Returning to the Edge of Space

SpaceShipOne on ascent, flight 13P
photo courtesy of Scaled Composites

Scaled Composites is now sending SpaceShipOne to altitudes where no winged aircraft
has gone since the X-15.     [not counting the Space Shuttle as a winged aircraft]

On June 21, 2004, SpaceShipOne crossed the FAI-defined boundary between air and space, reaching an altitude in excess of 100 kilometers (328,084 feet).

On September 29, 2004 SpaceShipOne flew to 337,500 feet in the first of two flights to win the X-Prize.
(see Scaled Composites web page for X-Prize flight , with links to videos of flight)

On October 4, 2004 SpaceShipOne flew to 367,442 feet (69.6 miles), winning the X-Prize and breaking the X-15's 42-year-old altitude record of 354,200 feet.
(see Scaled Composites web page for X-Prize flight 2, with links to videos of flight, photos, and other features)

On May 13, 2004, SpaceShipOne reached an apogee of 211,400 feet, or 40 miles (about 65,000 meters) on its third powered flight. It became the first winged aircraft to have reached such an altitude since the last X-15 was retired in 1968.

SpaceShipOne is has now recorded 3 flights over 100,000 kilometers (328,084 feet, or about 62 miles), claiming theX-Prize and breaking the X-15's unofficial altitude record of 354,200 feet. The X-15's official FAI altitude record of 314,750 feet in a class for winged aircraft still stands, since the FAI considers this an atmospheric flight and places space flights (over 100,000 kilometers) in a different class.

In this author's opinion SpaceShipOne is the most remarkable of all of Burt Rutan's engineering and design achievements in aviation, extending now to space. Rutan and the staff of Scaled Composites have developed this vehicle with highly innovative technology, going well beyond the usual practice of building incrementally on the prior state of the art.

SpaceShipOne feathered near apogee, flight 14P
SpaceShipOne in feather configuration, near apogee on flight 14P, about 211,000 feet
Photo courtesy of Scaled Composites

Additional photos
on the Scaled Composites web site
Here are a few of the many ways that SpaceShipOne is succeeding by breaking with "conventional wisdom"...
  • Its rocket engine burns rubber and laughing gas!
    This is not a joke, it's truly inspired engineering. The hybrid rocket motor uses solid propellant, hydroxy-terminated polybutadiene -- HTPB for short -- a form of rubber. Its oxidizer is nitrous ozide, which self-pressurizes and does not need the complezity of a turbopump to feed  the rocket engine. Both the fuel and the oxidizer are separately quite safe. In contrast, the X-15's anhydrous ammonia and liquid oxygen (LOX) were quite dangerous, as was the hydrogen peroxide that powered its turbopumps, APUs, and BCS thrusters.  (APU is auxilliary power unit, BCS is ballistic control system -- small rocket thrusters for attitude control in space)..

  • Variable geometry permits reentry at a relatively low speed, around Mach 2.
    The airframe's high-drag "feather" configuration allows reentry at a lower speed than the X-15, and a much lower speed than the Space Shuttle. This eliminates the extreme temperatures experienced in X-15 and Shuttle reentries. Feather configuration  also eliminates the X-15's need for precise piloting on climbs and reentries to avoid overheating or overstressing the airframe.
  • Mike Melville, test pilot for several of SpaceShipOne's milestone flights, is 62 years old.
    If he were an airline pilot he would have been required by law to retire two years ago.

  • SpaceShipOne and its carrier aircraft, White Knight, are a private civilian venture.
    The X-15 and other flight research programs were conducted mainly by NASA and the Air Force. SpaceShipOne is funded primarily if not wholly by Paul Allen, cofounder of Microsoft.

  • SpaceShipOne was developed very quickly, and very inexpensively in comparison with government programs for manned  flight at high altitude and in space.

This writer's opinion:

Burt Rutan and Scaled Composites have accomplished far more than the flights now in progress, they are pioneers such as this country has not seen for nearly half a century. They are continuing to demonstrate the spirit and the ability to innovate and to develop technologies that would never be considered by an industry, a government, and a public  which has become technologically conservative.

Industry conservatism is not just a question of being risk-averse in the interest of safety -- SpaceShipOne demonstrates technology that significantly reduces risk to the lives of its pilot, passengers, and support crew.  It also significantly reduces financial risk to its sponsors. Most importantly, it renews a sense that our ability to be space-age pioneers is limited mainly by our imagination.

"Conventional wisdom" is that we are safest if we build on what has gone before by cautious evolution. Rutan and Scaled Composites have shown that we can learn from what has gone before while focussing on imaginative innovation. Creativity is the key enabling factor when combined with sound engineering and science. It's partly an issue of human knowledge and largely an issue of human spirit.

My personal respect and admiration for the X-15 program was for very similar reasons. The X-15 was a pioneering research program of even greater magnitude, undertaken when we had only more basic knowledge of many areas -- hypersonic aerodynamics, structures for very hot airframes flying at high dynamic pressures, human factors and life support for space environments, and much more. This was a product of the "golden years" of progress in aviation and space technolog, which I would identify as the 1940s through the 1960s, but especially the 1950s.

After that, the trend was toward technological and economic conservatism at the expense of innovation and discovery. I can add the same comment about computing, based on my own professional background, but would suggest that computing's golden age of exploration and innovation lagged that of aviation by about a decade.

I've heard similar comments from many people who were at the heart of "golden age" work -- from a conversation with Scott Crossfield, a lecture by Neil Armstrong, videotaped comments by Pete Knight, and so on. Beyond those who became famous as test pilots, I've heard similar comments from many others who saw that period first-hand in places such as NASA Dryden and the U.S. Air Force Flight Test Center at Edwards Air Force Base.

To Burt Rutan and Scaled Composites,

I offer my personal congratulations and sincere appreciation. I hope our country and the world will learn from your successes, to better understand where we can go and what we can accomplish through creative ingenuity.

Send questions and comments on the SierraFoot X-15 web pages to Paul Raveling.
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