5 . Space X Makes Space History

Recycling isn't just for cans, bottles and unwanted gifts anymore. South African businessman Elon Musk's space transport company Space X has recycled its way into history and redefine the future of space flight.

On March 30, Space X successfully launched a “pre-flown” rocket. It marked the first time anyone has relaunched a booster (助推器) into space. Musk called it “a milestone in the history of space.” SpaceX hopes to turn space flight into a profitable business. To make it a reality, the company has long realized that reusable rockets will be an important part of its business model. A typical rocket launch of the type performed by SpaceX costs around 62million.A one-time-use rocket, which, once used, falls to earth and breaks up, makes up as much as 30 percent of the launch price.

Musk's ambitions (雄心), however, are not without risks. Last September, one of SpaceX's rockets exploded on its launch platform, destroying the booster, the spacecraft and its cargo-a multimillion-dollar satellite. The explosion set back the company's plan to relaunch a used rocket, but Musk seemed to be even more hopeful. The businessman believes that most rocket parts can be used dozens of times.

Following the success in March, Space X now plans to push on. Its plan is to have rockets launched, landed and then relaunched with 24 hours. Those rockets, the company hopes, will make the flights without maintenance (维护), and up to 100 flights in total. It's not clear how much effort that will take, but if Space X makes it a reality, the company will quickly achieve a position of power in the space industry.