Weather-wary NASA clears space shuttle for launch

By Irene Klotz

CAPE CANAVERAL, Florida (Reuters) – With a wary eye on the
weather, NASA managers on Friday cleared the U.S. space shuttle
Atlantis for launch from Florida on Sunday to restart
construction of the International Space Station.

The shuttle and six astronauts are scheduled to lift off at
4:30 p.m. (2030 GMT) on the first station assembly mission
since before the 2003 Columbia accident.

“We feel very good about where we are going into the
weekend,” said LeRoy Cain, the senior shuttle program manager
at Florida’s Kennedy Space Center.

The U.S. space agency needs to fly 16 missions to the
orbital outpost to finish construction of the half-built, $100
billion space station before the shuttle fleet is retired in
2010.

“This is the first of many steps we must take to complete
the space station,” program manager Mike Suffredini said.

Getting Atlantis off the ground will be the first
challenge. Thunderstorms and rain are expected to clear the
area by the shuttle’s launch time, which is determined by the
rotation of Earth relative to the space station’s orbit, as
well as other factors such as daylight launch requirements.

That rule was imposed after the Columbia disaster, which
was triggered by a piece of falling foam insulation that fell
off the fuel tank and struck and damaged the shuttle. The ship
broke apart 16 days later over Texas as it flew through the
atmosphere to land, killing the seven astronauts aboard.

Any rain during liftoff might damage the spaceship’s
heat-shielding tiles, and a lightning strike could knock out
the computers that control the ship. Even some kinds of thick,
high clouds make launch hazardous.

Atlantis’ mission follows two test flights, one in July
2005 and another last month, to demonstrate that safety
upgrades made after the accident were successful.

Another disaster or serious problem likely would end the
shuttle program and jeopardize the space station’s future.

Engineers were assessing a lighting strike at the shuttle’s
seaside launch pad on Friday. The bolt is believed to have
struck a cable that is part of the pad’s lightning protection
system, with no impact to the vehicle, launch director Mike
Leinbach said.

NASA managers also were keeping tabs on a newly developed
tropical storm that could threaten the Gulf Coast late next
week. The fifth named storm of the season, Ernesto, is expected
to develop into a Category 1 hurricane by Monday, with 65-knot,
or 74-mile-per-hour (119-km-per-hour), winds.

If NASA’s Mission Control Center in Houston had to be
evacuated, the shuttle likely would be forced to land early.

Suffredini said the launch team would do everything
possible to install the 35,000-pound (15,876-kg) power module
Atlantis is hauling to the station before coming home.

“We would undock from the space station and de-orbit the
(shuttle) at the first safe opportunity,” Cain said.

If necessary the shuttle could land with the module still
in the cargo bay, but Cain said that would be last-choice
option.

“I don’t know that we’ve ever landed with that much cargo
in the payload bay before,” he said.