Spacewalks
Two 6.5 hour spacewalks were conducted by three astronauts to test hardware and tools to be used in the assembly of the International Space Station starting in late 1998. EVA-1 on flight day five consisted of Crewmembers Leroy Chiao (EV1) and Dan Barry (EV2). After taking a few minutes to acclimate themselves in the payload bay, first-time spacewalkers Chiao and Barry attached a portable work platform to the end of the robot arm, operated by Pilot Brent Jett and Mission Specialist Koichi Wakata. Jett used the arm to grapple various pieces of hardware designed to hold large modular components, mimicking the way equipment boxes and avionics gear will be moved back and forth in assembling the Space Station. Chiao and Barry unfolded a cable tray diagonally across the forward portion of the cargo bay housing simulated electrical and fluid lines similar to those which would later connect modules and nodes of the Space Station. The rigid umbilical, as it is known, was tested for its ease of handling and the ability of the astronauts to hook up the lines to connectors on the side of Endeavour's bay. While Chiao unraveled various lengths of cable from a caddy device, Barry spent time practicing the hookup of the various cables in the rigid umbilical to connectors in the bay, testing his ability to manipulate tiny bolts and screws in weightlessness. He reported that most tasks could be accomplished with little difficulty. Barry and Chiao then traded places, as Barry mounted the portable work platform to evaluate its worth. The first EVA lasted 6 hours, 9 minutes. EVA-2 on Flight Day 7 consisted of Leroy Chiao (EV1) and Winston Scott (EV2), lasting 6 hours, 53 minutes. Chiao and Scott worked with utility boxes, slidewires and a portable work stanchion affixed to Endeavour's robot arm to gather additional data on methods and procedures which would be incorporated in the techniques used to assemble the International Space Station. Late in the spacewalk, Scott climbed into foot restraints on the OAST-Flyer satellite platform for a thermal evaluation exercise. Endeavour was maneuvered to the coldest position possible, with its payload bay facing out toward deep space and allowing temperatures to dip to about 104 degrees below zero at the point where Scott was positioned to test the ability of his spacesuit to repel the bitter cold temperature of space.
Read more about this topic: STS-72