At 7:30PM this evening, China will launch its first crewed mission to the Tiangong-2 space station, which will test the station’s life support and conduct a variety of experiments over the next 30 days. The mission will be the longest flight the country has conducted to date.

This is the first crewed mission for the country since 2013, and will be carried out by a pair of taikonauts: Jing Haipeng and Chen Dong. The pair will ride into space aboard the Shenzhou-11, which will launch atop China’s Long March-2F rocket from the Jiuquan launch site in the Gobi desert. The crew will arrive at Tiangong-2 two days after launching. This will be the longest crewed mission China has conducted: the prior record for the country was 15 days, during the Shenzhou 10 mission.

China launched the Tiangong-2, an 8.6 metric ton space station, into orbit on September 15th, and is designed as a testbed for the country’s larger ambitions in low-Earth orbit, which include a much larger, permanent space station to be launched in the 2020s. Tiangong-2 will replace the Tiangong-1 space station, which was originally launched into orbit in 2011. The country recently lost control of the original station, which is expected to reenter the Earth’s atmosphere sometime next year.

So, finally some rollout pics of #Shenzhou11 and its Long March 2F at Jiuquan from Monday. Just under 5 hours from launch now. pic.twitter.com/wVz6J7Yar2 — Andrew Jones (@AJ_FI) October 16, 2016

According to SpacePolicyOnline, the Taikonauts will carry out experiments, which will include "taking ultrasound measurements for the first time in space, cultivating plants, and testing the three winners of an experimental design competition in Hong Kong for secondary students." A second mission designed to refuel the station is planned for April 2017.