Discovery's liftoff delay raises troubling issues

The scrubbing of the launch of space shuttle Discovery on Wednesday is disappointing, disheartening and troubling.
The long-awaited mission was delayed 21/2 hours before liftoff because of a malfunctioning fuel sensor. A fuel gauge said full when it should have said empty.
The setback is disappointing because millions had anticipated a timely liftoff and had recognized the singular importance -- both real and symbolic -- of the mission. It is the first manned space flight NASA has attempted since the entire crew of space shuttle Columbia was killed when the spacecraft broke apart on its return to Earth in February 2003.
The flight represented America's dogged determination to rise above adversity, to soar back into the heavens and to continue to reap the scientific and technological dividends that the shuttle program has provided since its inception. The launch symbolized the strength of American grit and ingenuity that have helped to make the United States the world leader in manned space exploration.
Safety lessons learned?
The delay is disheartening because NASA has strived over the past two years to impress upon the nation that it was working tirelessly to ensure trouble-free missions and to improve its so-called "safety culture." Columbia accident investigators had concluded that the culture of safety had broken down seriously during the ill-fated 2003 mission.
That's why it's particularly troubling that some early warning signs of safety problems with Discovery appeared to have been ignored. When the same type of potentially fatal fuel sensor problem cropped up during a test three months ago, it was accepted as an "unexplained anomaly" and the countdown to this week's blastoff was set. Some engineers had pushed for further testing at the pad before committing to a liftoff.
We find it an unexplained anomaly why any signs of trouble would be minimized on a mission for which the eyes of the nation and world would be focusing squarely on safety.
It is troubling, too, that one day before the scheduled liftoff, a window cover caused damage to some of Discovery's thermal tiles -- the very thing that NASA had worked to avoid after Columbia's wing was pierced at liftoff by a chunk of foam insulation from the fuel tank. Discovery's tiles were quickly replaced.
What next?
NASA now has until the end of July to launch Discovery; otherwise it must wait until September.
While we hope the mission proceeds Sunday or next week, we would not want to compromise safety simply to lift the spirits of Americans eager to see their nation return to outer space.
The flight of the Discovery is one of the most important in U.S. manned space history because it will signify America's perseverance and resilience in remaining the world's leading player in space exploration. Repeated delays will only fuel skeptics and naysayers who continue to question the value and return on investment of the program.
Despite the delay, we are pleased the problems were found before liftoff, and the potential for trouble or tragedy for the crew was averted. We only wish those problems could have been dealt with much earlier.
While we hope that the mission will proceed expeditiously, it must not proceed expediently. The political or public relations value of our return to space must never take a back seat to safety.