Roc Engenders Speed Metal

Stratolaunch, the Seattle-based aerospace company and hypersonic flight-test pioneer, cut short a test-flight of its mammoth carrier aircraft, Roc.

The twin-fuselage, six-engined, high-wing, mono-plane—which takes its name from the Roc, an enormous mythological bird of prey—has been undergoing flight-testing at Mojave Air and Space Port in preparation for upcoming missions during which it will serve as a launch-vehicle for rocket-powered, hypersonic, test-aircraft.

The abbreviated, 09 June test-flight sought to determine the effects of a newly installed pylon on Roc's in-flight stability and performance. The pylon, which weighs approximately eight-thousand pounds and spans 14-feet of Roc’s 95-foot, center wing-section, will be used to securely transport and release Stratolaunch’s Talon-A hypersonic vehicles. In addition to transporting and releasing subject vehicles, the pylon includes a mechanism designed to lift them from the ground and onto a staging platform.

According to reports, Roc departed the Mojave runway at approximately 15:23 local time. Sometime thereafter, vibrations were detected and a sensor on the aircraft’s left wing malfunctioned. It is not clear if the two occurrences are related.

In a post-flight statement, Stratolaunch asserted that the flight, which reached an altitude of 15,000 feet, afforded the crew opportunity to complete a number of test objectives, including testing the airplane’s performance and controllability subsequent the addition of the pylon, and assessing its landing gear system. 

The flight, Roc’s sixth, remained aloft for only one-hour and 26 minutes of the mission’s planned, 3.5 hour flight-time. The aircraft performed four flybys for purpose of burning fuel enough to touch-down below its maximum landing weight.

Imperfections notwithstanding, the 09 June test-flight brings Stratolaunch nearer its objective of flight-testing hypersonic vehicles later this year.

Zachary Krevor, Stratolaunch’s CEO and President states: “Today’s flight builds on previous successful flights and hardware enhancements … We will leverage this flight experience as we complete integrated testing in the coming months and prepare for Talon-A test flights.”

FMI: www.stratolaunch.com