A Chinese cargo craft Tianzhou-2 successfully docked with the space station core module Tianhe on May 30, becoming the first spacecraft to visit the core module.
Rendezvous and docking is one of the basic technologies of manned space activities, as well as a prerequisite for in-orbit services of space stations and space transport systems, including assembly, recycling, replenishment, maintenance, astronauts substitution and rescue.
Dang Rong, deputy chief designer of Tianzhou-2 from the China Academy of Space Technology (CAST), introduced that it normally takes two to three days from the launch of a spacecraft to its rendezvous and docking, and the process also calls for much manned intervention.
Quickness was the highlight of the docking between Tianzhou-2 and Tianhe, said the deputy chief designer, adding that the whole process took around eight hours with no intervention from ground station, similar to driverless cars.
The Tianzhou-2 cargo freighter is composed of a pressurized cargo section and a propulsion section. Measuring 10.6 meters in length, it has a maximum takeoff weight of 13.5 tonnes and carries 6.8 tonnes of goods and materials. The cargo craft will operate in orbit for at least one year. Its power supply capacity is not less than 2,700 watts. Different from the Shenzhou manned spacecraft, the Tianzhou-2 cargo freighter only carries cargos.
In April 2017, Tianzhou-1, China’s first cargo spacecraft, successfully conducted automated docking with the orbiting Tiangong-2 space lab, and then carried out the first in-orbit refueling. As an important part of China’s space station, Tianzhou-2 is responsible for transporting materials to, refueling for, and taking away the waste from the space station.
According to Feng Yong, commander-in-chief of the Tianzhou-2 mission from the CAST, the carry-on onboard the cargo craft includes consumables that are designed to support three astronauts on their space missions for three months, space suits for missions outside cabin and other supplies. Apart from living materials, Tianzhou-2 also carries propellants to refuel the core cabinet.