Reuters reports that the joint Boeing-Lockheed Martin firm, United Launch Alliance (ULA), which builds and markets the Atlas V and Delta IV rockets, will be investigated by the Federal Trade Commission (FTC) for anti-trust violations in allegedly using an exclusivity clause to prevent the US-Russian built rocket engine, the RD Amross RD-180, from being used by other rocket firms.
According to the report, Orbital Sciences Corp would like to use the LOx (lIquid oxygen)/kerosene RD-180 for later versions of its Antares rocket. The Antares first stage currently uses two Aerojet produced AJ-26-500 engines, which are refurbished Russian-built NK-33 LOx/kerosene rocket engines, 30 of which powered the unsuccessful Soviet-era N-1 moon rocket. When the N-1 rocket programme was cancelled in the early 1970s after four launch failures, the production line for the NK-33 was stopped. The remaining supply of unused NK-33 engines was stored until Aerojet recovered them for refurbishment and modernisation to the AJ-26-500 standard.
Comment by David Todd: While the AJ-26-500 is regarded as a very efficient LOx/kerosene engine, both in terms of its specific impulse and thrust-to-weight ratio, it only has about half the thrust of an RD-180. However, it is really the prospect that the supply of AJ-26-500 engines eventually running out, that appears to be the main reason why Orbital Sciences wants to find an alternative engine for its Antares launch vehicle.
