In an unprecedented session attended by more than 200 university students and secondary school pupils in Hong Kong on Friday, eight of them asked questions of three astronauts – Liu Boming, Nie Haisheng and Tang Hongbo in space – and senior Chinese space engineers and experts, such as former astronaut Yang Liwei, in Beijing. These were some of the highlights.

Secondary school pupils and university students at a session with the astronauts, space engineers and experts.

Where and how do you get the water you drink in space? Can you show us? (pupil from St Paul’s Co-educational College)

Liu: Recycled water either comes from the condensate collected inside the cabin, or the urine we collect. Through the urine treatment, it will become distilled water.

The size of the water bubble can’t be too large, as it will float away sometimes. If it is too small, it is not enough for me to drink. So squeezed to just the right amount, at this size, it is ideal for me to drink.

When you step out of the cabin, can you see Hong Kong? Can you see the satellites from the space station? Are the stars that you see in space the same as those you see from the ground? (pupil from Chinese Foundation Secondary School)

Liu: We can see what our beautiful Earth looks like through this window in front of me. It is all deeply imprinted on my mind. The most memorable moment was when I opened the door and stepped out of the station. The word “beautiful” is not enough for me to describe what I saw.

We can see the smoke in Syria and Afghanistan … we can see the cityscapes of Beijing and Hong Kong at night, and think of Victoria Harbour. We can see six rings of highways encircling Beijing. We hope that our friends from Hong Kong will join us – the Chinese dream, and the aerospace dream, includes you and me.

The Chinese astronauts demonstrate how they exercise and get the water they drink in space.

Can you exercise in space? What do you usually do? Can you demonstrate it? (pupil from Scientia Secondary School)

Nie: We must exercise in space. Due to the gravity-free condition in space, we will experience muscle and bone loss, which will affect our health and ability to work in the long term. When we reach the ground, we will feel dizzy and our muscles cannot function well. We have a space bike, handgrip strengthening tools and other equipment to train our breathing. Allow me to introduce the space treadmill, which is different from those we have on the ground.

Riding this space bike can enhance our strength and cardiovascular function. This bike is different. As we don’t have gravity, we can use this pad to support our body on the bike. We can use this exercise bike to train our leg muscles, as well as our arm muscles, like this … [I’m] using my arms to paddle this bike. After these exercises, we need to cool down with tai chi moves or do some stretching.

The zero-gravity condition in space is a very unique environment for conducting experiments. Can you introduce the experiments that are conducted in the space station? (student from the University of Hong Kong)

Tang: We conducted experiments related to zero-gravity physics, aerospace medicine and engineering. We studied how physical conditions and space travelling under zero-gravity environments affect astronauts’ physical and mental health, and how their bodies operate in such a situation. It can better help humans work and live in space for a long time.

This is a cap to detect neural signals. By analysing our neural signals, we will know the functions, conditions and fatigue level of our brains when we are working. In the future, we can conduct research into how brains and computers can work together.

This is the equipment which can measure the grip and rotational strength of our hands. The scientific data we obtained can be the basis for finding out how to increase the work efficiency of astronauts and those on the ground. This other tool can measure the changes in our blood flow, muscle loss and bone density.

Uncle Yang, I was born in the year when you travelled to space. I am 18 years old. I want to become an astronaut. What do you think is the coolest thing about the job? (pupil from Clementi Secondary School)

Yang: When I was your age, I wanted to become a pilot. When I finished the gaokao at 18, I entered an aviation academy and fulfilled my dream. When I became a pilot, I was very interested in aerospace. My passion for space and the needs of our country prompted me to enter this industry and become an astronaut.

The coolest things are working in space, in the modules that astronauts showed on different missions. For me, the most unforgettable thing was to hold a national flag and express my greetings to Chinese people around the world when I was in space back then.