China has launched a cargo mission to its new space station, just days after astronauts departed the orbiting outpost.
A Long March 7 rocket topped with the robotic Tianzhou 3 freighter lifted off from Wenchang Satellite Launch Center in southern China's Hainan Province today (Sept. 20). Liftoff occurred at 3:10 p.m. local time (3:10 a.m. EDT; 0710 GMT).
Three astronauts recently departed the 54-foot-long (16.6 meters) Tianhe after a three-month stay, landing safely in Inner Mongolia early Friday (Sept. 17) to wrap up their Shenzhou 12 mission.
The 35-foot-long (10.6 m) Tianzhou 3 is loaded with thousands of pounds of supplies, scientific equipment and propellant that will help get Tianhe ready for its next astronaut crew, which will arrive soon. The three-astronaut Shenzhou 13 mission is expected to launch toward the core module in mid-October. (Firm target dates are hard to come by, because China tends not to announce many details of its spaceflight plans in advance.)
Tianhe is the heart of a three-element space station called Tiangong ("Heavenly Palace"), which China aims to finish building in 2022. It will take a total of 11 launches to fully assemble and equip Tiangong, which will be about 20% as massive as the International Space Station (ISS), Chinese space officials have said. (China is not a partner on the ISS, which has been hosting rotating astronaut crews continuously since November 2000.)
Tianzhou 3 was the fourth of those 11 launches. Tianhe was the first, lifting off on April 28. Tianzhou 2 launched to Tianhe a month later and remains attached to the core module. Shenzhou 12 took flight on June 16.
In case you were wondering, the first Tianzhou vehicle launched to the prototype Tiangong-2 space lab in April 2017. The cargo craft performed a series of refueling and rendezvous maneuvers before being deorbited in September of that year. Tiangong-2 was steered to a fiery death over the Pacific Ocean in July 2019.
Tianzhou translates as "Heavenly Vessel." Shenzhou continues the cosmic naming theme, translating as "Divine Vessel."
Editor's note: This story was updated at 1:10 p.m. EDT on Sept. 20 with news of Tianzhou 3's arrival at Tianhe.
Mike Wall is the author of "Out There" (Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.