Antares lifts off from Wallops Island. (Credit: NASA)

Space News has an update on Orbital Sciences’ search for a new engine for its Antares launch vehicle:

The company also said it is evaluating three bids — two Russian, one U.S. — to produce main-stage engines for Orbital’s Antares rocket. The engines being offered include the Russian-built, U.S.-modified engine currently used for Antares.

In a conference call with investors, Orbital Chief Executive David W. Thompson said his company has a sufficient supply of the current Russian-built engines for three more years of Antares operations. Orbital has three Antares first-stage structures, built by a Ukrainian manufacturer, at an Orbital facility, with two more to be shipped soon.

Dulles, Va.-based Orbital has been hunting for an alternative engine supplier in part because the current Russian manufacturer, NK Engines,would need to restart long-ceased production activities to maintain a supply for Antares beyond the next few years. The engines are imported to the United States by Aerojet Rocketdyne of Sacramento, Calif., refurbished and sold to Orbital as the AJ26.

Thompson said it would take another two or three months to decide on a winning bidder, but that both the alternatives to the current supplier “may be preferable to continuing with our current engines.”

Once the decision is made, he said, Orbital will conclude a block purchase of engines to cover Antares launches between 2017 and 2020. Thompson said he has made clear to all three bidders that they will have to absorb any nonrecurring engineering costs associated with filling the order and then recover those costs over time through engine orders.