China is all set to launch the second module for its crewed space station after rolling out a Long March 5B heavy rocket to the pad at Wenchang spaceport.
The Wentian module is expected to launch atop the giant Long March 5B rocket early on July 24 and join the Tianhe core module in orbit hours later, marking a major step in the country's plans to build its Tiangong space station.
Three Shenzhou 14 mission astronauts are currently aboard Tianhe awaiting the arrival of the new module.
The 174 feet (53 meters) tall Long March 5B heavy lift rocket containing the Wentian module was transferred vertically from an assembly building to the launch pad on the coast of Hainan island early on July 18.
The 1.87 million pound (849,000 kilograms) rocket was transported roughly 9,200 feet (2,800 meters) to the pad over the course of two hours.
Various launch function checks and joint tests will now be conducted in the days leading up to launch, according to the China Manned Space Agency (CMSA). While Chinese authorities have not publicly revealed a time and date for launch, SpaceNews reports the launch is expected around 02:20 a.m. EDT (0620 GMT, 2:20 p.m. Beijing time) on July 24.
Wentian is encased in a 67 feet (20.5 meters) long payload fairing which will be jettisoned once the spacecraft clears most of Earth's atmosphere.
After launch Wentian will match the flight of Tianhe, currently orbiting at 236 miles (381 kilometers) above the Earth, and rendezvous and dock with the Tianhe's docking hub.
Wentian will then be transpositioned from the forward docking port to a lateral or side port, where it will remain and be prepared for operation. Tianhe's 33 feet (10 meters) long robotic arm will be used to reposition Wentian.
Wentian is designed to house a series of experiment cabinets for conducting science experiments in orbit. It also features extra astronaut sleeping quarters to allow China to conduct crew handovers, meaning six crew members can temporarily stay aboard Tiangong.
The Long March 5B has a core stage diameter of 16.4 feet (5 meters) and four side boosters adding extra thrust, allowing it to launch payloads like the roughly 48,500 pounds (22,000 kilograms) modules for China's space station.
The Wentian launch is planned to be one of two modules to be sent into orbit this year. China is scheduled to launch another experiment-hosting module, named Mengtian, in October.
The pair will join the orbiting Tianhe core module to form a T-shaped space station that China plans to operate for at least a decade.