For the first time in over fifty years, the United States has successfully re-entered the era of reusable hypersonic flight testing. This achievement is attributed to an autonomous drone, the Talon A2, developed by Stratolaunch. The Defense Department confirmed on May 5th that the hypersonic vehicle surpassed Mach 5—the threshold for hypersonic speed—during two Pentagon-backed test flights in December 2024 and March 2025.

These flights represent the first reusable hypersonic tests conducted by the U.S. since the X-15 program concluded in 1968. The X-15, a collaborative effort between NASA, the U.S. Air Force, and the Navy, operated for almost a decade, reaching a record speed of Mach 6.7 and significantly contributing to advancements in the Mercury, Gemini, Apollo, and Space Shuttle programs.

Stratolaunch, established in 2011 by Microsoft co-founder Paul Allen, operates the Talon-A. The tests were part of the Multi-Service Advanced Capability Hypersonic Test Bed (MACH-TB) program, a Department of Defense initiative focused on accelerating hypersonic weapons development using commercially available testing platforms. Stratolaunch works under a contract from Leidos, which manages MACH-TB for the Pentagon’s Test Resource Management Center (TRMC). "Demonstrating the reuse of fully recoverable hypersonic test vehicles is an important milestone for MACH-TB," stated George Rumford, director of the TRMC.

Launched from Stratolaunch's Roc carrier aircraft—renowned for its 385-foot wingspan—the Talon-A2 drone was released over the Pacific Ocean. It achieved speeds exceeding Mach 5 before landing at Vandenberg Space Force Base in California. Stratolaunch highlights its reusable platform as a cost-effective and time-efficient alternative to traditional expendable systems, enabling quicker data acquisition and repeated testing.

The success represents a significant turnaround for Stratolaunch, which faced financial challenges following the death of Paul Allen in 2018. Acquired by Cerberus Capital Management in 2019, the company shifted its focus to hypersonic testing, a move that has proven well-aligned with the increasing military demand. A previous flight in March 2024 using the expendable Talon-A model (TA-1) achieved high supersonic speeds, approaching but not reaching Mach 5. The TA-2, however, is fully reusable.

The Pentagon's prioritization of hypersonic weapons stems from concerns over advancements by China and Russia. These weapons are designed for mid-flight maneuverability and evasion of traditional missile defenses. This has spurred the U.S. to accelerate its development programs and deploy defense systems, such as the Golden Dome layered missile defense system. The Talon-A2 utilizes Ursa Major’s Hadley rocket engine, a 5,000-pound-thrust, reusable engine designed for small launch vehicles and hypersonic applications.