Earlier today, China’s first automated cargo spacecraft successfully docked with the country’s Tiangong-2 space station, according to Reuters. The Tianzhou-1 mission is the first such mission to the station, and is part of the country’s plan towards establishing a permanent presence in Earth orbit.

The successful docking is a milestone for the country — it’s the first mission for the Tianzhou-class spacecraft, which was launched into orbit onboard a Long March 7 rocket on Thursday from the Wenchang space center on Hainan Island in Southern China. The spacecraft is the heaviest vehicle that the country has put into orbit, and and can reportedly carry up to six tons of supplies and two tons of fuel.

The uncrewed ship will remain docked for to Tiangong-2 for two months, where it will conduct “several months of robotic demonstrations,” according to Spaceflight Now. Once its mission on the station is complete, it will detach and orbit the Earth to conduct several additional experiments for three months before landing. These experiments, which will include docking and re-docking to the station, as well as refueling, are crucial steps for China’s space agency to practice as it prepares to launch a larger space station into orbit.

Launched in September 2016, the Tiangong-2 is designed for such practice missions, with the first modules of its replacement expected to be launched into orbit as early as next year. In October 2016, Chinese astronauts first visited Tiangong-2 for a 32-day mission, the country’s longest crewed mission. Onboard, the two astronauts conducted a variety of experiments before returning home in November.