Launch from Cape Canaveral (KSC) after it was called off for two times because of bad weather; landing on Cape Canaveral (KSC); ISS ULF-1.1.

After the Columbia accident, NASA decided that two test flights would be required and that activities that were originally assigned to STS-114 would need to be divided into two missions because of the addition of post Columbia safety tests.

The main purposes of the mission were to test new safety and repair techniques introduced following the Columbia disaster of February 2003 as well as to deliver supplies, equipment. Enroute to the ISS, the 50 foot long Orbiter Boom Sensor System (OBSS) tipped with two types of lasers and a high resolution television camera was used to inspect the underside of the shuttle for damage.

Following a two days solo flight the Discovery docked to the ISS on July 06, 2006. In the next nine days the crew performed common work with the ISS expedition 13. Thomas Reiter was transferred the to ISS to become member of the expedition 13.

The Multi-Purpose Logistics Module Leonardo was mated to the space station's Unity module. It was carrying:
- -80 °C Freezer. This freezer is known as the Minus Eighty Degree Laboratory Freezer for ISS (MELFI). The French built unit comprises four independent drawers which can be set to operate at different temperatures. Initially, temperatures of -80 °C, -26 °C, and +4 °C will be used during on-orbit ISS operations. Both reagents and samples will be stored in the freezer. As well as storage, the freezer is designed to be used to transport samples to and from the ISS in a temperature controlled environment. The total capacity of the unit is 300 liters.
- The European Modular Cultivation System (EMCS) for biological experiments. This consists of a gas tight incubator in which there are two centrifuges, each able to carry four experimental cartridges. Two "Ground controls"—exact copies of the equipment and experiments—will be run on the ground, one in Europe and one at NASA's Ames Research Center.
- New oxygen generation system. This device is considered a test for an equipment design with potential for use on proposed future long durations to the Moon and Mars. The system will initially run below its maximum capacity, though it is designed for enabling the ISS to support a crew of six in the future. It will supplement the Russian-built Elektron system operating in the Zvezda module.
- New cycling machine for the ISS crew. A Danish built device, the Cycle Ergometer with Vibration Isolation System (CEVIS).
- Replacement common cabin air assembly heat exchanger used to control the internal air temperature of the ISS.

Also carried in the payload bay: an Integrated Cargo Carrier with the Trailing Umbilical System (TUS) for the Mobile Transporter (returning old one); an EATCS/Pump Module (PM); and 2 Fixed Grapple Bars for PM & TUS relocation during EVA. As well as an LMC carrying the DTO-848 TPS Repair Box.

The first EVA was performed by Piers Sellers and Michael Fossum on July 08, 2006 (7h 31m) for maintenance on the station’s mobile transporter and a test of astronaut movement on the end of the robotic arm boom extension for possible heat shield repairs during future flights.

The second EVA by Piers Sellers and Michael Fossum occured on July 10, 2006 (6h 47m) for installation of a spare thermal control system pump on to the outside of the Quest Airlock and replacement of reel assembly for a cable that provides power and data to the station’s mobile transporter.

The third and final EVA by Piers Sellers and Michael Fossum was conducted on July 12, 2006 (7h 11m) to demonstrate on orbit heat shield repair techniques.

Thomas Reiter landed on December 22, 2006 at 22:32 UTC with STS-116.