(09/09/1997) --- STS-86 Mission Specialist David A. Wolf dons a gas mask as part of training exercises during the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. Wolf is wearing the patch from his first and only mission to date, STS-58 in 1993. STS-86 will be the seventh docking of the Space Shuttle with the Russian Space Station Mir. During the docking, Wolf will transfer to the orbiting Russian station and become a member of the Mir 24 crew, replacing U.S. astronaut C. Michael Foale, who has been on the Mir since the last docking mission, STS-84, in May. Launch of Mission STS-86 aboard the Space Shuttle Atlantis is targeted for Sept. 25