In response to progress from China and Russia, the US Air Force is pushing to rapidly develop hypersonic cruise missiles in coordination with the other services, but can’t predict when those missiles will be deployed.

Heather Wilson, secretary of the air force, said in testimony before the Senate Armed Services Committee that the USAF is pursuing two hypersonic weapons prototyping programmes simultaneously: a hypersonic conventional strike weapon, or HCSW, which was contracted to Lockheed Martin Space on 18 April, and an air-launch rapid response weapon, or ARRW, which has not been contracted.

“The services are working very closely together on these technologies,” said Wilson. “The guidance is to go fast and to leverage the best technology available.”

When asked by Sen Tim Scott of South Carolina when the USAF would be able to deploy hypersonic weapons aboard aircraft, Gen David Goldfein, chief of staff of the USAF, said that the service couldn’t predict a date.

DARPA and the USAF have other hypersonic initiatives, such as the boost glide programme. In a boost glide system, a rocket accelerates its payload to high speeds; the payload then separates from the rocket and glides unpowered to its destination.