Atlantis Astronauts Hit a Few Snags in Space Station Work

How many astronauts does it take to unscrew a bolt?

“Apparently, it takes three. Two outside and one inside,” said Pam Melroy of mission control at Johnson Space Center in Houston.

Melroy’s jest was at the expense of astronauts from the space shuttle Atlantis, who were trying without much success Wednesday to continue installing power-generating solar arrays -- delivered by Atlantis -- on the International Space Station during a spacewalk.

After grunting and groaning in their bulky spacesuits, Steve MacLean and Dan Burbank, with astronaut Joe Tanner advising from inside the space station, had to return to a toolbox for a new wrench to pry loose the recalcitrant bolt.

The bolt, which held the solar arrays in place during Atlantis’ launch Saturday, was one of two difficulties to crop up during the second of three scheduled spacewalks. Another bolt drifted away from the work site, the second time in two days of spacewalking construction work.

The bolts are small, and mission managers said neither would pose a threat to the space station or Atlantis.

Astronaut training stresses the need to take care of tools during spacewalks. Several thousand pieces of space junk orbit Earth, some large enough to pose a danger to the space station.

The problems aside, NASA called Wednesday’s more than seven-hour spacewalk a success.

The principal task was to put into operation a large joint allowing the solar arrays to swivel and face the sun as the space station orbits.

After the astronauts loosened six launch restraints, four thermal covers and 16 launch locks, mission controllers rotated the joint 5 degrees, then 180 degrees.

“We had numerous battles with hardware. It was almost like giving birth today,” said John McCullough, lead flight director for the space station.

But in the end, everything appeared to work out. “What a great day,” he said.

Overnight, the solar arrays will be unfurled to their full length of 240 feet.

When put into operation, the arrays will double the amount of power produced by the space station.

Atlantis is the first construction mission to the half-built space station in about four years. The shuttle carried a truss, attached to the solar arrays, that was added to the port side of the station Tuesday.

While downplaying the seriousness of the lost bolts, NASA officials said engineers were studying the events to determine whether they needed to change any procedures to prevent losses during future spacewalks.

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john.johnson@latimes.com