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.
Like Patsayev and Volkov, crew members aboard Salyut 6 cared for the plants like doting fathers. One cosmonaut, Vladimir Kovalenok, used what he called the “simple peasant’s way” to help the onions grow, carefully trimming rotting stalks as they poked out of the Vazon’s top. To his delight, the trimming helped the healthy stalks grow faster. Still, the onions died prematurely from thirst—without gravity, even proximity isn’t enough to enable roots to absorb water.
Though their greenhouse designs were clever, Soviet botanists were hampered by government secrecy, which forbade them from publishing detailed scientific papers. Scientists, including Galina Nechitailo, a space botanist from Ukraine who was a major player in Energia’s plant research program, weren’t allowed to reveal their research. “It was a totally secret program,” Nechitailo says. “I couldn’t move about. I was forbidden to go anywhere.”
Nechitailo routinely gave advice and instructions to Salyut 6’s cosmonauts in an effort to improve the plants’ chances. In one conversation, Kovalenok’s crewmate Alexander Ivanchenkov repeatedly hinted to Nechitailo that he couldn’t possibly use all the onion bulbs on board for their plant experiments. Why did they need so many? How should he store them? Did she plan some other use for them? Nechitailo took the hint. “Keep the four best onions for the experiment and use the rest as you like,” she said. Ivanchenkov gleefully responded, “Thanks, I’ve been probing for that,” and ate the extras.
He would not be the only cosmonaut to take advantage of Salyut 6’s plant experiments. Two years later, as he prepared for a second extended stay, Ryumin decided to smuggle aboard a cucumber from his launch-day breakfast. During the mission’s first space telecast, fellow cosmonaut Leonid Popov panned his camera to one of the station’s greenhouses. Among the dead stalks and seeds left over from the last crew eight months earlier sat one full-sized cucumber. Ryumin innocently explained that it must have grown during the cosmonauts’ time away. Everyone in mission control was speechless. After peppering the men with questions, scientists on the ground concluded that it was a joke and the cucumber was plastic. “We should have taken a bite while we were on television!” Ryumin thought afterward.
Despite the cosmonauts’ humor, space gardening remained difficult, though Ryumin proved to have quite a green thumb. He cultivated onions, peas, radishes, lettuce, wheat, garlic, cucumbers, parsley, and dill from ready-grown sprouts that were delivered to the station by space freighters, and he turned the space station into a veritable jungle by growing them in empty film cassettes, equipment casings, and food containers hung everywhere on the station’s walls. But his and Lyakov’s attempts to get seeds to reproduce proved futile. Despite the best efforts of several crews, most of Salyut 6’s seeds grew poorly or died. Like the flax plants aboard the first Salyut, those that managed to sprout were tiny and stunted. Later, Ryumin would write that it seemed as if the seedlings petered out once they’d used up all the nutrition contained in the seeds themselves.
Perhaps the cosmonauts should have expected as much; over eons, the plants they were testing had evolved physiologies dependent on a terrestrial environment that was yet to be replicated well in space. On Earth, plants need lots of sunlight and water, and vast areas of land to thrive, but spacecraft have little spare power or room, and their limited environmental control systems aren’t tuned to deal with vegetation; in fact, botanists would later discover that onboard atmospheres are often toxic to plants.
Ryumin and Popov’s failure was not in vain. The greenhouses were revised again, and on the next long-term mission aboard Salyut 6, Vladimir Kovalynok and Viktor Savinykh got an Arabidopsis plant in the Fiton greenhouse to bud, the first time seed heads (the pods in which seeds normally grow) had ever appeared in space. Though the heads were sterile and seedless, Ryumin, now working in mission control, wondered whether the latest Fiton design, which kept the plant’s atmosphere separate from the station’s, had accounted for the success.
His guess was correct. Salyut 6’s atmosphere recycling equipment was unable to purify the air thoroughly enough for plants to prosper. On this and previous missions, unexpected trace gases released by the station’s equipment, food, and human crew had stifled plants exposed to the crew cabin. Consequently, the Soviets put a new suite of greenhouses on their next space station, Salyut 7, which launched in 1982.
As flight engineer of the Salyut 7’s first crew, Valentin Lebedev was in charge of the plant experiments. Inside Oasis, the roots of pea plants grew wildly while their leaves suffered from brown and white molds. Soon the plants died. Svetoblok, yet another greenhouse module, produced a stunted tomato plant. But inside a Fiton module that used anti-bacterial filters to keep the air pure, a breakthrough was emerging.
Since launch, Lebedev had mostly ignored Fiton because its watering system worked automatically and nothing seemed to grow. But in July, after months of inactivity, tiny Arabidopsis stems wove their way out of the artificial soil. They looked more like loose floating jumbles of thin twine than plants. On August 4, pods appeared on the plants. Less than two weeks later, Lebedev announced with glee, “Hurrah! A pod has burst: It spilt seeds!” It was the first time seeds had developed in space.
To Nechitailo, the seeds were worth more than gold. “Keep them safe,” she told him anxiously. “We need them all alive.” Lebedev harvested roughly 200 space-grown Arabidopsis seeds. Once back on Earth, they quickly germinated and produced healthy plants. After more than a decade of effort, the Russians had finally proven that plant life could reproduce in space, and that future space explorers could grow their own food. Space didn’t have to be a barren and lifeless place.
Despite this triumph—which should have propelled the Soviet space biology program to even greater achievements—a series of accidents and political changes stopped the program in its tracks. Most of Lebedev’s Arabidopsis seeds were lost in an attempt to launch them back to Salyut 7 for further experiments. When Soyuz T-8 failed to dock with the space station, the crew capsule separated to return to Earth, and the orbital module in which the seeds were stowed was abandoned to burn up in the atmosphere as usual. Then, in February 1985, Salyut 7’s batteries drained, leaving the unmanned station frozen and dying. A rescue crew revived the station, but Soviet botanists decided to concentrate their energies on Mir, which launched in 1986.
However, Communist party general secretary Mikhail Gorbachev’s efforts to reform the Soviet Union had extended to its space program as well. On board the new space station, pure scientific research was de-emphasized, replaced by a focus on commercial profit. Mir’s only greenhouse, a Bulgarian-Russian unit dubbed Svet, had been included mostly for political purposes and was far less advanced than earlier Russian greenhouses.
“Technologically it was similar to Oasis, 20 years before,” says Nechitailo. “We couldn’t learn anything from it.” Except for one failed attempt to grow wheat in 1991, the effort by Nechitailo and her partners at Energia and IMBP to grow plants in space was over, leaving unanswered the question of whether seeds produced in space could grow and produce viable second-generation seeds in orbit.
By the time NASA and the Russian space agency began a partnership in 1996, the Soviet Union had disintegrated and Nechitailo, who was closely tied to the Soviet power structure, had been forced out of the agency’s plant research programs. NASA brought new ideas and new equipment to Mir, and infused the program with a large amount of cash.
The first great success came with American Michael Foale’s stay on Mir in 1997. In May of that year, Foale planted 52 seeds of Brassica rapa—better known as mizuna, a wild plant that produces tasty light-green leaves that can be cooked, mixed in salads, or simply plucked off and eaten. Like Arabidopsis, its life cycle is short; it flowers only 14 days after being sown. It is also resistant to ethylene, a gaseous plant hormone that tended to linger in Mir’s atmosphere and had been blamed for ruining a past wheat-growing experiment. Foale’s plan was to coax two generations of seeds from the mizuna seeds.
During previous missions to Mir, U.S. astronauts had refurbished the Svet greenhouse. “We worked with the Bulgarians to get new components built for Svet,” says Gail Bingham, a professor in the Plants, Soil, and Biometerology Department at Utah State University. Bingham’s USU team developed sensors that monitored the amount of moisture reaching the roots as well as the carbon dioxide and oxygen levels surrounding the plants. The team installed light banks and new fans to keep the greenhouse atmosphere circulating and clean of toxins, and replaced Svet’s artificial soil with a set of fabric sheets that were packed with seeds and then folded around perforated stainless steel watering tubes. Both the tubes and fabric were then enclosed in a calcite clay embedded with pellets that released nutrients over time.
After four weeks—twice as long as it would take on Earth—the plants were ready to be pollinated. Foale became a human bee, collecting pollen from the one- to two-inch plants and depositing it on their stamens, but his efforts were almost for naught—a Progress resupply vehicle collided with Mir. Damages and emergency maneuvers cut into the station’s power supply. The plants floated in darkness for three days, with no fans to circulate the air around them. Temperatures dropped to near-freezing. But just days after power was restored, several plants developed seed pods. “It was pretty clear that they were full of seeds,” Foale remembers. In between putting Mir back together—shifting batteries about and wiping up globs of water—Foale carefully harvested the pods, reserving half the seeds for return to Earth and preparing the rest for replanting in space. He gently inserted a half-dozen seeds back into Svet’s root modules.
For the next month, he helped each seed find light, delicately feeding them a precise amount of water. By September 1997, four of Foale’s six seeds had germinated, growing leaves and pods packed with seeds. After almost three decades of effort by both Soviets and Americans, a second generation of healthy plants had been grown in space. Six seeds were planted on Earth; two of them developed into viable plants, and the vision of self-sufficient space exploration seemed a little closer to reality.
Since Foale’s success, work has continued, first on Mir and then on the International Space Station. In 1998 and 1999, Russians on Mir were able to grow two generations of wheat, with the second generation producing healthy offspring back on Earth. In 2001, astronauts on ISS again grew Arabidopsis through an entire life cycle, confirming the work Lebedev had done two decades earlier.
In 2002, Utah State University’s Space Dynamics Laboratory and the Russian space agency teamed up to build a greenhouse dubbed Lada (after the Russian goddess of spring, with a nod to the boxy Soviet car) and installed it on the Russian side of the ISS. Lada’s aim is to grow edible vegetables instead of crops. “We aren’t ready yet to grow wheat and turn it into bread,” says Bingham. “Instead, we are trying to grow a salad machine.”
The costs of Lada’s design, construction, approval, and flight were many times less than they would have been if the greenhouse had been submitted to the complicated and time-consuming bureaucratic process NASA requires to get an experiment into space. Bingham says the U.S. side of the partnership contributed only about $300,000—a figure that owes much to free work done by USU students. There is no estimate of the amount contributed by the Russians. Bingham notes, “If you are really lucky and really well thought of in the NASA community, you might get two or three experiments in your lifetime. In contrast, we’ve already flown 10 experiments on Mir and the Russian side of ISS over 10 years.”
The Russian crew members spend their personal time tending Lada’s garden in exchange for the right to eat half their crops; the other half is reserved for analysis. Last November, cosmonauts reaped Lada’s first crop of leafy greens, greedily devouring half a harvest of Brassica rapa. (NASA would not grant permission for U.S. astronaut Peggy Whitson to eat any—the greens had not been certified as safe for consumption—though her hand did mysteriously appear in a photograph of cosmonauts munching on their work.)
Like their Soviet predecessors, Bingham’s astro-farmers have been so taken by their work that they’re no longer automatically agreeing to do the tests Bingham and the other scientists propose. “They’ve become just as good at farming as we are,” says Bingham of the cosmonauts. “We think we ought to do something to the plants, and they’ll tell us, ‘I don’t want to do that.’ They know what’s best for the plants.”
Not that Bingham is really complaining. His goal is the same as that of the pioneering botanists who developed greenhouses for the Salyut stations: to make it possible for space explorers to feed themselves, no matter how far they may be from Earth. Lada’s success leaves Bingham optimistic that future space gardens will significantly reduce food shipments from Earth. “We hope to grow peas, mizuna, and radishes,” he says. “Enough to where we are providing crews with an occasional salad.” And, perhaps, a certain amount of good cheer.