PAIR ABOARD SHUTTLE `EXCITED' AT CHANCE TO WALK IN SPACE

                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: SUNDAY, January 17, 1993                   TAG: 9301170034
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A-6   EDITION: METRO  
SOURCE: Associated Press
DATELINE: CAPE CANAVERAL, FLA.                                LENGTH: Medium
PAIR ABOARD SHUTTLE `EXCITED' AT CHANCE TO WALK IN SPACE
Two Endeavour astronauts, raring to go on the ultimate Sunday stroll, checked their spacesuits Saturday for a five-hour spacewalk intended as a drill for station construction.
It will be the first spacewalk by Americans in nearly a year.
"We're really excited about it," said astronaut Gregory Harbaugh.
The mood at Mission Control also was upbeat.
"Any time we get ready to go do an EVA, I think the excitement level comes up a little bit," said mission operations director Lee Briscoe. EVA stands for extra-vehicular activity.
Harbaugh and Mario Runco Jr. plan to move about the shuttle payload bay and practice working with varying loads. One exercise calls for them to take turns carrying one another from one end of the 60-foot-long bay to the other.
NASA wants to see how much time it takes, and how difficult it is, to move large objects in space before astronauts start building space station Freedom in 1996. The exercise also will show what it would be like for a spacewalker to carry an incapacitated partner.
Each crewman weighs more than 400 pounds in his spacesuit, at least on the ground. In the weightlessness of space, it's the bulkiness that complicates matters.
Officials added the spacewalk to the six-day mission just two months ago to give astronauts and flight controllers more spacewalking experience. Only six Americans have walked in space since before the 1986 Challenger accident, and the last ones to do so encountered unexpected difficulties.
It took three spacewalks and three spacewalkers to capture the stranded Intelsat satellite in May. Astronauts making the fourth spacewalk on that mission, to practice station assembly techniques, found it took them much longer than expected to get things done.
"We are trying to help identify outer boundaries of the human performance envelope, if you will, in doing spacewalks," Harbaugh said.
Added Runco: "In the past, we haven't had the luxury to just try and quantify the time it takes for us to do each task, how much force is necessary."
As they circled Earth for the fourth day, the five astronauts got another reminder from Mission Control regarding their new $23 million toilet. This time it was the urinal fan that was left running. On Thursday, someone left the lid up and a solid waste fan running.
Shuttle Commander John Casper promised he and his crew would be more observant.
Endeavour's major science payload, a $14 million X-ray spectrometer, still wasn't up to speed Saturday despite three days of troubleshooting by controllers at NASA's Goddard Space Flight Center in Greenbelt, Md.
A burst of charged particles apparently damaged the twin detectors of the instrument Thursday. Controllers thought they had fixed both detectors, but the one on the right side of the cargo bay continued to show higher-than-desired radiation readings, said Wilton Sanders, an astrophysicist at the University of Wisconsin.
Despite the trouble, Sanders said he expects to collect almost all the data he originally sought. The spectrometer measures low-energy X-rays emitted from the space between stars, or interstellar medium.
The mission is scheduled to end Tuesday.

by Bhavesh Jinadra by CNB