The flight was an overwhelming success with the airplane out performing many of the pre-flight expectations. And with the hard work of a first flight behind him, Siebold wanted to make the flight again for the pure joy of flying an airplane he and the team at Scaled have spent the past several years developing.

“After we landed, I looked over to Mike and said, ‘can we do that again?’”

Unfortunately with no motor, Siebold, Alsbury and SpaceShipTwo were stuck in the middle of runway 30 at the Mojave Air and Space Port waiting for a tow back to the hangar. The flight was the second time Siebold had piloted the first flight of a new aircraft design in the past two years. In December of 2008 he piloted SpaceShipTwo’s mother ship, Eve, on its maiden flight.

The glide flight of SpaceShipTwo also marks the second time in less than a decade the team at Scaled Composites have developed and flown a privately funded vehicle designed for suborbital space flight. And in preparation for Sunday’s flight, much of the experience gained from developing and flying SpaceShipOne was put into use.

Right off the start Siebold says the experience paid off and they were able to get straight to work.

“We released at 45,000 feet, it was very clean release, much less negative g [force] than we had anticipated, a very comfortable release” he says of being dropped from the mother ship. “We trimmed the airplane and the first maneuver we performed was an approach to stall.”

Even though it was the first time SpaceShipTwo had been released and flown on its own, that first stall maneuver and everything that followed was old news for Siebold, Alsbury and the entire flight test team.

Like other first flights, the team at Scaled has relied heavily on simulators for designing, preparing and practicing just about every conceivable aspect of the SpaceShipTwo program. Scaled uses both ground based and flight based simulation to prepare the entire flight test team. A complete cockpit replica can be connected to the mission control team on the ground to simulate complete missions including a wide range of potential emergencies. NASA similarly relies heavily on ground based simulators for every space shuttle flight.

And in the air, the mother ship Eve can be configured to fly the same approach as the spacecraft.

“The mother ship has turned out to be a phenomenal in-flight training vehicle that can fly the same descent profile with its speed brakes and a combination of engine power settings, where we can descend at the same air speed and flight path angle as the space ship does” says Siebold.

Eve and SpaceShipTwo on the morning of the first glide flight.

Siebold says flying the descent profile in Eve helps the pilots become comfortable with the descent angles and the out the window views for the various landing approaches.

“Getting those subtle cues, the seat of the pants feedback, the g [force] that you’ll experience from low key to final, it really gets you the rest of the way to the 100 percent ready for the flight.”

In the lead up to Sunday’s flight, the flight test team at Scaled at completed 19 sim sessions in the ground based simulator, each of which included multiple flights.

“We’re talking at a least 100 simulated flights with the full crew participation, and that doesn’t count what we’ve been doing with Eve.”

Authors: Jason Paur

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