NASA's space shuttle Discovery on Monday returned to the launch pad for its final flight to the ISS. Discovery's 39th and final launch has bee scheduled for February 24 at 4:50 p. m. EST.

It is the second time that Discovery has returned to the launch pad. Project managers at NASA were repeatedly forced to postpone Discovery's launch because of cracks in its external fuel tank.

Discover mounted to its two solid rocket boosters and recently prepared external tank, was shifted atop its mobile launch platform.

Expressing happiness on shuttle's return to the launch pad, Stephanie Stilson from NASA said, "The team has worked really hard to get us to the point where we're able to get back out to the launch pad ... It's a beautiful sight."

Discovery will carry six astronauts, a new storage closet module, a humanoid robot- Robonaut 2, and other essentials to the ISS. After accomplishing its final mission, Discovery will retire with the rest of NASA's orbiter fleet.

After the retirement of NASA's orbiter fleet, Russian Soyuz spacecraft and international unmanned cargo vessels will deliver crew and supplies to the ISS.