Orbital Tethers
Catch and Release
Shave precious delta-V off the cost to orbit
Why Orbiting Tethers
• Orbiting tethers: long tethers making one revolution per orbit, with the same end pointing down at all times
– The tether becomes a lower energy upper stage in the launch profile – example saves >1400 m/s over orbit velocity
• Orbiting tethers provide distinct advantages over spinning tethers and non-tethered LV approaches
– Tethers reduce final velocity to allow smaller fuel/oxidizer tanks, and lighter aero-shields for reentry
• Tether mass is only dependent on speed savings and target mass, regardless of type (and location)
– Orbiting tethers allow a low speed approach to the terminal, providing a much wider target box than spinning tethers
• Equatorial LEO Orbiting tethers allow 15 launch windows/day
