“Another Green World,” by Jessica Camille Aguirre:

NASA has also dabbled in space agriculture. In the late Nineties, it conducted experiments at the Johnson Space Center in Houston called the Early Human Testing Initiative, enclosing volunteers in sealed chambers for up to three months at a time. In one experiment, the oxygen for a single crew member was supplied by 22,000 wheat plants. A more ambitious project to enclose four people, named BIO-plex, was planned for the early Aughts, but was ultimately shelved because of budget concerns. Still, NASA researchers have continued work on space agriculture, albeit on a more modest scale. A few years ago, astronauts succeeded in growing lettuce aboard the International Space Station in a miniature garden called Veggie.

Most recently, the China National Space Administration has collaborated with Beihang University to build Yuegong-1, or Lunar Palace 1, a sealed structure with small apartments and two growing chambers for plants. Beginning in 2018, eight student volunteers lived in the capsule, rotating in groups of four for over a year. Their diet consisted of crops they grew, including strawberries, along with packets of mealworms fed with biological waste. Like the ESA’s loop, carbon dioxide was cycled through plants, which were enriched with nitrogen from processed urine. Yet even Lunar Palace 1 fell short of being a truly closed system. While it managed to recycle 100 percent of its water and oxygen, it managed to do so for only 80 percent of its food supply.

A fascinating story about biospheres and other strategies for living in places other than the Earth.