Project Icarus Study Group1
Project Icarus: Solar Sail Technology
for theIcarus Interstellar Mission
Project Icarus Study Group
Internet: http://icarusinterstellar.org/ E-mail: [email protected]
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Project Daedalus
Design study between 1973—1978• Considered the challenges of
interstellar travel• Used current/near-future
technology • Reach destination within a human
lifetime• Allow for a variety of target stars
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Project Icarus
• Tau Zero Foundation initiative in collaboration with The British Interplanetary Society.
• Officially began30 September 2009.
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Icarus Project Requirements
• Unmanned probe• Current or near-future technology• Reach destination as fast as possible• Variety of target stars• Propulsion mainly fusion based• Deceleration for prolonged encounter time
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Icarus Parameters
• Interstellar cruise speed 0.1—0.2c• Launch mass (Daedalus) ≈ 50,000 tonnes• Encounter mass (Daedalus) ≈ 50,000 kg
Potential Sail Uses
• Boost from solar system• Deceleration at target star• Deployment of gravitational lens relay• Deployment of sub-probes in target
system
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Case #1
Deceleration at Target Star
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Deceleration at Alpha Centauri A
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Deceleration – Realistic Sail
• Hollow-Body Beryllium Sail• Capture at 0.066 AU• σsail = 4 × 10−5 kg/m2
• ρ = 0.9
Sail Deceleration (Hollow-Body Sail)
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Sail Deceleration (Hollow-Body Sail)
• Limiting case of no payload:vi ≈ 0.004c (1200 km/s)
• Therefore 96-98% of deceleration must occur before the sail is used
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Deceleration – ‘Ideal’ Sail
• Capture at 0.066 AU• σsail ≥ 0• ρ = 1
Sail Deceleration (Ideal Sail)
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Sail Deceleration (Ideal Sail)
Assume:• Icarus encounter mass = 50,000 kg• Interstellar speed = 0.1c
Sail diameter required ≈ 944 km
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Case #2
Deployment of
Gravitational Lens Relay Station
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Gravitational Lens Relay Station
Not to scale!
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Gravitational Lens Relay Station
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Grav Lens Relay Deployment
Assume:• 10 GW laser (λ = 1μm)• Lens diameter = 1 km• Sail ρ = 0.85• σ = 1 g/m2
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Grav Lens Relay Deployment Time
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Grav Lens Relay Deployment
Payload mass of 300 kg
Delivered to 700 AU in 10 years
Sail diameter ≈ 620 m
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Case #3
Boost from Solar System
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Boost from Solar System
Assume:• Icarus launch mass = 50,000 tonnes• Sail ρ = 0.85• Laser pushed
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Boost from Solar System
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Boost from Solar System
Assume:• 100 GW laser (λ = 1μm)• Lens diameter = 100 km• σ = 1 g/m2
Then:• Terminal velocity ≈ 0.002c• Sail diameter ≈ 250 km
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Case #4
Deployment of Sub-Probes in Target System
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Deployment of Sub-Probes
• Assume Icarus is captured into a close orbit of the star
• Analogous to deploying interplanetary probes in our solar system
• Could reach outer planets in a decade or two
• Non-Keplerian orbits possible• Change of inclination e.g. cranking
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Summary
• Sails not realistic for boost or deceleration of main craft
• Potential for deployment of gravitational lens relay (using laser push
• Potential for deployment of sub-probes
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Project Icarus
Internet: http://icarusinterstellar.org/