If I was in charge of a space botany program and had to choose which plants to grow in space, I don’t think orchids would make it onto the list. For one thing, they’re not that simple to grow – orchid seeds only germinate in the presence of their chosen fungal partner. And although they’re beautiful, orchids are hardly an essential crop (even though some of them produce an edible starch that is used to make a drink called salep and ice cream and is one of my ethnobotanical fascinations). The Soviet Union, however, made a different choice, sending tropical orchid plants and seeds to the Salyut 6 space station.

On 9 April 1980, cosmonauts Leonid Popov and Valery Ryumin arrived in the Soyuz 35 spacecraft to begin a stay of 185 days, which would be the longest visit to the station. They brought with them four Malachite (also spelled as Malachit and Malakhit) plant boxes, containing mature orchid plants and fresh orchid seeds. 

USSR postage stamp (1981): Salyut 6 – 185 days in space – L. I. Popov, V. V. Ryumin
[Image via Wikimedia]

According to Zabel et al. in their Review and analysis of over 40 years of space plant growth systems, the Malachite experiment flown on Salyut 6 was “the first experiment specifically designed to investigate the psychological benefits of crew interaction with plants”, and that was why orchids were chosen. 

FLIGHT International gave a different explanation in January 1981, reporting that “Orchids were chosen for the experiment because they do not always grow upwards on Earth—in the jungle, for example, orchid roots often grow upward.”

Actually, they’re both right. The official write-up states that the scientists behind the experiment felt that orchids would have a high tolerance for space flight, due to their ability to grow in poor soils and small root volumes and to survive without weeks without watering. The optimal temperature for orchids is similar to that for a cosmonaut, they’re pretty and cheerful, and orchid pollen doesn’t tend to spread through the air and cause allergic reactions.

The species they chose for their experiment were epiphytes (‘air plants’):  Epidendrum radicans, Doritis pulcherrima, and Dendrobium kingianum. They also sent some epigeal (‘soil-dwelling’) species for comparison: Paphiopedilum hyrbrida hort., Paphiopedilum insigne, and Anoectochilis dawsonianus.

Malachit plant growth system as exhibited in the Memorial Museum of Astronautics in Moscow
(Photo taken by M. Bamsey in 2014).

During their launch to the space station, the orchids were subjected to acceleration of up to 4.5 g for 15 minutes, and substantial vibration, but they arrived with no visible damage. However, once they were in space, they weren’t happy. The experiment showed that different species had different tolerances for space flight. Two of the orchid containers returned to Earth after 60 days in space. The rest of the orchids spent either 110 or 171 days in space. Their flowers wilted quickly. One species, which blooms for 87 days on Earth, kept its flowers for just 7 days in space. Others had buds that withered without opening. 

The Epidendrum was the happiest in space, although its growth rate slowed. The Dendrobium plants lost their leaves in space and eventually died back on Earth. The growth rate of the Doritis plants slowed in space but doubled once they were back on Earth. Subsequent generations, even 3 years later, still showed enhanced growth. All of the epigeal orchids died in orbit.

According to Brian Harvey and Olga Zakutnyaya in their 2011 book Russian space probes: scientific discoveries and future missions*: “The cosmonauts were disappointed with the results, especially considering the loving care they gave to the plants, for minding them was a highlight of the mission.”

Nonetheless, the researchers concluded that:

“epiphyte orchids are a suitable model for studying the characteristics of the processes which control growth and shape during long-term space flights and the physiological changes which occur in plants, as well as for improving the aesthetics of cosmonaut living quarters.”

The end of this story is even sadder.

In April 1988, the Los Angeles Times reported that Soviet police had arrested the thief who stole an orchid named “Cosmonaut” from the Academy of Sciences botanical garden in Kyiv (Kiev) the month before. The paper says that “Cosmonaut” was grown on Salyut 6 and returned to Earth on Soyuz 36 in 1980, making it “the only orchid ever grown in outer space”. The theft was traced to Vladimir Tyurin, a gardener at the botanical gardens. Sadly, Cosmonaut died during the bungled flower-napping.

“Cosmonaut” was considered priceless and was still being used in biological and genetic experiments because of its space origin. Years of study have been wasted because of the early demise of the space orchid, the only one ever grown in a weightless environment. 

Los Angeles Times, April 1988
Tropical orchid at Kew

Reference

Cherevchenko TM et al. Prospects for future use of tropical orchids in space research. Kosmicheskaya Biologiya i Biotechnologyia: Sbornik Nauchnykh Trudov [Space Biology and Biotechnology: A Collection of Scientific Papers] (1986).
Accessed in USSR Space Life Sciences Digest, Volume 12, via Google Books.

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