Presentation to the Nuclear Systems Strategic Roadmap Committee 5 April 2005

1. The B612 Mission Concept: A Candidate For Prometheus 1 Russell L. Schweickart, Chairman B612 Foundation www.B612Foundation.org Presentation to the Nuclear Systems Strategic Roadmap Committee 5 April 2005

2. Introduction • Presentation of the B612 concept as a candidate for the Prometheus 1 mission • Background • B612 Foundation • Near-Earth object (NEO) environment • Assumption • Presentation will be summary in nature with details of interest left to Q&A at end • Related technical and professional papers are available for those interested

3. B612 Foundation Basics • What we are - • 501(c)3 non-profit corporation formed 9/7/02 • Who we are - • A group of astronomers, astronauts and engineers involved in or with NEO issues • Why we formed - • Concerned with coming high NEO discovery rate but no organized work on deflection • Our adopted goal - • “to deflect an asteroid, in a controlled manner, by 2015”

4. B612 Founders William Bottke; Southwest Research Institute Dennis Byrnes; NASA/Jet Propulsion Laboratory Franklin Chang-Diaz; NASA/Johnson Space Center Clark Chapman; Southwest Research Institute Tony Dobrovolskis; NASA/Ames Research Center Dan Durda; Southwest Research Institute John Grunsfeld; NASA/Johnson Space Center Mike Houts; NASA/Marshall Space Flight Center Piet Hut; Institute for Advanced Studies Don Korycansky; UC Santa Cruz Stanley Love; NASA/Johnson Space Center Ed Lu; NASA/Johnson Space Center

5. B612 Founders Andrew Petro;NASA/Johnson Space Center Dan Mazanek; NASA/Ames Research Center Bill Merline; Southwest Research Institute David Morrison; NASA/Ames Research Center Steve Ostro; NASA/Jet Propulsion Laboratory David Poston; Los Alamos National Laboratory Dan Scheeres; University of Michigan Rusty Schweickart; Independent Jared Squire; NASA/Johnson Space Center Bobby Williams; NASA/Jet Propulsion Laboratory

6. The NEO Environment Spaceguard Survey NASA’s goal: “Discover 90% of the NEO population (1 kilometer in diameter or larger) within 10 years (i.e., 2008)” NASA NEO Science Definition Team “...recommends that the search ... produce a catalog that is 90% complete for potentially hazardous objects (PHOs) larger than 140 meters.”

7. The NEO Environment • Current Potential Impacts • Actual data: updated daily; catalogs all NEAs with non-zero probability of Earth impact in next 100 years. • List will likely expand to hundreds of objects within the next 10 years as the search focuses on smaller dangerous objects (>100MT)

8. An Interesting Case The 2004MN4 Situation as of 23 Dec 04

9. Situation on 28 Dec 04 Situation on 23 Dec 04

10. Vrel=5.86 km/sec Vrel=5.86 km/sec deltaV=2.83 km/sec 28 deg 2004MN4 close pass geometry Encounter, 13 April 2029 @ 21:44:35 GMT This NEA will be a magnitude 3 naked eye object in the early evening sky in Northern Europe It will pass by Earth slightly inside the geostationary orbit

11. Sun Geostationary Orbit 2029 Close Encounter Nominal path and error ellipse of 2004 MN4 on 4/13/29 relative to Earth (as of 4/1/05)

12. An Interesting Case V Required to Deflect Note: Preliminary results only. Shown by special permission of Andrea Carusi, University of Pisa. 2029 close approach

13. Mission Concepts • A1 - Actual deflection of incoming NEO • Conceptual only; to determine feasibility and establish design requirements • D2 - Full demonstration • Full demonstration of capability; dress rehearsal • D1 - Basic demonstration • Initial capability demonstration and gathering of critical engineering design information (Note: engineering design data could be gotten more timely and cheaply via early conventional mission) • Rationale: top to bottom • Mission sequence: bottom to top

14. A1 – Actual Deflection • Assumptions • ~200 meter diameter • rubble pile • principal axis rotator • getting there and basic pre-docking surveillance for asteroid characterization and docking site are assumed • Docking (not landing) • gast ~ 2.6 x 10-6 gearth(s/c weight <0.1 lbs) • dock at pole • probably requires 3 axis control

15. A1 – Rotation Considerations • For efficient use of fuel and time thrust must be applied parallel to the asteroid’s velocity vector (Vast) • Since asteroids rotate with periods of 2 to 10 hours (200 meter diameter & above) this must be accounted for in the mission design • Rejected concepts • Pulse thrust only when near parallel with Vast • Dock at equator; despin asteroid, orient asteroid to align thrust parallel Vast and thrust to obtain required V

16. A1 – Rotation Considerations • Since the structural balance of the asteroid is tied to its rotation reducing it to zero would likely cause fundamental restructuring, i.e. an asteroid quake. • Survival of the s/c in this event is problematic. De-spin then thrust

17. A1 – Rotation Considerations • There is always a depression angle where the resultant torque during thrusting maintains H directly below V • Once aligned all fuel goes into achieving the desired V Re-align spin then thrust

18. A1 – Off Axis Thrusting • Thrusting other than through the asteroid center of mass will require lateral support and a gimbaled engine. • Additional knowledge of asteroidal surface structural characteristics is required for design. Lateral support

19. D1 – Basic Demonstration • Dock at pole and push asteroid to achieve a pre-planned V of 0.2 – 1.0 cm/sec in inertial direction • Deploy scientific package to obtain critical data on surface structure • Conduct additional scientific research • Collect and return surface sample to Earth (optional)

20. D2 – Full Demonstration • Build on D1 mission by deploying lateral support mechanism • Complete full deflection mission objectives • Determine via onboard remote sensing capability the required spin axis orientation for acceleration program • Torque asteroid spin axis to pre-derived orientation • Thrust parallel to asteroid velocity vector to achieve predetermined V

21. Candidate Asteroid Selection • Since B612 is a demonstration mission, the target asteroid should be representative of an actual deflection but also “convenient” • Low V to rendezvous • No threat to Earth before or after mission • Preferably a rubble pile (worst case challenge) • Slow principal axis rotator to minimize fuel required while validating attitude control technique • B612 Foundation selected candidate asteroid 2000EH26 and JPL ran initial evaluation

22. Candidate Asteroid Selection • JPL subsequently ran evaluations on more favorable asteroid candidates and selected 2004KE1 as most favorable in current catalog • Following pages show JPL analytical results for initial 2000EH26 evaluation and notation for re-analysis using 2004KE1 as target asteroid • Asteroid comparison (selected parameters) Designation a e i H G Ref ----------- ---------- ---------- --------- ----- ---- ------ 2004 KE1 1.2993152 0.18115408 2.88147 21.95 0.15 JPL 6 2000 EH26 1.8528199 0.47718265 0.39343 21.27 0.15 JPL 35

23. 2004 KE1 Analytic Assumptions • Target asteroid: 2000 EH26 • Mass = 1.0 x 1010 kg • Total V imparted to asteroid: 1.0 cm/s or 0.2 cm/s (along spin axis) • Launch date: 2011-2013 • Two scenarios for starting conditions • Launch to 1000 km orbit with spiral out to Earth escape • Launch to Earth escape (C3 = 0 km2/s2) • Launch vehicle: Delta 4050H (i.e., Delta 4 Heavy) • Capability to 1000 km orbit: ~21,000 kg • Capability to C3 = 0 km2/s2: ~9,000 kg • Three initial spacecraft acceleration levels: 0.12, 0.15, and 0.18 mm/s2 • Spacecraft dry mass: 18,000 kg • Electric propulsion system characteristics: • Power to electric propulsion system is calculated to achieve specified initial spacecraft acceleration level • Efficiency = 70% • Isp = 7000 s

24. Analytic Process • Spacecraft dry mass is fixed • Total V imparted to asteroid is fixed at 1.0 or 0.2 cm/s • Earth spiral out, interplanetary transfer and rendezvous Vs are determined from optimized low-thrust trajectories assuming three different levels of initial spacecraft acceleration • Power level available to electric propulsion system is calculated to achieve specified initial spacecraft acceleration level • Initial spacecraft mass is calculated from specified dry mass and mission propellant requirements for the following: • Earth spiral out V (if applicable) • Interplanetary transfer V • Rendezvous V • Navigation V (fixed 200 m/s allocation) • Total V imparted to asteroid • Calculate launch vehicle margin from initial spacecraft mass and launch vehicle capability

25. Revised numbers for 2004KE1 via personal communication with Lou D’Amario/JPL Revised numbers 1.81 yrs 1.89 yrs 1.77 yrs Revised numbers 4.00 yrs 4.63 yrs 3.59 yrs Revised numbers 10.8 km/s 11.5 km/s 10.6 km/s Revised numbers 5,182 kg 4.953 kg 4,884 kg Revised numbers -1,953 kg -1,884 kg -2,182 kg Results for Asteroid V = 1.0 cm/s

26. Revised numbers for 2004KE1 via personal communication with Lou D’Amario/JPL Revised numbers 1.81 yrs 1.89 yrs 1.77 yrs Revised numbers 3.30 yrs 3.76 yrs 3.01 yrs Revised numbers 10.8 km/s 11.5 km/s 10.6 km/s Revised numbers 3,352 kg 3,217 kg 3,141 kg Revised numbers -352 kg -217 kg -141 kg Results for Asteroid V = 0.2 cm/s

27. Rationale and Considerations • Mission meets Prometheus goals for testing engine and power systems with modest demands • Mission can be accomplished by 2015 using early spiral Prometheus capability • Mission opens multiple exploration doors • Demonstrates capability to protect planet • Opens capability for in situ resource exploitation • Offers excellent in situ science opportunity • Deflection of NEAs can only be done using Prometheus technologies

28. Rationale and Considerations • Public safety and planetary protection goal offer superior rationale for use of nuclear reactor in space • Within a decade there will be growing public concern about potential asteroid impacts due to a major increase in the discovery rate of 100 meter class NEOs • Public safety cannot be assured re NEO impacts without the use of the Prometheus technologies including nuclear power and high performance propulsion

29. Title B612 is an attractive alternative for Prometheus 1: • Less than one third the ΔV required for JIMO • No extreme radiation environment • Robust exploration goals that are well-matched to Vision for Space Exploration objectives and that are embraced and readily understandable by the public

30. Questions & Discussion