Atlantis lifts off to return the station to Assembly

http://www.cnn.com/2006/TECH/space/0....ap/index.html

CAPE CANAVERAL, Florida (AP) -- Space shuttle Atlantis blasted off on a mission to resume construction of the international space station Saturday.

NASA stopped Friday's attempt only 45 minutes before its scheduled launch. This time it was a faulty fuel tank sensor -- the same glitch that thwarted two previous missions. The launch delay cost NASA $616,000.

The shuttle's external fuel tanks were filled as scheduled in about 3 hours Saturday morning, exhibiting no problems with any sensor. Weather continued to look favorable, with only a 20 percent chance of storms interfering.

"Hi Mom," astronaut Heidemarie Stefanyshyn-Piper said, waving to a television camera, as she and her five crew mates finished dressing in their orange flightsuits. They were then driven to the launch pad in a specially equipped van. They strapped into the shuttle, and the hatch was sealed.

From the space station 220 miles above Earth, astronaut Jeff Williams inquired how launch preparations were going.

"Hopefully, we'll have some visitors heading on their way to you before long," Mission Control in Houston told him.

Atlantis was supposed to launch on its 11-day mission on August 27. But the shuttle has been kept earthbound by a lightning strike to the launch pad, Tropical Storm Ernesto, a glitch with a 30-year-old motor in an electricity-generating fuel cell, and finally the fuel tank sensor error. Originally scheduled for May 2003, the mission was first postponed by the 2003 Columbia accident.

Saturday was considered the last time NASA had to launch Atlantis before having to go to the back of the line, behind a Russian Soyuz capsule that is slated for liftoff September 18 on a flight to the space station. Both Atlantis and the Soyuz cannot be at the space station at the same time.

If Atlantis were unable to lift off on Saturday, it would have had to wait at least until late September. And even then, NASA would have to waive a rule that says launches must be conducted in daylight so that the spaceship could be photographed for signs of damage.

Friday's launch was scrubbed because a sensor in the hydrogen fuel tank gave an abnormal reading during a test as the shuttle was being fueled.

Atlantis had been fueled with more than 500,000 gallons of supercold liquid hydrogen and oxygen, the six astronauts had strapped themselves in, and the hatch to the shuttle had closed, when NASA decided to postpone Friday's launch.
'We follow the rules'

After problems in previous flights with the sensor, NASA created a new rule requiring a stand-down of 24 hours when one of the hydrogen tank's four engine cutoff sensors doesn't work properly. Such a delay would allow engineers to gather more data on the problem.

"We had a lot of discussion. ... We follow the rules," launch director Mike Leinbach radioed Atlantis' crew, notifying them about the scrub. "Ought to feel good that we did that."

"We understand. We concur 100 percent," responded Atlantis' commander, Brent Jett. "It's the right thing to do."

A large number of managers favored flying, but opposition to launching was led by NASA's flight crew operations director.

Shuttle program manager Wayne Hale said top officials "decided staying with the plan ... was the prudent thing to do."

Aboard Atlantis is one of the heaviest payloads ever carried into space -- 17½ tons of girders that will be added to the half-built space station. It includes two solar arrays that will produce electricity for the orbiting outpost.

Atlantis' crew members will make three spacewalks during the 11-day mission to install the $372 million addition.

Construction on the space station has been at a standstill ever since Columbia broke apart on its return home in 2003, killing its seven astronauts.

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Although this mission hasn't gotten as much press as STS-114 and STS-121, it's just as crucial. The installation of the P3/P4 trusses and the installation of the new solar arrays will provide a major power boost to the station, as will the future missions to install the S3/S4, P5/P6, and to move the S5/S6 trusses to configuration, enabling the installation of additional laboratorys, including the ESA and JAXA modules.

For more information on STS-115 and it's mission, there's the Media Press Kit:

http://www.nasa.gov/pdf/154433main_s...press_kit3.pdf

For a look at where your space agency is going, here's a great animation put together for NASA by Media Fusion:

http://www.fusiononline.com/nasa_esas.htm[/url]