Along the Slow Road to Hypersonic Flight

Founded in 2011 by software mogul Paul Allen and aerospace engineering legend Burt Rutan, Mojave, California-based Stratolaunch LLC provides high-speed flight test and orbital launch services.

The company’s reusable, air-launched testbeds enable rapid and iterative testing in the hypersonic environment, thereby affording clients longer periods of time in the hypersonic condition. By partnering with Stratolaunch, government, military, commercial, and academic clients are afforded opportunity to avail themselves of high-quality data by which to accelerate the designs of new hypersonic concepts, mature extant technologies, and pursue spiral development—a family of software development processes characterized by repeated iteration of a set of elemental development processes.

Currently, Stratolaunch’s fleet comprises primarily a carrier aircraft dubbed Roc, after the mythical, giant bird of prey; and Talon-A, an autonomous, reusable, rocket-powered, hypersonic flight vehicle.

Roc features a twin-fuselage design slung beneath a 385-foot wingspan—the longest ever flown—and boasts a 550,000-pound payload and a Maximum Gross Takeoff Weight (MGTOW) of one-million-three-hundred-thousand pounds.

Talon-A’s relatively diminutive 28-foot (8.5-meter) fuselage and 11.3-foot (3.4-meter) wingspan belie the machine’s six-thousand-pound (2,700-kilogram) launch mass and airspeed envelope of Mach 5.0 to Mach 7.0 (3,334 to 4,667-knots).

Ultimately, Roc will be capable of carrying up to three Talon-A vehicles contemporaneously, making possible rapid constellation deployment to differing inclinations.

Paired, the two machines constitute a genuine aerospace spectacle—a syncretism of dizzying immensity and blistering speed borne respectively aloft on columns of burning Jet A-1 and rocket fuel.

On 28 October 2022, Stratolaunch commenced captive carry in-fight testing of the Talon-A prototype. Roc ascended into the azure vastness above California's Mojave Desert with the test-vehicle slung to a purpose-built amidships attachment pylon. The flight, Roc’s eighth, lasted just over five-hours, reached a maximum altitude of FL230 (7,000 meters), and reportedly met the entirety of its engineering, performance, and telemetric objectives.

On 13 January 2023 at 14:51 PST, Roc and Talon-A rose as one from the Mojave Air and Space Port, climbed to an altitude of 22,500-feet (6,858-meters), and remained aloft for six-hours—the giant aircraft’s longest sortie to date—before returning to Mojave and landing without incident. By way of such carefully orchestrated captive carry tests, Stratolaunch is establishing the foundation for a series of Talon-A drop tests slated to commence later this year.

Stratolaunch CEO and President Zachary Krevor extolled in an email statement: “Our amazing team is continuing to make progress on our test timeline, and it is through their hard work that we grow closer than ever to safe separation and our first hypersonic flight tests.” Mr. Krevor added: “The thorough evaluation of release conditions will provide data to reduce risks and ensure a clean and safe release of Talon-A during future tests. We are excited for what’s ahead this year as we bring our hypersonic flight test service online for our customers and the nation.”

In addition to being Roc’s longest flight, the 13 January test mission occasioned the mammoth aircraft’s first departure from the local Mojave area—likely to the bewilderment of terrestrial spectators.

In 2011, Stratolaunch Systems signed a twenty-year agreement with the Kern County Airport Authority, Mojave, California, for the lease of 81,000-square-meters (twenty-acres) at the Mojave Air and Space Port upon which to build production and launch facilities.

FMI: www.stratolaunch.com