A private U.S. space shuttle has successfully undergone ground tests in California designed to assess the spacecraft's braking and landing systems, NASA said.

Dream Chaser -- being developed by Sierra Nevada Corp. -- is being tested under NASA's Commercial Crew Program, which is facilitating the development of American-made spacecraft and rocket combinations that can launch from U.S. soil.

A pickup truck pulled the flight vehicle across concrete runways at NASA's Dryden Flight Research Center at Edwards Air Force Base at speeds of 10, 20, 40 and 60 mph to verify the integrity of spacecraft's performance under landing and rollout conditions.

"The dedicated Dream Chaser team has been putting the test spacecraft through comprehensive integrated testing on the runway, ramps and hangar of the historic California site, finding issues on the ground and addressing them in preparation for upcoming free flights," said Cheryl McPhillips, NASA Partner Manager working with Sierra Nevada Corp..

The tests were the fourth in a series of taxi tow tests.

"We are very excited to complete this series of tests and achieve another critical milestone for our Dream Chaser flight test program," Steve Lindsey, senior director of programs for SNC's Space Systems and a former NASA astronaut, said. "Watching Dream Chaser undergo tow testing on the same runway where we landed several space shuttle orbiters brings a great amount of pride to our Dream Chaser team."