Spaceflight Now STS-110

Leak repaired for Monday's launch of shuttle Atlantis
Posted: April 7, 2002;
Updated: 4:40 p.m. EDT with actual launch time

With the leaky launch pad hydrogen vent line successfully repaired, NASA is gearing up for another attempt to get shuttle Atlantis off the ground to deliver the keystone truss segment to the International Space Station.

Liftoff is targeted for 4:39:31 p.m. EDT (2039:31 GMT) Monday afternoon. The available launch window extends nearly 10 minutes from 4:34:31 p.m. EDT to 4:44:30 p.m. EDT.

Thursday's countdown was aborted about 8 hours before liftoff as Atlantis' external fuel tank was being loaded with a half-million gallons of super-cold liquid hydrogen and liquid oxygen propellants. About an hour into the three-hour fueling processing, a significant leak developed on the hydrogen vent line that runs along the side of the mobile launcher platform upon which the shuttle sits.

Engineers later determined a weld around the circumference of the line had given way, allowing gaseous hydrogen to escape. The leak created a dramatic scene of vapors billowing from the side of the launch pad.

Late Friday and early Saturday workers completed the job of welding a clamshell-like sleeve over the vent line's leak. The two-piece aluminum sleeve is about 10 inches wide; the vent line is 16 inches in diameter.

View from launch pad camera shows the sleeve installed over the leak on the vent line. Photo: NASA TV/Spaceflight Now
With the fix in place, technicians performed a series of tests on Saturday to ensure the leak was plugged. The checks including a dye penetrant test, pumping liquid nitrogen into the line for a cold shock test, as well as a pressure leak and decay tests.

"All of those tests and leak checks were successful and we are confident that we have a good vent line," said NASA Test Director Pete Nickolenko. "All of our flight and ground systems are now looking good and our team is ready to support launch on Monday."

At launch pad 39B today, the three power-generating fuel cells beneath Atlantis' payload bay are being serviced to top off their supplies of hydrogen and oxygen reactants, which were originally loaded aboard the ship last week. The cryogenics naturally boil away, so they have to be replenished to ensure the shuttle has enough onboard to generate electricity and drinking water for the full 11-day mission.

The massive rotating service structure, which provides the primary access and weather protection for Atlantis while at the launch pad, will be swung away from the shuttle at about 10 p.m. EDT. Overnight the pad will be secured and cleared of all workers in preparation for fueling Atlantis.

Mission managers will convene a meeting at 6:30 a.m. to review the progress of work and receive a weather briefing before giving approval to start loading the shuttle's external tank, which could start by 7:45 a.m.

The weather forecast for Kennedy Space Center on Monday is somewhat iffy with a 40 percent chance high winds will prohibit launch.

"High pressure off the east coast of the U.S. combined with low pressure in Texas on Monday causes a tight pressure gradient in Florida. The result is gusty winds expected at KSC," said Launch Weather Officer Kathy Winters.

The launch time forecast calls for scattered cumulus clouds at 3,500 feet, southeasterly winds from 120 degrees at 22 peaking to 30 knots at the pad, visibility of 7 miles, a temperature of 73 degrees F and relative humidity of 59 percent.

The winds are mainly a concern for violating the headwind limits at the KSC shuttle runway where Atlantis could return in the event of a major problem during the first minutes of flight.

Should the launch slip to Tuesday or Wednesday, Winters predicts a 20 percent chance of a low cloud ceiling scrubbing liftoff on either day.

Weather at abort landing sites shouldn't be a factor on Monday or Tuesday, with at least one site expected to have acceptable conditions. However, all three Transoceanic Abort Landing sites are forecast to have poor weather on Wednesday.

The seven Atlantis astronauts remained at the Cape over the weekend, NASA said. Their activities have been mostly a secret, shielded from the public's eye under the agency's new security policy.

Now showing
For Spaceflight Now+Plus service (subscribers only):

Launch pad cameras capture this dramatic video of the ruptured hydrogen vent line on the east side of the mobile launch platform and the resulting cloud of vapors. (1min 06sec file)
  QuickTime or RealVideo

NASA Launch Director Mike Leinbach briefs reporters on the hydrogen vent line leak and repair options at the post-scrub press conference at Kennedy Space Center. (26min 31sec file)
  QuickTime or RealVideo

See full listing of video clips.

Recent updates

01:30 PM
Quick-look Data

07:30 AM
Entry Timeline

12:00 AM
Master Flight Plan

Daily Flight Plan (FD-11/12)

12:50 AM
Undocking timeline

11:50 PM
NASA TV Sked (rev. I)

05:40 PM
Spacewalk Stats

Gemini 7
Gemini 7: The NASA Mission Reports covers this 14-day mission by Borman and Lovell as they demonstrated some of the more essential facts of space flight. Includes CD-ROM.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Apollo patches
The Apollo Patch Collection: Includes all 12 Apollo mission patches plus the Apollo Program Patch. Save over 20% off the Individual price.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Mars Rover mission patch
A mission patch featuring NASA's Mars Exploration Rover is available from our online.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Apollo 9 DVD
On the road to the moon, the mission of Apollo 9 stands as an important gateway in experience and procedures. This 2-DVD collection presents the crucial mission on the voyage to the moon.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Gemini 12
Gemini 12: The NASA Mission Reports covers the voyage of James Lovell and Buzz Aldrin that capped the Gemini program's efforts to prove the technologies and techniques that would be needed for the Apollo Moon landings. Includes CD-ROM.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

STS-134 Patch

Free shipping to U.S. addresses!

The final planned flight of space shuttle Endeavour is symbolized in the official embroidered crew patch for STS-134. Available in our store!

Final Shuttle Mission Patch

Free shipping to U.S. addresses!

The crew emblem for the final space shuttle mission is now available in our store. Get this piece of history!

Apollo Collage
This beautiful one piece set features the Apollo program emblem surrounded by the individual mission logos.

STS-133 Patch

Free shipping to U.S. addresses!

The final planned flight of space shuttle Discovery is symbolized in the official embroidered crew patch for STS-133. Available in our store!

Anniversary Shuttle Patch

Free shipping to U.S. addresses!

This embroidered patch commemorates the 30th anniversary of the Space Shuttle Program. The design features the space shuttle Columbia's historic maiden flight of April 12, 1981.

Mercury anniversary

Free shipping to U.S. addresses!

Celebrate the 50th anniversary of Alan Shephard's historic Mercury mission with this collectors' item, the official commemorative embroidered patch.

ERROR: Random File Unopenable

ERROR: Random File Unopenable

The random file, as specified in the $random_file perl variable was unopenable.

The file was not found on your file system. This means that it has either not been created or the path you have specified in $trrandom_file is incorrect.
Get e-mail updates
Sign up for our NewsAlert service and have the latest news in astronomy and space e-mailed direct to your desktop (privacy note: your e-mail address will not be used for any other purpose).

Enter your e-mail address:

Columbia Report
A reproduction of the official accident investigation report into the loss of the space shuttle Columbia and its crew of seven.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Mars Panorama

DISCOUNTED! This 360 degree image was taken by the Mars Pathfinder, which landed on the Red Planet in July 1997. The Sojourner Rover is visible in the image.
 Choose your store:

Apollo 11 Mission Report
Apollo 11 - The NASA Mission Reports Vol. 3 is the first comprehensive study of man's first mission to another world is revealed in all of its startling complexity. Includes DVD!
 Choose your store:
U.S. - U.K. - E.U. - Worldwide

Rocket DVD
If you've ever watched a launch from Kennedy Space Center, Cape Canaveral, Vandenberg Air Force Base or even Kodiak Island Alaska, there's no better way to describe what you witnessed than with this DVD.
 Choose your store:
U.S. - U.K. - E.U. - Worldwide



© 2014 Spaceflight Now Inc.