Antares AJ-26
Antares AJ-26. Credit: Orbital ATK

PARIS — Orbital Sciences is investigating “two or three alternatives,” all of them Russian, to the current AJ-26 engine that powers the company’s Antares rocket, Orbital Chief Financial Officer Garrett E. Pierce said March 3.

Orbital’s exploration includes filing suit against United Launch Alliance of Colorado in an attempt to break ULA’s exclusivity contract with the makers of Russia’s RD-180 engine, which powers the first stage of ULA’s Atlas 5 rocket.

In a presentation to a conference organized by Raymond James investment advisers, Pierce said Dulles, Va.-based Orbital and its suppliers have enough AJ-26 engines to complete Orbital’s Commercial Resupply Services (CRS) space station cargo-supply contract with NASA, which totals eight Antares missions, and several additional missions as well. NASA is preparing to solicit bids for a follow-on contract that would call for four to five flights a year between 2017 and 2024.

“Right now we are exploring the various avenues that could be available to the company to continue to use the AJ-26 or to use other rocket systems — Russian-sourced systems — we’re looking at right now,” Pierce said. “There are two or three alternatives. Right now the AJ-26 is the standard rocket [engine] that we use on the Antares for the [CRS] contract and a bit beyond that. Then we’ll have the option — this is a few years out — to change the system or continue with it.”

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Peter B. de Selding was the Paris Bureau Chief for SpaceNews.