LOS ANGELES — Sierra Nevada conducted a captive-carriage test flight of the Dream Chaser engineering test article on Aug. 22 at NASA’s Dryden Flight Research Center at Edwards AFB, Calif., in preparation for the start of approach and landing free flight tests in September.

The test, which saw the lifting-body space vehicle lifted above the Edwards dry lake bed below a Sikorsky S-64 Skycrane, follows completion of tow tests earlier this month. Pulled by a truck, the Dream Chaser has performed four sets of slow- and high-speed ground tow tests since July with runs completed at 10 mph, 20 mph, 40 mph and 60 mph to verify integrated spacecraft performance under landing and rollout conditions.

Sierra Nevada says systems verifications included flight computer and flight software, instrumentation, guidance, navigation and control, braking and steering performance, flight control surface actuation, mission control and remote commanding capability, and landing gear dynamics.

“The tests ensure the Dream Chaser would operate properly upon landing and that the spacecraft will come to a controlled stop after touching down on the runway,” it adds. Following the captive-carry test, the evaluation will culminate with at least one approach and landing free flight test.

Sierra Nevada is competing with the lifting body vehicle against alternative capsule designs developed by Space Exploration Technologies (SpaceX) and Boeing for NASA’s commercial crew program under a $212.5 million Commercial Crew Integrated Capability contract awarded in August 2012. The Dream Chaser design is based primarily on NASA’s HL-20 lifting body and is capable of carrying seven astronauts to orbit. The vehicle is designed to launch from Cape Canaveral atop a United Launch Alliance Atlas V 402.