Sierra Nevada Corp. released this video of the one-minute drop test of its Dream Chaser prototype over Edwards Air Force Base, which clearly shows the apparent mechanical failure of a landing gear that marred an otherwise successful demonstration.
An Erickson Aircrane S64F helicopter lifted the atmospheric test article, which is comparable to the Enterprise space shuttle prototype tested on the same runway more than 30 years ago. Like Enterprise, the Dream Chaser used in the drop test was designed to collect data on the vehicle's performance after it returns from space and glides to a horizontal landing.
At 12,500 feet, the helo crew released the unpiloted Dream Chaser. It's sophisticated flight software guided it through a 50-degee dive before flaring for final approach and linking up with the runway. Alas, the good-luck dice hung in the cabin window didn't work.
Triggered by a radar altimeter, the flight computer ordered the landing gear to deploy. The nose skid and the right wheel did, but the left gear hung up. It stayed that way through the rest of the flight, and the vehicle skidded off the runway before it stopped.
Despite the sour ending, engineers at Sierra Nevada say they collected almost all of the data they expected to get from the test, including the g-loading at touchdown. That could be an important selling-point for the company later on, when it begins to compete for NASA business with capsules developed by Boeing and SpaceX.
Sensors inside the test article measured the g-load at "less than 2," according to Mark Sirangelo, who heads the space unit at Sierra Nevada. That is well below the loads a capsule payload would experience splashing down in the ocean or using airbags to cushion a touchdown on dry land.
Sirangelo says the test article probably can be repaired, and an investigation to find the root cause of the mishap is underway. The company plans to begin piloted atmospheric tests next year.
Editor's note: The model of the lifting helicopter has been corrected.