Rocket nozzle beauty

Rocket nozzle1

Here’s some very insider, pretty cool information about the little rocket engine that could – the hybrid motor of SpaceShipOne. The orange colored nozzle of the rocket motor is molded from high temperature phenolic materials. The first photo you see shows the rocket engine before firing.

Now look at the other image of the nozzle. You again are looking straight into the rocket motor from behind, but this engine has been fired. In fact, this is the hybrid motor that made history by propelling the first private, manned ship past the start of space – the Karman line. The rubber fuel has all been burned in the presence of a strong oxidizer, liquid nitrous oxide, and some of the burning rubber has been deposited onto the inside of the nozzle, and the nice orange color has all been severely burned.

The motor was run on this June 21, 2004 flight in Mojave for 76 seconds by test pilot extraordinaire Mike Melvill.  The extremely hot rocket plume (burning rubber) rushing out of the nozzle burned away some of the Quartz in the throat area, which was perfectly circular before the motor was fired in SpaceShipOne, and is now a kind of flower shape (I find it beautiful!).

This erosion of the throat of the rocket motor nozzle caused the Space Ship to not fly perfectly straight up. This meant that Melvill )and Scaled Composite’s other right stuff pilot Brian Binnie) had to continuously make small corrections to stay on course as the rocket throat began to wear out. This does not happen to the Space Shuttle because their rocket nozzles were made of titanium and very expensive metals to prevent the problem. The talented and scrappy team at Scaled, led by Burt Rutan, did not have the budget to use such very expensive materials, and chose to use phenolic and quartz which are much cheaper. Before space – after space!

A view from space


I’ve met a lot of remarkable people doing reporting for my new book on the XPRIZE and the private race to space. One of the most remarkable is Mike Melvill, the world’s first commercial astronaut. He is modest, funny, smart, and very very daring. He worked for another guy, aviation great Burt Rutan in Mojave. Melvill and his wife, Sally, were Burt’s first employees at the Rutan Aircraft Factory. Mike would fly any plane that the wildly creative Rutan dreamed up. Eventually, when Rutan designed a homemade spaceship, it was his wingman and best friend Mike who would attempt to fly the rocket to space. (I’ll come back to more of the story on another day.) The photo of earth on my homepage was taken by Mike, from inside Burt’s homebuilt spaceship.

Here is what Mike told me about the photo – thought it was very interesting. Hope you do too!

“In this photo, you can see the Owens Valley, with Mammoth Ski resort near the top under some could northwest of Bishop, just visible under the edge of the clouds over the top of the Owens Valley. In the center of the Owens Valley, is the Owens dry lake. You can see San Francisco Bay near the top left corner of the pic. The San Juaquin valley extending down from SF almost to Bakersfield on the left. The Sierra Nevada mountain range runs from top to bottom of the pic, and Mount Whitney, the highest mountain in the lower 48 states at 14505 feet is visible almost in the center of the photo. Mojave is just off the bottom of the photo about 30 miles south of the small round green dots in the bottom right corner. Burt told me that the distance from my eyeball in the cockpit, to the horizon top center of the pic, was 800 miles!!! The thin blue line that follows the curvature of the Earth, is the atmosphere. The black triangular shape is the color of space in the daytime, jet black!”