The milestone moves Orbital closer to beginning commercial cargo services to the International Space Station next year.
The Antares first stage, designed by Yuzhnoye and built by Yuzhmash in Ukraine, moved one mile from its hangar to pad 0A at Wallops Flight Facility on Virginia's Eastern Shore. The rollout was delayed from last week due to a technical issue with the rocket's transporter, according to Orbital. Officials say the hotfire will occur about four or five weeks following integration and checkout of the Antares first stage with the launch pad's liquid fueling systems. The first stage's two AJ26 engines will ignite for about 30 seconds during the hold-down firing, allowing engineers to check the launch pad's integrity. The AJ26 engines are provided by Aerojet, which converted Russian NK-33 engines into an AJ26 engine by removing some harnessing, adding U.S. electronics, qualifying it for U.S. propellants, and modifying the system to gimbal for steering.
No other Wallops launch pad or Orbital Sciences rocket uses large liquid propellant systems.
"MARS has completed construction and testing operations on its launch complex at Wallops Island, the first all-new large-scale liquid-fuel launch site to be built in the U.S. in decades," said David Thompson, Orbital's president and CEO.
"Accordingly, our pad operations are commencing immediately in preparation for an important series of ground and flight tests of our Antares medium-class launch vehicle over the next few months." NASA gave approval for Orbital to begin operating the Wallops launch pad last week. Orbital will remove the Antares first stage from the launch pad after the hold-down engine test. Another full-up Antares vehicle with a solid-fueled second stage and a mock payload will roll to the launch pad for the launcher's first flight, which is a demonstration mission to prove out the rocket. The second Antares launch, scheduled for early next year, will carry Orbital's Cygnus resupply craft on a test flight to the space station.
Orbital said in a statement Monday the space station test flight will haul approximately 550 kilograms, or 1,212 pounds, of cargo to the complex and will remove about 1,000 kilograms, or 2,204 pounds, of trash for disposal.