HOUSTON Whether they prefer to think of themselves as high-flying mechanics or orbital brain surgeons, Discoverys four spacewalkers have all sorts of special gadgets in their tool belt.
Some items are part of the shuttle toolbox, while others are designed specifically for work on the Hubble Space Telescope. A few of the tools will also be used or modified for construction of the International Space Station.
All told, the Hubble repair crew has more than 150 different items going aloft -- along with tools are aids such as foot restraints, tethers and handholds.
Most of the tools look vaguely familiar but have been modified or designed for use in the extreme temperatures and vacuum of space and to fit the gloved hand of astronauts.
Heres a brief look at some of the implements:
Power Ratchet Tool:
Originally designed for the first Hubble repair mission in 1993, this tool can be used manually or with its motor. It looks much like a large version of a conventional ratchet except this one is connected to a battery pack by an umbilical cord.
Pistol Grip Tool:
This is the workhorse for spacewalkers. Experience with the Power Ratchet Tool led to the development of the PGT. It resembles a large, silver-colored, cordless drill -- but this tool has some high-tech twists. The PGT is computer-controlled and can set precise torque, speed and number of turns. An LED readout on top of the tool indicates its performance.
Coaxial Connector Tool:
Twisting the coaxial connector on the back of a TV may not be much of a problem on Earth, but try doing it with thick gloves on. Spacewalkers face that touchy problem in replacing a radio transmitter on the Hubble. The original units werent designed to be changed in orbit, so technicians designed a ratcheting wrench to grab the nut on the coaxial connector so it can be loosened.
The replacement radio has "jumpers" installed for the coaxial connectors providing a larger surface for the astronaut to twist.
Capture Tool:
Since the Hubbles radio transmitters were not designed for removed in space, any orbital repairman faces several problems. First, the nuts and washers used to fasten the radio inside the Hubble are free floating once loosened. Second, a lip overhangs the nuts, putting them at a difficult angle that makes it difficult for an astronaut to use the ratchet tool to loosen them all the way.
Tool designers came up with a special contrivance to finish loosening the nuts and washers and then capture them. An astronaut uses the ratchet tool to loosen the nuts and then attaches the capture tool. He twists a knob on the capture tool to finish loosening the nut. A claw-like part of the device holds the nut and washer securely before being placed in a caddy.
The replacement radio uses wing nuts for easier installation and removal.
Lubricant Applicator:
Spacewalkers might be performing the first lube job in space with this tool. During the 1997 Hubble repair mission, astronauts had trouble loosening bolts on the Hubbles hatches. On this mission, astronauts will use the applicator to apply a small amount of lubricant on bolts that may be stuck.
The astronaut squeezes the applicators handle to dole out an amount of lube to the tip of the device. After each application, a switch must be thrown on the tool to repeat the process. This prevents too much from being applied.
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