It's the one area of space science in which you get to eat the experiment.
- By Robert Zimmerman
- Air & Space magazine, September 2003
EACH EVENING, AFTER DOING HIS EXERCISES, Viktor Patsayev glided over to Oasis, a little square greenhouse attached to a wall of the Salyut 1 space station, to water the flax plants inside. A sad-faced man with a precise manner, Patsayev would push a handle to pump water from a reservoir into the layers of resin that held the seeds. After about a week, two little flax shoots poked up through the artificial soil. Patsayev and crewmate Vladislav Volkov carefully tended to the fragile seedlings like parents. The cosmonauts seemed to be cheered by them. “These are our pets,” Patsayev said. “They are our love,” noted Volkov unabashedly.
Scientists at Energia, the agency responsible for the Soviet manned space program, had not designed the greenhouse to comfort the cosmonauts on the 1971 mission. Oasis and its flax plants were among the first experiments that looked toward the future—when colonies in orbit, or bases on the moon or Mars, would depend on space agriculture to help recycle oxygen and feed their crews. Until humans learned how to grow crops in microgravity, the cost of resupplying such outposts would be prohibitive, and lengthy missions away from Earth would be impossible. And like all facets of the space race, growing crops was something the Soviets wanted to do first.
Still, Energia’s scientists were so impressed with the psychological effects exo-gardening had on cosmonauts that by the time Salyut 6 was launched in the late 1970s, the Soviets had begun to think of the research in a new way—as a tool to boost crew morale. In 1979, when Valeri Ryumin and Vladimir Lyakhov struggled with loneliness and depression during their unprecedented half a year in space, Energia sent interior decorations—flowering tulips and a mature kalanchoe plant—to the station via a resupply vehicle. Ryumin and Lyakhov were cheered immediately. They named the kalanchoe “life tree” and made sure it was always in the picture during television broadcasts from the station. Later, aboard Salyut 7 in 1982, Valentin Lebedev observed that gardening calmed him. “I water the plants regularly, happily,” he wrote in his diary. “I spoil them; I am too generous with water.”
Yet despite the ancillary emotional benefits, the primary goal of raising crops from seeds in microgravity was not to be easily reached. A long road lay ahead for scientists. They were to be frustrated by plants’ fickleness, hampered by a series of unsuccessful greenhouse designs, and thwarted by unforeseeable factors and events.
Soon after Salyut 1’s flax shoots emerged from the resin, it became apparent that they were suffering; their leaves seemed small, and they grew far slower than flax shoots on Earth. Botanists at Energia and the Institute of Medical and Biological Problems (IMBP) in Moscow waited eagerly for samples to be returned for study, but it was not to be. On June 29, Patsayev, Volkov, crewmate Georgi Dobrovolsky, and their plants died when their Soyuz descent capsule depressurized while reentering Earth’s atmosphere. Without live samples, Soviet scientists could only guess that the plants’ problems had something to do with Oasis’ watering system—the cosmonauts had noted that it seemed to work poorly.
Four years later, aboard Salyut 4, crews again tried to grow plants. Oasis had been redesigned so that water could be automatically and precisely administered—or so Soviet scientists thought. Pea plants and onion bulbs grew slowly, then died. “First the water didn’t go in, then it went the wrong way,” wrote cosmonaut Georgi Grechko. In a zero-G environment, there is no way for water to be naturally distributed to roots that grow in all directions. On Earth, water hits the soil and is pulled downward by gravity to where a plant’s web of roots can absorb it, but in orbit, the water that the cosmonauts pumped into the artificial soil simply stayed put, waterlogging some areas and leaving others parched. Energia botanists needed to devise a system to bring roots and water together.
From 1977 to 1981, five crews on Salyut 6 lovingly attended to an assortment of flora, once more attempting to nurture plants and vegetables through an entire growth cycle—from seed to plant to seed to plant. To improve the crews’ odds for success, botanists sent up a variety of greenhouses. Oasis was revised to better distribute water. Another greenhouse, which resembled a foot-wide metallic starfish, rotated to create centrifugal force, allowing cucumber and flax seeds to grow in simulated gravity. The structure was called Biogravistat, and from it scientists would learn that plant cells could respond to as little as .0001 G. Vazon containers, a third method, were designed to grow bulbs like onions and tulips and were periodically rocketed to the station. Bulbs would be placed in a container’s base and then topped with cone-shaped covers that directed the growth of sprouts while the base was filled with water.
Inside Fiton, a greenhouse the size of a coffee table book, attempts were made to grow Arabidopsis thaliana, a weed often found in junkyards and dumps. The species had been chosen because its entire life cycle was only 40 days. To sow an Arabidopsis seed, a cosmonaut released a spring, which caused a plunger to push a seed into one of five glass cups of nutrient-saturated artificial soil. The plant was then to grow on its own, with no watering necessary.