S: Hi everyone. Welcome to CBN Friday Special, I’m Stephanie LI.
R: And I’m ZHANG Ran.
S: Ran, do you cry often?
R: Hmm, sometimes. More often when I was a little girl. Why do you ask?
S: Well, do you know that technically, astronauts can not cry?
R: Why not?
S: In micro-gravity, your eyes make tears but they stick as a liquid ball. In other words, astronauts technically can’t cry, China’s first female Taikonaut Wang Yaping told students on the second live class from China’s space station held on Wednesday.
R: Ah, yes! I must have missed that part of the lecture. Shenzhou-13 crew members Wang Yaping, Zhai Zhigang, and Ye Guangfu conducted several scientific experiments during the hour-long class, such as the crystallisation of supersaturated solution, a liquid bridge demonstration, water-oil separation and throwing objects under the zero-gravity condition, amazing numerous students on Earth. How about you, Stephanie, which experiment impressed you the most?
S: I would say it"s the first micro-gravity experiment. In this demonstration, Wang used a bag of supersaturated sodium acetate solution to demonstrate its crystallisation in micro-gravity. After Wang squeezed the solution from the bag, it became a transparent fluid ball floating in front of the camera. She then used a small stick covered with crystal nuclei to touch the fluid ball and it quickly became crystallised. It looks like an ice ball, but Wang told the class that it"s actually warm.
R: Yes, that was really impressive. The space teacher explained that the solubility of sodium acetate in water of higher relative temperature is very high, and it very easily forms a supersaturated solution. Just a small trace of crystal nuclei causes the sodium acetate to crystallize, releasing a lot of heat.
Another micro-gravity experiment showed how to separate oil from water in space. Wang and the students followed the same procedure to mix oil and water into a fluid mixture. But the students found their mixture gradually separated into oil and water again, while the fluid in space remained as a mixture. Do you know why that happened, Stephanie?
S: Yes, I do. In the weightless environment of space, Taikonauts have to separate oil and water by spinning the mix, using the influence of centrifugal force. Wang also told us that the space station is equipped with a centrifuge, which the crew can use to separate and prepare medical samples such as blood and urine.
R: Yes, you’re right. Wang and Ye then jointly introduced two laboratory cabinets aboard the Tiangong space station. They first showed how they used the high-quality microgravity experiment cabinet, which can conduct more precise experiments to enhance the measurement accuracy. They then showed students the “container-less” experiment cabinet, in which samples can float in the middle to avoid possible contamination and shape changes caused by the contact with the container surface.
S: In fact, China plans to conduct more frontier scientific experiments on Tiangong space station with “Wentian” and “Mengtian”, the two laboratory modules, scheduled to be launched this year. The experiments include raising fish, growing vegetables, setting up the most precise clocks in space, developing new materials, studying physical laws and exploring how humans can survive in space for long periods. Both Chinese and foreign scientists will then have the opportunity to carry out research aboard China"s space station, which will serve as a space experiment platform for the world.
R: The session lasted less than an hour, but students were fired up with questions about the cosmos even after waving goodbye to the crew. At the end of the class, Wang said, “we hope you will continue to gain scientific knowledge and explore the mysteries of science. The future space station is waiting for you guys.”
S: It’s true. For ordinary people, like you and me, a space tour is no longer a fantasy. In September 2021, US private spaceflight firm SpaceX sent four tourists, not astronauts, into the space. Other private aerospace manufacturers, such as Blue Origin and Virgin Galactic, have succeeded in sending passengers on their spacecrafts and made it back.
With the development of space tours during the 14th Five-Year Plan period, the general public in China may have a chance to visit the country"s space station in the next decade, China"s first astronaut Yang Liwei said earlier in March.
R: We are witnessing the history of China’s manned aerospace. With the Shenzhou-13 trio set to conclude their six-month mission in orbit and prepare next week for their return to Earth, the Shenzhou-14 and -15 manned missions will be rolled out this year. According to the plan, China will complete construction of its Tiangong space station by the end of this year, drawing a satisfactory conclusion to the 30th anniversary of China"s manned aerospace history.
S: And the space industry is also developing fast on the ground. For example, Wuhan has vowed to develop a 100-billion yuan space industry by 2025 and become the country"s "valley of satellites." According to a notice from the Wuhan municipal government on Wednesday, Wuhan is offering firms up to 50 million yuan in financial incentives each in projects related to the manufacturing of satellites, rockets and spacecraft. By 2030, Wuhan will form a new ecological space industry which will be deeply involved in global commercial space development, striving to create a commercial aerospace industry base with international impact, the plan said.
R: There’s so much more to expect in the near future for China’s exploration of the vast cosmos. Before we finish today’s program, a quick look at the stock market. Chinese stocks closed lower on Friday as the benchmark Shanghai Composite declined 1.17 percent, while the Shenzhen Component dropped 1.89 percent. The Hang Seng Index fell 2.47 percent. The TECH Index took a tumble with tech giants Bilibili, JD.com recorded losses of over 8 percent.
3月23日下午，中国空间站“天宫课堂”再度开课，“太空教师”翟志刚、王亚平、叶光富演示了太空“冰雪”实验、液桥演示实验、水油分离实验、太空抛物实验等。
在第一项实验演示中，透明的液球飘在半空中，王亚平用一根小棍点在液球上，球体瞬间开始“结冰”，几秒钟就变成通体雪白的“冰球”。王亚平说，这枚“冰球”摸上去是温热的。“太空’冰雪’实验实际上是过饱和乙酸钠溶液形核、结晶的过程，过程当中会释放热量。”中国科学院空间应用工程与技术中心研究员张璐介绍，过饱和溶液结晶通常需要外界“扰动”，而这个实验的“玄机”就在于小棍上沾有晶体粉末，为过饱和乙酸钠溶液提供了凝结核，进而析出三水合乙酸钠晶体。
在接下来的实验中，王亚平用力摇晃一个装有水和油的瓶子，让水油充分混合，瓶中一片黄色。时间一分一秒过去，瓶中没有发生任何变化，油滴仍然均匀分布在水中。叶光富前来助力，抓着系在瓶上的细绳甩动瓶子。数圈后，水油明显分离，油在上层，水在下层。“ 水油在天上成功分离的原因是，瓶子高速旋转时类似离心机，可以理解为离心作用使得浮力重新出现了。”张璐说。
在“天宫课堂”上，叶光富给大家展示了两个新的科学实验柜——高微重力科学实验柜和无容器材料实验柜，令人眼前一亮。“有了高微重力科学实验柜，就可以开展需要更高微重力水平的实验，可以对爱因斯坦广义相对论中的等效原理进行高精度检验。” 随后，叶光富展示了更炫酷的另一台实验柜——无容器材料实验柜。“在这里面，实验样品可悬浮，与容器表面不接触。因此，我们可以更精确地测量样品的重要物理性质。”
此外，今年“问天”和“梦天”实验舱计划升空，支持开展大规模、多学科科学研究。“等到‘问天’实验舱和‘梦天’实验舱发射入轨之后，太空站将会增加更多的实验柜，开展更多领域的科学实验项目。届时，中外科学家都可以依托实验柜开展研究，而中国空间站将成为造福全人类的太空实验室。”叶光富向同学们生动讲述了中国空间站的宏伟蓝图。
在课堂的尾声中，航天员们对同学们提出了殷切的希望。“期待你们提出自己的科学实验设想，说不定我们下次在太空中展示的就是你的实验。”
今年，按照计划，我国载人航天空间站工程进入空间站建造阶段，神舟十三号航天员乘组自去年10月进入太空，目前状态良好，待返回后，地面科研人员会对空间站的核心舱进行验证评估。评估完成后，神舟十四号、神舟十五号载人飞船和两艘货运飞船以及问天、梦天实验舱将继续完成接下来的工作，最终形成空间站T字构型。
近年来，各国在载人民用航天方面取得了诸多进展，让“太空旅行”不再是遥远的梦想。2020年8月3日，SpaceX载人龙飞船在完成了首次载人飞行后成功溅落海面，商业载人项目的试验阶段正式宣告成功。SpaceX表示，每年将有多达六次商业载人飞行。2021年7月11日，维珍银河成功完成了又一次载人航天任务，将两名飞行员和四名乘客送至8.6万米的高空进行亚轨道太空飞行，并顺利返回。2021年12月，由亚马逊创始人杰夫·贝索斯旗下太空探索技术公司“蓝色起源”成功完成了第三次载人太空飞行任务，将六名成员送入太空，太空舱在10分钟后成功返航着陆。
而在我国，根据《2021中国的航天》白皮书，“十四五”期间我国将培育发展太空旅游。近日，全国政协委员、中国载人航天工程副总设计师杨利伟在回答“普通人能否在"十四五"期间来到空间站参观”的问题时就表示，这有可能，因为商业航天也是整个航天发展的一个大趋势。他说，从工程来讲，我们也希望能有更多不同性质的企业参与进去，这对整个行业的发展是一个很好的助力。从这个角度来讲，将来普通老百姓进入空间站是没有问题的。只要有这种需求，我们的资源允许，这应该不是一个很长远的问题。在“十五五”或者可能在十年内实现，不是个技术问题，主要看需求。
根据国家航天局发布的“十四五”及未来一个时期发展重点规划，中国的行星探测工程，统筹考虑工程技术发展和热点科学问题研究的需要，明确在2030年前，以火星探测为重点和主线，按照“一步实现绕着巡、二步完成取样回”的路线进行，首次火星探测任务已经圆满完成绕着巡的既定目标，下一步拟于2028年实施火星取样返回任务。同时还将在2025年前后实施近地小行星取样返回和主带彗星的环绕探测，2029年实施木星系及行星际穿越探测任务。
不少城市也瞄准了航天产业的巨大前景。3月16日，武汉市人民政府发布《市人民政府关于加快推进我市航天产业发展的实施意见》（以下简称《意见》），明确锚定“中国航天第三极”发展目标，聚焦主导产业，拓展延伸基础产业，建设成为国内一流的航天产业发展先行区和商业航天产业基地。
《意见》要求，到2025年，打造“航天运载火箭及发射服务、卫星平台及载荷、空间信息应用服务、航天地面设备及制造等”四大主导产业，带动全市航天产业规模达到千亿元级；到2030年，形成主导引领、基础夯实、配套完善的新型航天产业生态，深度参与全球商业航天发展。
期待中国在航天事业上继续取得新的突破。最后来看股市收评。周五A股午后扩大跌幅，沪指全天收跌1.17%，深成指跌1.89%，创业板指跌2.5%。市场情绪表现低迷，1740股上涨，2750股下跌。港股受挫，恒指收跌2.47%，恒生科技指数跌4.98%，美团跌超8%，哔哩哔哩跌超10%。
（欢迎大家提供意见和反馈，请联系主播李莹亮：liyl@21jingji.com）
Executive Editor: Sonia YU
Editor: LI Yanxia
Host: Stephanie LI
Writer: Stephanie LI, ZHANG Ran, CHEN Zihui
Sound Editor: ZHANG Ran, CHEN Zihui
Graphic Designer: ZHENG Wenjing, LIAO Yuanni
Co-produced by 21st Century Business Herald Dept. of Overseas News & SFC Audio/Video Dept.
Presented by SFC
编委: 于晓娜
策划、编辑：李艳霞
播音：李莹亮
撰稿：李莹亮、张然、陈梓慧
音频制作：张然 、陈梓慧
设计：郑文静、廖苑妮
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