Reaction engines, whose SSTO Skylon concept has been making the rounds for nearly a decade, seems to be getting more support, specifically, it has scored a large contract with DARPA to demonstrate its precooler engine technology:

Reaction Engines has achieved a major breakthrough in the U.S. market with a contract from the U.S. Defense Advanced Research Projects Agency (DARPA). The award covers conducting high-temperature testing of the precooler technology at the heart of its proposed hypersonic air-breathing, combined-cycle Sabre rocket concept.

Reaction has seen interest grow in the U.S. about elements of Sabre, particularly the precooling heat exchanger, ever since the concept was first independently validated by the U.S. Air Force Research Laboratory in 2015 (AW&ST Aug. 3-16, 2015, p. 63). Designed to chill airflow from over 1,800F to −240 F (1,000C to −150C) in less than 1/20th of a second, the heat exchanger is pivotal to the process of extracting oxygen from the air for use by the rocket.

However, the heat exchanger can also be used more generically to precool other engine cycles and reduce heating on engine components in high-speed flight. According to Reaction, the design, dubbed HTX, “could enable new classes of vehicles and operational possibilities.” The precooler will be tested at speeds up to Mach 5 in a new high-temperature airflow evaluation facility to be built in Castle Rock, Colorado, as a base for REI (Reaction Engines Inc.), the U.S. subsidiary of the UK-based company.

It does appear that their technology is getting funding and support, so I’m hoping to see a flight test article in the next 5 years or so.

Previous posts about Reaction Engines here.