By November 1985, DTI and RAE discussions noted that Rolls-Royce were seeking American data on ramjet technology to support their work on the engine, which it referred to by the name "Swallow". Reportedly, the United States Air Force were interested in the technology used in the Swallow engine for its own purposes. In November 1985, discussions between Prime Minister Margaret Thatcher, Minister without portfolio David Young and US President Ronald Reagan's scientific advisor George Keyworth noted American interest in collaboration on developing hypersonic vehicles such as HOTOL, and that a prototype could be flying as early as 1990.