Core Viewpoint - Zhao Chuandong, one of China's first astronauts, reflects on his journey and the importance of pursuing dreams despite not having flown into space, emphasizing the value of experience and inspiring the next generation [1][5][6]. Group 1: Personal Journey - Zhao Chuandong was selected as one of the first 14 astronauts in China after a rigorous selection process from thousands of candidates [3]. - Although he participated in training for missions from Shenzhou 5 to Shenzhou 10, he did not have the opportunity to fly, which he considers a lifelong regret but not a source of regret [1][5][6]. Group 2: Educational Outreach - During a science class, Zhao shared his experiences with students, encouraging them to set ambitious goals and strive for their potential [5][6]. - He highlighted the significance of the Kármán line, which separates aviation from space, as a metaphor for personal and professional boundaries [3]. Group 3: Inspirational Message - Zhao encourages students to look up at the stars and broaden their horizons, emphasizing the importance of teamwork and collective effort in achieving future goals [6][8]. - He conveyed that exploring the universe allows one to appreciate both the smallness and greatness of humanity, reinforcing the idea that every individual's contribution is vital [6].

Group 1 - The article discusses the distinction between aviation, aerospace, and astronautics, with the "Kármán line" serving as a boundary between the atmosphere and outer space [5][7][8] - The Earth's atmosphere is divided into five layers, with commercial flights operating within the troposphere and stratosphere, while the Kármán line is located at an altitude of 100 kilometers [5][7] - The Chinese space station orbits the Earth approximately every 90 minutes, allowing astronauts to witness 16 sunrises and sunsets in a single day [9] Group 2 - The article highlights the challenges of launching rockets in cold temperatures, referencing the successful launch of the "Shenzhou 4" spacecraft in 2002, which required the use of blankets for insulation [11] - It mentions the development of technologies from space applications that have been adapted for civilian use, such as high-absorbency materials that led to the creation of diapers [12] - The article explains how astronauts can temporarily grow taller in a weightless environment due to the expansion of spinal discs, resulting in a height increase of 2-5 centimeters [14]