Selected by NASA in April 1996, Phillips reported to the
Johnson Space Center in August 1996. After completing astronaut candidate training, he held various jobs in the Astronaut Office, including systems engineering and CAPCOM for the
International Space Station (ISS). He served as a backup crew-member for ISS
Expedition 7.
Spaceflight experience , Phillips participates in a
spacewalk.
STS-100 (Space Shuttle Endeavour, April 19 to May 1, 2001). STS-100 was a 12-day mission to the ISS. During the mission, the crew successfully delivered and installed the
Canadarm2 Robotic Arm. They also delivered experiments and supplies aboard the
Multi-Purpose Logistics Module Raffaello on its maiden flight. Phillips was the Ascent/Entry Flight engineer and was the intravehicular activity coordinator during two spacewalks.
Expedition 11 (April 15 to October 11, 2005). Expedition 11 was a six-month mission to the ISS. On April 15, 2005, Phillips, along with his fellow crew-members
Sergei Krikalev, and
Roberto Vittori launched to the ISS aboard
Soyuz TMA-6. On June 14, 2005, Phillips became the first person to testify before Congress from the ISS, or
outer space in general. He gave testimony to the
United States House of Representatives Science Space Subcommittee via a live video feed. The hearing was to evaluate the space station's usefulness as an orbiting laboratory. On August 18, 2005, Phillips and Krikalev completed a five-hour spacewalk to retrieve several experiments and install a video camera for the new docking procedure. Phillips and Krikalev, along with Space Flight Participant
Gregory Olsen, returned to Earth aboard Soyuz TMA-6 on October 11, 2005.
STS-119 (Space Shuttle Discovery, March 15 to 28, 2009). STS-119 was a 12-day mission to the ISS flown during March 2009. It delivered and assembled the fourth starboard
Integrated Truss Segment (S6), and the fourth set of solar arrays and batteries to the station. The launch took place on March 15, 2009. Discovery successfully landed on March 28, 2009. Phillips was detailed to the U.S. Naval Postgraduate School in Monterey, California, from 2009 to 2011 as the Smith/McCool NASA Chair Professor. ==Awards and decorations==