On 18 February 2000 Pratt & Whitney (USA) and Snecma (France) announced their signing of a memorandum of understanding to jointly design and develop a new upper-stage cryogenic engine for the upgraded Ariane-5, the Atlas-5, and other new vehicles. Rocketdyne had already begun work on the MB-60, slated for first use on the Delta-4 in 2004. Pratt & Whitney and Snecma identified the SPW-2000 as the successor to the now-defunct Pratt & Whitney RL-50, whose early development work was to be transferred to the new engine. The SPW-2000 was to have a thrust comparable to the RL-50’s, in the 200-270 kN range. However, the SPW-2000 venture was rejected by ESA on 22 June 2000 due to concerns about competition with European rocket engine manufacturers and problems in setting up a work-sharing agreement among the two companies and their subcontractors. Instead, ESA decided to proceed with development of the all-European Vinci project, initiated in March 1999 but never pursued, to develop an all-cryogenic restartable engine that would boost Ariane-5’s capability from 6,300 kg to 11,500 kg into a geosynchronous transfer orbit.