In 1988,
RSC Energia directed
KBKhA to begin work on a new preburner-less LOx/LH2 rocket engine for use on upper stages, the RO-95. Though this engine never left the design phase, its development confirmed the reliability and performance of the expander cycle to KBKhA. In 1999, a new expander-cycle engine project began. In that year,
GKNPTs Khrunichev awarded a contract to KBKhA to develop a new engine, the RD-0146U, for use on its Proton and Angara launch vehicles. The engine was to be of around thrust class. Soon after, on 7 April 2000, the American company
Pratt & Whitney Rocketdyne entered an agreement with KBKhA, financing the development of the RD-0146. Pratt & Whitney would gain exclusive international marketing rights to this variant. In 2002, RSC Energia awarded KBKhA with a contract to develop the RD-0146E variant for use on its Onega launch vehicle, a Soyuz-2 variant with a fully cryogenic upper stage. In 2009,
TsSKB Progress selected the RD-0146 for use on the new
Rus-M launch vehicle's second stage. The first RD-0146 engine was planned to be delivered to Pratt & Whitney in May 2001. Delays attributed to subcontractor production troubles postponed this, and the first live firing of a production engine took place on 9 October, 2001. A second engine was built and fired in December 2002, and was subsequently delivered to Pratt & Whitney in March 2003. The RD-0146 used a different testing methodology than previous Soviet and Russian engine trial programs. Individual components and subsystems would be tested separately, while earlier testing would use an all-up method, in which an entire engine was assembled and tested. This meant that a single component failure would make it necessary to disassemble the system to detect flaws. In order to facilitate test firings of the RD-0146, a new liquid hydrogen production plant was constructed, with a capacity of per day. This became the second such facility in Russia. ==Description==