First Reusable Hypersonic Tests Since the X-15 Era
The United States has resumed reusable hypersonic flight testing for the first time in over 50 years. This milestone was achieved through test flights of Stratolaunch’s Talon-A2 autonomous drone, which exceeded Mach 5 in both December 2024 and March 2025. These missions were confirmed by the US Department of Defense on 5 May.
This achievement marks the first reusable hypersonic test programme since the legendary X-15 project, which concluded in 1968. The X-15, developed in partnership with NASA, the US Air Force, and the Navy, reached speeds of up to Mach 6.7 and played a major role in early spaceflight developments, including the Mercury and Apollo programmes.
A New Chapter with Talon-A2 and MACH-TB
Stratolaunch’s Talon-A2 drone is part of the Pentagon-backed Multi-Service Advanced Capability Hypersonic Test Bed (MACH-TB) programme. This initiative aims to fast-track hypersonic technology by using commercially available platforms. The MACH-TB effort is managed by Leidos under the direction of the Pentagon’s Test Resource Management Center (TRMC).
The Talon-A2 was launched from Roc, Stratolaunch’s enormous carrier aircraft, which has a wingspan of 385 feet—the largest ever built. During its recent flights over the Pacific Ocean, Talon-A2 achieved hypersonic speeds before safely landing at Vandenberg Space Force Base in California.
According to Stratolaunch, the drone’s reusability offers a more cost-effective and efficient testing platform than traditional expendable systems. Reusable vehicles allow faster turnarounds and more frequent data collection, helping the Pentagon accelerate its hypersonic research.
TRMC director George Rumford emphasised the milestone, stating that successful reuse is a critical advancement for the MACH-TB programme.
A Strategic Pivot for Stratolaunch
Founded in 2011 by Microsoft co-founder Paul Allen, Stratolaunch initially aimed to launch rockets into orbit. After Allen’s death in 2018, the company struggled until it was acquired by Cerberus Capital Management in 2019. The firm shifted its focus to hypersonic flight, aligning with rising military demand for advanced missile systems.
The March 2024 flight of Stratolaunch’s earlier expendable Talon-A model, TA-1, reached high supersonic speeds but fell just short of Mach 5. The new version, TA-2, is fully reusable and represents a significant upgrade.
Hypersonic weapons have become a top priority for the US military amid advances by China and Russia. These systems are capable of mid-flight manoeuvres, making them harder to intercept. In response, the Pentagon is speeding up development of offensive and defensive systems, including a proposed multi-layered defence known as the Golden Dome.
The Talon-A2 is powered by Ursa Major’s Hadley rocket engine, a 5,000-pound-thrust, reusable engine designed for small launch and hypersonic applications. This engine uses an oxygen-rich staged combustion cycle with liquid oxygen and kerosene as propellants.
with inputs from Reuters