Managers had held out hope, however slim, that they might be able to launch Discovery within a few days. But with engineers no closer to figuring out why the fuel sensor malfunctioned Wednesday – a potentially deadly problem – NASA had no choice but to call for a lengthy standdown.

NASA is up against the clock. If extensive repairs are needed and the shuttle has to be moved off the launch pad and into the hangar, the flight could end up being bumped into September to ensure a daylight liftoff. —Marcia Dunn —NASA Delays Discovery Launch Indefinitely (AP|MyWay)

Bummer… but of course it’s nothing at all compared to what might have happened if the shuttle had launched with a major unexplained problem.