He entered space for the first time on July 4, 2006 as a mission specialist of mission STS-121 to the International Space Station where he participated in three spacewalks.
On July 8, Fossum with Piers Sellers conducted a 7 and a half hour spacewalk making a repair to the ISS and testing using the Shuttle's arm as a platform for making repairs to the Shuttle.
Fossum became the first Texas A&M undergraduate to travel to space.

In 2008, Fossum assumed the role of mission specialist on board STS-124 launching on May 31, 2008.
The mission's primary objective was the delivery and installment of Japan's Kibo Laboratory module.
Once attached, this module became the largest and most scientifically capable addition to the International Space Station.
Fossum took part in the installation as lead spacewalker, EVA-1, accompanied by fellow spacewalker Ron Garan.
They would ultimately performed three spacewalks during the 14-day mission.

On June 7, 2011 Fossum launched with crewmates Sergey Alexandrovich Volkov and Satoshi Furukawa on Soyuz TMA-02M from the Baikonur Cosmodrome, Kazakhstan, to the ISS to join the crew of Expedition 28.
Upon the departure of Expedition 28, Fossum served as ISS Commander during Expedition 29 from September 9 until November 21, 2011.
He returned to Earth on November 22, 2011.

During Expedition 28, Fossum performed his seventh EVA with Ronald Garan which lasted 6 hours and 31 minutes.
During the EVA They retrieved a failed pump module for return to Earth, installed two experiments and repaired a new base for the Canada Arm 2.
He entered space for the first time on July 4, 2006 as a mission specialist of mission STS-121 to the International Space Station where he participated in three spacewalks. On July 8, Fossum with Piers Sellers conducted a 7 and a half hour spacewalk making a repair to the ISS and testing using the Shuttle's arm as a platform for making repairs to the Shuttle. Fossum became the first Texas A&M undergraduate to travel to space.
In 2008, Fossum assumed the role of mission specialist on board STS-124 launching on May 31, 2008. The mission's primary objective was the delivery and installment of Japan's Kibo Laboratory module. Once attached, this module became the largest and most scientifically capable addition to the International Space Station. Fossum took part in the installation as lead spacewalker, EVA-1, accompanied by fellow spacewalker Ron Garan. They would ultimately performed three spacewalks during the 14-day mission.
On June 7, 2011 Fossum launched with crewmates Sergey Alexandrovich Volkov and Satoshi Furukawa on Soyuz TMA-02M from the Baikonur Cosmodrome, Kazakhstan, to the ISS to join the crew of Expedition 28. Upon the departure of Expedition 28, Fossum served as ISS Commander during Expedition 29 from September 9 until November 21, 2011. He returned to Earth on November 22, 2011.
During Expedition 28, Fossum performed his seventh EVA with Ronald Garan which lasted 6 hours and 31 minutes. During the EVA They retrieved a failed pump module for return to Earth, installed two experiments and repaired a new base for the Canada Arm 2.
Michael E. Fossum