内容来源：分享美国 地址链接：http://go.usa.gov/cA6rB  

从国际空间站(International Space Station)返回的斯科特·凯利(Scott Kelly)比他的同卵双胞胎兄弟马克(Mark)高了两英寸。

在太空的一年中，斯科特·凯利与俄罗斯宇航员米哈伊尔·科尔尼扬科(Mikhail Kornienko)密切合作，承担为人类进行长途太空旅行作准备的各种实验。美国航空航天局、俄罗斯联邦航天局（Roscosmos）和其他国际合作伙伴正在研究宇航员在视力、肠道微生物、细胞和心理以及,其他方面的变化。

这对双胞胎和科尔尼扬科已经向研究人员提供了大量的身体数据，在接下来的几年中将对这些数据进行分析并予以发表。

下一步是什么？斯科特说：“去火星是可行的。” 虽然他并不会踏上这个旅程。他宣布4月份将从NASA退休。 “我们已经很接近了，如果我们做出选择，我认为我们可以做到这一点。”

科学实验并不是斯科特·凯利在太空的一年中做的唯一的事情。在其他数百个实验的间隙，他拍摄到一些令人惊叹的照片，还与他的兄弟一起悄悄地将一种不同的宇航服带进空间站！

Scott Kelly returned from the International Space Station two inches taller than his identical twin, Mark.

Temporary tallness is one of the many strange effects of spending almost a year aboard the International Space Station. It’s fairly simple to explain: Without normal gravity pushing down on the body, the spine expands, then quickly returns to normal back on Earth.

Researchers are trying to understand what happens to the human body during lengthy missions to prepare for an eventual — and much longer — journey to Mars and back. Now, for the first time ever, scientists are comparing Scott’s year in space and Mark’s year on earth in a “twin study.”

Twin studies enable scientists to better understand the relative importance of genetics or the environment in a study’s results.

As identical twins, the two men share essentially the same genetics. Both have spent significant time in space, with Mark logging 54 days aboard the Space Shuttle. Mark does note a few differences, however, when the two were in high school:

“I think I took the harder classes, because, you know, [Scott] had a hard time with those,” he joked in an interview with NASA.

A collaborative effort

https://share.america.gov/wp-content/uploads/2016/03/scottkellykornienko-1024x756.jpgDuring a long spaceflight, astronaut Scott Kelly and cosmonaut Mikhail Kornienko pose with one of their experiments: space-grown zinnias. (NASA)

Throughout his year in space, Scott Kelly worked closely with Russian cosmonaut Mikhail Kornienko on experiments to prepare humans for long trips in space. NASA, the Russian space program Roscosmos, and other international partners are studying changes in astronauts’ eyesight, gut microbes, cells and psychology, among other things.

The twins and Kornienko have released a trove of health data to researchers, which will be analyzed and published over the next several years.

What’s next? “Going to Mars is doable,” said Scott, although he won’t be the one making the journey. He announced his retirement from NASA as of April. “We’re close enough that if we make the choice, I think we can do it.”

Science isn’t all Scott Kelly did in his year in space. In between hundreds of other experiments, he was able to take some amazing pictures — and collude with his brother to sneak a different sort of spacesuit onto the station!