SpaceShipOne (SS1) is the name Burt Rutan gave his mini space plane, the spaceborne part of his effort to win the X Prize. The SS1 is carried to a high altitude (over 60,000 ft.) attached to the underside of a carrier plane called the White Knight, which is based upon an earlier high-altitude aircraft design Rutan created called the Proteus. The craft is projected to provide over 5 minutes of microgravity for its occupants, with a re-entry G stress of up to 6 G's for less than 10 seconds. The SS1 has stubby wings that fold up during re-entry to stabilize the vehicle for reentry, orienting the vehicle to a belly-first attitude that increases its drag and reduces its speed.

The SS1 is designed to take three people in a shirtsleeve environment (as opposed to having to wear pressure suits) to an altitude of 100 kilometers, over 60 miles up. By pressurizing the interior of the craft, it is able to carry more people, as the added bulk and weight of pressure suits are eliminated, as well as make the ship more amenable to tourist flights and other commercial use. Of course, without pressure suits, there is an increased danger, but as Columbia and Challenger have demonstrated, when something goes wrong at a high altitude, it isn't usually the low pressure that kills you.

The engine in the SS1 is a hybrid solid/liquid rocket using nitrous oxide and hydroxyl-terminated polybutadiene (A kind of rubber). The combination actually burns together rather cleanly, releasing mostly water vapor, carbon dioxide, hydrogen, and nitrogen in a powerful chemical reaction. A further advantage is that the components are easy to handle and far less toxic than most rocket fuels.

The space transport system began as a concept in 1996, with the full development program starting in 2001 under complete secrecy. The two craft were unveiled on April 18, 2003, and Rutan was immediately labelled as the front-runner for the X prize, as his company has completed 34 manned research aircraft, and none were announced until they were ready to fly.

With the exception of the nozzle and fuel casing, the entire system is reusable. If successful, and I believe it will be, it will change the way we look at space travel, the progenitor of a new paradigm of cheap, easy, and safe access to space.

Rutan's company, Scaled Composites, has a web site at

Update December 17, 2003
The SS1 has broken the speed of sound in its second powered test flight. It is the first time in history a privately created aircraft (or in this case, spacecraft) has travelled faster than sound.

Update May 17, 2004
The SS1 broke Mach 2 and reached an altitude of 40 miles. This is the highest and fastest a privately developed and built vehicle has ever travelled.

Update June 21, 2004 THEY DID IT!

Michael Melvill successfully piloted the SpaceShipOne to a suborbital trajectory reaching over 100 kilometers (62 miles) high. He is the first private astronaut in recorded human history.

Update Oct 4, 2004

SpaceShipOne wins the X_Prize!
On this date, Brian Binnie flew the spacecraft for the second time in almost as many days to over 100 kilometers up while carrying the weight of two additional passengers, meeting the requirements of the Ansari X-Prize. Mike Melville, the first man to take the SS1 into space, flew the first qualifying trip for the prize a few days prior. By demonstrating that they can provide a repeatable business service into suborbital space, Rutan and SS1 have written history as the first successful private space effort.