Fuel Line Problems Finally Yield To Probe By Experts; Shuttle Flight Is Safe With No Foam Insulation Problems Seen
Discovery Set To Reenter, Land On March 28
And we have liftoff.
Spewing brilliant yellow flames and a pink contrail through a deep blue sky at dusk, Space Shuttle Discovery finally launched on its 13-day STS-119 Mission to add the last major structural component to the International Space Station.
The repeatedly-delayed liftoff finally came last night, right on time at 7:43 p.m. ET, after NASA conquered obstinate fuel system problems. Those woes had kept Discovery stuck on Launch Pad 39A at Kennedy Space Center, Fla., long after its originally scheduled Feb. 12 launch date.
In a reflection of NASA caution ever since the Space Shuttle Columbia accident in 2003, the space agency held Discovery on the ground while considering whether a flow control valve problem found in Space Shuttle Endeavour on a mission in November could possibly occur in Discovery or other shuttles in the remaining eight or nine missions before the shuttle fleet is pushed into retirement.
The valves can crack, and a piece of metal can break off, with the enormous fuel-flow pressure accelerating any shrapnel-like piece to bullet-like velocities that could rupture the fuel line and cause catastrophe, some experts feared.
But experts decided using fresh valves with no cracks would provide a sufficient safety margin, since cracking and then breakage wouldn’t both be likely to occur in just a single mission. (Please see Space & Missile Defense Report, Monday, March 9, 2009.)
A fire-hazard problem last week, when hydrogen leaked from a line during fueling operations, didn’t recur this time to mar the Discovery pre-launch activities. Mike Leinbach, space shuttle launch director, said the countdown and liftoff was “pretty smooth,” leading to “the most visually beautiful launch” he has seen. And mission management chairman Mike Moses said the flight “went off perfectly.”
During the launch and ascent, no problem was detected in the Discovery fuel system. Also, no foam insulation pieces were seen ripping off the external fuel tank that might have damaged the orbiter vehicle, briefers told space journalists after the launch.
Foam pieces have been an issue since the Columbia accident, when a chunk of insulation ripped from the external fuel tank and hit the leading edge of an orbiter vehicle wing during the ascent to space, punching a hole in the critical heat shield on the wing edge. Later, as Columbia attempted its return to Earth, fiery hot gases of reentry rushed through the hole into the wing and caused its structural failure. The ship and crew of seven were lost.
The lesson here is that “we have to fly, and we have to fly safe,” Bill Gerstenmaier, associate NASA administrator for space operations, said.
But no major safety issues were seen in the Discovery launch. The one fatality here might have been a bat that was seen hanging on the outside of the external fuel tank before launch, which NASA categorized as “unexpected debris.” No dead bat was seen after Discovery soared aloft, so perhaps at launch the creature flew away from the flaming shuttle exhaust like a bat out of hell.
NASA also has been concerned about shuttle safety issues since Space Shuttle Challenger more than two decades ago perished shortly after launch, when O-rings failed in a fiery explosion. That incident also took seven lives.
The Discovery flight was the 100th mission since the Challenger accident.
For Discovery and its crew, this is a crucial flight, attaching the final solar arrays to the space station to bring it up to full electrical generation power that would suffice for about 42 homes.
“We’re able to accomplish everything we want on this flight,” Gerstenmaier said.
It will take three spacewalks to perform all the needed work.
Discovery not only will carry aloft the S-6 truss and final solar array, it also will carry a more significant piece of equipment: a replacement for a water purification system that turns human urine, exhaled breath vapor and condensation into pure drinking water.
This is indispensable for long-distance explorations, such as voyages to Mars, where vehicles carrying NASA astronauts couldn’t possibly carry enough water for them to drink on journeys lasting more than two years.
Yukihide Hayashi, Japan Aerospace Exploration Agency vice president, said he was delighted with the launch of Discovery carrying Japanese astronaut Koichi Wakata to the orbiting laboratory, where he’ll take his place as Expedition 18 and 19 flight engineer on the space station.
Commander Lee Archambault leads Discovery’s crew of seven, along with Pilot Tony Antonelli, and Mission Specialists Joseph Acaba, John Phillips, Steve Swanson, Richard Arnold and Wakata.
Wakata will replace U.S. astronaut Sandra Magnus, who has been on the station for months since riding to orbit on that Space Shuttle Endeavour flight in November.