On 8 December at 10.42am local time, a sleek white rocket with the word "SpaceX" emblazoned on its side blasted off from a US Air Force base in Florida with a payload of French cheese, circled the Earth twice and splashed back into the Pacific Ocean three hours later.
The cheese, a wheel of Le Brouère, was a rather unusual cargo, but then this was no ordinary flight. It was the first time an entirely private company had launched a rocket into space and successfully landed it.
Ever since the Soviet Union put the Sputnik satellite into space in 1957, extraterrestrial travel has almost exclusively been the preserve of governments, the only organisations with enough cash, firepower or desire to fund such costly expeditions. But the private sector is now playing an increasingly vital role in the exploration of space.
The most obvious example of space travel's growing commercialisation is the myriad of satellite companies that have developed their own launch vehicles to take their hardware into space. Then there is tourism. The Russian Federal Space Agency will take you to the International Space Station for $35m (return). A small number of private companies such as Virgin Galactic and Armadillo Aerospace are also investing in a cheaper alternative, suborbital space flights that will one day take tourists above the Karman line separating the Earth's atmosphere and outer space.
These projects tend to grab headlines because they offer us a tantalising glimpse of a potential future where space becomes a holiday destination, even if it will be accessible only for the super-rich.
But in many ways the more sensational revolution in space travel is the use of private companies to build a new generation of rockets that could one day replace the need for governments to build their own. This is where the space gold rush is really happening.
SpaceX is one of two rocket start-ups that have been subcontracted by Nasa to create a successor to the Space Shuttle, the trusty packhorse of American space travel that is due to be retired this year after 30 years of service.
Founded by the colourful PayPal entrepreneur Elon Musk, the California company has signed a $1.6bn contract with Nasa to run 12 cargo flights to the International Space Station. As a bonus for its successful test flight last month, it received a further $25m "thank you" from Nasa.
Chief competitor Orbital Sciences, based in Virginia, is a little behind SpaceX but well on the way to developing its own rocket, the Taurus II. Last month, it successfully test-fired the rocket's engines and plans a full launch later this year.
But it is SpaceX that is seen as the company most likely to do what, until now, only governments have been able to do and become the first fully private enterprise to launch a human into space.
Denise Chow, a staff writer for Space.com who witnessed last month's successful launch of the Falcon 9, sums up the momentousness of the occasion as the 178ft rocket sliced through the blue skies of Florida.
"It is not a stretch to call the success of the SpaceX launch the dawn of a new era," she says. "For the first demonstration flight under Nasa's Cots [Commercial Orbital Transportation Services] programme designed to spur development of private spacecraft, the stakes for SpaceX were undoubtedly high. In light of the successful mission, however, the pay-off is likely [to be] even higher."
Musk, not known to shy away from superlatives, had this to say once his Dragon capsule had orbited the Earth three times at a speed of 17,000mph and safely splashed down into the Pacific with its cheese payload intact.
"It's actually almost too good," he said. "There's a natural reaction that sort of blows my mind, and it's hard to be articulate with a blown mind." It was Musk's idea to put a wheel of cheese on board the test flight in tribute to the Monty Python cheese shop sketch.
That the entire operation was done for just shy of $800m is regarded as something of a financial miracle within Nasa, where some employees have reportedly begun wearing T-shirts emblazoned with the letters "WWED", standing for "What Would Elon Do?"
Over the past six years, America's space agency has spent $10bn developing its Ares I rocket and Orion capsule, the equivalent to what SpaceX has produced and the vehicle that was meant to replace the Space Shuttle as the main transport system for getting astronauts to the International Space Station.
With the Shuttle programme due for retirement later this year, the US will be entirely reliant on Russia to ferry its astronauts to the space station until it builds a replacement fleet. Back when the financial times were good, the George W Bush administration ordered Nasa to construct a fleet of new rockets that would take astronauts to the Moon by 2020, with the ultimate aim of conquering Mars using Ares V, a heavy-lift rocket that could feasibly travel farther into space.
But last year, under pressure to rein in spending, President Obama announced the abolition of the Constellation programme, effectively scrapping the Ares I and V rockets.
The decision was one of the few political issues of 2010 that managed to spark substantial bipartisan co-operation among Republicans and Democrats, mainly from politicians in states that are heavily reliant on the space industry for jobs.
Neil Armstrong, James Lovell and Eugene Cernan, commanders of three Apollo missions, helped the opposition along with a joint letter to the White House warning that the cuts would have a "devastating" effect on science and American prestige. Eventually, a compromise was reached. Over the next five years, Nasa would begin developing a stripped-down version of the Ares rockets that could produce a feasible heavy-lift vehicle.
To allow Nasa to concentrate on deep-space exploration and missions to the Moon, nearby asteroids and, eventually, Mars, the transport of astronauts to the International Space Station will be almost entirely subcontracted to private companies.
But there are those who fear that handing over something as vital and dangerous as space travel to the commercial sector is risky. Nasa may be slow and expensive, but it has the kind of checks and oversight that many private companies will lack because they are trying to cut costs.
In a recent interview with Time magazine, Mike Griffin, Nasa chief from 2005 to 2009, expressed his misgivings about giving too much power to the commercial sector. "Every time we fuck up," he said, "it's because something that we didn't think mattered turns out to matter. Who knew that a briefcase-size piece of foam could bring down an orbiter? The stuff that kills us isn't going to be the thing we think will hurt us."
An organisation such as Nasa, free from the constraints of market forces, is generally able to spend as much money and time as is needed to get a vehicle working safely.
But the lure of reducing the eye-watering costs of space travel is proving too strong for the naysayers to have any major effect on the debate, and private companies are here to stay.
Armadillo and Masten, two space tourism companies, are both expected to test-fly supersonic aeroshells that will take off vertically and achieve the kind of speed and height needed to break out of the Earth's atmosphere. If Virgin Galactic manages to complete development on its new solid fuel and liquid oxidiser engines, we may even see a powered flight in its six-passenger SpaceShipTwo.
SpaceX, meanwhile, will begin work on its next goal, sending the Falcon rocket and Dragon space capsule into space and actually docking with the International Space Station. If those tests are eventually successful, we could easily see private companies running a taxi service to the space station within five years. Complete with a billion-dollar meter on board.Reuse content