Live: Astronauts suiting up for launch

The astronauts are suiting up for launch this hour.

The seven crew members are donning orange partial-pressure suits that would help protect them in the event of problems during ascent.

The astronauts are set to leave their quarters for the launch pad at 3:53 p.m.

Helicopters with gun-toting security teams are fluttering overhead in the area of the Vehicle Assembly Building and Launch Control Center, where the astronauts will be driven past on their way out to Pad 39A.

A red team at the launch pad has successfully adjusted a gas pressure valve in the mobile launcher platform that was posing problems earlier. It was never a threat to the launch, but NASA did want to get the pressure back to normal if possible.