Martian wannabes will have to wait a little bit longer before landing on the enigmatic red planet, according to NASA.

美国国家航空航天局称，火星迷们在登上这颗神秘的红色星球前，还需要再等上一段时间。

The space agency says it's about 25 years away from sending the first human to Mars and has spelled out what it will take to make this space travel plan pan out.

该航天机构表示，将首个人类送上火星还需要大约25年的时间，并阐明了如何才能使这一太空旅行计划成功。

Scientists still have to work out major kinks -- such as deadly radiation from the cosmos, potential vision loss, and atrophying bones -- before sending a human to Mars, known for its unpredictable atmosphere.

科学家们在将人类送上以不可预知的大气而闻名的火星之前，还需要解决一些重大问题，比如来自宇宙的致命辐射、潜在的视力丧失和骨骼萎缩。

They're also trying to shave some time off the commute: It could take nine months or so to reach the red planet, which is located about 140 million miles from Earth.

他们还试图减少往返时间：目前需要9个月左右的时间才能到达这颗距离地球1.4亿英里的红色行星。

Also, floating in prolonged zero gravity can cause acute medical conditions, such as irreversible changes to blood vessels in the retina, leading to vision degradation, and the skeleton can leach calcium and bone mass.

此外，在失重状态下长时间漂浮会导致急性疾病，比如视网膜血管发生不可逆转的变化导致视力下降，骨骼会流失钙和骨质。

With former astronaut Tom Jones admitting budget constraints will hobble NASA's attempts to send its first human for about 25 years, those of us dreaming of a vacation to Mars dubiously look to Space X as our only hope.

前宇航员汤姆·琼斯承认，有限的预算将阻碍美国国家航空航天局，使得他们要花大约25年才能尝试将首位人类送上火星，我们当中那些梦想着去火星度假的人只能试着把美SpaceX公司视为唯一的希望了。