STS-76 Mission Control Center Status Report # 9 Tuesday, March 26, 1996, 5 p.m. CST The Johnson Space Center Newsroom will reopen at 10:30 p.m. Tuesday in preparation for the upcoming spacewalk activities. At 5 p.m. Tuesday, Atlantis' astronauts were nearing the end of their sleep period, due to awaken at 6:43 p.m. Preparations for the spacewalk by astronauts Rich Clifford and Linda Godwin begin at approximately 8:45 p.m. CST. The hatches between Atlantis and Mir were closed early Tuesday, as was the hatch between Atlantis and the SpaceHab module. The astronauts then depressurized the Shuttle's cabin from its standard 14.7 pounds per square inch to 10.2 psi, a standard pre- spacewalk protocol. At the same time, Godwin and Clifford breathed pure oxygen to begin the process of purging nitrogen from their bodies for the spacewalk. The SpaceHab and Shuttle-Mir hatches will remain closed until the spacewalk is completed. The two spacewalkers currently are scheduled to float out of Atlantis' airlock just after midnight, marking the start of the first extravehicular activity to be conducted around the Mir by American astronauts. During the spacewalk, four experiment containers designed to characterize the environment around Mir will be attached to handrails on the space station. The packages will be retrieved in a subsequent spacewalk in about 18 months and will provide information on the quantity and type of orbital debris and contaminants found in the same general altitude and orbital inclination planned for the International Space Station. Atlantis' astronauts viewed Comet Hyakutake early this morning as it continued its close pass by Earth, and they told reporters the comet was brilliant and could be seen almost from horizon to horizon. The comments came during an in-flight press conference with the Atlantis/Mir crews taking questions from reporters at NASA centers and in Russia. The astronauts and cosmonauts also took time out from their transfer and resupply activities to talk with Charlie Gibson of "Good Morning America" shortly after 4 a.m. central time today. The Atlantis-Mir complex continues to orbit the Earth every 90 minutes at an altitude of about 240 statute miles with systems on both spacecraft operating normally.