Space Shuttle Launch: Discovery Set for Thursday Liftoff (WATCH)

NASA is preparing to launch the first of three final space shuttle missions this week, sending the Space Shuttle Discovery on its final voyage to the International Space Station on Thursday afternoon.

Liftoff is set for Thursday afternoon at 4:50 p.m. EST from the Kennedy Space Center.

Problems with Discovery’s fuel tank have delayed the mission since November of last year. The launch had to be cancelled due to an unrelated hydrogen leak on November 5, 2010.

Technicians later found a crack in the insulating foam that covers Discovery’s fuel tank, which could be a critical safety issue.

“The teams have done a great job. I think we’re ready to go next week,” said Bill Gerstenmaier, NASA’s associate administrator for space operations.

Space Shuttle Discovery will be carrying a storage room that will be tacked onto the ISS, which is finally almost done after being under construction for 12 years.

The shuttle also will deliver food and science equipment to the six ISS crewmembers as well as a prototype humanoid robot.

There will be two planned spacewalks during Discovery’s stay at the station, which will last one week.

The space shuttle program is winding down due to high costs and also to free up more funds to develop rockets and spacecraft that can travel beyond the station’s 220-mile-high orbit.