Tianzhou ship launches and docks with Chinese space station

A Long March 7 rocket lifts off with the Tianzhou cargo mission. Credit: CASC

An unpiloted Chinese cargo ship launched and docked with the Tiangong space station Monday, delivering supplies to support the next three-person crew on the complex for six months after their arrival in October.

The automated Tianzhou 3 supply freighter took off from the Wenchang launch base on Hainan Island — China’s southernmost province — at 3:10 a.m. EDT (0710 GMT; 3:10 p.m. Beijing time) Monday, according to the China Manned Space Agency.

A 174-foot-tall (53-meter) Long March 7 rocket carried the Tianzhou 3 cargo ship into orbit.

The kerosene-fueled rocket ignited six booster engines to climb off the launch pad at Wenchang with 1.6 million pounds of thrust. An on-board guidance computer commanded the rocket to head southeast over the South China Sea, lining up with the Tiangong 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 consumed 45,000 gallons, or 170 cubic meters, of kerosene fuel in combination with cryogenic liquid oxygen during the 10-minute ascent into orbit.

The China Manned Space Agency said the Tianzhou 3 cargo ship deployed from the Long March 7 rocket, deployed its solar panels, began a series of maneuvers to match its orbit with that of the Tiangong space station around 240 miles (385 kilometers) above Earth.

The supply craft autonomously docked with the rear port of the space station’s Tianhe core module at 10:08 a.m. EDT (1408 GMT), around seven hours after blastoff, Chinese officials said.

The orbital link-up delivered more than 12,000 pounds, or 5.6 metric tons, of cargo to the Tiangong station. Fully loaded, the Tianzhou 3 spacecraft weighed about 26,500 pounds (12 metric tons) at launch, according to the China Manned Space Agency.

The Tianzhou 3 mission ferried provisions for the next crew to live on Tiangong. The Shenzhou 13 crew is scheduled to launch in mid-October for a six-month expedition on the space station.

Tianzhou 3 also delivered a spare spacesuit for spacewalks outside the Tiangong station, propellants, experiments, and other equipment for the new crew.

The docking of Tianzhou 3 comes days after the departure of Shenzhou 12, the first three-man crew to live on the new space station. Shenzhou 12 undocked from Tiangong on Sept. 15 and landed in northwestern China on Sept. 17, completing a 92-day mission, the longest human spaceflight so far in China’s space program.

Shenzhou 13 will attempt to double that record. Chinese officials have not announced the identities of the Shenzhou 13 crew members.

With the arrival of the Tianzhou 3 cargo ship, the Tiangong station has two Tianzhou supply ships docked on each end of the Tianhe core module. Tianzhou 2, which launched in May, is attached to the forward port of the Tianhe module.

Tianzhou 2 detached from the rear port of Tianhe on Saturday, flew around the station, and reconnected with forward docking port. Chinese officials said Tianzhou 2 will perform in-space refueling tests at the forward port.

The launch of the Tianzhou 3 spacecraft Monday was the fourth of 11 missions to support construction of China’s Tiangong space station.

The first section of the complex, the Tianhe core module, launched in April on a heavy-lift Long March 5 rocket. The Tianzhou 2 cargo ship launched in May, and the Shenzhou 12 crew mission took off in June.

After the launch of Shenzhou 13 next month, China plans six more missions in 2022, including the launch of the large Wentian and Mengtian laboratory modules to complete the initial assembly of the space station. Two more Tianzhou cargo ships and two Shenzhou crew spacecraft are also scheduled for launch in 2022.

China’s Tianzhou cargo ships — Tianzhou means “heavenly vessel” in Chinese — are designed to transport supplies and fuel to the Tiangong space station. Astronauts can pack trash into the Tianzhou spacecraft for disposal during a fiery re-entry back into the atmosphere at the end of each mission.

While docked to the Tiangong station, Tianzhou cargo ships can provide propulsion to change the orbit of the complex .

The Tianzhou cargo craft is similar in function to Russia’s Progress resupply ships for the International Space Station.

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