Deep Impact Launch Vehicle Separation Sequence
The animation opens with the joint flyby and impactor spacecraft before separation from the third stage. The Boeing Delta 2925 uses a spin-stabilized Star 48 upper stage to provide the final energy and injection accuracy, sending Deep Impact on a 6 month journey towards comet Tempel 1. But before releasing the spacecraft the launch vehicle must despin the system from approximately 60 rpm to less than 5 rpm. This is accomplished using a yo-yo despin system which unwraps two cable-weight assemblies, raising the mass inertia, and slowing the system in a manner not unlike an ice skater throwing her arms out to slow her rotation.
Following third stage separation the Deep Impact flight system deploys it's two solar array panels and stabilizes itself by firing its reaction control thrusters. The flight system then enters sun-acquisition mode and begins electrical power generation necessary for the long voyage.
CREDIT: All Video Production, Inc., Boulder, CO