STS-74 was a Space Shuttle Atlantis mission to the Mir space station. It was the fourth mission of the US/Russian Shuttle-Mir Programme, and it carried out the second docking of a space shuttle to Mir. Atlantis lifted off for the mission on 12 November 1995 from Kennedy Space CentreCentre launch pad 39A, and landed back at Kennedy 8 days later. The mission delivered the Russian-built Mir Docking Module to the station along with a pair of solar arrays, and was the second in a series of seven straight missions to the station flown by Atlantis.

During the three-day docking, the Russian, Canadian and American astronauts transferred various supplies from Atlantis to Mir, moved several long-term experiments, pieces of equipment and manufactured products from Mir to the Atlantis, and made use of various new pieces of equipment to upgrade Mir, most notably attaching the Docking Module to Mir's Kristall module for use by all of the following docked missions in the Shuttle-Mir Program.

The crew's preparation for the mission had begun some thirteen months earlier in 1994, with the crew being trained in the operation of the space shuttle, the mating and docking procedures that would be required as Atlantis approached Mir later in the mission, and the management of the various scientific experiments being carried on the orbiter during the mission.

Preparation of Atlantis itself for mission STS-74 began with the replacement of three thrusters in Atlantis's right-hand Orbital Maneuvering System pod in bay 2 of the Orbiter Processing Facility on 25 August 1995. Installation of the three Space Shuttle Main Engines (SSMEs) on Atlantis was completed on 5 September 1995, as were closeout operations on the Russian docking module.

On 7 November, engineers determined that there was no additional work needed to verify the solid rocket boosters for flight, following discovery of small cracks in the hold-down posts attached to boosters that had flown earlier that year. Close inspections of the STS-74 stack determined that no such cracks were present on the boosters to be used for the mission.

Pad 39A was cleared on 9 November in preparation for loading of the onboard cryogenic tanks with the cryogenic oxygen and hydrogen reactants that provided electricity through the three onboard fuel cells, and water for the flight as a by-product.

The initial launch attempt, scheduled for 11 November 1995 at 7:56 am EST (12:56 UTC) was postponed due to poor weather at the Transatlantic Abort (TAL) site. The original launch window was 6 min 57 secs and the countdown had begun on schedule. The crew was on board when the postponement was called at the T-minus 5 minute mark at approximately 7:51 am EST (12:51 UTC)