Discovery Mission

Turn on your TV sets around 3 p.m Eastern to get ready for Discovery's blastoff. The stakes are large for NASA -"A triumphant launch and especially a safe landing is deemed an "absolute prerequisite" to NASA’s future plans, suggested John Logsdon, Director of the Space Policy Institute at George Washington University’s Elliott School of International Affairs in Washington, D.C.

"NASA needs to get shuttle flying to finish the International Space Station. It needs to retire the shuttle as soon as possible and replace it with newer, safer, systems," Logsdon told SPACE.com , while getting started on human exploration beyond Earth orbit.

"None of this is likely to happen if this mission fails badly," Logsdon advised. "So this launch ranks up there with Alan Shepard and John Glenn’s Mercury missions and Apollo 11 in its significance."

For more about what will take place on the shuttle, head to Mission: Safety .