First trip this year to space station ready

The first spacecraft to visit China's Tiangong space station this year — the Tianzhou 7 robotic cargo ship — is scheduled to launch in the coming days, according to the China Manned Space Agency.

A Long March 7 carrier rocket, tasked with lifting the Tianzhou 7, has been moved to its launch service tower at the Wenchang Space Launch Center in Hainan province, the agency said in a news release on Monday.

Tianzhou 7 will become the 12th spaceship to visit the Chinese space station.

It will deliver propellants, science payloads and necessities for the Shenzhou XVII astronauts, who have been in orbit for 81 days.

The ground equipment at the Wenchang center is in good condition, the agency said, adding that the final functionality tests are taking place on systems involved in the launch mission.

Pang Zhihao, an expert on space exploration technology who worked at the China Academy of Space Technology for decades, said that the Tianzhou 7 is expected to transport living necessities and work materials to the Tiangong to support the Shenzhou XVII and XVIII mission crews.

"Starting from the Tianzhou 6, our cargo vessels now have more inner space and thus can contain more payloads for the crew, so launching three cargo ships is enough to support a two-year stay in orbit for astronauts," he said. "Our Tianzhou series has been well developed and improved, and can be fully relied upon."

The Long March 7 rocket to lift the Tianzhou 7 was transported to the Wenchang center in late December and then underwent prelaunch checks with the cargo ship.

The Long March 7 model is a liquid-fueled rocket developed by the China Academy of Launch Vehicle Technology. The rocket has a height of 53.1 meters, a core-stage diameter of 3.35 meters, and a liftoff weight of 597 metric tons. With six 120-ton-thrust engines, the launch vehicle can send 13.5 tons of payload to a low-Earth orbit or 5.5 tons to a sun-synchronous orbit.

On Friday afternoon, the Tianzhou 6 cargo craft undocked from the Tiangong space station and started a period of solo flight.

The space agency said the Tianzhou 6 will fall back to Earth soon, and most of the spaceship will burn up during reentry, and a small amount of debris is expected to fall into secure areas in the South Pacific Ocean.

Orbiting Earth at about 400 kilometers above the ground, Tiangong has three permanent parts — a core module and two science capsules — and is regularly connected to several visiting crew and cargo spaceships.