phase. James Acton characterized the proliferation of hypersonic vehicles as never-ending in October 2021; Jeffery Lewis views the proliferation as additional arguments for ending the arms race. Doug Loverro assesses that both missile defense and competition need rethinking. CSIS assesses that hypersonic defense should be the US' priority over hypersonic weapons. In 2021, DoD was codifying flight test guidelines, knowledge gained from Conventional Prompt Strike (CPS) and the other hypersonics programs, for some 70 hypersonics R&D programs alone, as of 2021. In 2021-2023, Heidi Shyu, the Under Secretary of Defense for Research and Engineering (USD(R&E)) is pursuing a program of annual rapid joint experiments, including hypersonics capabilities, to bring down their cost of development. A hypersonic test bed aims to bring the frequency of tests to one per week. Other programs France, Australia, India, Germany, Japan, South Korea and North Korea and Iran also have hypersonic weapon research programs. Australia and the US have begun joint development of air-launched hypersonic missiles, as announced by a Pentagon statement on 30 November 2020. The development will build on the $54 million Hypersonic International Flight Research Experimentation (HIFiRE) under which both nations collaborated on over a 15-year period. Small and large companies will all contribute to the development of these hypersonic missiles, named SCIFIRE in 2022. Proposed Hypersonic aircraft I-Plane 14-X Avatar (spacecraft) Advanced Technology Vehicle DARPA XS-1 Destinus hydrogen-powered hypersonic cargo aircraft Dream Chaser NASA X-43 HyperSoar HyperStar hypersonic passenger airliner Falcon HTV-2 Boeing Commercial Airplanes hypersonic airliner Concept Lockheed Martin SR-72 Kholod Ayaks waverider spaceplane Programme for Reusable In-orbit Demonstrator in Europe (PRIDE) Sänger II HyShot Hytex Horus SHEFEX Skylon Reaction Engines A2 Hypersonic Air Vehicle Experimental (HVX) with Concept V aircraft Spartan HEXAFLY SpaceLiner STRATOFLY Zero Emission Hyper Sonic Transport Hermeus Quarterhourse unmanned hypersonic demonstrator designed to land and take-off on conventional runways. Hermeus Halcyon hypersonic transport Hypersonic bomber Expendable Hypersonic Air-Breathing Multi-Mission Demonstrator ("Mayhem") Based on § HAWC and HSSW: "solid rocket-boosted, air-breathing, hypersonic conventional cruise missile", a follow-on to AGM-183A. As of 2020 no design work had been done. By 2022 Mayhem was to be tasked with ISR and strike missions, as a possible bomber. Leidos is preparing a system requirements review, and a conceptual design for these missions. Draper Labs has begun a partnership with Leidos. Kratos is preparing a conceptual design for Mayhem, using Air Force Research Laboratory (AFRL) digital engineering techniques in a System design