Three Chinese astronauts Wang Yaping, Zhai Zhigang and Ye Guangfu (from left to right) give a space lecture on Dec 9 . TUCHONG / IC
“Hello, everyone! Welcome to Tiangong Class.” With this greeting, a special lecture began on Tiangong space station about 400 kilometers above Earth on Dec 9.
“各位同学，大家好！欢迎来到天宫课堂。”伴随着一句问好，12月9日，在距地球400公里的天宫空间站上，一节别开生面的“太空课”开讲了。
Lasting for about an hour, the space lecture was broadcast live to millions of students. Three astronauts from the Shenzhou XIII crew – Zhai Zhigang, Wang Yaping and Ye Guangfu – hosted the lecture, demonstrating how they live and work on the space station and conducting some interesting experiments that can only be done in space.
天宫课堂第一课持续了大约一个小时，面向全球现场直播。神舟十三号乘组航天员翟志刚、王亚平、叶光富进行太空授课，展示了中国空间站工作生活场景，并演示了一些只有在太空才能进行的有趣实验。
This is the second live space lecture in China. In 2013, with the assistance of two other Shenzhou X crew members, Wang delivered the country’s first live space lecture to over 60 million schoolchildren across China.
这是中国第二次太空授课直播。2013年，在神舟十号另外两位航天员的协助下，王亚平为全国6000多万名学生进行了中国首次太空授课直播。
More space to teach
授课空间更开阔
Compared with the class eight years ago, this year’s space lecture is greatly different. According to Pang Zhihao, a Beijing-based space expert, the “classroom” is bigger. Instead of Tiangong I experimental module, this year Wang delivered the space lecture in the Tianhe space core module, which is the biggest spacecraft developed by China. According to Xinhua, the launch of Tianhe signifies that China’s space station construction has entered the full implementation stage.
与8年前的课堂相比，今年的天宫课堂有很大的不同。北京航天专家庞之浩表示，这次“教室”更大了。今年，王亚平不是在天宫一号实验舱教学，而是在天和核心舱进行太空授课，该核心舱是中国研制的最大航天器。据新华社报道，天和核心舱发射成功，标志着中国空间站建造进入全面实施阶段。
Technological development
技术进步
The quality of space to ground interaction and communication is also much improved.
天地互联互通的质量大大提高。
The space lecture eight years ago sometimes faced the challenges of the video freezing and an unclear picture, but this year’s lecture is different.
8年前，太空授课有时会遭遇视频卡顿、图像模糊等挑战，但今年的太空授课大不相同。
With the help of China’s Tianlian relay satellites, the transmission speed has been highly increased and the whole live broadcast has run smoothly.
在中国天链中继卫星的帮助下，（信号）传输速度大大提高，整场直播顺利进行。
According to Xinhua, these changes show that Chinese aerospace industry has made great strides in the past eight years.
据新华社报道，这些变化表明中国航天工业在过去的八年里取得了长足进步。
Bigger curriculum
授课内容更广泛
Along with the technological progress, this year’s space lecture discussed more disciplines of science. Eight years ago, Wang showed students the laws of physics and focused on the interesting phenomenon of weightlessness in space. But this year, biology was added. The astronauts compared the growth and shape of cells in artificial gravity and zero gravity, so as to study their changing rules and mechanisms.
随着技术进步，今年的太空授课涉及了更多学科。8年前，王亚平向学生们展示了物理定律，着重演示了太空中失重的有趣现象。但今年，授课中加入了生物学。航天员们比较了人工重力和零重力环境下细胞的生长和形状，研究了细胞的变化规律和机制。
Though these space lectures showed various topics, the aim behind the lectures has never changed. According to China Daily, the space lectures aim to “spread knowledge about manned spaceflights and spark enthusiasm for science among young people”.
虽然太空授课的主题多种多样，但目的始终如一。据《中国日报》报道，太空授课旨在“传播载人航天知识，激发广大青少年对科学的兴趣”。
“The spirit of science in the youth is an important driver of the progress of mankind,” Zhou Jianping, designer-in-chief of China’s manned space program, added. “Space activities can help them build the spirit of pursuing science and facing challenges.”
“青少年的科学精神是人类进步的动力。”中国载人航天工程总设计师周建平补充说，“航天活动可以为青少年树立这样一种理念：爱科学、学科学并勇于面对科学风险。”
