Week 4: February 8th, 2007 Structures Group Group Leader, Ares 1, Earth Taxi, Mars Taxi, Depart Mars, Arrive Mars, Depart Earth, Arrive Earth, Mars Launch vehicles Chemical Propulsion Tanks: Sizing and Configuration

AAE450 Senior Spacecraft Design Maguire,2 Size and Thickness of Fuel Vessels Size of dE, aM, dM & aE optimized –Constrained to Ares V dimensions Height – 20 m Diameter – 8 m LH2 – 75% Volume LOX – 25% Volume (more dense) Extra volume/mass for other systems Thickness of Fuel Vessels –Material was 7090 Al-Li 2090 –Buckling Stress Accounts for launch effects (10g) –Cylindrical Stress Longitudinal/Axial Stress Hoop Stress –Spherical Stress Hoop & Longitudinal stresses are same More efficient pressure vessel geometry Cut down on thickness Optimized Tank Size VolumeThicknessEmpty Mass External Tank938 m m8.9 mt LOX Tank102.2 m m0.386 mt LH2 Tank295.1 m m1.60 mt CAD drawing developed by Matt Fox

AAE450 Senior Spacecraft Design Maguire,3 Breakdown of Ares V Launches

AAE450 Senior Spacecraft Design Maguire,4 End of Presentation

AAE450 Senior Spacecraft Design Maguire,5 Future Work – Backup Slide Look into other materials –Doesn’t effect mass too much Attempt to optimize tanks and external shell –Constrained due to Ares V mass specification and LOX density –Currently keeping unused volume of LOX/LH2 tanks under 35% Look into meteorite optimization –What conditions effect thickness of wall Built in room for added weight Pressurization, Axial and Lateral effects –Already touched on, but look in depth Orientation of fuel vessels on TV –Already initiated designs Collapsible Tanks to land on Mars –Is it plausible? –Requirements to build around

AAE450 Senior Spacecraft Design Maguire,6 Mass & Volume of LOX and LH2 Propellant – Backup Slide Numbers based from Catherine Frey’s calculations

AAE450 Senior Spacecraft Design Maguire,7 Material and Fuel Properties – Backup Slide Material Props of Al-Li 2090 Internal Pressure Constants of LOX and LH2

AAE450 Senior Spacecraft Design Maguire,8 Determination of Pressure Vessel Thickness – Backup Slide Thickness of Cylindrical Structure Hoop StressLongitudinal StressHoop & Longitudinal Stress Thickness of Spherical Structure

AAE450 Senior Spacecraft Design Maguire,9 Hoop & Longitudinal Stress for LOX/LH2 Tanks – Backup Slide Hoop and Longitudinal Stress for LOX & LH2 Tanks

AAE450 Senior Spacecraft Design Maguire,10 Launch Effects and Buckling – Backup Slide Buckling stress for unpressurized, isotropic monocoque cylinder Human Space Flight P.694, Brandon Anderson Axial Stress

AAE450 Senior Spacecraft Design Maguire,11 Resourses Dr. Damon F. Landau. “Strategies for the Substained Human Exploration of Mars” Thesis Submitted to the Faculty of Purdue University, Dec Virgil Hutchinson, “Estimation of Launch Vehicle Propellant Tank Structural Weight Using Simplified Beam Approximation”, AIAA, Jul. 2004