From 1993 until 1996, he worked as an ascent/entry Guidance and Procedures Officer (GPO) in Mission Control. An ascent/entry GPO has both pre-mission and real time Space Shuttle support responsibilities in the areas of onboard guidance, navigation, and targeting. During that time, he supported seventeen missions as a flight controller. In April 1996, Mastracchio was selected as an Astronaut Candidate. In August 1996, he started two years of training and evaluation. Successful completion of initial training will qualify him for various technical assignments leading to selection as a mission specialist on a Space Shuttle flight crew.
Atlantis was launched from Kennedy Space Center's Launch Complex 39B. Solid rocket boosters RSRM-75 and external tank ET-103 were used to loft the orbiter into space. The inital orbit of 72 x 328 km x 51.6 deg was circularised by the Shuttle's OMS engines at apogee.
Atlantis docked with the PMA-2 adapter on the International Space Station at 05:51 GMT on September 10. The orbiter's small RCS engines were used to gently reboost the station's orbit several times.
Astronauts Lu and Malenchenko made a spacewalk on September 11 beginning at 04:47 GMT. They rode the RMS arm up to Zvezda and began installing cables, reaching a distance of 30 meters from the airlock when installing Zvezda's magnetometer. Total EVA duration was 6 hours 21 minutes.
During their 12-day flight, the astronauts spent a week docked to the International Space Station during which they worked as movers, cleaners, plumbers, electricians and cable installers. In all, they spent 7 days, 21 hours and 54 minutes docked to the International Space Station, outfitting the new Zvezda module for the arrival of the Expedition One crew later this fall.
The Shuttle undocked from ISS at 03:44 GMT on September 18 and made two circuits of the station each lasting half an orbit, before separating finally at 05:34 GMT. The payload bay doors were closed at 04:14 GMT on September 20 and at 06:50 GMT the OMS engines ignited for a three minute burn lowering the orbit from 374 x 386 km x 51.6 deg to 22 x 380 km x 51.6 deg. After entry interface at 07:25 GMT, the orbiter glided to a landing on runway 15 at Kennedy Space Center with main gear touchdown at 07:56:48 GMT for a mission duration of 283 hr 11min.