Sierra Nevada Dream Chaser test article

[Updated] Sierra Nevada’s Dream Chaser test article suffered a mishap on Saturday. Following a successful flight, the left main landing-gear (derived from the Northrop F-5E Tiger II jet fighter) failed to deploy. As a result, the vehicle reportedly flipped on landing. [Update: Sierra Nevada says the vehicle did not flip, but skidded alpng the runway.] Accounts of the landing vary: some are rather dramatic, but Alan Boyle of NBC News quotes a Sierra Nevada engineer saying the pilot would have walked away, if the test article had been manned. The test article is “fully intact,” According to Sierra Nevada Space Systems chairman Mark Sirangelo.

“The pressure vessel was completely pristine, the computers are still working, there was no damage to the crew cabin or flight systems,” Sirangelo told Space News. “I went inside it myself and it was perfectly fine. There was some damage from skidding…. It’s not going to affect our schedule in the long term [but] It might affect whether we do another free flight test this year or next year. We’re still assessing that.”

According to a Sierra Nevada press release, the unmanned vehicle was released from its carrier aircraft, an Erickson Air-Crane helicopter, at approximately 11:10 AM PST, as planned. Following release, the automated flight-control system steered the vehicle to its intended glide slope. The vehicle followed the planned flight trajectory, flared, and touched down on on the centerline of Edwards Air Force Base’s Runway 22L less than a minute later.

Previous statements show the drop was planned to take place at an altitude 12,000 feet, followed by a 30-40 second glide at an angle of 23 degrees.


It should be noted that landing-gear failures are not uncommon in flight test. One of the reasons for test flights is to uncover such anomalies.

Fighter pilots have a saying: “A MiG on your six is better than no MiG at all.” From that perspective, we view the Dream Chaser’s landing-gear mishap as a positive sign. It means that people are flying and testing things.

That is not to say we shouldn’t take steps to reduce the frequency of landing-gear mishaps.

The Dream Chaser is not the first rocket vehicle to suffer a landing-gear failure. The Delta Clipper Experimental, SpaceShip One, and the Armadillo Aerospace Pixel/Texel lunar-landing demonstrator had landing-gear failures as well.

At this point, we get to say, “I told you so.” Several years ago, we suggested that NASA fund a series of modest prizes for the development of robust, light-weight landing-gear concepts for spacecraft applications.

NASA’s Centennial Challenges prize fund was bare, however, due to Congressional inaction, and the usual suspects were less than helpful. They told us that prizes were politically incorrect, a distraction from Commercial Crew and Cargo, which was deemed more important. In addition, we were told that politicians could not predict who was going to win a prize. As a result, they don’t know who to approach for campaign donations. (They considered this a bug. We view it as a feature.)

Now, one of the Commercisl Crew and Cargo vehicles has suffered a landing-gear failure. Sierra Nevada has not yet determined if the test article will be repaired. The orbital version of Dream Chaser is already under construction, and it is possible that the flight test provided sufficient data for Sierra Nevada to proceed to the next step of the program. In the worst case, however, there could be a domino effect that would affect the entire program. In that case, the result could be the loss of hundreds of millions of dollars for US taxpayers, Sierra Nevada stockholders, or both.

By funding prizes for the development of critical systems, NASA would be following in the tradition of its predecessor agency, the National Advisory Committee on Aeronautics (NACA), which did basic aeronautical and systems research applicable to commercial and military aviation in the 30’s and 40’s. It would also be fulfilling the mandate of its charter, which requires the agency to “seek and promote, to the fullest extent possible, the commercial use of outer space.”

After Saturday, the failure of NASA and Congress to fund technology prizes for systems such as landing gear seems penny-wise and pound-foolish.

Written by Astro1 on October 27th, 2013 , Sierra Nevada

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