China is set to launch the Tianzhou 4 cargo freighter for the country’s space station at approximately 1:56 p.m. EDT (1756 GMT) Monday, a resupply mission to stage hardware and provisions at the complex before arrival of the next long-duration crew in June.
Chinese state television is expected to broadcast the launch, and the video stream is embedded on this page.
The unpiloted cargo ship will dock with China’s space station about six-and-half hours after liftoff. The three astronauts training to launch on China’s Shenzhou 14 mission, set for liftoff next month, will unpack the cargo from the Tianzhou 4 spacecraft after they arrive at the station.
A 174-foot-tall (53-meter) Long March 7 rocket will loft the Tianzhou 4 cargo ship into orbit from the Wenchang launch base on Hainan Island, China’s southernmost province.
The Long March 7 rocket will be powered by six kerosene-fueled engines during the climb off the launch pad at Wenchang. The engines will generate 1.6 million pounds of thrust, and the Long March 7 will steer southeast over the South China Sea to line up with the Chinese space station’s orbit inclined 41.5 degrees to the equator.
The Long March 7 is a two-stage rocket augmented with four strap-on boosters. The rocket will consume 45,000 gallons, or 170 cubic meters, of kerosene fuel in combination with cryogenic liquid oxygen during the 10-minute ascent into orbit.
After separating from the Long March 7, the Tianzhou 4 cargo ship will extend solar panels and begin automated thruster firings to link up with the Chinese space station some 240 miles (385 kilometers) above Earth.
The cargo ship carries food, hardware, and propellant, and other provisions for the space station and the next crew to live and work on the research complex. The Tianzhou logistics vehicle is analogous to SpaceX’s Dragon cargo ship, Northrop Grumman’s Cygnus freighter, and Russia’s Progress supply craft that support the International Space Station.
The mission is the fourth flight of China’s Tianzhou cargo ship design, and the third Tianzhou mission in support of the Chinese space station, following an initial test flight in 2017. The Tianzhou 3 supply ship, which launched last September, remains docked to the Tianhe core module at the Chinese station, following an automated maneuver last month to relocate from the core module’s rear port to the forward port on Tianhe.
The older Tianzhou 2 cargo ship departed the Tianhe module in March and burned up on re-entry into Earth’s atmosphere, as designed, disposing of trash and other unnecessary equipment loaded into the spacecraft by the station’s previous crew.
The three astronauts of the Shenzhou 13 crew left the station and landed in China’s Inner Mongolia region on April 15, completing a 182-day mission in orbit, the longest Chinese human spaceflight to date.
After the launch of the three Shenzhou 14 crew in June, China plans to launch two new lab modules to expand the Chinese space station in July and October.
Email the author.
Follow Stephen Clark on Twitter: @StephenClark1.