Williams has logged approximately 2,000 hours in more than 50 different aircraft.
Objective of mission STS-101 was repair, resupply and construction tasks aboard the international space station. This was the first launch with new electronic cockpit displays and other upgrades. The solid boosters separated at 10:13 GMT and the main engines cutoff at 10:19 GMT. The external tank, ET-102 then separated, with both orbiter and ET-102 in a 52 x 320 km initial orbit. At 10:54 GMT the OMS engines fired to raise perigee to 159 x 329 km x at 51.6 deg. Atlantis docked with the International Space Station's PMA-2 docking adapter on the Unity node at 04:31 GMT on May 21. At that time the ISS was in a 332 x 341 km orbit.
On May 22 mission specialists Jeff Williams and James carried out external maintenance work on the ISS.
On May 23 at 00:03 GMT the Atlantis crew opened the first hatch to PMA-2 and entered the Station. The crew replaced a set of batteries in Zarya, installed fans and ducting to improve airflow, and delivered supplies and equipment. Three hour-long orbit raising burns on May 24 and 25 by the RCS engines on Atlantis raised the station to a 372 x 380 km x 51.6 deg orbit.
The STS-101 crew left the station on May 26, closing the PMA-2 hatch at 08:08 GMT and undocking at 23:03 GMT. Atlantis performed a 180 degree flyaround of the station and departed the vicinity around 23:44 GMT.
Atlantis closed its payload bay doors around 02:30 GMT on May 29 and fired the OMS engines for deorbit at 05:12 GMT. The vehicle landed on RW15 at Kennedy Space Center at 06:20 GMT. Atlantis was to be turned around for the next ISS shuttle flight, STS-106.
Left in orbit was the renovated International Space Station, equipped with an upgraded electrical system, new fans, filters, fire extinguishers, smoke detectors and communications gear.
The crew reattached the US crane, attached the Russian Strela transfer boom, and replaced a faulty antenna on the Unity node. EVA handrails were fixed to the station exterior for use on later spacewalks.