Australia’s Defence Science and Technology Organisation (DSTO) and the United States Air Force have signed an agreement to advance research into hypersonic (Mach 5 or higher) flight. The 8-year program has been established as a Project Arrangement under an existing research and development agreement between Australia and the USA, and the USD $54 million Hypersonic International Flight Research Experimentation (HIFiRE) project is one of the largest collaborative ventures to be undertaken between the two nations. It will have obvious implications for projects like DARPA’s FALCON, both as a boost to its ambitions for lower-cost satellite launches and an obvious feed-in to spaceplane projects (see our FALCON HTV Focus Article). Hypersonics also has potential implications for missile projects like the $120 million RATTLRS contract, not to mention the dual-combustion ramjet approach of HyFly et. al.