She became the first in a planned continuous U.S. astronaut presence on Mir until 1998. New Supplies Brought Up on Atlantis In the joint portion of the mission, the two crews loaded into the station more than 1 ton of U.S. science equipment, almost 2 tons of Russian supplies and 15 containers of water totaling about 1.5 tons. Approximately a ton of excess equipment, waste and science payload was transferred from Mir to Atlantis. From their vantage point in orbit, the crews were treated to a good view of the comet Hyakutake. Some of the spacecraft hardware items brought up by Atlantis were replacement gyrodyne, a seat liner kit for Lucid to be placed in a Soyuz module if emergency return to Earth was required and three Russian storage batteries which had been replenished on Earth. Experiment Supplies Some of the new supplies and equipment for onboard experiments included replacement hardware for the Mir glovebox stowage experiments, Mir electric field characterization hardware to measure radio interference inside and around the complex, and a liquid phase sintering experiment that would use the Optizon furnace to bond different metals. Spacehab Module Work On flight days 4, 5 and 7, the crew worked on the Biorack in the Spacehab module in the Orbiter payload bay. The Biorack contained eleven experiments to investigate the effects of microgravity and cosmic radiation on plants, animal tissues, bacteria, and insects. The various experiments were designed by France, Germany, the U.S., Switzerland and the Netherlands. Pre-EVA Procedures In preparation for the EVA, Atlantis's cabin air pressure was lowered from 14.7 to 10.2 psia. the hatches were closed between Mir and Atlantis and Atlantis and Spacehab throughout the EVA to allow for sustained cabin depressurization. The Mir crew, including Lucid, stayed inside Mir and the Atlantis crew stayied inside the Orbiter cabin, with Ronald Sega coordinating the space walk activities from inside. SAFER Backpacks Worn Attached to their regular portable life support system backpack, Godwin and Clifford donned new self-contained backpacks with propulsion systems to allow enough free-flight capability to return an un-tethered astronaut to the spacecraft in an emergency. The device, called the Simplified Aid for EVA Rescue (SAFER), was designed for EVAs on docked vehicles which would be unable to quickly retrieve a drifting spacewalker. The backpack was test-flown on STS-64 in September 1994. First EVA by U.S. Astronauts at Mir On March 27, Godwin and Clifford