Photos: Atlas 5 rolls out for launch

Several NASA astronauts, plus Boeing test pilot Chris Ferguson, recently participated in a training session at Cape Canaveral, practicing how they would evacuate from the Atlas 5 rocket’s launch pad in the event of a countdown emergency.

SpaceX’s Falcon 9 rocket is awaiting liftoff from Cape Canaveral’s Complex 40 launch pad as soon as Tuesday after three scrubs caused by propellant loading problems and a boat that strayed into restricted waters in the Atlantic Ocean.

The rollout operation on Tuesday followed a day of evaluations using Boeing’s weight and center-of-gravity machine to determine the final measurements on the spacecraft. Launch is still targeting May 6 at 10:34 p.m. EDT (0234 UTC).