Space Shuttle
Atlantis lifted off from Launch Complex 39A at Kennedy Space Center at 19:29:00 p.m. EST on November 26, 1985. The launch marked the second night launch of the Space Shuttle program, and the ninth and final flight of 1985. A key element of the mission's objectives was
EASE/ACCESS, an experiment in assembling large structures in space. EASE/ACCESS was a joint venture between the
Langley Research Center (LRC) and the
Marshall Space Flight Center (MSFC). ACCESS was a "high-rise" tower composed of many small struts and nodes. EASE was a geometric structure shaped like an inverted
pyramid, that was composed of a few large beams and nodes. Together, these experiments demonstrated the feasibility of assembling large preformed structures in space. Astronauts Ross and Spring performed two
spacewalks on the mission, which marked the 50th, and 51st
extravehicular activity (EVAs) for the United States, and the 12th and the 13th for the Shuttle program. An
IMAX camera mounted in the cargo bay filmed the activities of the astronauts engaged in the EASE/ACCESS work, as well as other scenes of interest. "This is probably not the preferred way of building a space station", Ross said later of EASE. The astronauts reported that the most difficult part of the spacewalks was torquing their own masses while holding the EASE beams. They found that ACCESS worked well, while EASE required too much free floating. The astronauts judged that performing six-hour spacewalks every other day over a five or six-day period was feasible, and recommended glove changes to reduce hand fatigue. Ross said in the EVA debrief that the crew had tried to have the
Manned Maneuvering Unit (MMU) manifested for use in the second spacewalk, because "for certain applications it would be very useful. In particular if you were building portions of a space station attached to the orbiter, then moving those portions farther than the manipulator arm could transport them". He added that the MMU could be used to attach cable runs and instruments in places that were out of reach of the shuttle's robotic arm (
Canadarm). During the mission astronaut Rodolfo Neri Vela accomplished a series of experiments, that were primarily related to
human physiology. He also photographed
Mexico and
Mexico City as part of the mission's
Earth observations. However, Commander Brewster Shaw installed a padlock on the hatch control because he was "particularly concerned" that the Mexican could "flip out" during the mission. Shaw had noted that he didn't think that Neri Vela noticed the padlock, but that the other members of the crew did. File:STS-61-B Morelos-B deployment.jpg|Deployment of the Morelos-2 satellite File:STS61B-21-008.jpg|STS-61-B crew portrait in-flight on the aft flight deck File:Atlantis lands at the end of STS-61B.jpg|Atlantis touches down at the lakebed runway at Edwards Air Force Base. This is its previous flight, STS-51J. STS-61B landed on concrete runway 22. == Spacewalks ==