Introduction
One of the more hopeful developments in space flight lately has to be the successful flights of SpaceShipOne, the first successful private space program, and the announcement of Virgin Galactic. SpaceShipOne is a major achievement for both its engineering innovation and daring entrepreneurism. Its Tier One Private Manned Space Program sets the stage for future private space flight, breaking down the barriers to public access to space.
The Ansari X Prize
Following in the footsteps of more than one hundred aviation incentive prizes between 1905 and 1935 which helped create today’s multibillion dollar aviation industry, the X Prize Foundation was formed in 1996 "to make space travel possible for all". With more than twenty teams from seven countries, the foundation was fully funded by private donation in 2005, guaranteeing a US$10 million prize for the first team that:
- Privately finances, builds and launches a spaceship able to carry three people up to a height of 100 kilometers
- Returns safely to Earth
- Repeats the successful launch with the same ship within two weeks
The Ansari X Prize was inspired by the early aviation prizes of the 20th Century, particularly the trans-Atlantic flight of Charles Lindbergh in The Spirit of St. Louis, which won the US$ 25,000 Orteig prize in 1927. Through privately driven innovation, The Spirit of St. Louis Organization demonstrated the capability and ingenuity of a small professional team to meet and exceed the efforts of large governments.
Vehicles designed for the Ansari X Prize will eventually serve not just the Space Tourism industry, but also create substantial benefits for low-cost satellite launching, world-wide same-day package delivery and rapid point-to-point passenger travel.
SpaceShipOne
The implementation of the X Prize’s winning spacecraft by Scaled Composites, LLC was completed in 2004, and in September coasted above the 100km altitude point and successfully completed the first of the two X Prize flights. On October 4, 2004, SpaceShipOne rocketed into history as the first private manned spacecraft to exceed an altitude of 100km twice within the span of a fortnight, and won the Ansari X Prize.
How does SpaceShipOne reach space?
In a two-stage process, the compact spacecraft is piggybacked to an altitude of 15km on the White Knight airplane. Ignition of the rockets then commences, and SS1 rapidly overtakes the airplane, escaping to its peak altitude of 100km above the Earth’s surface.
SS1’s engine design is known as a hybrid rocket motor, because it utilizes featurs from both solid and liquid motors. Instead of high grade rocket fuel, the rocket propellant is a mixture of HTPB or rubber, and Nitrous Oxide - laughing gas - as the oxidizer. These fuels suit the small-scale craft perfectly: they can be safely stored without special precautions and will not react when put together until ignited, and N2O is self-pressurizing at room temperature, avoiding the necessity of complicated turbo pumps or plumbing to move the oxidizer into the combustion chamber.
The rocket’s exhaust is also much greener than conventional rocket propellant, producing a mixture of water vapour, carbon dioxide, hydrogen and some carbon monoxide. This makes SS1 very attractive, with increasing environmental concerns over the large-scale use of passenger jet travel over the past decades and the large amount of pollution produced by mammoth rocket engines such as Titan and Saturn rockets traditionally used for access to space.
Another innovation by Scaled is the reentry technique of SS1. Its wings fold into a shuttlecock shape, giving the ship extremely high drag as it reenters the atmosphere. This dramatically reduces the forces and heating on the spacecraft’s structure, and automatically aligns the ship to a belly-first attitude giving the pilot a less critical flight control task. An another benefit of the shuttlecock design is that as altitude is higher after entry deceleration, the pilot can glide for further - around 100km - before converting the spacecraft back to its non-feathered glider shape.
Virgin Galactic
Shortly before the successful flights of SS1, Richard Branson announced the Virgin Group was entering into an agreement to license the technology developed by the Tier One program in order to found the first commercial passenger spaceline. Mojave Aerospace Ventures, the company behind the Tier One program’s funding, signed a deal with Virgin worth up to US$21.5 million over the next fifteen years.
Commenting on the announcement, Branson said: "We’ve always had a dream of developing a space tourism business and Paul Allen’s vision, combined with Burt Rutan’s technological brilliance, have brought that dream a step closer to reality. The deals with both their companies, being announced today, are just the start of what we believe will be a new era in the history of mankind, making the affordable exploration of space by human beings real. We hope to create thousands of astronauts over the next few years and bring alive their dream of seeing the majestic beauty of our planet from above, the stars in all their glory and the amazing sensation of weightlessness. The development will also allow every country in the world to have their own astronauts rather than the privileged few."
According to Virgin Galactic’s website, the first passengers will be able to launch in 2.5 - 3 years time. Ticket costs are expected to be approximately US$190,000. An article on Business Week ran a down-to-earth review of the business viability of V.G., finding that "Branson has ‘all the details worked out’". Construction of the first commercial passenger spaceship, the VSS ENTERPRISE, is expected to begin sometime in 2005.