SpaceX announced a successful satellite launch on Sunday — but failed an attempted sea-landing of a rocket booster, missing a goal that has repeatedly eluded¹ the grasp of the Los Angeles-based rocket company.

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 Musk²’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 apparently³ falling over during landing. The rocket tipped over after one of its four landing legs failed to lock, said founder⁴ 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 mishap⁵ 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 flexibility⁶ 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 cargo⁷ 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)。