登月50年：愿人类步履不歇
But why, some say, the Moon? Why choose this as our goal?
And they may well ask, why climb the highest mountain?
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We choose to go to the Moon!
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We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard...
Because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one we intend to win, and the others, too.
John F. Kennedy
1969年7月20日以前，“阿波罗”还仅仅是希腊罗马神话中的一个人物。
那天之后，它成为一个被历史铭记的名字，连同一个人——尼尔·阿姆斯特朗。
那一天，“阿波罗11号”宇宙飞船在跨越了38万公里征程后，承载着全人类的梦想踏上了月球表面。
On July 20, 1969, American astronaut Neil Armstrong set his feet on the surface of the Moon, marking mankind's first physical contact with the Earth's only permanent natural satellite.
Apollo 11 Blast-Off, Kennedy Space Center, Florida,1969 / United Press International
“这是个人的一小步，人类的一大步。”
美国宇航员尼尔·阿姆斯特朗小心翼翼地踏上月球表面，说出了如今响彻世界的这句话。
50年弹指一挥间，回望60年代漫长而艰辛的探月之路，各种美好臆想纷至沓来。
然而，阿波罗登月计划的初衷，并非是为孤独的人类寻找同伴。
它是美苏冷战时局下的一场太空竞赛，是政治争霸的产物。
但成功登月所带来的意义，早已超越时空与国界，成为20世纪人类最伟大的成就之一。
Lunar Photograph, South Pole,1890 / Paul Henry
关于人类登月的执着，美国总统肯尼迪说过一句名言：“我们选择在这个十年内（1960年代末之前）登月，并非因为容易，而恰恰因为其困难。”
很难，但依然要去做。
从1961年到1972年的11年间，共有12名宇航员成功踏上月球土地。
今年3月，探索者俱乐部（Explorers Club）在纪念登月50周年的年度晚宴上为8位阿波罗登月宇航员拍摄了一张合影：
左二的Buzz Aldrin和右二的Michael Collins都是与阿姆斯特朗一同执行“阿波罗11号”任务的成员。
Photo of Buzz Aldrin on the moon/Neil Armstrong
而照片最左边的这位Charles Duke，则是人类史上最年轻的登月宇航员。
关于他还有另一个暖心的小故事：
他留了一张全家福在月球上。
NASA Photo
On the back of the photo, he wrote:
This is the family of astronaut Charles Duke from planet Earth who landed on the moon on April 20, 1972.
This is the first and only family photo on the moon.
豆瓣网友“我累特”评论说，这是人类最真实温暖的一面——“在大堆科研实验，月球车，样本采集任务中，有一个男人摇摇晃晃地拿出准备好的全家福，仔细放在地上拍照，家人就算是都来过月球了。”
用Duke自己的话说，这是“太空探索中人类的一面”（the human side of space exploration）。
Ongoing moon exploration
今年4月，NASA宣布将在2024年重返月球，进行更深入的月球地质研究。
再过两天，印度将发射“月船2号”探测器，探测目标之一是寻找月球上的水。而探测器的预计降落地点，是迄今为止还没有人去过的月球的另一面——月球南极附近。
In April, NASA announced its lunar program "Artemis" to land humans on the Moon's South Pole by 2024. The space agency unveiled two phases of the program – landing astronauts on the Moon in five years, and establishing a sustained human presence on and around the Moon by 2028.
India is also pursuing the goal of exploring the Moon. The country launched "Chandrayaan-1" probe in its first lunar mission in 2008. The probe did not land on the Moon but carried out a search for water using radar.
India will launch its second lunar mission, landing "Chandrayaan-2" probe on the Moon, scheduled on July 22, 2019 after a planned launch was called off due to a "technical snag" on July 15.
中国的探月工程也在不断升级。今年1月，嫦娥四号首次登陆月球背面。而嫦娥家族的更多“新动作”已经蓄势待发。
Chang'e-5 probe is going to be launched by the end of this year to bring samples from the Moon, according to China Aerospace Science and Technology Corporation. Chang'e-6 probe plans to go to the South Pole of the Moon to take samples. Chang'e-7 probe will conduct a comprehensive exploration of the Moon's topography, material composition and space environment at the South Pole.
In addition to continuing scientific exploration experiments, Chang'e-8 probe will also carry out experiments on some key technologies to see the possibility to build houses on the Moon using lunar soil by 3D printing technology, for jointly building a lunar research base in the future with other countries.
Why do we explore?
1972年12月11日，“阿波罗17号”载人飞船在月球着陆。
自此以后的40多年，再没有人造访月球，甚至再没有载人航天器离开过地球轨道。
50年前能做到的事情，为什么现在做不到？
重新思考登月的意义和目的，也许远比重新将人送上月球更重要。
Dr. Brian Cox said in BBC's documentary series "The Planets":
浩渺星辰中有答案。
愿人类步履不歇。