NASA has set a June 28 target date for the space shuttle program’s final launch, the STS-135 mission the U.S. Congress in 2010 ordered the agency to fly.

NASA space shuttle officials on Jan. 20 put the launch on the official schedule, clearing the way for mission preparations to begin.

The STS-135 mission, which will be flown by the Space Shuttle Atlantis with a four-person crew, will carry the Raffaello multipurpose logistics module to deliver supplies and spare parts to the international space station. NASA spokesman Mike Curie said the mission also will fly a system to investigate the potential for robotically servicing on-orbit spacecraft and return a failed ammonia pump for troubleshooting.

Congress directed NASA to fly the STS-135 mission in the NASA Authorization Act of 2010 that President Barack Obama signed into law last October. Although Congress has yet to approve funding for the mission, Curie said the temporary spending measure, known as a continuing resolution, that lawmakers passed in December provides enough money for NASA to begin preparations, including detailed mission planning and crew training. The space shuttle program, he said, “has funding in the [continuing resolution] to begin these steps toward flying STS-135.”