BEIJING, Sept 20 (Reuters) - A Chinese robotic resupply cargo spacecraft successfully docked with an orbiting space station module on Monday in the fourth of 11 missions needed to finish building China's first permanent space station by the end of next year.

A Long March-7 rocket carrying the Tianzhou-3, or "Heavenly Vessel" in Chinese, blasted off at 3:10 p.m. Beijing time (0710 GMT) from the Wenchang Space Launch Center on the southern island of Hainan, state media reported.

It successfully docked with the core Tianhe module of the space station at 1408 GMT.

Tianzhou-3 will deliver fuel and supplies for three astronauts due to travel to the Tianhe module in October. Their planned six-month stay would be the fifth mission in the series and the last for this year.

Next year, China will launch two additional core modules for the space station - Wentian and Mengtian - on Long March 5B rockets - China's most powerful space transport vehicles.

China began building the three-module space station in April with the deployment of Tianhe, followed by a three-month crewed mission that ended last week.

The station, on completion, will rival the International Space Station (ISS), which is backed by countries including the United States, Russia and Japan. China was barred from participating in the ISS by the United States.