SpaceShipOne (SSl)-A Different Kind of Space Flight

April 1, 2004, FAA/AST granted the first license ever issued for a private, crewed, suborbital flight. The award went to a company founded by aero­nautical pioneer Burt Rutan, Scaled Composites, in conjunction with joint venturer Paul Allen. Rutan, an aerospace engineer, gained a reputa­tion for developing new, unconventional air­plane designs built of strong, light, composite materials. In 1986, his Voyager aircraft was the first to fly around the world without refueling.

Just one year before being awarded the fed­eral license, Scaled Composites revealed that it was working on a spacecraft design to compete
for the Ansari X Prize.33 At the time, there were 27 announced competitors for the prize. The Ansari X Prize, in the amount of $10 million, was offered by the X Prize Foundation for the first private, non­governmental launch of a reusable manned space­craft, capable of carrying three people into space with safe return, twice within a two-week period. The Ansari X Prize is patterned after the early 20th century practice of awarding monetary prizes to aviators in order to spur greater achievements in the then-nascent aviation field. In particular, it is reminiscent of the Orteig Prize of $25,000 that was posted by Ray Orteig in 1919 for anyone who suc­cessfully completed a nonstop flight between New York and Paris. The Orteig Prize was claimed by Charles Lindbergh in 1927. (See Chapter 13. See also the NASA Centennial Challenges below.)

The Ansari X Prize stipulated that the spacecraft exceed 100 kilometers as the

required threshold of space (the Karman line) at 62.1 miles above the earth. The SSI flights origi­nated from the Mojave Airport Civilian Flight Test Center (now Mojave Spaceport) in Califor­nia. SpaceShipOne was aerially launched from a specially Rutan-designed carrier jet called “White Knight.” The spacecraft was powered by a hybrid rocket engine that used nitrous oxide (laughing gas) as the oxidizer and synthetic rubber as the fuel. (See Figures 41-9, 41-10, and 41-11.)

The first competitive flight in the Ansari X Prize competition occurred on September 29, 2004, achieving an altitude of 102.9 kilometers and a maximum speed of 2.92 Mach. On Octo­ber 4, 2004, SpaceShipOne duplicated its earlier successful suborbital flight, this time to 111.996 kilometers and a maximum speed of 3.09 Mach, thereby completing all requirements for the Ansari X Prize. That date was the 47th anniversary of the first Sputnik flight.

SpaceShipTwo is a follow-on suborbital, air-launched space vehicle being developed by a joint venture between Scaled Composites and the Virgin Group (Virgin Galactic). The vehicle was introduced to the public in December 2009 and, as of July 2012, is undergoing glide tests. The company is taking bookings for suborbital flights set to start late in 2013 at a price of $200,000.

The joint venture plans orbital flights using its planned SpaceShipThree, assuming success in its Virgin Galactic project. Orbital flight is much more difficult to achieve than is suborbital flight since the speed necessary to gain escape veloc­ity is on the order of 7 to 8 times that required to reach suborbital altitudes. While SpaceShipOne reached the Karman line by accelerating to a little over 3 Mach, orbital vehicles will require 25 Mach to achieve escape velocity. Reentry is also much more complex, since all of the excess speed must be dissipated on reentering earth’s atmosphere.