AeroJet owns pretty much all of the existing NK-33 inventory and a license to manufacture them. The work for integrating the NK-33 into the Antares rocket was a

AeroJet owns pretty much all of the existing NK-33 inventory and a license to manufacture them. The work for integrating the NK-33 into the Antares rocket was actually done by a Ukrainian firm: http://en.wikipedia.org/wiki/Antares_%28rocket%29#Design http://en.wikipedia.org/wiki/Antares_%28rocket%29#Design