SpaceShipOne - Scaled Composites

UPDATE: Scaled composites have announced that SpaceShipOne flew into space for the first time on 21st June 2004! This was not, however, a shot at winning the Ansari X-Prize. Instead an X-Prize attempt is rumoured to be made towards the end of September 2004.

SpaceShipOne is a privately funded 3-person spacecraft which is designed to reach suborbital altitudes. This marks a historic milestone in the story of manned space exploration. It has, for the first time, signaled the opening of space to private corporations and individuals. In the next 2 to 3 years space travel will not only be available to government funded astronauts, but also to private individuals.

The Ansari X-Prize

The X-Prize is a $10 million award which will be given to the first non-governmental agency to fly a 3-person craft above 100 Km, to return the craft safely to earth, and to repeat the same flight with the same craft within 2 weeks. The aim of the X-Prize is to provide an incentive for private companies to develop manned space programmes and space tourism. 100Km is the altitude at which space begins. The atmosphere here is so exceedingly thin that it has no effect on the control surfaces of aircraft. There is, however, still enough atmophere to exert a drag on a spacecraft and to prevent it from remaining in orbit. This is why flights at this altitude are called "suborbital". The minimum altitude for orbital flight is about 150Km.

In the years 1908 to 1912 the world went from a grand total of just ten airplane pilots to hundreds of airplane types and thousands of pilots in 39 countries. It is hoped that the X-Prize will provide a similar jumpstart to the spacetravel industry.

The X-Prize idea was conceived in 1996 by aerospace engineer and entrepreneur Peter Diamandis. Since then a foundation of trustees has been formed, comprising of Diamandis himself and several other engineers, entrepreneurs, and astronauts. The prize money is funded from a wide array of donors including wealthy corporations and individuals who are interested in space.

There are currently 26 teams from a number of different countries competing for the X-Prize. The clear favourite to win is SpaceShipOne built by Scaled Composites.

SpaceShipOne and Scaled Composites

Scaled Composites is a private aerospace company which was founded and is led by aerospace engineer Burt Rutan. Since it's foundation in 1986, Scaled have developed 23 unique manned research aircraft types. In 1996 they began the concept work for a suborbital spacecraft. The project is funded by Microsoft co-founder Paul Allen.

Scaled's concept is that ground launched rockets are too risky and too expensive. A ground launched rocket must be twice weight of a rocket which is launched from 50,000 ft up.

So instead of ground launch, Scaled has chosen to use two aircraft - White Knight, the mother craft, and SpaceShipOne, the space craft itself. White Knite lifts the spaceship to an altitude of 50,000 feet. This takes about an hour of flying. From there the spacecraft will be released and it's rocket fired. The craft climbs steeply for over a minute reaching a speed of 2,500 mph. It then coasts up to the peak altitude of 100Km before falling back down again. For the fall the craft changes the configuration of it's wings into a high drag format. This is called the "feather" configuration. After re-entry to the atmospher the craft reverts to it's normal glide configuration and glides the remaining 80,000 feet back down to the runway.

SpaceShipOne can carry 3 astronauts. The maximum forces experienced within the cabin are about 5 G's for less than 10 seconds. With the pilot and passengers reclined, these forces are quite tolerable for anyone in reasonable health. The primary structure of the spacecraft is carbon fibre and epoxy resin, making it light and strong.

SpaceShipOne Rocket Motor

The key component of SpaceShipOne is the rocket motor. This motor is being developed by SpaceDev.

It is a hybrid motor, meaning it is powered by both liquid oxidiser and solid fuel.

The solid fuel component is simple polyurethane rubber (tyre rubber), chemical name: hydroxy-terminated polybutadiene, or HTPB for short. The fuel is housed in the tubular motor casing.

The liquid oxidizer is Nitrous Oxide (N20 - laughing gas). This is stored in the large bulbous tank in the center of the craft.

Hybrids are amongst the safest and simplest of rocket motors. They combine the performance of liquids with the simplicity of solids. The combination of N2O and rubber is particularly safe as neither components are explosive at room temperature.

Timeline

The concept for SpaceShipOne began in 1996. Preliminary development was commenced in 1999 and full development in April 2001. On 18th December 2003 SpaceShipOne made its first manned flight and broke the sound barrier.

Scaled Composites release flight test updates about once a month [here]. The next update will likely be around mid-May 2004. The press will be invited for the first flight over 100Km and you'll be sure to hear about it in all the news. Scaled Composites themselves are unwilling to release an exact flight schedule. They prefer to fly only when they are sure they are ready. An amateur look at their progress, however, enables a rough guess that the X-Prize will be won
either late 2004 or early 2005.

Links:

Scaled Composites
SpaceDev
The X-Prize