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Spacewalkers to give space station external upgrades BY WILLIAM HARWOOD STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION Posted: May 17, 2010 
Astronauts Garrett Reisman and Stephen Bowen are suiting up for a planned six-and-a-half-hour spacewalk to install a backup Ku-band dish antenna on the International Space Station, along with a robot arm equipment mounting platform.
This is the 144th spacewalk devoted to station assembly and maintenance since construction began in 1998, the eighth so far this year and the first of three planned by the shuttle Atlantis' crew. Bowen is making his fourth spacewalk and Reisman is making his second. Total space station EVA time going into Monday's excursion was 893 hours and 33 minutes, or 37.2 days. Reisman and Bowen spent the night in the Quest module at a reduced pressure of 10.2 pounds per square inch to help purge nitrogen from their bloodstreams, a routine protocol intended to prevent decompression sickness, or the bends, when working in NASA's 5 psi spacesuits. "It's going to be a long EVA," said station flight director Scott Stover. "We have two major objectives. The first one is installing the new space-to-ground antenna system that came up with Atlantis. What this is going to be is a backup high-data-rate antenna that's used for space station video and experiment data. Right now there's only one on board the space station and this will be a backup for that. "Garrett will be on the end of the arm and he will be handling the big pieces of this antenna, moving (them) back and forth while Steve is there to run cables and bolts to make sure everything is being attached," Stover said. "So you'll see multiple times where Garrett is getting a piece of equipment off the ICC (integrated cargo carrier) and moving it over to the right place on space station for it to be installed by Steve." The second objective of the spacewalk is to install an enhanced spare parts storage platform on the Canadian special purpose dexterous manipulator, or DEXTRE, a hand-like robot arm attachment that can be used to install replacement components or service external experiments. "The current one that's installed on DEXTRE can only handle one spare box," Stover said. "This new enhanced version is able to handle multiple boxes, so what Garrett and Steve are going to do is remove the old one, temporarily stow it on that on the space station and install the new one." The backup antenna dish and its support beam, along with robot arm storage platform and six new solar array batteries, are mounted on the integrated cargo carrier. The carrier was pulled from the shuttle's cargo bay after docking Sunday and mounted on the robot arm transporter on the front side of the station's solar power truss. After exiting the airlock, Reisman and Bowen will make their way to the cargo pallet and install foot restraints, one on the pallet itself and one of the robot arm. The eight-foot-long boom that will support the spare antenna will be removed from the pallet, and Reisman, riding on the end of the robot arm, will carry it to the Z1 truss atop the station's central Unity module. The spacewalkers then will secure the boom with two bolts. While Bowen is making electrical connections, Reisman will ride the arm, operated by Piers Sellers from the new multi-window cupola, in a windshield wiper-like trajectory back to the cargo pallet to pick up the six-foot-wide Ku-band antenna. "The dish is pretty fragile and we're instructed not to bump that into anything," Reisman said. "Piers is going to be operating the big arm, and I'll be standing on the end of it while we bring the dish out. At that point, the dish comes very close to the boom of the arm. "The worrisome thing for me is I can't really see it because I have a big face full of dish, and the boom is on the other side. So I'll be counting on Piers to talk me through it and give me nice calls. We'll have to coordinate very carefully. It's definitely an area of concern." Reisman, holding the dish, will follow another windshield wiper trajectory back to the top of the Z1 truss where Bowen will help move it into position before driving four bolts to hold it in place and hooking up two electrical connectors. After installing insulation around the base of the antenna, Reisman will ride the arm back to the cargo pallet to retrieve an equipment stowage platform that will be attached to the Canadian special purpose dexterous manipulator, or SPDM, robot arm extension. The platform will be used down the road to temporarily hold components that are being replaced by the space crane. Once the platform is in place the astronauts will turn their attention to a get-ahead task if time is available, loosening the bolts holding new solar array batteries to the cargo pallet. "While the pallet's based on the truss there, we can actually break all the torque on the bolts with a ratchet wrench instead of using this heavy torque multiplier," Reisman said. "Just like lug nuts on your car, we can do it very quickly." Bowen said the key to the first spacewalk is "a very intricate choreography." "And the reason for that is using the arm to remove the pieces off the pallet and then taking them all over station to install them. ... I get to climb all over, he gets to fly all over. But the choreography is key to EVA-1. If the choreography works and the timing works out and we complete all the tasks on EVA-1, we will be well set up for EVA-2. "Everything has to work," he said. "Any one of these EVAs, a single bolt can put everything behind. So we have to be very efficient and hopefully get through our tasks in a very nominal timeframe so the next piece is ready to go." Here is an updated timeline of today's activity (in EDT and mission elapsed time; includes revision B of the NASA television schedule; best viewed with fixed-width font): EDT........DD...HH...MM...EVENT 05/17 03:20 AM...02...13...00...Crew wakeup 04:00 AM...02...13...40...EVA-1: Airlock repress/hygiene break 04:45 AM...02...14...25...EVA-1: Airlock depress to 10.2 psi 04:50 AM...02...14...30...ISS daily planning conference 06:40 AM...02...16...20...EVA-1: Spacesuit purge 06:55 AM...02...16...35...EVA-1: Spacesuit prebreathe 07:10 AM...02...16...50...Docking playback 07:45 AM...02...17...25...EVA-1: Crew lock depressurization 08:15 AM...02...17...55...EVA-1: Spacesuits to battery power 08:20 AM...02...18...00...EVA-1: Egress 08:35 AM...02...18...15...EVA-1: Setup 08:45 AM...02...18...25...EVA-1: Pallet preps 09:40 AM...02...19...20...EVA-1 (Reisman): SGANT installation 10:05 AM...02...19...45...EVA-1 (Bowen): SGANT installation 12:20 PM...02...22...00...EVA-1 (Reisman): EOTP install 01:15 PM...02...22...55...EVA-1 (Bowen): EOTP install 01:50 PM...02...23...30...EVA-1 (Reisman): SSRMS cleanup 01:50 PM...02...23...30...EVA-1 (Bowen): Battery preps 02:15 PM...02...23...55...Cleanup and ingress 02:45 PM...03...25...00...EVA-1: Airlock repressurization 02:55 PM...03...35...00...Post-EVA servicing 03:45 PM...03...01...25...ISS daily planning conference 04:00 PM...03...01...40...Mission status briefing on NTV 04:15 PM...03...01...55...EVA tagup 06:20 PM...03...04...00...ISS crew sleep begins 06:50 PM...03...04...30...STS crew sleep begins 07:00 PM...03...04...40...Daily highlights reel   The final planned flight of space shuttle Atlantis is symbolized in the official embroidered crew patch for STS-132. 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