Antimatter Rocket Propulsion

1. Antimatter Rocket Propulsion Space Physics Program College of Arts & Sciences ERAU-Prescott Dr. Darrel Smith World Space Congress October 17, 2002 ERAU Space Physics Program

2. Space Physics Outline • The Space Physics degree program • Motivation for advanced propulsion • Antimatter propulsion • Possible missions (timescales) • Experiment to measure Isp ERAU Space Physics Program

3. Space Physics B.Sc. Space Physics Degree Program Embry-Riddle Aeronautical University Nick Devereux’s talk (yesterday)Space Science Education & Outreach Program Starts Fall 2003 Four areas of concentration ERAU Space Physics Program

4. Space Physics Motivation Why Antimatter Propulsion ? The “long” mission ERAU Space Physics Program

5. Space Physics Problems with the “long” mission Prolonged zero-g environment Weightlessness triggers a reduction in density of weight-bearing bones 1-2% a month severe osteoporosis ERAU Space Physics Program

6. Space Physics Problems with the “long” mission 2. Radiation Exposure Mars vehicle is no longer shielded from galactic and solar radiation ERAU Space Physics Program

7. Advanced Propulsion Systems Goal: Obtain the highest Isp Antimatter Isp ~ 107 sec. Antiprotons Positrons ERAU Space Physics Program

8. Space Physics Antiprotons Momentum Thrust The production of massive particles reduces the thrust. ERAU Space Physics Program

9. Space Physics Positrons Momentum Thrust The production of “massless” particles (e.g., photons) enhances the thrust. “Photon Drive” ERAU Space Physics Program

10. Space Physics The Engine Positron-electron annihilation occurs behind an absorber/reflector at the rear of the spacecraft. thrust ERAU Space Physics Program

11. Space Physics The Photon Drive ERAU Space Physics Program

12. Space Physics Spacecraft Performance Thrust: Specific Thrust: ERAU Space Physics Program

13. Space Physics Mission Parameters Minimum flight time for rendezvous (Mars, Jupiter) Use a Direct Trajectory Optimization Method (D.A. Kluever, 1997) • Start in a heliocentric orbit with the same position, velocity vectors as the Earth. • The spacecraft is transferred to heliocentric orbits around Mars and Jupiter ERAU Space Physics Program

14. Space Physics Mission Parameters to Mars & Jupiter ERAU Space Physics Program

15. Space Physics Mission Parameters to a-Centuari ERAU Space Physics Program

16. Measuring the specific thrust Store 1015 positrons in a Penning trap. G. Smith, LLL Release the positrons in a time window of 100 ms. The positrons annihilate the electrons on a tungsten target which is mounted on a torsion pendulum. We expect to measure a force of ~1.3 mN by measuring the amplitude of motion of the torsion pendulum. This will be the first measurement of the specific thrust due to matter-antimatter annihilations. ERAU Space Physics Program

17. Conclusions Something like a “photon drive” engine will be required to achieve interplanetary and interstellar manned space travel. The major hurdle to overcome will be the technology required to produce and store many kilograms of positrons. High-flux, relatively low-energy accelerators will be needed to produce the volume of positrons required. New accelerator technology is needed. The need for compact, high-energy sources of fuel will be in high demand, so commercial markets may be the “driving force” in developing thisbreakthrough technology. ERAU Space Physics Program

18. ERAU Space Physics Program