总部位于旧金山的火箭公司SpaceX上周日宣布成功发射一颗卫星，但未能在海上成功回收火箭推进器，没有完成该公司多次未能完成的目标。

　　Elon Musk’s SpaceX has been focused on mastering the art of returning booster rockets on Earth after a launch, in the hope this will enable the company to lower costs by re-using these rockets.

　　艾伦氠斯科(Elon Musk)旗下的SpaceX一直关注于在火箭发射后在地球上回收火箭推进器的技术，希望能够通过火箭再利用令该公司降低成本。

　　Sunday’s launch from Vandenberg Air Force base in California put a climate-change monitoring satellite, the Jason-3, in orbit around the North and South Poles. The satellite, sponsored by US and European agencies, will be used to monitor sea levels.

　　上周日该公司从加州凡登堡空军基地发射火箭，成功将一枚监测气候变化的卫星“Jason-3”送入南北极附近的轨道上。这枚卫星由欧美机构赞助，将用于监测海平面。

　　However the return of the booster was less successful. Images showed the rocket lying on its side on the sea dock after apparently falling over during landing. The rocket tipped over after one of its four landing legs failed to lock, said founder Elon Musk in a Tweet.

　　然而，火箭推进器的返回却不那么成功。图像显示，火箭在着陆过程中明显倾倒，一侧撞在海上回收平台上。艾伦氠斯科在Tweet上发文称，火箭是在4个着陆架中的其中一个未能锁定后倾倒的。

　　Although SpaceX had its first successful landing of a reusable booster on land just last month, sea landings have proven to be more challenging. Sunday’s mishap follows two failed sea landings last year.

　　就在上月，SpaceX曾首次成功将一枚火箭推进器在地面着陆，但事实证明，海上着陆更具挑战性。在上周日火箭着陆失败前，该公司去年曾两次海上着陆失败。

　　Mastering the sea landings is important because it would give a company such as SpaceX greater flexibility in terms of where to land its rockets.

　　掌握海上着陆的技术很重要，因为这将令SpaceX等公司在将火箭在何处着陆方面获得更多灵活性。

　　The company has suffered bigger setbacks before this, such as when a rocket exploded in mid-air last June.

　　SpaceX此前曾遭受更严重挫折，例如，去年6月一枚火箭在空中爆炸。

　　SpaceX recently won a six-year cargo contract worth as much as $14bn from Nasa, along with Sierra Nevada and Orbital. SpaceX has also won a contract to help Nasa deliver astronauts to the International Space Station, along with Boeing.

　　SpaceX与波音(Boeing)赢得一项合约，将帮助美国国家航空航天局(NASA)将宇航员送入国际空间站(International Space Station)。