The space shuttle made it possible for a craft to be sent into orbit and return to Earth to be used again. But what about the hugely powerful (and hugely expensive) rockets needed to take it beyond the atmosphere? If only there were a way to re-use them, space travel could become much more affordable, and therefore much more commonplace. SpaceX is one group which is hoping to find the answer.
More ambitious than Virgin’s high-profile space tourism, SpaceX, the company started by PayPal magnate Elon Musk, made the first of its three trips to the International Space Station in 2012. And as part of its multi-billion-dollar contract with NASA, the company is developing rockets that can deliver payloads into space, and come back to be used again, making the idea of regular space travel much more feasible than it ever has been.
Development is still underway, but as it stands, the launch has two stages. The first, Falcon 9, has nine Merlin engines powered by liquid oxygen and rocket-grade kerosene that together can deliver 6,672,332 Newtons of thrust – equal to five 747s at full power.
Falcon 9 takes the craft beyond Earth’s atmosphere and is then jettisoned. But rather than simply falling back to Earth, it can be controlled remotely, and use its remaining fuel to effect a landing. There have been tests, but the landing stage has still to be refined.
Then Falcon 9’s second stage takes over. Powered by a single Merlin engine, it takes the payload through orbit to its destination. That payload may be a satellite, but it could also be the Dragon spacecraft, which has already delivered cargo to the ISS. Dragon has an unpressurised section for non-delicate cargo and a pressurised section, which has so far only carried cargo, but is being adapted to carry crew.
Despite some setbacks, the theory seems sound, and SpaceX hopes to make its first flight with a pre-used Falcon 9 later this year.
It’s all still hugely expensive of course. Previous Falcon 9 launches to low Earth orbit have cost around $53 million each – and the company claims that’s the cheapest in the industry. The reusable version should significantly reduce that cost, possibly bringing it down to around $5 million. And with more trips more often, that could reduce even more. Like the advent of jet aircraft, in the 1930s it would have been hard to imagine thousands of planes flying around the world, carrying passengers at the kind of prices we’re now paying. Reusable rockets could make the same change for space travel.
And with private funding taking the onus off governments, and the savings generated by reusing equipment, as well as more efficient technologies being developed as part of the process, there are even more ambitious plans afoot. After the ISS, manned trips to the moon could be back on the agenda. And after that, says Elon Musk, Mars.