"Orbital Sciences Corporation today announced that the next launch attempt for the new Antares rocket will be no earlier than Saturday, April 20, at 5 p.m. The mission management team met this afternoon to evaluate weather forecasts and optimum crew work schedules to provide two back-to-back opportunities for a launch attempt."
Keith's note: For some reason Orbital Sciences seems to be uninterested in posting these graphics on their website or otherwise distributing them to people in the Greater Washington DC/Virginia/Maryland area such that people can see the launch of Antares. Yet another odd PR decision from Orbital.
Keith's update: Orbital posted some (but not all) of these charts via Twitter after @NASAWatch pestered them. Alas, they do not know how to post them on their website, so they tweet a link to our posting at SpaceRef where all of their charts are posted. Odd.
"On Saturday, Orbital conducted the wet dress rehearsal for the Antares rocket in preparation its Test Flight scheduled for later this week on April 17. Late in the countdown, at about T-16 minutes, the test was halted because the launch team had detected a technical anomaly in the process. Orbital has determined that a secondary pyro valve aboard one of the two first-stage engines used in the propellant chilldown process was not functioning properly. A replacement unit will be installed within 24 hours with the goal of maintaining the April 17 launch date."