105 days in 'miniature Earth' raising fruit, veg ... and bugs

Moon Palace 1 Captain Xie Beizhen (center) with crew members Dong Chen (left) and Wang Minjuan pose for a photograph before leaving the module yesterday after 105 days. (Photo: Xinhua)

Three Chinese volunteers on Tuesday ended an experiment that saw them live for 105 days in an enclosed capsule, eating only laboratory-raised plants and insects.

This was China's first manned test of Moon Palace 1 — Yuegong-1 — a 500-cubic-meter module that is China's first and only the world's third bioregenerative life support base.

In a closed lab on the campus of Beihang University, volunteers Xie Beizhen, Dong Chen and Wang Minjuan fed themselves by cultivating grain, vegetables, fruit and grubs.

Featuring a cabin and two plant growing labs, the system also produces water and fertilizer, processes waste and recycles air.

Liu Hong, chief designer of the system, described it as a miniature version of the Earth's biosphere.

It can help make it possible for astronauts to live safely on space stations for long periods without deliveries of supplies, explained Liu.

The cabin includes living quarters, a room for socializing, a bathroom, a waste treatment room, plus a room for breeding insects for the dinner table.

Two plant cultivation rooms offer different temperatures and levels of humidity.

Liu said the research team cultivated five grains, 15 types of vegetables, one kind of fruit, plus yellow mealworm — providing protein for the volunteers.

The team of 26 scientists began investigating the system in 2004 and all facilities and techniques are domestically developed, said officials.

It is said to be one of the world's most advanced systems of its kind, providing core technology for manned space exploration.

In the closed system, waste produced by the inhabitants is used to fertilize the soil.

Carbon dioxide produced by inhabitants and insects is used to facilitate photosynthesis, while oxygen from the process is returned to the human cabin.

Some distilled water is collected for drinking, with the remainder plus urine used to irrigate plants.

Last June, three Chinese astronauts spent 12 days in Heavenly Palace 1 — Tiangong-1 —in the country's longest manned space mission.

China's manned space mission has entered its second decade with ambitious plans including building a permanent space station and launching a manned lunar probe.