Colorado Space Grant Consortium

1. Gateway To Space ASEN 1400 / ASTR 2500 Class #23 T-18 Colorado Space Grant Consortium

2. Today: • Announcements • - Guest Lecture – Spacecraft Propulsion • Launch is in 18 days

3. Announcements… Brady’s Talk… - What did you think? HW #8… - Everyone turn it in? Movie Night Tonight… - Show of hands as to who is coming

4. Next Class… Guest Lecture on Structures + Mission Simulations Colorado Space Grant Consortium

5. Next Class… Guest Lecture on Structures + Mission Simulations Colorado Space Grant Consortium

6. Mission Simulations… Bring all hardware - Be prepared to give a 60 second into - Be prepared to activate at beginning of class - Be prepared to give a 60 second wrap up at end

7. Spacecraft Propulsion Steve Hevert Lockheed Martin Colorado Space Grant Consortium

8. http://my.execpc.com/~culp/space/as07_lau.jpg An Introduction toSpace Propulsion Stephen Hevert Affiliate Professor Metropolitan State College of Denver

9. www.hearlihy.com What Is Propulsion? • Initiating or changing the motion of a body • Translational (linear, moving faster or slower) • Rotational (turning about an axis) • Space propulsion • Rocket launches • Controlling satellite motion • Maneuvering spacecraft • Jet propulsion • Using the momentum of ejected mass (propellant) to create a reaction force, inducing motion At one time it was believed that rockets could not work in a vacuum -- they needed air to push against!!

10. Air-Breathing Systems Also called duct propulsion. Vehicle carries own fuel; surrounding air (an oxidizer) is used for combustion and thrust generation Gas turbine engines on aircraft… Rocket Propulsion Vehicle carries own fuel and oxidizer, or other expelled propellant to generate thrust: Can operate outside of the Earth’s atmosphere Launch vehicles, upper stages, Earth orbiting satellites and interplanetary spacecraft … or …or go karts! … a rocket powered scooter! www.gadgets-reviews.com www.the-rocketman.com Jet Propulsion Classifications

11. Space Propulsion Classifications Systems that use an expellant (e.g. on-board propellant) • Electric • Electrothermal • Electrostatic • Electromagnetic • Stored Gas or Vapor • Compressed gas • Ammonia • Butane • Nitrous Oxide • Chemical • Liquid • Solid • Hybrid We’ll look at some of these today… • Nuclear • Nuclear thermal • Nuclear electric • Antimatter • Beamed Energy • Laser thermal • Microwave thermal • Microwave electric • Solar • Solar thermal • Solar electric Systems that do not carry an expellant (extract energy/force from external source) • Beamed Energy • Laser reflector (light sail) • Microwave (Starwisp) • Sails • Solar sails (light or solar wind) • M2P2 (charged particles) • Interstellar Ramjet • Bussard drive • Tethers • Stationary • Rotating • Electrodynamic • Pumped • Aero/Gravity Assist • Aero assist • Aero braking • Aero capture • Gravity assist • Breakthrough Propulsion Physics • Space drives (warp drives) • Wormholes • Antigravity

12. blog.wired.com Space Propulsion Applications www.army-technology.com Tactical Missiles Sounding Rockets Ballistic Missiles Terrestrial/Atmosphere/ Suborbital Earth to Orbit Launch Vehicles In-Space Realm of Existing Technology Orbit Transfer Earth Orbiting Upper Stages & Satellites Lunar Missions Interplanetary Missions Space Exploration The Future Interstellar Space Exploration Star Trek!! www.psrd.hawaii.edu

13. Space Propulsion Functions • Primary propulsion • Launch and ascent • Maneuvering • Orbit transfer, station keeping, trajectory correction • Auxiliary propulsion • Attitude control • Reaction control • Momentum management www.ksc.nasa.gov www.nasm.si.edu

14. onenew.wordpress.com Wan-Hu tried to launch himself to the moon by attaching 47 black powder rockets to a large wicker chair! (…Chinese folk tale) Dr. Goddard goddard.littletonpublicschools.net Prof. Tsiolkovsky Dr. von Braun www.britannica.com A Brief History of Rocketry • China (1232 AD) • Earliest recorded use of rockets • Black powder • Russia (early 1900’s) • Konstantin Tsiolkovsky • Orbital mechanics, rocket equation • United States (1920’s) • Robert Goddard • First liquid fueled rocket (1926) • Germany (1940’s) • Wernher von Braun • V-2 • Hermann Oberth • Russia (USSR) • Phenomenal contributions… • Korolev, Glushko, Keldysh www.geocities.com

15. Primary or auxiliary propulsion High pressure gas (propellant) is fed to low pressure nozzles through pressure regulator Release of gas through nozzles (thrusters) generates thrust Currently used for momentum management of the Spitzer Space telescope Propellants include nitrogen, helium Very simple in concept Propellant Tank Gas Fill Valve Pressure Gage P Filter High Pressure Isolation Valve Pressure Regulator Low Pressure Isolation Valve Thruster Stored Gas Propulsion

16. Liquid Propellant Pump Fed Launch vehicles, large upper stages Pressure Fed Smaller upper stages, spacecraft Monopropellant Fuel only Bipropellant Fuel & oxidizer Solid Propellant Launch vehicles, Space Shuttle, spacecraft Fuel/ox in solid binder Hybrid Solid fuel/liquid ox Sounding rockets, X Prize www.aerospaceweb.org en.wikivisual.com news.bbc.co.uk Chemical Propulsion Classifications

17. Hydrazine fuel is most common monopropellant. N2H4 Decomposed in thruster using iridium catalyst to produce hot gas for thrust. Older systems used hydrogen peroxide (H2O2) before the advent of hydrazine catalysts. Typically operate in blowdown mode (pressurant and fuel in common tank). Monopropellant Systems Nitrogen or helium Hydrazine Propellant Tank Pressure Gage P Fuel Fill Valve Isolation Valve Filter Thrusters Thrusts of 1 to 400 N (0.2 to 100 lbf) are common.

18. Monopropellant Systems 5 lbf thrusters used on the Compton Space Telescope (Gamma Ray Observatory) Northrop Grumman 1 lbf thrusters manufactured by Northrop Grumman www.aerojet.com

19. A fuel and an oxidizer are fed to the engine through an injector and combust in the thrust chamber of the engine Combustion products accelerate in a converging-diverging nozzle Hypergolic: no igniter needed -- propellants react on contact in thrust chamber Cryogenic propellants include LOX (-423 ºF) and LH2 (-297 ºF). Igniter required Storable propellants include kerosene (RP-1), hydrazine, nitrogen tetroxide (N2O4), monomethylhydrazine (MMH) P P Bipropellant Systems OX FUEL Isolation Valves Thrust Chamber Engine Nozzle

20. Bipropellant Thrusters 4 N AMPAC-ISP Astrium AMPAC-ISP Bipropellant thrusters are used for orbit transfer and for attitude control, with thrusts ranging from 4 to 440 N (1 to 100 lbf)

21. Liquid Propellant Systems • Pump fed systems • Propellant delivered to engine using turbopump • Gas turbine drives centrifugal or axial flow pumps • Large, high thrust, long burn systems: launch vehicles, space shuttle • Different cycles developed. H-1 Engine Turbopump A 35’x15’x4.5’ (ave. depth) backyard pool holds about 18,000 gallons of water. How quickly could the F-1 turbopumpsempty it ? Ans: In ~27 seconds! • F-1 engine turbopump: • 55,000 bhp turbine drive • 15,471 gpm (RP-1) • 24,811 gpm (LOX) Photos history.nasa.gov F-1 Engine Turbopump

22. www.answers.com Rocket Engine Power Cycles • Gas Generator Cycle • Simplest • Most common • Small amount of fuel and oxidizer fed to gas generator • Gas generator combustion products drive turbine • Turbine powers fuel and oxidizer pumps • Turbine exhaust can be vented through pipe/nozzle, or dumped into nozzle • Saturn V F-1 www.aero.org/publications/ crosslink/winter2004/03_sidebar3.html

23. science.nasa.gov Rocket Engine Power Cycles - cont • Expander • Fuel is heated by nozzle and thrust chamber to increase energy content • Sufficient energy provided to drive turbine • Turbine exhaust is fed to injector and burned in thrust chamber • Higher performance than gas generator cycle • Pratt-Whitney RL-10 www.aero.org/publications/ crosslink/winter2004/03_sidebar3.html

24. Rocket Engine Power Cycles - cont • Staged Combustion • Fuel and oxidizer burned in preburners (fuel/ox rich) • Combustion products drive turbine • Turbine exhaust fed to injector at high pressure • Used for high pressure engines • Most complex, requires sophisticated turbomachinery • Not very common, but very high performance • SSME (2700 psia) www.rocketrelics.com www.aero.org/publications/ crosslink/winter2004/03_sidebar3.html shuttle.msfc.nasa.gov

25. Main Engine Space Shuttle 374,000 lbs thrust (SL) LOX/H2 RD-170 1.78 million lbs thrust (SL) LOX/Kerosene F-1 Engine Saturn V 1.5 million lbs thrust (SL) LOX/Kerosene spaceflight.nasa.gov www.aerospaceguide.net www.flickr.com The Big Engines…

26. Fuel and oxidizer are in solid binder. Single use -- no restart capability. Lower performance than liquid systems, but much simpler. Applications include launch vehicles, upper stages, and space vehicles. www.aerospaceweb.org www.nationalmuseum.af.mil www.propaneperformance.com Solid Propellant Motors

27. Combination liquid-solid propellant Solid fuel Liquid oxidizer Multi-start capability Terminate flow of oxidizer Fuels consist of rubber or plastic base, and are inert. Just about anything that burns… Oxidizers include LO2, hydrogen peroxide (H2O2) and nitrous oxide (NO2) Shut-down/restart capability. Oxidizer Tank Ox Control Valve Solid Propellant Nozzle Hybrid Motors

28. Thrust & Specific Impulse Thrustis the amount of force generated by the rocket. Specific impulseis a measure of performance (analogous to miles per gallon) Units are seconds Rocket Equation Propulsion Calculations Rocket equation assumes no losses (gravity effects, aerodynamic drag). Actually very accurate for short burns in Earth orbit or in deep space!

29. Stored gas Monopropellant hydrazine Solid rocket motors Hybrid rockets Storable bipropellants LOX/LH2 60-179 sec 185-235 sec 280-300 sec 290-340 sec 300-330 sec 450 sec This thruster was used on the Viking Lander. It has a specific impulse of about 225 seconds. www.rocketrelics.com Specific Impulse Comparison Specific impulse depends on many factors: altitude, nozzle expansion ratio, mixture ratio (bipropellants), combustion temperature, combustion pressure

30. Mission Delta-V Requirements LEO = Low Earth orbit (approx. 274 km) That’s actually very low….

31. Propellant Calculation Exercise • Determine the mass of propellant to send a 2500 kg spacecraft from LEO to Mars (0.7 yr mission). • Assume the 2500 kg includes the propellant on-board at the start of the burn. • Assume our engine has a specific impulse of 310 sec (typical of a small bipropellant engine). • Use the rocket equation: Most of our spacecraft is propellant! Only 383 kg is left for structure, etc! How could we improve this?

32. Classifications Electrothermal Electrostatic Electromagnetic Characteristics Very low thrust Very high Isp > 1000 sec Requires large amounts of power (kilowatts) www-ssc.igpp.ucla.edu Electric Propulsion This image of a xenon ion engine, photographed through a port of the vacuum chamber where it was being tested at NASA's Jet Propulsion Laboratory, shows the faint blue glow of charged atoms being emitted from the engine. The ion propulsion engine is the first non-chemical propulsion to be used as the primary means of propelling a spacecraft.

33. Electrical power is used to add energy to exhaust products Resistojet Catalytic decomposition of hydrazine is augmented with high power electric heater 800 – 5,000 W Arcjet High voltage arc at nozzle throat adds thermal energy to exhaust Various gaseous or vaporized propellants can be used. rocket.itsc.uah.edu www.fathom.com www.nasa.gov www.waynesthisandthat.com Electrothermal Propulsion

34. Electrostatic forces are used to accelerate charged particles to very high velocities Xenon Ion Thruster Xenon propellant Xenon is ionized by electron bombardment Thermionic cathode Positively charged particles accelerated by grid Electrons routed to second anode and injected into beam to neutralize Electrostatic Propulsion www.plasma.inpe.br ESA’s SMART-1 uses a xenon ion propulsion system (XIPS) aerospace.engin.umich.edu

35. Electromagnetic forces are used to accelerate a plasma A gas consisting of positive ions, electrons 5000 – 9000 R Neutral beam is produced Higher thrust per unit area than electrostatic thruster Classifications Magnetoplasmadynamic Pulsed plasma Electric discharge creates plasam from solid Telfon Hall effect Developed in Russia Flew on U.S. STEx mission (1998) Electromagnetic Propulsion www.nasa.gov

36. Interstellar Missions – The Future • The challenges are formidable • Immense distances… • Alpha Centauri = 4.5 LY (closest interstellar neighbor) • 1 LY = 9.46x1012 km = 5.878x1012 mi • Universe = ~156 billion LY across • Immense size & mass & energy & speeds required… • Propulsion systems with dimensions of 1000’s km • Power levels 1000’s x greater than Human Civilization now produces ( > 14 TW est.) • Speeds ~ .4c - .6c (c = speed of light) • Trip times… Robotic Rendezvous goals • 4.5 LY in < 10 years • 40 LY in < 100 years (radius of nearest 1000 stars) • Relativistic effects… • Because of time dilation and mass increase; length contraction • On telecommunications • From collisions with interstellar matter

37. Consider the Voyager I Spacecraft… spacetoday.org • 29 years after launch in 1977: • It had travelled ~100 AU • Far beyond Pluto • ~150 million km • 13.9 light-hours from sun • Moving at 17.4 km/s • 0.006% of the speed of light • One of the fastest man-made vehicles • It would take another 74,000 years to reach Alpha Centauri at this rate • Advanced technologies and breakthroughs will be necessary to reach the stars… Source: Frisbee, R., “Impact of Interstellar Vehicle Acceleration and Cruise Velocity on Total Mission Mass and Trip Time,” AIAA 2006-5224, July 2006

38. Future Propulsion Technologies Interstellar Ramjet Beamed Energy Laser Light Sails Driven by massive space-based laser and space-based optics • Bussard Drive (1960) • Electromagnetic scoop gathers interstellar hydrogen for propellant • EM “Scoop” is 1000’s of km in size! bibliotecapleyades.net daviddarling.info

39. Future Propulsion Technologies- cont Matter-Antimatter Other Space Drive Ideas… • Highest energy per unit mass of any reaction known in physics • Energy released by annihilation of matter by antimatter counterpart

40. Future Propulsion Technologies- cont Breakthrough Physics • Yes, NASA funds research on • Wormholes • Warp drives Wormhole: a “shortcut” through the spacetime continuum bibliotecapleyades.net daviddarling.info When I began my career in the late 1970’s, we’d joke about electric propulsion being the “propulsion of the future…and always will be!” Today it is used on communications satellites and interplanetary spacecraft. What does the future hold for interstellar propulsion? Now it is the “propulsion of the future”... but will it always be?

41. References • Theory and design • Sutton, G. P. and Biblarz, O., Rocket Propulsion Elements, 7th ed. ,Wiley, 1987 • A classic; covers most propulsion technologies • Huzel, D.K, and Huang, D. H., Modern Engineering for Design of Liquid Propellant Rocket Engines (revised edition), Progress in Aeronautics and Astronautics, Vol. 147, American Institute for Aeronautics and Astronautics, 1992 • Dieter Huzel was one of the German engineers who came to the U.S. after WW II. • Humble, R. W., et. al., Space Propulsion Design and Anaylsis (revised edition), McGraw-Hill, 1995 • Covers chemical (liquid, solid, hybrid), nuclear, electric, and advanced propulsion systems for deep space travel

42. References - cont • Rocket engine history • Macinnes, P., Rockets: Sulfur, Sputnik and Scramjets, Allen & Unwin, 2003 • Clary, D. A., Rocket Man: Robert H. Goddard and the Birth of the Space Age, Hyperion Special Markets, 2003 • Ordway, F. I. and Sharpe, M., The Rocket Team, Apogee Books, 2003 • The story of Werner von Braun, the V-2 and the transition of the German engineers to the United States following WW II • Sutton, G. P., History of Liquid Propellant Rocket Engines, American Institute for Aeronautics and Astronautics, 2006 • New, over 800 pages of rocket engine history

43. When things go badly… http://www.youtube.com/watch?v=gDnkEOKR1BE