The maiden Antares launch was aborted about 12 minutes before a scheduled 5 p.m. EDT launch because of a premature separation of an umbilical line on the second stage of Orbital Sciences’ new rocket.
Commentators on the live webcast indicated that there would likely be a 48-hour turnaround on the launch.
I will update this page as I learn more.
UPDATE: A mission update from Orbital:
Dulles, VA (17 April 2013) – Orbital Sciences Corporation (NYSE: ORB), one of the world’s leading space technology companies, today announced that a premature separation of a launch pad umbilical connection to the Antares upper stage used for data communications halted today’s countdown of the Antares test launch at the Mid-Atlantic Regional Spaceport at NASA’s Wallops Flight Facility on Wallops Island, Va. Engineers are currently analyzing what occurred to determine what measures will be taken to resolve the issue
During a launch countdown, safeguards are put in place to periodically verify that all systems are functioning as planned. With twelve minutes left in the count, the launch team identified the anomaly and called a scrub of today’s test launch attempt.
The next launch attempt is tentatively set for no earlier than Friday, April 19, pending final resolution of the issue and acceptable weather conditions.
“We are still examining all of the data, but it appears that the issue is fairly straightforward,” said Mr. Frank Culbertson, Orbital’s Executive Vice President and Mission Director for the Antares Test Flight. “With this being the first launch of the new system from a new launch facility we have taken prudent steps to ensure a safe and successful outcome. Today, our scrub procedures were exercised and worked as planned. We are looking forward to a successful launch on Friday.”