The U.S. Space Shuttle Discovery has undocked from the International Space Station and begun its two-day journey back to Earth.

Discovery pilot Jim Kelly flew the shuttle around the space station, allowing the shuttle crew to photograph the orbiting outpost. He then fired the craft's jet thrusters to head home.

Discovery is scheduled to end its 13-day mission with a landing early Monday in Florida.

While docked, the shuttle serviced the space station with tons of supplies and equipment. The crews also removed pieces of heat-shielding material from the shuttle's underbelly during a spacewalk.

Insulation foam came off the external fuel tank and hit the shuttle during launch, the same problem that doomed the shuttle Columbia. NASA has grounded future space flights until the problem is fixed.