Abseiling Into The Spacelab

Preparing Columbia for this marathon mission, which would also become her last long-duration flight for almost five years, was as complicated an affair as the Neurolab experiments themselves. After having been transferred to Pad 39B on 23 March 1998, in anticipation of a 16 April launch, many of her mammalian and aquatic passengers had to wait until the very final hours of the countdown before they could be loaded into their cages in the Spacelab module. This proved an interesting event, worthy of comment, particularly as the Shuttle was positioned vertically, on her tail.

Working from Columbia's middeck, two technicians were lowered, one at a time, in sling-like seats down the 6-m-long tunnel into Neurolab in the payload bay. One technician waited in a shelf-like 'bend' in the tunnel, while the other entered the module itself to await the animal cages and aquariums that were then lowered on separate slings.

''The late stow is a 13-hour activity that will conclude about 3:30 am [on the 16th],'' said Payload Operations Manager Scott Higginbotham before the intricate procedure got underway. ''The stow itself is made up of three 'waves' of activity. The first wave [is] when we will install some passive items into the Spacelab, we'll activate the life science laboratory equipment refrigerator and, once it's chilled down, we'll install a number of chemical sets into it. And then we'll activate the Research Animal Holding Facilities in Racks 3 and 7. Wave Two is basically devoted to Rack 10: the vestibular function experiment unit. We'll activate that unit and install four fish packages. Each of these fish packets contains [a] single oyster toadfish.'' The final step was to load 24 cages, holding a total of 132 mice, into the lab. ''Then, we'll begin four hours of module closeout activities,'' he concluded.

The delicate procedure was completed without a hitch, although telemetry from a couple of fish subjects - whose heads had been 'wired' with tiny transmitters -proved spotty, which Higginbotham attributed to ''the fish not cooperating''. When a fish 'hid' in the corner of its tank, for example, the antenna system used to gather telemetry data occasionally did not work properly. It was expected that accurate telemetry from all of the fish would be available as soon as Columbia reached orbit.

Otherwise, readying NASA's oldest Shuttle for her 25th trip into space was proceeding as 'swimmingly' as the fish themselves, with US Air Force meteorologists predicting on 13 April an 80% probability of acceptable weather for an on-time launch. Searfoss and his six crewmates, who arrived at KSC in their fleet of four T-38 jets that evening, were equally enthusiastic and were even treated to a visit by President Bill Clinton the following day.

''I hope you find out a lot of things about the human neurological system to help me," he told Searfoss with a grin, ''because I'm moving into those years where I'm getting dizzy and I'm having all these problems, and I expect you to come back with all the answers!''

''Well, thank you, Mr President,'' replied Searfoss. ''We'll take that on board as one of the challenges we'll try to meet.''

"INCREDIBLE!"

The answers Clinton required would be another day in coming, because Columbia's 16 April launch was postponed 24 hours to allow technicians to replace a faulty Network Signal Processor (NSP) - one of two devices that relay voice and data communications between the astronauts and Mission Control. According to Shuttle integration manager Bob Sieck, the device was over a decade old. ''Although the other unit on board was functioning fine, should it fail, your only ability to communicate with the vehicle would be via UHF radio and you would not have any ability to uplink or update [Columbia's] computers from the ground. So we went by our Launch Commit Criteria - our rules - that say this redundancy has to be in place prior to the mission. And when we tried every capability of this box to restore this uplink capability and all those failed, we had no choice but to delay the launch and change out this hardware.'' A replacement NSP was 'borrowed' from Columbia's sister ship, Endeavour, and took most of 16 April to fit in place. Otherwise, said Sieck, no issues were being tracked by his team. ''It's just unfortunate that the

After a one-day delay, Columbia heads for orbit on 17 April 1998.

hardware picked this time to fail! I wouldn't say it's wearing out. We all know solidstate hardware usually fails when you turn it on or the previous time when you turn it off, and that looks to be the case here. The word 'bummer' comes to mind. Hardware does this to you at times and you have to accept this as part of the business. There's always the opportunity to do more training and the weather's great [in Florida]. It would be a good day to spend at the beach!''

By the evening of the 16th, the replacement unit had been installed in its correct place in an avionics bay behind a row of lockers in the middeck and satisfactorily tested. Meanwhile, during the day, the animal-holding lockers - carrying 18 pregnant mice and 1,514 crickets - were removed for maintenance and later replaced. Another delay on 17 April was expected to lead to a four-day postponement because many more of the animals would have to be replaced. Fortunately, launch that day went without a hitch and Columbia speared for the heavens at 6:19 pm.

''Ascent was incredible!'' wrote Canadian astronaut Williams, making his first spaceflight, in his diary. For launch, he rode into orbit on the flight deck, giving him a spectacular all-round view of the dynamic eight-and-a-half-minute climb. ''The view was very impressive as we completed the roll programme [manoeuvre, 10 seconds after liftoff] and progressed to SRB separation. Before SRB separation, there was a lot of vibration but the ride quickly became very smooth as we climbed to our final orbital altitude.'' As with the STS-87 ascent, Columbia had a never-before-tried surprise in store for Williams and his crewmates.

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