For the first time, the US Air Force successfully recovered a reusable rocket sled that flew at hypersonic speeds The test at the end of March 2022 was part of the hypersonic sled recovery (HSR) program of the US air force, which successfully stopped the sled flying at 5.6 times the speed of sound.
Hypersonic flight technology has great potential to completely change military and civil applications, but the research in this field has been very difficult. A major problem is the intense heat generated in hypersonic flight at a speed of five times the speed of sound. The temperature generated in this process can reach more than 1800 ° f (1000 ° C), which will damage materials, avionics and flight systems, and bring a lot of thermal stress to the fuselage.
Because of this, engineers are very keen to study the effects of this heat and other factors. However, they did not have much chance in the post inspection, because the flight test related to the missile throwing from the mother ship usually ended with the test ship falling into the sea and disappearing into the abyss.
As an alternative, the vehicle can be tested on a hypersonic test track. The latest test of the Holloman high speed test track (hhstt) of the 846th test squadron at Holloman Air Force Base in New Mexico involves the use of rockets to accelerate a vehicle on a monorail on the ground. These spectacular hypersonic drag races pay special attention to the development of high-speed braking technology to recover the vehicle for analysis.
Such sled tests allow engineers to have more control over flight variables and simplify analysis. In addition, flying on the ground is also very useful because military hypersonic missiles must fly at low altitude if they are to become practical weapons.
According to the air force, hhstt is the only sled track that can recover hypersonic vehicles. Although the speed of previous rocket sleds has exceeded Mach 8, these faster sleds have not been recycled. In early March, a sled flying at 6400 ft / S (1951 M / s) on a monorail track was successfully stopped.
"Your achievement marks the fastest recycling of monorail sleds in more than 30 years, and it is also the first time that we recycle reusable sleds in the program at this speed," Lieutenant Colonel Paul Dolce, commander of the 846th test Squadron, congratulated the team, "In my opinion, this is indeed historic. It would not have been possible without everyone working on the track. These efforts will now prepare for the success of our future hytip (hypersonic test and evaluation portfolio) operations and add a new capability to our hypersonic customers."