US aerospace start-up Stratolaunch has completed the much-awaited first hypersonic flight with its reusable Talon-A vehicle.
That inaugural flight took place in December, but was only revealed by the Pentagon on 5 May. The announcement also confirmed the successful completion of a second Talon-A hypersonic flight in March.
In both tests, the experimental autonomous aircraft was dropped over the Pacific Ocean from Stratolaunch’s massive captive carry aircraft known as Roc. The rocket-powered Talon-A then accelerated to speeds beyond Mach 5 – the generally accepted threshold for hypersonic flight – before landing at Vandenberg Space Force Base in California.
The achievement marks the first instance of an American craft breaking the hypersonic barrier since the conclusion of the manned North American X-15 programme in 1968.
Notably, such milestones may now start coming more frequently.
While there was a three-month gap between the first two Talon-A hypersonic sorties, a Pentagon official overseeing hypersonic development says the data collected will help reduce vehicle turnaround time “from months down to weeks”.
Stratolaunch chief executive Zachary Krevor says an initial review of data from the most recent Talon-A flight “confirmed the robustness” of the vehicle’s design and its ability to meet the performance capabilities expected by customers.
“We’ve now demonstrated hypersonic speed, added the complexity of a full runway landing with prompt payload recovery and proven reusability,” Krevor says.
Stratolaunch has received multiple research and development contracts from the US Air Force Research Laboratory to help fund the test campaign, although the company is primarily funded by private investors.
The company’s goal is to create a reusable flight vehicle capable of reliably reaching hypersonic speeds for use as a test bed for lowering the cost and time associated with developing hypersonic technologies.
Enough capital has been raised to cover the fabrication of at least three Talon-A vehicles, two of which are meant to be reusable. These are designated Talon-A2 and Talon-A3.
Talon-A2 completed both the December and March flights that reached M5.
Stratolaunch completed the first sub-hypersonic powered flight of Talon-A in March 2024 using a non-reusable variant designated Talon-A1.
Each vehicle is powered by a single Hadley rocket engine, developed by Colorado-based manufacturer Ursa Major.
Stratolaunch’s Roc mothership is believed to be the largest aircraft currently flying anywhere in the world. The all-composite, overwing jet (registration N351SL) was developed by Scaled Composites as a purpose-built air-launch vehicle for Stratolaunch.
Roc boasts a 117m (385ft) wingspan and is powered by six engines originally developed for the Boeing 747. Stratolaunch says Roc boasts payload capacity of 226,800kg (500,000lb).
The company is also developing a second captive carry aircraft named the Spirit of Mojave, based on a modified 747-400 passenger jet.
