The countdown reached all the way to practically zero Saturday morning for the SpaceX Falcon 9 rocket. The engine ignition sequence started up, but there was an automatic shutdown by on-board computers. So instead of blasting off on a delivery mission to the space station, the rocket stayed on its launch pad amid a cloud of engine exhaust.
Even NASA's most seasoned launch commentator was taken off guard.
"... 3-2-1, zero, and liftoff," announced commentator George Diller, his voice trailing as the rocket failed to budge. "We've had a cutoff. Liftoff did not occur."
Billionaire rocket designer Elon Musk attributed the problem to slightly high combustion chamber pressure on engine No. 5. "Will adjust limits for countdown in a few days," he wrote via Twitter.
Tuesday is the earliest that SpaceX can try again to send its cargo-laden Dragon capsule to the space station. The California-based company - formally known as Space Exploration Technologies Corp. - is targeting every third day for a launch attempt to save fuel in case of rendezvous problems at the space station.
This was the first launch attempt by one of the private U.S. companies hoping to take over the job of delivering cargo and eventually astronauts to the space station for NASA. Only governments have accomplished that to date: the United States, Russia, Europe and Japan.
NASA is looking to the private sector to take over flights to orbit in the post-shuttle era. The goal is to get American astronauts launching again from U.S. soil. SpaceX officials said that could happen in as little as three years, possibly four. Several other companies are in the running.
An estimated 1,000 SpaceX and NASA guests poured into the launching area in the wee hours of Saturday, hoping to see firsthand the start of this new commercial era. They left disappointed.
Everyone, it seemed, was rooting for a successful flight.
"Go SpaceX," read the sign outside Cape Canaveral City Hall. Until NASA's space shuttles retired last summer, the sign had urged on the launches of Discovery, Endeavour and, finally, Atlantis. Those ships are now relegated to museums.
Late last month, SpaceX conducted a test firing of the nine first-stage rocket engines at the pad. No major problems were found.
For Saturday's launch attempt, Musk was in the SpaceX Mission Control in Hawthorne, Calif. He helped create PayPal and founded SpaceX 10 years ago. He also runs Tesla Motors, his electric car company.
