In this case, the 'tanking' process was started on 9:28 p.m. Eastern Daylight Time (EDT) on Sunday night, and was finished up at about 12:12 a.m. EDT on Monday morning.
The fuel inside the ET is fed into the three space shuttle main engines during the shuttle's ascent into space.
The countdown proceeded nominally, with a planned hold at T-3 hours (three hours before the scheduled liftoff of the STS-131 astronauts, at 6:21 a.m. EDT).
At 2:26 a.m. EDT the countdown resumed and the NASA final inspection team made their final check out of the launch pad and the shuttle.
A final closeout crew was waiting as the astronauts' arrived at about 3 a.m. EDT.
The seven STS-131 astronauts were awakened at 8 p.m. on Sunday night inside the Astronaut Crew Quarters (inside the Operations and Checkout Building) at the NASA Kennedy Space Center (KSC) in preparation for their trip into space.
Page two continues the STS-131 countdown.
At this time, NASA officials stated that there were not any technical issues that were standing in the way of a launch at 6:21 a.m. EDT.
The Closeout Crew helped each astronaut through the side hatch of the space shuttle and into their seats inside Discovery.
KSC officials stated that weather conditions continue to be good for an on-time launch of STS-131.
As the seven astronauts are checking out their communications between the Control Center and their vehicle for their trip into space, astronaut Chris Ferguson was flying a Shuttle Training Aircraft around the Florida sky in order to access the weather conditions. All was deemed good.
After strapping in the astronauts the Closeout Crew closed the side hatch to Discovery, and make sure it was properly sealed. They then make a cabin check, assuring that it was not leaking, from their location inside the White Room.
Page three follows the countdown to liftoff of STS-131.
The Close out crew left the pad after making sure all was ready for the launch. The countdown clock resumed with all aspects of the launch going nominally.
The space shuttle Discovery and its seven STS-131 astronauts are ready to be launched into space and toward the International Space Station.
With sunrise less than one hour away, Discovery and its crew launched at 6:21 a.m. from its launch site along the Florida coast. Launch director Pete Nickolenko, a few moments before launch said to the crew, 'It's time for you to rise to orbit, Good luck and Godspeed.'
Commander Alan Poindexter responded with a 'Let's do it!"
The blastoff of the shuttle lit up the night sky with various colors as the exhaust plume rose high from the ground..
The 4.5-million pound (mass) shuttle accelerated from 0 to 100 miles per hour in under seven seconds.
Watch a replay of the launch at the USA Today article 'Space shuttle Discovery, 7 astronauts blast off.'