Selected by NASA in May 1984, Hammond became an astronaut in June 1985 and qualified for assignment as a pilot/commander on
Space Shuttle flight crews. His technical assignments included serving in Mission Control as an ascent/entry
spacecraft communicator (CAPCOM). In that capacity he was directly involved in the decision-making process for flight rules, procedures, techniques, and launch commit criteria. He was also assigned as an Astronaut Support Person (ASP), or "Cape Crusader," responsible for monitoring Orbiter status as it undergoes testing and maintenance at
John F. Kennedy Space Center during preparations for the next flight. Hammond also served as the lead astronaut supporting the
Shuttle Avionics Integration Laboratory (SAIL) which tests and verifies the flight
software for each Shuttle mission. Hammond was the lead astronaut supporting Orbiter software development and changes, including the
Global Positioning System (GPS) avionics upgrade. He also worked on designing new
cockpit flight instruments/systems displays for the Multifunctional Electronic Display System (MEDS), a major cockpit upgrade to electronic display systems. A veteran of two space flights, Hammond logged over 462 hours in space. He flew on
STS-39 in 1991, and
STS-64 in 1994. He was the pilot on STS-64 aboard the Discovery. Mission highlights included: first use of
lasers for
environmental research; deployment and retrieval of a
solar science
satellite;
robotic processing of
semiconductors; use of RMS boom for
jet thruster research; first untethered
spacewalk in 10 years to test a self-rescue
jetpack. Mission duration was 10 days, 22 hours, 51 minutes. ==Aviation career==