After completing the space flight and docking at the ISS on Oct 5, 2021, Peresild, the director and their Russian cosmonaut guide floated inside to receive a welcome from seven other crew members, including those from Russia and the United States.

"We unloaded our filming equipment and were given a tour of the cabin, and shown essential items, such as masks and fire extinguishers. Although we felt a bit uneasy, we had to wake up at 6 am the next day due to the very intense shooting schedule," Peresild recalls.

The good news about space is that people need not worry about gaining weight in the gravity-free environment. Mentioning that an astronaut's regular caloric intake is around 3,000 calories each day, Peresild recalls she had a good appetite and found she tended to favor spicier foods while in space.

"The coffee in the American module is quite good, but the canned food in the Russian module is tastier," she says of the epicurean delights on offer.

Another lesson she quickly learned was how to adapt to the microgravity in space. As the film crew only consisted of two members, the actress had to do her own makeup, using adhesive hooks to keep cosmetic items in place and prevent them from floating away.

Looking out of the window of the Russian module offered her a once-in-a-lifetime opportunity to witness a spectacular view, but it also posed danger. She recalls a moment when the director instructed her to remain near the window as the Earth was aligning closely with the sun.

"We could see a blue arc line at the edges of the sun and Earth. He exclaimed, 'Wow, it's incredibly beautiful. Stay right there. Don't move.' The entire sequence lasted just 30 seconds. However, after that shot, I ended up with sunburn," she recounts.

Without the protection of the ozone layer in the stratosphere that shields the Earth, it's easy to get over exposed to ultraviolet rays, according to Chen Zheng, an associate professor of physics at the Beijing Jiaotong University and an expert of the Tiangong Class, China's first extraterrestrial lecture series.

Chen comments that the movie gives the audience an extremely realistic account of space travel, especially the scenes featuring Peresild as the surgeon entering the ISS with her hair floating upward.

"As a physics teacher, I am a bit obsessed with details," says Chen. "So, I always focus on the actress' hair while watching the movie. When she enters zero gravity, her hair stands upright and floats. This weightless feeling cannot be achieved on Earth by any physical means."