Orbital, NASA Looking For A Launch Window For Antares Rocket
April 21, 2013

Orbital, NASA Looking For A Launch Window For Antares Rocket

Lawrence LeBlond for redOrbit.com - Your Universe Online

Orbital Sciences´ new Antares medium-class space launch vehicle is set for a launch today at 5:00 pm EDT, according to a company statement. The rocket, which was originally scheduled for lift-off on Wednesday April 17, is being launched from the Mid-Atlantic Regional Spaceport (MARS) at NASA´s Wallops Flight Facility on Wallops Island, Virginia, from Launch Pad 0A.

Dubbed the A-ONE mission, the Antares rocket launch was delayed on Wednesday due to unfavorable weather conditions. After Thursday and Friday launch windows were also scrubbed due to continued weather issues, Mission Managers moved to a Saturday launch. However, high altitude winds were deemed too unstable for a Saturday launch and the team moved the launch to today.

As long as weather and winds permit, the launch will occur this afternoon at 5:00 pm EDT. Coverage of the launch will be broadcast live on NASA TV beginning at 4:30 pm EDT.

The goal of the A-ONE mission is to demonstrate the operational capabilities of the Antares launch system and to boost a simulated payload to a target of 155 miles. A successful launch will herald in the next phase for Orbital, cargo missions to the International Space Station (ISS). After completion of a demonstration mission under the NASA Commercial Orbital Transportation System (COTS) agreement, Orbital will begin fulfilling a Commercial Resupply Services (CRS) contract with NASA.

Once Antares does launch (whether it be today or sometime later), Orbital has a pretty good idea what will occur in the minutes following lift off.

About 230 seconds after lift-off, the main engine should cut off at about 64 miles in altitude. Stage-one separation should occur five seconds later at an altitude of 68 miles. At 319 seconds into flight and 110 miles up, fairing separation should occur, with stage-two ignition 9 seconds later. After stage-two burnout at approximately 483 seconds and 153 miles over Earth, payload separation should occur nearly 120 seconds later at roughly the same altitude. Find out more at Orbital's mission overview.

Antares will be carrying a simulated Cygnus payload for the test mission. Mission length from lift-off until payload separation should take less than 11 minutes — 10 minutes and three seconds to be exact.

Stayed tuned for further updates as weather or wind could still force Mission Managers to postpone the launch at least another day.