NASA busy ahead of shuttle launch

NASA is preparing to ramp up the pace of its shuttle missions as Atlantis is poised to blast off this week in a bid to finish the assembly of the international space station by a 2010 deadline.

After a three-month delay, the year's first mission is set to launch from NASA's Kennedy Space Center in Florida at 6:38 p.m. Friday.

A half-dozen station-assembly missions are planned over the next 12 months, enough new construction to outfit the station with European and Japanese research modules.

Atlantis leads the parade with a crew of seven astronauts trained to deliver and install a $367.3 million solar-power generation module during an 11-day mission. The new module's outstretched solar panels will give the station a new look as well as gains in electrical power for the new labs.

Also, the shuttle will return to Earth with U.S. astronaut Sunita "Suni" Williams, whose 6 1/2 -month mission to the space station is drawing to a close. Her 192-day mission will be the longest flown by any woman. She will be replaced in space by American Clayton Anderson, one of the Atlantis astronauts.

"This is a pretty intense period for us," said Mike Suffredini, NASA's space station program manager. "From a concentration standpoint, this is one of our most challenging periods."

At the planned pace the space agency should finish the station's assembly by September 2010, the date established for the shuttle fleet's retirement by the White House.

Atlantis was poised for a March 15 liftoff when a hail storm pummeled the protective foam insulation that jackets the ship's external fuel tank, leaving 4,200 divots. The agency, which responded with an around-the-clock repair effort, is not expecting wiggle room in the 2010 deadline, though some experts believe NASA should have leeway to respond to hail storms, hurricanes and other events beyond its control.

"We have no plans to fly past that date at all," said NASA's Wayne Hale, the shuttle program manager.

Reason for deadline

The cap was imposed by the White House in 2004 to free billions in funding for the shuttle's replacement, a new spacecraft that can launch astronauts to the moon as well as the space station.

"What's so sacrosanct about 2010?" asked Jerry Grey, director of science and technology policy for the American Institute of Aeronautics and Astronautics, the nation's largest professional organization for engineers in the two fields.

"Suppose the shuttle is still flying in 2011. Aside from not conforming exactly to the president's original timetable, what's the difference?" Grey said. "Space exploration cannot be done effectively on a tight schedule — it's a long-term activity and should be programmed as such."

In response to the Feb. 26 hail storm, NASA repaired the foam by filling in the largest divots with liquid foam patches and spray-overs. Minor blemishes were sanded away.

The foam prevents a crust of ice from forming as the towering metal fuel tank is filled with super-cold propellants during countdown and protects the tip from destructive overheating as the ship accelerates through the Earth's atmosphere.

If unleashed in flight, pieces of ice or foam become destructive projectiles if they strike the ship's vulnerable heat shield.

The shuttle Columbia's deadly breakup in 2003 was traced to a break in the heat shielding caused by a hunk of breakaway fuel tank foam.

NASA's planned flight rate over the next year will match the peak of six station-assembly missions launched in 2001.

That pace, the space agency acknowledges, could test safety standards NASA embraced after the Columbia tragedy.

"Clearly, having a schedule helps us organize our work," said Hale. "But we fully intend to keep all of our safety practices in place. We can't let the schedule drive us to do something dumb."

He took that message to many of the 17,000 people who work on the shuttle through "all-hands" sessions this year at major NASA installations.

"We can't take our eye off the ball," he warned them.

The agency has time to launch up to 15 flights to the space station as well as a repair mission to the Hubble Space Telescope before the shuttle is retired, said Bill Gerstenmaier, NASA's associate administrator for space operations.

Process is slow going

Atlantis' mission will trace ground broken by missions in September and December, which marked a revival of station construction that ground to a halt after Columbia's loss.

In September, spacewalkers struggled with tools to remove stubborn restraint bolts, the fasteners required to immobilize 17 tons of new station hardware during the shuttle's launching. If stuck in place after installation, the launch restraint bolts would have prevented rotations of a mechanism that enabled a pair of long solar panels to track the sun while the station orbits Earth.

In December, astronauts extended the mission to add a spacewalk after having difficulties retracting a solar panel on an older power module. The 110-foot panel was jammed repeatedly by misaligned guidewires and sluggish hinges.

The Atlantis crew will deliver a solar-power module identical to the hardware launched on the September mission. The crew also will retract a solar panel identical to the one that proved troublesome in December.

"This flight is a lot like a couple of previous flights," said Jim Reilly, the astronaut who will quarterback the mission's three spacewalks. "We have to do the same things those guys did — only better."
Source :http://www.chron.com