A premier aerospace and defense company Solar Sail Space Weather Capabilities Solar Sail Space Weather Capabilities Dr. Bruce Campbell Dr. Bruce Campbell ATK Space Systems Division 1
Introduction A premier aerospace and defense company Solar sails offer unique capabilities to perform heliophysics missions in space • Discussion Topics: – How solar sails “work” – How solar sails “work” – Some possible solar sail missions – An example space weather solar sail mission (GeoStorm) 2
Solar Radiation Pressure A premier aerospace and defense company Solar Photon Pressure (R=0.9) 1000.0 100.0 (N/km^2) Pressure (N 10.0 10.0 1.0 0.1 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Destance to Sun (Au) P = 2 W L S W = W E = 1368 W/m 2 P E = 9.15 x 10 -6 N/m 2 Energy Pressure 4 P r 2 c 3
Solar Sail Force = Acceleration A premier aerospace and defense company • Photons carry Momentum - r r = h n /c n – f tot • h = Planck’s, n = frequency, c = speed n n - of light f i • Force generated on Reflective - f r f r Surface Surface – Resultant force approximately perpendicular to surface • The bigger the surface, the more the force Can “steer” sail by changing pitch angle a a – sail a Area Reflected • Small, but potentially Constant A radiation Acceleration Incoming radiation – Potentially unlimited “delta V” – Allows some otherwise impossible orbits P I 4
q a Solar Sail Performance A premier aerospace and defense company • For a 100 kg sailcraft, 100 m x 100 m square sail: • Force (maximum, perp. to sun, perfect/flat reflector) – 0.09 N • Acceleration (maximum) 0.92 x 10 -3 m/s 2 (0.9 millimeters/sec 2 ) – or q i ) • Force decreases with increasing pitch angle ( a 2 ˆ ( ) f tot = 2 P I A cos q i n Solar Sail Total Force (Thrust) Vs. Sun-Incidence Angle (For a 100 x 100 meter perfect sail @ 1 A.U.) 5
Solar Sail Performance A premier aerospace and defense company • Force on a 100 m x 100 m square sail: 6
Solar Sail Orbital Maneuvers A premier aerospace and defense company • Increase or Decrease orbital energy – Spiral in/out from the Sun • Force out of orbital plane can change inclination – “Crank” up and over the sun 7
Solar Sail GN&C A premier aerospace and defense company • Sail Attitude Control Concepts – Center of Pressure vs Center of Mass (C P /C M ) – Control Vanes – Other: • Sail Articulation/Manipulation • Variable Reflectivity • Variable Reflectivity • Micro-thrusters • Sail Navigation – Attitude control is Trajectory control! • Entire sail moved to achieve required force vector – Effects on other systems: • Attitude determination systems • Navigation & communications systems • Science instruments 8
Solar Sail Orbits A premier aerospace and defense company • Keplerian • Non-Keplerian – Plane changes (out of ecliptic) – Artificial LaGrange Points – Low thrust transit (Geostorm) • Spiral in/out – Pole-Sitters (PASO) • Flyby – Displaced Conic Orbits – Fast Hyperbolic Transfer – Node Precession (slot walking) • Solar Photonic Assist • Solar Photonic Assist – – Libration point highway (JPL) Libration point highway (JPL) • H – reversal – Other? 9
Heliophysics Solar Sail Missions A premier aerospace and defense company Solar Polar Imager Solar Polar Imager L-1 Diamond L-1 Diamond Interstellar Probe Particle Accel. Solar Orbiter Geostorm 10 10
Geostorm: Solar Storm Warning Mission A premier aerospace and defense company Not to scale 11
The Geostorm Mission A premier aerospace and defense company Use a solar sail to achieve a non-Keplerian orbit near the sun-earth line, twice as far from the earth as the current warning system, NOAA’s Advanced Composition Explorer (ACE) at the L 1 point Geostorm will double the warning time to enable the reconfiguration and securing of space systems (and ground electrical power grids) to avoid: • Complete or partial loss of HF & satellite communications • • Degraded navigational and geo-locational capability Degraded navigational and geo-locational capability • False returns on ATC and early warning radars • Satellite system disruption and lock problems Geostorm, being propellantless, could result in a significantly longer mission lifetime 12
Trajectory Plot A premier aerospace and defense company From GTO to L1 to Sub-L1 at 0.98 AU and Position Keeping From GTO to L1 to Sub-L1 at 0.98 AU and Position Keeping (a0=0.306 mm/s2) (a0=0.306 mm/s2) 2e+6 2e+6 Halo orbit Halo orbit Halo Orbit (L1 ) insertion Halo Orbit (L1 ) insertion 1e+6 1e+6 1/25/2009 1/25/2009 Depart Halo Depart Halo ²V1 = 5.7 m/s ²V1 = 5.7 m/s 3/26/2009 3/26/2009 Arrive Sub-L1 Arrive Sub-L1 10/11/2008 10/11/2008 10/18/2009 10/18/2009 GTO Perigee @100 n.m. GTO Perigee @100 n.m. Y (km) Y (km) FT=206 d FT=206 d ²V = 739 m/s ²V = 739 m/s to Sun to Sun 0e+0 0e+0 Earth Earth Orbit about Sub-L1 Orbit about Sub-L1 158 d loop. 158 d loop. To maintain a loop, thrust To maintain a loop, thrust 11/09/2008 11/09/2008 cone oscillate between 0- cone oscillate between 0- ²V1 = 9.8 m/s ²V1 = 9.8 m/s 10 degrees 10 degrees -1e+6 -1e+6 Run-away orbit if Run-away orbit if exactly sun-pointed. exactly sun-pointed. -2e+6 -2e+6 -1e+6 -1e+6 0e+0 0e+0 1e+6 1e+6 2e+6 2e+6 3e+6 3e+6 4e+6 4e+6 5e+6 5e+6 X (km) X (km) 13
“Sailcraft” Concept A premier aerospace and defense company SPACECRAFT SPACECRAFT BUS BUS 70 m SAIL SAIL SAILCRAFT BUS (TOP VIEW) SAILCRAFT BUS (TOP VIEW) 14
Sailcraft Sizes A premier aerospace and defense company 15
Prior Solar Sail Studies A premier aerospace and defense company • NASA: – Halley’s Comet 1 (1977), Columbus 500 2* (1989), ST-5 1 (1999), ST-7 1* (2001) • NOAA/USAF: – Geostorm 1 (1996) – Geostorm (1996) • ESA/DLR: – ODISEE 1 (1998) 1 : JPL Halley Sail 2 : APL Mission * : GSFC involvement 16
Past Activities A premier aerospace and defense company IAE/NASA NGST Sunshade Cosmos 1 DLR/Germany AFRL/NOAA Znamya/Russia Encounter MSFC ISP SSP 17
NASA In-Space Propulsion Development A premier aerospace and defense company • Raise the Technology Level (TRL) of Solar Sail Technologies • Approx. $35 M invested CP1 Tensioned Sail (NASA/ATK) Mylar Draped Sail (NASA/L’Garde) 18
JAXA IKAROS A premier aerospace and defense company • Japanese Solar Sail Technology Experiment • Launched on way to Venus 19
NASA/OCT-STMD/L’Garde Sunjammer A premier aerospace and defense company • Technology Demonstration (2014 launch?) 35 ft. 20
NASA New Technology A premier aerospace and defense company In-Space Propulsion Technology Roadmap 21
NASA New Technology A premier aerospace and defense company Solar Sail Roadmap GeoStorm <1000 m 2 <2500 m 2 IKAROS L1 Diamond Orbit Demo Orbit Demo 22
Conclusion A premier aerospace and defense company • Solar Sail technology is ready to show its applicability for use in space flight missions • Solar Sails offer a unique capability to enhance and enable new solar weather monitoring methods that would benefit science and mankind. 23
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