6月17日，航天員聶海勝、劉伯明、湯洪波先後順利進駐天和核心艙，
標誌著中國人首次進入自己的空間站。
自1992年載人航天工程啟動以來，從神舟一號到神舟十二號，神舟飛船12次飛向太空；從2003年楊利偉首訪太空到2021年聶海勝、劉伯明、湯洪波3位航天員順利升空，我國共有12名航天員飛上太空。
中華民族的飛天征程，站在了新的起點上。
按照空間站建造任務規劃，中國將在今明兩年實施4次載人飛船發射任務，經過精心挑選出來的12名航天員將繼續探索太空的新領域。
據悉，航天員系統按照新老搭配、統籌規劃的原則，綜合航天員的飛行經驗、與任務的匹配度、彼此之間的心理相容性以及協調配合的能力等因素，在2019年12月完成了從神舟十二號到神舟十五號四個飛行乘組的選拔。
四個飛行乘組，每個乘組是由三名航天員組成，指令長都是由參加過航天飛行任務且經驗豐富的航天員來擔任。
中國載人航天工程航天員系統總設計師黃偉芬認為此次執行飛行任務的三人組是一個很完美的組合。
她表示：“聶海勝不僅有兩次飛行的經驗，而且他有組合體飛行的經驗，還有過空間手控交會對接的經驗，這很重要。選擇劉伯明是因為他配合翟志剛完成過出艙活動，他也有出艙活動的經驗。選擇第二批的湯洪波來參加神舟十二號乘組，因為湯洪波在神十一任務的時候是備份航天員，這說明他各方面表現很出色。”
A dozen of handpicked Chinese astronauts， or taikonauts as they are called， are set to explore new horizons in space in four manned flight missions within two years。 In the first of these missions， three taikonauts aboard the Shenzhou-12 spacecraft have already successfully made it to space。
The flight crews for Shenzhou-12 to Shenzhou-15 were selected in December 2019。 China has picked four teams for different missions。 Each team is led by an experienced captain， who will command another two taikonauts。
For Shenzhou-12 mission， three taikonauts， namely Nie Haisheng， Liu Boming and Tang Hongbo， became the first to enter the Chinese space station。
“I think the trio is a great combo，” said Huang Weifen， deputy chief designer of the astronaut system of China‘s manned space program。 “We chose Nie as the captain for his two-time space flight experience and Liu Boming for his previous experience in extravehicular activity， while Tang is the backup taikonaut for Shenzhou-11 mission and he excelled in every area。”
The selection has been made based on aspects such as experience， age， individual characters， physical performance and mental health。 The synergy or compatibility among different members is also a big factor。
載人航天是一項艱鉅的事業。因為太空環境十分艱苦惡劣，人在航天過程中要經受巨大的加速度、噪音、振動、失重、宇宙射線等不良因素的影響，而且航天員在這樣的環境中還要完成複雜的駕駛、操縱、實驗和觀測任務，甚至還可能會遇到一些意想不到的情況，需要正確、及時和果斷地進行處理。
正因如此，對宇航員的選拔和訓練都很嚴格，要求有強壯的身體，能耐受各種惡劣的環境；有良好的心理素質，以掌握複雜的操作技能和應付意外情況；有獻身精神，以適應航天探險活動等。
黃偉芬表示，“候選人必須身心健康——身體素質要好，對航天環境要有很好的耐力和適應性，而且心理素質要好，年齡、身高、體重、教育背景和職業背景都必須滿足要求。”
預備航天員選拔涉及基本條件、醫學、心理選拔以及綜合評價等4個方面，需要滿足43個方面的要求。滿足預備航天員條件後，還需優中選優，進行飛行乘組選拔。
在這個過程中，航天員們需要經歷17項生理功能檢查。例如，航天員進入太空後的前三天，在失重環境下，容易出現和地面“暈車”類似反應，這就需要對航天員的“前庭功能”進行測試。
同時，在心理層面，還會採用調查、會談、觀察等形式，以及國際上通用的心理測驗方法和評價標準，以選出心理素質優秀的人。
經過20多年的研究和實踐，我國已經建立了一套完整的航天員選拔方法和標準，這個標準涵蓋了航天駕駛員、航天飛行工程師和載荷專家三種類型。對不同型別的航天員，會採用不同的選拔標準。
只有符合種種標準，經過大浪淘沙，才有可能成為一名航天員。
The qualification criteria includes basic， physical， mental and overall evaluations。 “There are about 43 aspects including age， height， education and professional background just in basic evaluation，” said Huang。
She said physical evaluation is about clinical and physical functions， such as cardio-pulmonary function and endurance to the space environment。 There are 17 physical checks just to test endurance and adaptation to the space environment。
Testing of the vestibular function is also one of the physical checks。 Huang explained that astronauts usually experience a unique physical reaction in the orbit during the first three days in space， similar to carsickness or seasickness。 Candidates who have weak vestibular function can become very dizzy and even vomit。
“It’s incredibly difficult to become an astronaut，” Huang said。
After over two decades of practice， China has set up a complete process to select taikonauts who can work as pilot astronauts， spaceflight engineers or payload specialists。
“The pilot astronauts need to meet the strictest requirements， and they are chosen from active aviators，” according to Huang。 She said engineers and payload specialists have different requirements， less strict but still many。
Huang said only clinical medical requirement for selection has over 120 clauses， each of which has multiple medical requests that a candidate must meet。
“It‘s a process to select from ’the best of the best，‘” said Huang。
經過多年的摸索，黃偉芬和她的團隊摸索並完善出八大類、百餘個航天員的訓練課目，每個課目又有很多訓練單元，涉及到醫學、生理、心理，還有科學理論和工程技術等諸多方面。因為此任務有艙外活動，她帶領航天員在水下進行幾個小時艙外作業訓練。
黃偉芬介紹，航天員們的訓練程度不亞於運動員。例如，每次下水進行訓練，航天員都要穿著二百多公斤水槽訓練服在水裡訓練4小時。
此外，航天員為了承受超重、失重、低壓等特殊環境因素的嚴峻考驗，超重力耐受訓練，或高重力訓練，也是必不可少的。
黃偉芬表示：“無論男女航天員都必須透過胸背向八個G的選拔和訓練，八個G就相當於自身八倍體重壓在胸口。每年做兩次，上半年做一次，下半年做一次，從入選接受訓練開始一直到退役，必須保持訓練不能中斷。只要他還是個職業的航天員，他就有責任和使命隨時準備去接受任務。”
Huang led the team to develop over a hundred types of training in eight categories in various fields， such as medicine， physics， psychology， science and engineering。 She also trained the Shenzhou-12 taikonauts under water to mimic the microgravity environment as there are extravehicular activities for the mission this time。
“They are trained for four hours each time under water， donning spacesuits over 200 kilograms，” said Huang。 “It’s grueling for our taikonauts。”
“In the early sessions， Tang said he could not even hold chopsticks after the training，” Huang said。 Tang has never been to the space before。
The astronauts are exposed to the pull of hypergravity when spaceships ascend and return。 During the hypergravity period， the blood moves to the legs， causing possible loss of vision and consciousness。 So， the training on tolerance to hypergravity， or high-G training， is also essential。
Huang said all male and female taikonauts have to pass the 8G criterion， which means they should be able to bear eight times the gravity force of their own body weight。 “The taikonauts go through it once every half a year。”
“As long as they are professional astronauts， it‘s their duty to keep going through the training， ready for the mission calls， until the moment they retire，” Huang said。