Stratolaunch LLC has announced the successful completion of its autonomous hypersonic drone tests. The company utilized its enormous Scaled Composites Model 351 “Roc” carrier aircraft to launch the reusable Talon-A2 vehicle. These achievements represent a major leap forward in U.S. hypersonic technology, showcasing fully autonomous operations from air-launch to hypersonic flight and eventual runway recovery.
The Roc, officially known as the Scaled Composites Model 351, boasts the world’s largest wingspan, measuring 385 feet (117 meters)—longer than a football field. This twin-fuselage giant, powered by six Boeing 747 engines, functions as an air-launch platform, deploying hypersonic test vehicles such as the Talon-A2 over the Pacific Ocean.
Originally designed for launching rockets into orbit, the Roc has been redirected since 2019 to support hypersonic research, a move that reflects pressing national defense needs.
During two significant flights, one in December 2024 and the other in March 2025, the Talon-A2 reached speeds surpassing Mach 5, which is more than 3,850 mph or 6,200 km/h. Fueled by Ursa Major’s Hadley liquid rocket engine, the autonomous drone proved its mettle by executing several critical maneuvers. These included a safe separation from the Roc, engine ignition, and a controlled acceleration that took it from the transonic range into hypersonic speeds. The drone then maintained flight and successfully landed on a runway at Vandenberg Space Force Base in California, as planned.
Stratolaunch’s announcement earlier this year highlighted the significance of the two hypersonic flights. “We’ve shown the expanding capabilities of autonomous systems,” the company stated, “including separation and engine ignition, controlled acceleration through the transonic range to the hypersonic regime, and programmed autonomous landing.”
These tests, part of the Department of Defense’s Multi-Service Advanced Capability Hypersonics Test Bed (MACH-TB) program, mark the first reusable hypersonic flights in the U.S. since the X-15 program concluded in 1968. The Talon-A2’s ability to be reused is a significant development. It can cut costs by as much as 60% when compared to systems designed for a single use, and it dramatically reduces data recovery time by 90%, allowing for quicker advancements in hypersonic technology.
Stratolaunch CEO Dr. Zachary Krevor commended the team’s work, stating, “We’ve demonstrated hypersonic speed, added the complexity of a full runway landing with prompt payload recovery, and proven reusability.” The company has a full schedule of flights planned through 2025, including missions for the Missile Defense Agency, and is already scheduling tests for 2026.
With international rivals rapidly developing hypersonic capabilities, Stratolaunch’s Model 351 Roc provides the U.S. with a unique opportunity to expedite testing and address key deficiencies in hypersonic weaponry and defense. This achievement highlights the significant role of private sector innovation in bolstering national security, ultimately enabling more frequent and cost-effective access to hypersonic flight.
For further information, please see stratolaunch.com.
