This story was updated at 10:14 p.m. ET.
China is readying the rocket that will carry the country's first prototype space laboratory into orbit Thursday (Sept. 29).
Officials at the Jiuquan Satellite Launch Center in Northwest China have fueled the Chinese Long March 2FT1 rocket that will blast the unmanned Tiangong 1 module into space. The launch is slated to occur between 9:16 p.m. and 9:31 p.m. local time at the launch site (Thursday morning in the United States), according to state media reports.
Tiangong 1, which means "Heavenly Palace" in Chinese, will test docking technology with the country's Shenzhou spacecraft during a series of test flights over the next two years. [Photos: China's First Space Station]
The space lab module is 8.5 metric tons (9.4 short tons), and is 34 feet (10.4 meters) long and 11 feet (3.35 m) wide. Tiangong 1 is designed to spend two years in space before its mission is complete, Chinese space officials said.
"All the preparatory works before launching are finished," China's Manned Space Engineering office spokeswomanWu Ping told reporters at the launch site, according to a translation provided by the office.
The prototype was originally set to liftoff earlier this week, but a forecasted cold weather front forced mission controllers to push the targeted launch date, according to state media reports.
China's space launch rally
China is expected to launch three additional spacecraft at a later time to connect with Tiangong 1 in space. The unmanned Shenzhou 8 mission is due to launch in early November to conduct the first docking tests between two Chinese spacecraft. The country then plans to launch the Shenzhou 9 and Shenzhou 10 to robotically attach to the Tiangong 1 module.
"The main tasks of [the] Tiangong 1 spaceflight include: to provide a target vehicle for space rendezvous and docking experiment; to primarily establish a manned space test platform capable of long-term unmanned operation in space with temporary human attendance, and thus accumulate experiences for the development of the space station; to carry out space science experiments, space medical experiments and space technology experiments," Wu said.
"It’s a big deal at several levels," said Dean Cheng, a research fellow on Chinese political and security affairs at the Heritage Foundation, a conservative public policy think tank. "If all goes according to plan this will be China's initial effort at docking, and of course docking is one of those sin qua nons for more prolonged exploration of space. They have to get this skill set down."
China had originally planned to launch the space lab module earlier, but last month, a Long March 2C rocket, which is similar to Tiangong 1's Long March 2F booster, malfunctioned shortly after liftoff and failed to reach orbit. Chinese officials temporarily halted plans for Tiangong 1 as they investigated the accident, which resulted in the loss of an experimental satellite.
China's growing space program
The launch of China's first space lab test module is considered an important milestone for the country and its growing space program. Chinese officials have voiced their intent to build a 60-ton manned space station by the year 2020. [Infographic: How China's First Space Station Will Work]
In addition to acting as an important test bed for these space station aspirations, Tiangong 1 will also carry medical and engineering experiments into space.
The module is expected to remain in orbit for two years, reported state news agency Xinhua.
China is only the third nation to independently launch humans into orbit, after the United States and Russia. The nation's first manned mission, Shenzhou 5, was piloted by Yang Liwei on Oct. 15, 2003. Liwei's 21-hour mission was followed by two more manned missions in 2005 and 2008.
You can follow SPACE.com staff writer Denise Chow on Twitter @denisechow. SPACE.com senior writer Clara Moskowitz (@ClaraMoskowitz) contributed to this report. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.