Roc flew for almost two hours and climbed up to 15,000 feet (4,572 meters). Compared to its last test flight (which took place in January), the airplane spent less time in the air, and it reached a lower altitude.
That's because the team did not focus on endurance, speed, or cruising altitude this time. Instead, pilots tested the landing gear. This was the first time the aircraft actually managed to successfully retract and extend its full landing gear. Roc's performance and handling characteristics were also evaluated during the flight.
"Today's successful flight demonstrates and validates improvements to the carrier aircraft's systems and overall flight performance," said Dr. Zachary Krevor, Stratolaunch President and Chief Operating Officer.
The company has been improving the capabilities of its carrier aircraft in order to better prepare it for the upcoming launch of the rocket-powered Talon-A hypersonic vehicles.
"The full landing gear retraction and extension brings the carrier aircraft closer to operational status, a milestone that is necessary to ready the aircraft for Talon-A separation and hypersonic flight tests later this year," explained Krevor in a statement.
Talon-A vehicles, which will be launched from Roc, are reusable testbeds designed for hypersonic research, experiments, and operational missions. They're capable of flying at speeds higher than Mach 5, and they can also carry various payloads.
Stratolaunch is continuing to work on system integration for two Talon-A test vehicles, the TA-0, and TA-1. A third vehicle, the TA-2, is currently under development. Once completed, this will be the first fully reusable hypersonic test vehicle.
The company plans to start hypersonic flight testing later this year. Stratolaunch estimates that it will start delivering services to both the government and commercial customers next year.