Mike from Iowa City, he asks, what factors are considered in determining the time of day this launch will occur?
Well, there are actually several factors, one of which is you have to have an orbiter that's ready to go fly, all systems go.
Two, there is a certain amount of energy that it takes to liftoff and rendezvous with the International Space Station.
And depending on where it is in space or on orbit, it can limit the times in which you can launch.
Also, up on space, or on orbit, there are temperature extremes, heat and cold, that drive your launch time.
And finally, for this particular mission and the next, we want to fly during daylight hours so that our
film cameras can pick up any debris that might come loose from the tank or the Solid Rocket Boosters.