1 RASC / HOPE Transportation Revolutionary Aerospace System Concepts Human Outer Planet Exploration Mission Systems concepts and trade space NASA Design Team Advanced Plasma Propulsion Option (VASIMR) February 5, 2003

2 RASC / HOPE Transportation VASIMR Propulsion System Technical Characteristics Basic Concept (Variable Specific Impulse Magnetoplasma Rocket): Hydrogen (or Deuterium) plasma is heated by RF energy to exhaust velocities up to 300 km/s. Exhaust velocity/thrust can be varied at constant power. Other propellants can also be used depending on Thrust/Isp mission requirements. Engine has no electrodes for plasma generation and acceleration so erosion problems are avoided. Magnetic ducting and RF heating enables high plasma power density. Projected performance Specific Power: 30 MWe Specific mass - VASIMR: 0.76 kg/kWe Specific Mass – Reactor (crew mission): 3.1 Kg/kWe Specific Mass – Reactor (cargo mission): 2.0 Kg/kWe Specific impulse: 3,000 to 30,000s Engine on-off Control Possible: Cost Phase – (Piloted 213days, Cargo 187days) (See Cost Arc Slide for more detail) Maturity/Feasibility TRL: (4-5) Critical mass of propulsion vehicle (VASIMR + Brayton Fission Reactor): MT Experiments in progress: vacuum chamber testing of kW system Planned experiments: space demonstration of kW system on the ISS (battery-driven, long (10min) pulses, with ion cyclotron heating and with magnetic nozzle) in ~3 years (pending funding) Operability Fuel: LH2, LD2, He, for High Isp ops. N2, Li, Ar, Xe for low Isp ops Throttle variability: Can be operated continuously or turned off and on as needed Power Requirement: 30 MWe Isp: continuously variable from 3000 s to 30,000s by modifying plasma flow via RF excitation By-products: exhaust is harmless (except for Li, where contamination may be an issue) Radiation: electromagnetic waves

3 RASC / HOPE Transportation Mission Architecture 1st Trip: Pre-deployment of essential assets at Callisto 2nd Trip: Crew transfer from Earth-Moon L1 to Callisto –Everything goes to Callisto in two mission flights: Mission Flight One: Transfer of Crew Lander, Surface Hab, ISRU and Crew mission flight return propellant from L1 to Callisto; Lander remains in orbit –VASIMR+Reactor M sp is approximately 2.76 Kg/kWe –Optimized with 3 Reactors at 10MWe per reactor (Mission can still be preformed with 2 reactors) –VASIMR+Reactor infrastructure can act as a contingency return vehicle or be utilized as an orbiting relay asset Mission Flight Two: Crew transfer from L1 to Callisto Orbit Insertion, including TransHab ONLY –Dock to orbiting Lander for surface descent of Crew (3) –VASIMR+Reactor M sp is approximately 3.86 Kg/kWe –Artificial gravity for all but one year of round trip mission duration –Two (2) TransHabs included in dry mass (Helps with artificial gravity spinning as also acts as a spare.

4 RASC / HOPE Transportation Cargo Mission Trajectory Begin Spiral from Earth at L1: 12/6/2043 Period of Earth / L1 Spiral: 15 days Heliocentric Transfer to SOI of Jupiter: 950 days Period of Jupiter Injection: 232 days Period of Callisto Injection: 17 days Arrival at 500km Parking Orbit: 3/29/2047 Total Mission Time: 1214 days (3.3 years) Crew Round Trip Trajectory Begin Spiral from Earth at L1: 2/19/2045 Period of Earth / L1 Spiral: 15 days Heliocentric Transfer to SOI of Jupiter: 680 days Period of Jupiter Injection: 170 days Period of Callisto Injection: 7 days Arrival at 500km Parking Orbit: 7/5/2047 Stay Time: 30 days Begin Spiral Out from Parking Orbit: 8/6/2047 Period of Callisto Escape Spiral: 9 days Period of Jupiter Escape: 140 days Heliocentric Transfer to SOI of Earth: 670 days Period of Earth Injection: 20 days Arrival at Earth / L1: 11/27/2049 Total Mission Time: 1741 days (4.8 years) Earth Escape Trajectory SOI of Earth Callisto Injection Trajectory SOI of Callisto Jupiter Orbit SOI of Jupiter Jupiter Injection Trajectory Cargo / Crew Mission Trajectory Profiles Callisto Mission using VASIMR Technologies

5 RASC / HOPE Transportation coast arc (engine-off period). Crew Mission Coast arc: Engine Off (Time Counter) Leg 1) Earth escape trajectory (Transit Time = 15 days) Coast arc : 1.32 days ( )day Leg 2) Heliocentric trajectory (Transit Time = 680days) Coast arc : days ( )day Leg 3) Jupiter injection trajectory (Transit Time = 170days) Coast arc : days ( )day Leg 4) Callisto injection trajectory (Transit Time = 7days) No Coast arc Leg 5) Callisto escape trajectory (Transit Time = 9days) No Coast arc Leg 6) Jupiter escape trajectory (Transit Time = 140days) Coast arc : 7.54 days ( )day Leg 7) Heliocentric trajectory (Total = 670days) Coast arc : days ( )day Leg 8) Earth injection trajectory (15days) No Coast arc Cargo Mission Coast arc: Engine Off (Time Counter) Leg 1) Earth escape trajectory (15days) Coast arc : 1.61 days ( )day Leg 2) Heliocentric trajectory (950days) Coast arc : days ( )day Leg 3) Jupiter injection trajectory (232days) Coast arc : days ( )day Leg 4) Callisto injection trajectory (17days) No Coast arc Example how to read this chart Cost arc: 1.32days – time in cost phase Time Counter (13.68 – 15)day – time in trajectory leg that engine is turned off

6 RASC / HOPE Transportation Direct transfer L1 departure to Callisto rendezvous: TRIP 1 Pre-deployment of return fuel, Surface Facility Habitat, Lander, & ISRU leaves L1 with “duplicate” VASIMR /Nuclear Reactor transport propulsion system Total wet mass from L1 is approximately 506 MT Transit to Callisto Orbit Injection Transit time from L1 to Callisto is approximately 1214 days (3.3 yrs) Callisto arrival: –Surface Facility Habitat and ISRU pre-deployed to surface, and setup for operational activation –VASIMR/Nuclear Reactor propulsion system, Descent/Ascent Lander, return fuel, etc. situated in 500 Km altitude Callisto orbit operations: –Eventual connection of Lander to Crew arrival spacecraft –Remaining VASIMR/Nuclear Reactor propulsion system can act as contingency spacecraft or as an orbiting relay asset Callisto Mission Trajectory Concept Cargo Transfer

7 RASC / HOPE Transportation Direct transfer L1 departure to Callisto rendezvous: TRIP 2 Callisto Mission Trajectory Concept Crew Transfer Six (6) person crew leaves L1 with VASIMR /Nuclear Power propulsion system, Structure, Fuel, and two equipped TransHabs L1 departure: Total mass from L1 is approximately 431 MT (118 MT LH2 needed) Transit to Jovian System with artificial gravity conditions equal (as a minimum) to Callisto gravity (~1/8 G) Transit time from L1 to Callisto is approximately 872 days (2.39years) Callisto arrival: (minimum 32 day stay) –Crew transport spacecraft docks with Orbiting Lander;3 person crew uses Lander to descend to surface –Return fuel transferred from Pre-deployed spacecraft to crew transport spacecraft –VASIMR/Nuclear Reactor propulsion system, 2 TransHabs, return fuel, etc. situated in orbit 500 Km) with remaining crew of 3 Callisto departure: Total mass from Callisto is approximately 421 MT (118MT LH2 is needed) –3 person crew departs surface (via Ascent Module from Lander) for rendezvous with Orbiting crew transport spacecraft –Picks up ~118 MT of fuel in orbiting Cargo spacecraft Transit time from Callisto to L1 is approximately 864 days (2.37 years)

8 RASC / HOPE Transportation J J Earth-Moon L1 departure (2/19/2045) “HOPE -- Callisto” Direct Transfer from L1 using VASIMR propulsion technology (circa 2045) S Callisto departure (8/6/2047) J VASIMR Propulsion (3,000 < I sp < 30,000 sec Variable Engine Efficiency Engine on-off Control ) Brayton Nuclear Fission Reactor Power (30 MWatt) 872 day transit (2.39 years) (L1- Callisto) 1/8 Artificial G 116 MT fuel use Total Spacecraft Mass at L1 launch: 432 MT (~118 MT of hydrogen fuel) Total Spacecraft Mass at Callisto departure: 421MT (~118 MT of hydrogen fuel) 2 TransHab Mass (w/consumables): ~ 105 MT Radiation Protection: wrapped LH2 fuel tanks + hydrogen Nanofiber sheathing (Crewed Mission) 864 day transit (2.37 years) (Callisto - L1) 1/8 Artificial G 112 MT fuel use Callisto arrival (7/5/2047) Fluid Transfer (Cargo and Piloted Ship)

9 RASC / HOPE Transportation Triangle Shaped Reactor Radiators SA= 3330m 2 Per Panel (13,320m 2 Total) Flat Panel and Cylindrical Radiators 4 Flat Panels SA=445m 2 Total 2 Cylindrical SA=455m 2 14m 26.4m 49m 30MWe Piloted Callisto Transfer Vehicle (PCTV) Artificial Gravity – Two TransHabs 198m 34.0m 22.8m 42.7m “Preliminary” PCTV Mass Properties (Two TransHabs – Total Wet Mass 430MT Series of 10MWe Brayton Fission Reactors provide 30MWe of electrical power for constant thrust Variable Isp (3000s to 30,000s) with an varying efficiency Eff = 1X10 -5 x Isp Total VASIMR Alpha = 0.76kg/kWe (Engine = 0.24kg/kWe, PPU = 0.52kg/kWe) Dry Mass = 207MT Propellant Capability = 118MT (NOTE: more tanks can be added) Payload Masses = 105MT Provides a constant 1/8g simulated gravity environment

10 RASC / HOPE Transportation Cargo and Crewed Mission masses

11 RASC / HOPE Transportation Basic Figures of Merit studied (Using Fuel Load Calculated by LARC Trajectory Code) ** Assumes a 32 day surface stay on Callisto

12 RASC / HOPE Transportation BACKUP SLIDES

13 RASC / HOPE Transportation 30MWe Brayton/VASIMR next to the ISS

14 RASC / HOPE Transportation Analysis Results -Trajectory transit times Earth-Moon L1 to Callisto Mass (metric tons) of a Crew spacecraft with 30MW VASIMR Patched Conic method to include gravitational effects of Earth, Jupiter, Callisto

15 RASC / HOPE Transportation Analysis Results -Trajectory transit times Callisto to Earth-Moon L1 Mass (metric tons) of a Crew spacecraft with 30MW VASIMR Patched Conic method to include gravitational effects of Earth, Jupiter, Callisto

16 RASC / HOPE Transportation Trajectory analyses -30MWe VASIMR Crewed Mission (Similar for Return Trip) Fig 1. An example of Earth Escape Trajectory

17 RASC / HOPE Transportation Y(AU) X(AU) Heliocentric Trajectory to Jupiter System Sun Earth Jupiter Thrust Vector Spacecraft Trajectory Entering Jupiter's Sphere of Influence Escaping from Earth Trajectory analyses - 30MWe VASIMR Crewed Mission (Similar for Return Trip) Fig 2. An example of Heliocentric Trajectory to Jupiter System

18 RASC / HOPE Transportation Y(Jupiter radii) Jupiter Injection Trajectory Entering Jupiter's Sphere of Influence Jupiter Injection Trajectory Jupiter's Sphere of Influence direction to Sun direction of Jupiter's orbital velocity Jupiter Thrust Vector Entering Callisto's Sphere of Influence Callisto's Orbit Trajectory analyses - 30MWe VASIMR Crewed Mission (Similar for Return Trip) Fig 3. An example of Jupiter Injection Trajectory

19 RASC / HOPE Transportation Trajectory analyses - 30MWe VASIMR Crewed Mission (Similar for Return Trip) Fig 4. An example of Callisto Injection Trajectory

20 RASC / HOPE Transportation from Earth L1 to Callisto Begin Spiral from Earth at L1: 2/19/2045, Propellant loaded (73.47mt, 32 small tanks), Total S/C mass: mt Period of Earth / L1 Spiral: 15 days, Propellant 1.28mt Heliocentric Transfer to SOI of Jupiter: 680 days, Propellant: 37.52mt Period of Jupiter Injection: 169 days, Propellant: 10.88mt Period of Callisto Injection: 8 days, Propellant: 5.07mt Arrival at 500km Parking Orbit: 7/5/2047 Total Flight Time: 872 days (2.39 years), Total Propellant used: 54.75mt (18.72mt fuel left) Stay Time: 30 days from Callisto to Earth L1 Begin Spiral from Parking Orbit: 8/6/2047, Propellant loaded (73.47mt, 32 small tanks), Total S/C mass: mt Period of Callisto Escape Spiral: 9 days, Propellant: 5.77mt Period of Jupiter Escape: 140 days, Propellant: 21.87mt Heliocentric Transfer to SOI of Earth: 670 days, Propellant: 30.03mt Period of Earth Injection: 17 days, Propellant: 1.18mt Arrival at Earth / L1: 11/24/2049 Total Flight Time: 836 days (2.29 years), Total Propellant used: 55.61mt (13.19mt fuel left) Total Mission Profile Total Mission Time: =1738 days (4.8 years), Propellant Used (54.75mt, 55.61mt) Crew Mission Trajectory Profiles 30MW VASIMR with Vapor Core Reactor 5 Year Round Trip

21 RASC / HOPE Transportation from Earth L1 to Callisto Begin Spiral from Earth at L1: 4/25/2045, Propellant loaded:149.32mt, Total S/C mass: mt Period of Earth / L1 Spiral: 9 days, Propellant 2.54mt Heliocentric Transfer to SOI of Jupiter: 380 days, Propellant: mt Period of Jupiter Injection: 100 days, Propellant: 15.16mt Period of Callisto Injection: 5 days, Propellant: 9.00mt Arrival at 500km Parking Orbit: 9/2/2046 Total Flight Time: 494 days (16.47 months), Total Propellant used: mt (4.82mt fuel left) Stay Time: 30 days from Callisto to Earth L1 Begin Spiral from Parking Orbit: 10/2/2046, Propellant loaded (149.32mt), Total S/C mass: mt Period of Callisto Escape Spiral: 5 days, Propellant 6.60mt Period of Jupiter Escape: 85 days, Propellant 25.40mt Heliocentric Transfer to SOI of Earth: 390 days, Propellant mt Period of Earth Injection: 10 days, Propellant 3.48mt Arrival at Earth / L1: 2/5/2048 Total Flight Time: 490 days (16.33 months), Total Propellant used: mt (6.77mt fuel left) Total Mission Profile Total Mission Time: =1014 days (33.80 months), Propellant Used (144.50mt, mt) Crew Mission Trajectory Profiles 200MW VASIMR with Vapor Core Reactor 3 Year Round Trip

22 RASC / HOPE Transportation “Preliminary” PCTV Mass Properties (Two TransHabs – Total Wet Mass 623MT 1Vapor Core Reactors provides 200MWe of electrical power (Alpha=0.29kg/kWe) Variable Isp (3000s to 30,000s) with an varying efficiency Eff = 1X10 -5 x Isp Total VASIMR Alpha = 0.76kg/kWe (Engine = 0.24kg/kWe, PPU = 0.52kg/kWe) Dry Mass = 368MT Propellant Capability = 150MT Payload Masses = 105MT 168m 22.5m 49m 52.5m 14m 200MWe Vapor Core Reactor Powered VASIMR

23 RASC / HOPE Transportation Two Sided Triangle Radiators SA = 3279m^2 4 (double sided )Flat Panels SA=968m 2 Total Cylindrical SA=612m 2 VAPOR Core Reactor Vapor Core / VASIMR VCR Radiator Assumptions: 1.Overall power output efficiency of 20% while allowing operation of the condensing radiator at constant heat rejection temperature of 1500K. 2.VCR-MHD fuel/working fluid (UF4) could condense at just under 1atm. 3.Waste heat load is estimated to be about 800 MW yielding an area of 3279 m2 (assuming.85 effective emissivity for the radiator) or 46 MT at 14 kg/m2. 4.Piping is made of molybdenum alloy (TZM or other similar strength alloys) with composite 5.The radiator surface is the carbon/graphite composite fins VASIMR Radiator Assumptions: 1.Thermal load = 900K using a molten salt coolant. At this temperature two-sided carbon fiber SiC radiator could be used and using the same conservative effective emissivity of.85 yield an area of 1580 m2 or MT at 6-8kg/m2. 2.estimate is based on using an overall efficiency of 50% for the VASIMR engine

24 RASC / HOPE Transportation 200MWe Crewed Mission masses