- Paul Rincon
- Scientific Affairs Editor, BBC News Network
Image source,Reuters
In May 2021, the Virgin Galactic Unity (VSS Unity) released its self-powered flight from the “mothership” over the US Spaceport in New Mexico.
For the past 15 years or so, Virgin Galactic has been preparing to launch a paid passenger service to and from the edge of space. We are here to review the long and tortuous road that Sir Richard Branson took to realize his childhood dream.
In the early 1990s, well-known aerospace engineer Burt Rutan set himself a challenge: designing a space plane.
Rutan recalled in 2004: “I want to try, I want to do it.”
Like many predecessors and comers, the inability of “ordinary people” to go to space is his motivation for doing this. The so-called “ordinary people” are actually talking about astronauts without government funding.
Rutan explained: “The child dreams of going up (space) to see this (earth) landscape-and I still treat myself as a child-but in the past 25 years, such a desire, such a dream, has been shrinking. It’s getting more and more obvious.”
The engineer believes that the experience of this kind of journey is similar to that of taking an airplane, rather than taking a rocket into the air and going down with a parachute like a big adventurer.
Image source,Getty Images
Burt Rutan wants to allow “ordinary people” to fly into space.
The result of his efforts was named SpaceShipOne. Rutan got his inspiration from the X-15 high-altitude testing machine from the 1950s to the 1960s.
On June 21, 2004, his spacecraft reached a historical milestone and performed the first privately funded manned space flight.
The 8.5-meter-long spacecraft set sail from an airstrip in the Mojave Desert, California. It was hung under an aircraft called the White Knight. At a distance of 14 kilometers from the ground, Spacecraft One broke away from the “mothership”, and its engine immediately ignited.
The spacecraft carrying the test pilot Mike Melvill climbed rapidly, and finally reached a point just above 100 kilometers above sea level, the official edge of space.
After Melville experienced weightlessness, the spacecraft returned to the atmosphere. During the return process, Spacecraft One changed the shape of the spacecraft as planned, allowing the design of increasing wind resistance and maintaining stability to work. This is the so-called “feather system”.
Image source,AFP
Spacecraft One landed safely in the Mojave Desert.
In the next few successful test flights, the spacecraft also won the X-Prize founded by space entrepreneur Peter Diamandis, with a prize of 10 million U.S. dollars. The purpose of the awards is to stimulate the development of the space tourism industry.
The public was invited to watch the flight, but the spacecraft not only impressed them—the founder of the Virgin series, Sir Branson, was also watching the spacecraft closely and was about to make a desperate effort on the spacecraft and its technology.
In September 2004, Sir Branson announced that he would use the spacecraft modeled on Spacecraft One to provide commercial space flights. At a press conference in London, the British entrepreneur said that a Virgin Galactic ticket would burn consumers’ wallets by $200,000.
Image source,PA Media
In September 2004, Sir Branson officially announced the Virgin Galactic paid manned spacecraft program.
Accompanied by Rutan, Sir Branson said: “We hope to create thousands of astronauts in the next few years, make their dreams come true, and see the magnificence of our planet and the glory of stars from a height. There is also the shocking feeling of weightlessness.”
Soon after the press conference, Rutan and Sir Branson established The Spaceship Company (The Spaceship Company) to receive the technology developed by Rutan’s Scaled Composites for the use of Virgin Galactic’s space tourism business. At that time, Virgin Group planned to send passengers into space in 2007.
But this spacecraft can’t just modify Spacecraft One slightly. Although it won the X prize, it can only take one pilot. Sir Branson hopes to have eight people-two pilots and six passengers-take part in the sub-orbital flight at once.
Well, Virgin’s spacecraft is much larger than its predecessor, and the White Knight aircraft carrying it must also be modified. Engineers also want to develop more horsepower engines to send the spacecraft to the edge of space.
In September 2006, two years after the Virgin Galactic conference in London, Sir Branson released the SpaceShipTwo model in New York.
Virgin Galactic had hoped to repeat such activities in the next few years, so that journalists and other guests would circle around the model. The company wants to show the functions of the spacecraft one by one, such as the windows that allow passengers to see the vast starry sky and the vastness of the sky.
Image source,Getty Images
In April 2013, the Virgin Galactic Enterprise was preparing for a test flight in the Mojave Desert.
They explained in detail how paying passengers can unfasten their seat belts and turn somersaults in a microgravity state, all of which draw an attractive picture to potential customers. However, the situation behind the scenes is not always good.
In July 2007, the scale complex encountered an accident. An explosion occurred during the test of rocket components for Spacecraft II, killing three employees and seriously injuring three.
After the accident, the scale complex transferred the motor development to Sierra Nevada Corporation as a contract.
The rocket motor design of the spacecraft uses a rubber-type solid fuel called hydroxy-terminated polybutadiene (HTPB), supplemented by nitrous oxide as an oxidant (fuel booster). This design of putting different propellants at different stages—in this case, solid plus liquid—is called a hybrid rocket motor.
Such a motor must be able to withstand continuous burning for at least one minute.
The first spacecraft II was named Virgin Galactic Enterprise (VSS Enterprise) and was put into testing in 2010. The first is various ground tests, and then the load-bearing flight, flying under the White Knight II carrier aircraft, but the spacecraft will not leave the aircraft midway.
In October of the same year, the spacecraft was launched in mid-air by a carrier aircraft for the first time, gliding safely and landing at the Mojave Air and Space Port (Mojave Air and Space Port).
The Enterprise flew on its own for the first time in April 2013. It was carried by Mark Stucky with Michael Alsbury as the co-pilot. The spacecraft successfully flew at supersonic speed over the Mojave Desert.
Sir Branson commented at the time: “Today’s successful flight at supersonic speed opened the possibility of rapidly expanding the flight envelope of the spacecraft. It is very feasible to achieve the goal of full space flight by the end of this year.”
Image source,Getty Images
In October 2014, the Virgin Galactic Enterprise disintegrated and crashed over the Mojave Desert.
“Today we are witnessing the birth of history, and I am extremely proud of everyone involved.”
However, Virgin Galactic was not satisfied with the shock of the engine prototype. Their partnership with Sierra Nevada Company ended in 2014, and the rocket development could only be taken back under its own umbrella. The company also announced that it will change the rocket fuel, from rubber-based to plastic-based thermoplastic polyamide (thermoplastic polyamide).
In October 2014, the Enterprise took off from the Mojave Spaceport and performed its 55th test flight to test new plastic fuels.
The Virgin Galactic Unity was separated from the carrier aircraft and launched into the air.
However, 11 seconds after the carrier plane was released, the Enterprise disintegrated and the co-pilot Aylesbury died unfortunately.
Pilot Peter Siebold was seriously injured but survived. When the spacecraft disintegrated, he unfastened the seat belt. When he lost consciousness in mid-air, the parachute opened automatically, and he finally landed safely in the desert.
After the incident, Sir Branson promised in front of reporters that if the problem that caused the crash can be overcome, “we will definitely let the dream continue.” In February 2016, the second Virgin Galactic spacecraft was launched, named VSS Unity by the British physicist Prof Stephen Hawking.
Although the fatal accident had nothing to do with the engine, Unity still used the original rubber material HTPB.
After several gliding and self-supporting flights, on December 13, 2018, Unity reached the edge of space for the first time and flew over 80 kilometers above sea level—a height recognized by individual groups as outer space.
In July 2021, Sir Branson finally took his seat on the Unity and flew to an altitude of 85 kilometers.
Sir Branson took off on a Virgin Galactic spacecraft, and returned and landed smoothly after about 40 minutes. This trip marks an important step in the popularization of space tourism.
However, the most widely accepted edge of space is the Karman line at 100 kilometers above sea level. This is the altitude recognized by the Fédération Aéronautique Internationale (FAI), which records space activities.
Dr. Branson’s rival in the space travel industry—Amazon founder Jeff Bezos—is looking to make money on his spacecraft, the New Shepard. The New Shepherd is scheduled to transport passengers above the Carmen line.
However, it was also pointed out that in terms of customer experience, this is of little significance. They can still feel the weightless state, floating freely while admiring the magnificent scenery.
For those who have change to spend, this is already worth the fare.