Team A Propulsion 1/16/01

Presentation Outline Chemical Propulsion: Expansion of gases as a result of chemical interaction/combustion Thermonuclear Propulsion: Expansion of gases as a result of heating by a nuclear generator Attitude Adjustment: Enroute course modifications with low thrust levels

Propulsion Systems First stage Second stage Attitude Launch vehicle - ground to LEO Chemical (Liquid) Second stage Departure V - LEO to Mars Chemical or Thermonuclear Attitude Course adjustments - enroute to Mars

Thermonuclear Propulsion Cold gas expanded by heat from nuclear fission generator Uranium used as nuclear fuel, running with a critical core, controlled by poison rods Shielding in place to protect systems and astronauts

Nuclear Engine Concept

Thermonuclear Advantages Higher Isp and potentially higher thrust than chemical engines Can use propellants of low molecular weight Performance really only limited by core temperature (surrounding materials) NERVA engine tested by NASA 1956-1973 was proven with full test program, except for an actual space flight test Reactor could possibly be used to provide power for the spacecraft enroute to Mars

Thermonuclear Disadvantages No off-the-shelf model available Radiation hazard (astronauts exposed to a whopping 2.8 rems for mission duration) Public is frightened of nuclear reactors flying What would we do with the reactor when we arrive at Mars?

Chemical Propulsion Since initial stages of launch system will be jettisoned nuclear propulsion is not an option There have been chemical launch systems built that are capable of lifting payloads required for this mission Once the high thrust portion of the launch is complete thermonuclear propulsion system can be used

Chemical Propulsion Launch vehicle chosen is the Russian built Energia Chosen for heavy lift capability as well as modular construction Another major factor is that the industrial base to construct this launch vehicle has been preserved

Energia Height: 60m Thrust 35 MN 4 strap on boosters having 4 liquid fueled (LOX/RP-1) engines 4 liquid fueled (LOX/LH2) central core engines Capable of delivering a 32 mTon payload to Mars with a chemical upper stage stored in the cargo module or 88 K kg to LEO

Alternatives Could build a similar launch system using 4 SRB’s and a modified external tank that would have liquid motors mounted as well as a cargo module Design a entirely new launch vehicle that would be similar in design to the Saturn V Costs of development as well as time constraints for mission timeline could prohibit second option

Attitude Control System For reference attitude control on the space shuttle uses three modules which house a total of 38 primary thrusters and 6 secondary Having the three modules provide redundancy because one module can be used to complete the mission

Attitude Control System Reaction control system uses MMH and N2O4 as the propellants The total system propellant is 3300kg The space shuttle also has orbital maneuvering thrusters which may not be necessary for this mission

Attitude Control System Alternatively heat from the thermonuclear propulsion system can be used to power thrusters for attitude control Reactor could also be kept active to produce power The higher performance would reduce the fuel needed

Casey Kirchner Hands-on experience in propulsion test and heat transfer experiments Experience with FEHT (heat transfer software) Courses taken AAE 439 – Rocket Propulsion AAE 590K – Advanced Energy Conversion ME 315 – Heat and Mass Transfer Courses taking AAE 539 – Advanced Rocket Propulsion

Adam Irvine Can program well in Matlab and use optimization routines Can use AutoCAD Taken: AAE590G, AAE439, AAE590K Currently taking: AAE590C and AAE539