Launch from Cape Canaveral (KSC); landing on Cape Canaveral (KSC). Due to a hydrogen leak the launch was scrubbed on April 04, 2002. ISS-13-8A Integrated Truss Structure S0, Mobile Transporter. With the launch of Atlantis, mission specialist Jerry L. Ross became the first human to have traveled to space seven times.

Following a two day solo flight the Atlantis docked to the ISS on April 10, 2002 and common work with the fourth expedition of the ISS was performed.

The main purpose of STS-110 was to attach the S0 Truss segment to the International Space Station (ISS) to the Destiny Laboratory Module. It forms the backbone of the station to which the S1 and P1 truss segments were attached (on the following missions STS-112 and STS-113, respectively).

STS-110 also delivered the Mobile Transporter (MT), which is an 885 kilograms (1,950 lb) (1,950 lb) assembly that glides down rails on the station integrated trusses. During the next shuttle mission, STS-111, the Mobile Base System (MBS) was mounted to the MT. This Mobile Servicing System (MSS) allows the Canadarm2 to travel down the length of the installed truss structure.

The first EVA was performed by Steven Smith and Rex Walheim on April 11, 2002 (7h 48m), installing the (S-Zero) truss segment.

The second spacewalk by Jerry Ross und Lee Morin occured on April 13, 2002 (7h 30m) to mate two large tripod legs of the truss to the Destiny Laboratory.

The third EVA was again performed by Steven Smith and Rex Walheim on April 14, 2002 (6h 27m). They rewired the Canadarm2 and readied the complex's newly-delivered rail-car (Mobile Transporter) to move.

The fourth and final EVA by Jerry Ross and Lee Morin was conducted on April 16, 2002 (6h 37m), installing a ladder, testing electrical switches for upcoming truss expansion and attaching external light and equipment to be used in future assembly work.