Liquid Hydrogen and liquid oxygen will flow into space shuttle Discovery’s orange external fuel tank for the next three hours as launch day preparations continue for the STS-133 mission. The process began at 5:58 a.m. EDT. Liftoff is scheduled for 3:04 p.m.
The hydrogen and oxygen will power Discovery’s three main engines during liftoff and ascent into orbit. Both propellants are kept extremely cold as they are pumped into the tank. The liquid hydrogen is minus 497 degrees F and the liquid oxygen is minus 297 degrees.
Steve Lindsey commands this mission to the International Space Station and he will be joined on the shuttle’s flight deck by Pilot Eric Boe and mission specialists Alvin Drew and Tim Kopra. Mission specialists Michael Baratt and Nicole Stott will sit on the lower level during launch.
The weather forecast improved overnight for today’s launch attempt. Forecasters are calling for a 70 percent chance of acceptable conditions at launch time. The prime concern is the possibility of high winds around NASA’s Kennedy Space Center in Florida, the shuttle fleet’s launch site.