Three video cameras are mounted aboard the Atlas 5 rocket to give engineers live views of critical events during Thursday's launch sequence.

• A downward-facing camera attached to the first stage will show liftoff and the rocket's climb away from Earth. Its engineering purpose is providing a clear view of solid rocket booster separation.
  
  
• An upward-facing camera on the first stage will be watching separation of the rocket's nose cone. One-half of the fairing is in the camera's field-of-view.
  
  
• The Centaur upper stage is carrying a forward-facing camera to see jettison of the fairing's load-support deck. This camera should also capture a partial view of the Rainbow 1 satellite payload being deployed.
  
  

These images provide a preview of what the three onboard cameras should see during the Atlas 5 launch. Credit: Lockheed Martin

"We do expect to have decent coverage and illumination if we launch in approximately the first half of the window. If we launch late in the window, the Sun will have set and we may lose the coverage for the boost-phase events, which are the SRB separation, the fairing and the Forward Load Reactor deck separation," said Jim Sponnick, Lockheed Martin's Atlas program vice president.

"If we get the video coverage during the separation events, it is valuable information to have. It is not absolutely necessary. We have other instrumentation onboard the vehicle, the solids...and all the information we are able to get from the payload fairing during the first second of separation."

The available launch window extends from 7:20 to 9:00 p.m. EDT (2320-0100 GMT) each day.

The cameras are supplied by Ecliptic Enterprises of Pasadena, California. Thursday's mission will mark the fourth time onboard video cameras have flown on Atlas rockets since 2000. The maiden flight of Atlas 3, a classified mission for the National Reconnaissance Office using an Atlas 2AS and the first Atlas 5 have carried cameras.