At 20:09 on December 4, Beijing time, the Shenzhou-14 crew finished their 183-day mission in space, returning safely to the earth’s surface. According to the Chinese Academy of Sciences, a third batch of experimental samples carried by the return capsule successfully arrived at a space technology center in Beijing in the early hours of December 5. Relevant personnel checked the state of the samples, confirmed that they were in good condition, then delivered them to scientists for further tests.
This is the first time that any country has completed a whole life cycle experiment of rice in space. During the orbit period of Shenzhou-14, the experiment was started by injecting nutrient solution on July 29 and ended on November 25. Rice and Arabidopsis seeds experienced 120 days of space cultivation and growth in the China Space Station, completing the whole process of seed germination, seedling growth, flowering and seed production.
During this period, Shenzhou-14 crew collected samples three times, including rice samples at the booting stage, Arabidopsis thaliana samples at the flowering stage and rice and Arabidopsis thaliana seeds at the mature stage. After collection, samples from the flowering or booting stages were stored in a low temperature storage cabinet at -80°C, while samples from the mature stage were stored at 4°C.
Scientists will now analyze the molecular biology, cytology and metabolism of the returned samples, assessing the molecular basis of the action of microgravity on Arabidopsis thaliana and rice, so as to provide a theoretical basis for further creating crops adapted to the space environment and developing and utilizing microgravity environmental resources.
At the same time, four boxes of experimental samples of non-container materials were returned. An experimental cabinet made from containerless material is the first experimental facility successfully operated in orbit in China and the second in the world. So far, it has achieved stable operations in orbit for more than 590 days, successfully completed an on-orbit experiment of seven boxes of material samples, and successfully heated 73 samples.
The three astronauts returned to the ground safely, drawing a successful conclusion for the Shenzhou-14 mission. During the orbit period, they cooperated with the ground center to complete the construction of the “T-shaped” China Space Station and performed the first handover at the space station with Shenzhou-15 crew. They witnessed many historic moments, such as a world-record time in the rendezvous and docking between cargo spacecraft and a space station. They will now have six months of recovery training, and after observation and evaluation, they will be transferred to normal training.