Russia is planning to build an orbiting factory that could be used to build spaceships outside Earth's gravity field.

Russian news service Interfax reported that the government has approved the plans, but development will not begin until after work on the International Space Station has been completed.

Construction of the factory units will begin in 2015, according to the report, and the first sections, and the personal to assemble them, will go into orbit by 2018.

The factory will be used to build spacecraft that are too heavy to escape Earth's gravity. These could then be used to take astronauts to Mars and beyond.

The European Space Agency (ESA) has already said that it wants to land humans on Mars by the 2030s, and joint missions to the Red Planet with other space agencies are also planned.

The ESA has begun work on the practicalities of the mission. Last year it asked for volunteers willing to spend 520 days in isolation to simulate the conditions required for a Mars mission.