1. AAE450 Spring 2009 Project X pedition Final slides outline for Orbital Transfer Vehicle Propulsion Week 11 Presentation Thursday, March 26, 2009 Brad Appel Propulsion Group 1

2. AAE450 Spring 2009 Propulsion on the Orbital Transfer Vehicle Brad Appel Propulsion Group Xenon Hall Thruster from Busek One low-power thruster for X-prize missions Cluster of five high-power thrusters for arbitrary payload Performance Specs: thruster tank feed system 2

3. AAE450 Spring 2009 Backup Slide 1: Electric Propulsion System Setup Brad Appel Propulsion Group 3 S 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 10 11 From PCDU S/C Communication 9 9 Xenon System Thermal System Power / Intercomm 0.2 m No redundancies, no integration costs

4. AAE450 Spring 2009 Brad Appel Propulsion Group Backup Slide 2: Xenon Thermal Analysis 4 Allowed temperature path of propellant Maximize storage pressure for volume efficiency (~ 150 bar) Maintain tank temperature for gaseous Xenon phase:  Balance heat due to radiation and pressure drop with a resistance heater Curve data from National Institute of Standards and Technology Temperature (K)

5. AAE450 Spring 2009 Outline for Backup Slides  Slide 1: Propulsion System Setup –Diagram and Parts list  Slide 2: Xenon Storage and Thermal Control –Phase diagram, description of heating system  Slide 3: Explanation of Sizing Process –Block diagram summarizing code algorithm  Slide 4: Miscellaneous Issues –Lifetime limit because of electrode erosion –Spacecraft charging and communication interference Brad Appel Propulsion Group 5