Space Shuttle Atlantis lifted off on its maiden voyage on 3 October 1985, on mission STS-51-J, the second dedicated Department of Defense flight. It flew one other mission, STS-61-B, the second night launch in the shuttle program, before the Space Shuttle Challenger disaster temporarily grounded the Shuttle fleet in 1986. Among the five Space Shuttles flown into space, Atlantis conducted a subsequent mission in the shortest time after the previous mission (turnaround time) when it launched in November 1985 on STS-61-B, only 50 days after its previous mission, STS-51-J in October 1985. Atlantis was then used for ten flights between 1988 and 1992. Two of these, both flown in 1989, deployed the planetary probes Magellan to Venus (on STS-30) and Galileo to Jupiter (on STS-34). With STS-30 Atlantis became the first Space Shuttle to launch an interplanetary probe.