CONVENTIONAL ROCKET PROPULSION NON-CONVENTIONAL PROPULSION SOLAR SAILS TETHERS ELECTRIC SAILS
THE REASON? DISTANCE!!!
CONVENTIONAL ROCKET PROPULSION NON-CONVENTIONAL PROPULSION SOLAR SAILS TETHERS ELECTRIC SAILS
A motional electromotive force is generated across a tether as it moves relative to the Earth s magnetic field given by Faraday s Law of Induction
A motional electromotive force is generated across a tether as it moves relative to the Earth s magnetic field given by Faraday s Law of Induction The tether moves relative to the Earth s magnetic field. The positive end of the tether collects ionospheric electrons forming an electrical current; a force on the wire will be generated via the Lorentz Force
14 Magnetic field strength and direction varies over each orbit Forces have components both: In-plane (orbit raising/lowering) Out-of-plane (inclination change) Tether current can be modulated over one or more orbits to change all six orbital elements
spacecraft launch date launch vehicle SEDS 1 + deployer SEDS 2 + deployer Mar. 30, 1993 Delta 7925 Mar. 10, 1994 Delta 7925 orbit 195 705 34 350 km (circular) mass 25 kg 25 kg
(0.5 km/sec V required for capture) Jovian Electrodynamic Capture V = 5 km/sec Electrodynamic Decay Region ( V in km/sec) Hyperbolic Intercept 0.03 0.06 Parabolic 100 Day Capture Orbit 0.12 0.33 0.73 Perijove = 1.2 R J
Tethered Satellite System before it broke Tethered Satellite System after it separated from the Space Shuttle
CONVENTIONAL ROCKET PROPULSION NON-CONVENTIONAL PROPULSION SOLAR SAILS TETHERS ELECTRIC SAILS
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Real Solar Sails Are Not Ideal Ideal Case Sail Incident Photons Thrust Vector Sun Angle Billowed Quadrant Sail normal vector Reflected Photons Diffuse Reflection Sail Sail Incident Photons Thrust Vector Incident Photons Thrust Vector Sun Angle Sun Angle Sail normal vector Sail normal vector Reflected Photons Reflected Photons 23
Thrust Vector Components Sail F(normal) CP F(total) Sun Angle F(tangential) CM Sail normal vector M(total) Reflected Photons 24
Image courtesy of Colorado Center for Astrodynamics Research 25
135-foot rigidized inflatable balloon satellite laminated Mylar plastic and aluminum placed in near-polar Orbit passive communications experiment by NASA on January 25, 1964 When folded, satellite was packed into the 41- inch diameter canister shown in the foreground. 26
Znamya (Space Mirror) Russian experiment that flew on Progress after undocking from Mir Space Station in 1993. Purpose was to reflect sunlight onto the ground from space. 20-m diameter sail successfully deployed 5-km spot illuminated Europe from France to Russia moving at 8 km/sec. Follow-on mission flew, but was damaged during deployment. 27
NASA GROUND TESTED SOLAR SAILS IN THE MID-2000 S Two solar sail technologies were designed, fabricated, and tested under thermal vacuum conditions in 2005: Developed and tested high-fidelity computational models, tools, and diagnostics Multiple efforts completed: materials evaluation, optical properties, long-term environmental effects, charging issues, and assessment of smart adaptive structures 28
400 m2
NANOSAIL-D DEMONSTRATION SOLAR SAIL 10 M 2 SAIL MADE FROM TESTED GROUND DEMONSTRATOR HARDWARE 31
NanoSail-D in Flight 32
Interplanetary Kite-craft Accelerated by Radiation of the Sun (IKAROS) 33
Interplanetary Kite-craft Accelerated by Radiation of the Sun (IKAROS) Jacob Peter Gowy's The Flight of Icarus 34
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4.5 LY INTERSTELLAR PROBE FLYBY 40 LY INTERSTELLAR PROBE RENDEZVOUS Solar Powered Laser Powered = Areal Density (Sail Mass/Sail Area) INTERSTELLAR MEDIUM EXPLORATION 4000-m DIA 0.1 g/m 2 TECH DEV INTERSTELLAR PROBE 2025-2050 TECH DEV NEAR-TERM SAILS 2010-2015 3 5 m DIA TECH DEV NanoSail-D LightSail InflateSail/CubeSail MID-TERM SAILS 2015-2025 5 to 100 m DIA = 10 g/m 2 TECH DEV 500-800-m DIA = 1-2.5 g/m 2 TECH DEV NEA Scout / Lunar Flashlight Solar Polar Imager NON-KEPLERIAN EARTH ORBITS 1-km DIA = 0.1 g/m 2 INTERSTELLAR PROBE EUROPA LANDERS COMET SAMPLE RETURN OORT CLOUD 4-km DIA = 0.1 g/m 2 1000-km DIA = 0.1 g/m 2
CONVENTIONAL ROCKET PROPULSION NON-CONVENTIONAL PROPULSION SOLAR SAILS TETHERS ELECTRIC SAILS
Electric Sail Concept