Our Last Chance To Look At This

Yet the spacewalk had not even reached its halfway mark, for Scott and Doi would remain outside for a total of 7 hours and 43 minutes, making this one of the longest excursions on record. Following the failure of Columbia's hatch to open in November 1996, which prevented Jernigan and Jones from testing a series of prototype International Space Station tools, most of their tasks were offloaded onto the STS-87 spacewalkers. Scott and Doi had trained to work with a small crane, which they would use to move a dummy station battery, and a variety of different safety tethers.

It was hoped that the almost 2-m-tall crane would prove useful in transporting Orbital Replacement Units (ORUs), such as batteries, with masses as great as 270 kg from translation carts on the station's external truss to various work sites. "We had a very successful test of the crane,'' Scott said later. "What we did not do was to get a chance to exercise all the options. The crane actually operates very, very smoothly. It's meeting most of our expectations. I say 'most' because there's a little bit of flexibility in the boom that we didn't anticipate."

Winston Scott (left) and Takao Doi get themselves into position to grab Spartan-201 with their gloved hands.

After the crane had been installed into its socket on the port-side of Columbia's payload bay, Doi evaluated its operating characteristics, while Scott removed a large 225-kg dummy battery and its carrier device from the starboard wall. These were attached to the end of the crane to assess its ability to move large masses. The crane's boom was extended by turning a ratchet fitting with a power tool or, as a backup, by using a manually operated hand crank.

The only problem the two men encountered was a jammed torque multiplier, used to tighten the mock battery onto its mounting location in the payload bay. However, Scott finally freed it by following instructions radioed to him by Capcom Chris Hadfield in Mission Control. Also in the control centre, watching a live televised downlink of the excursion, were the spacewalkers' wives.

''I just wanted to tell you that in the viewing room here, Marilyn and Hitomi are wearing their EVA shirts and proudly watching you fellows at work,'' Hadfield told them.

''All right! Tell Marilyn and Hitomi both 'hello' from Winston,'' Scott replied. ''We're glad they're there.''

''And hello from Takao,'' Doi chimed in. ''Thanks for watching us.'' ''And for Marilyn,'' Scott added, with a grin, ''I just had to stop by and pick up a satellite. I'll be home by suppertime!''

After stowing the crane and mock battery, the spacewalkers cleared away their tools, before returning to Columbia's cabin; the excursion officially ended at 7:45 am, when they repressurised the airlock and switched their spacesuits off internal battery power. ''On behalf of all of us here on the ground, congratulations!'' Hadfield radioed from Houston. ''That was a long and challenging spacewalk. It was the first one from Columbia and Winston, you've now been outside for 10 times around the world. And Takao's definitely got more EVA time than any Japanese citizen in history!''

One of the tasks assigned to each of the astronauts performing these practical evaluations of potential space station tools was to fill in a questionnaire to capture their initial thoughts. In general, Scott and Doi gave most of the activities they performed 'As' and 'Bs', which helped engineers to finalise the designs before committing them to actual construction missions. The responses from the STS-87 crew were particularly important, because theirs was the last scheduled mission to involve a spacewalk before the first station components were due to be hauled into orbit in the summer of 1998.

''This is our last chance to look at this before we employ it somewhere down the line on [the] space station,'' said Greg Harbaugh, a former astronaut and then-acting head of the EVA Projects Office. ''We have to recognise that EVA is very much fundamental to the success of [the] station. It is going to be an almost everyday occurrence for the next several years, so we'd better get used to it. If we have any misgivings about EVA, it's time to get those behind us. Starting with STS-88 [the first station-assembly mission], we are into what we call the 'EVA wall' and we better be ready to step up to it. It's a gigantic undertaking, something like three times the amount of EVA work that we've ever done in the history of the American space programme. But I think we're up to the challenge. I think we're going to be ready for it and we're going to succeed. But the best way to do that is to mitigate the risk as you go along, to gather what information you can as you go along.''

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