AstroPlant: seeds in space

Our replacement AstroPlant has been behaving much like the first one we recorded here, which is good news but also means there’s not necessarily a lot to say about it. So, instead, let’s take a look at some of the research that’s brought us to this point: the earliest experiments involving plant matter in space.

We’ve talked before about how the history of plants in space is only a couple of decades shorter than the history of humans in space. Technically, though, that refers to growing plants. If we consider seeds, plants actually made it into space before we did.

In July 1946, 15 years before Yuri Gagarin became the first human in space, Harvard and the US Naval Research Laboratory worked together to launch a series of V-2 rockets into space, carrying seeds. The goal was to study the effect of space radiation on living tissue, although the first two batches of seeds were never retrieved.

The maize seeds launched on 30 July 1946 were successfully brought back to Earth and sent to Harvard for study: our first reassurance that a living thing could enter space and still be alive on its return. The next year, on 20 February 1947, another V-2 was launched, this one carrying the first living creatures to be sent to space: fruit flies. The flies returned alive and apparently unscathed by radiation.

Moon Trees: tree seeds in lunar orbit

1971 saw another experiment involving seeds. NASA’s Apollo 14 mission was the third manned moon landing, carrying Alan Shepard and Edgar Mitchell, two of the twelve people who have walked on the moon to date. Right now, though, we’re more interested in Stuart Roosa, who stayed in orbit around the moon without landing.

Roosa had worked with the US Forest Service as a firefighter in the 1950s. On Apollo 14, in collaboration with the Forest Service, he brought about 500 tree seeds into space. Along with Roosa, the seeds orbited the moon for 66 hours and 35 minutes.

After the mission returned to Earth, the Forest Service germinated many of the space seeds and compared them to less adventurous seedlings of the same five species: sycamore, Douglas fir, loblolly pine, American sweetgum and redwood. The seeds seemed to have suffered no ill effects, fortunately, and to this day there’s no apparent difference between a redwood that’s stayed on Earth for its entire life and one that travelled around the moon as a seed.

In 1975 and 1976, to celebrate the 200th year of American independence, the Forest Service gave many of the trees away, to be planted across the USA. A few made it to other countries, such as Brazil, Switzerland and Japan: relatively short journeys, after their early voyage to the moon.

Many ‘Moon Trees’ are still alive and can be visited, if you find yourself in the right area. NASA has a list of known Moon Trees, and a little more detail on the experiment, over here.

How seeds cope with long exposure to radiation

The Conversation has an interesting article on some more recent experiments involving seeds in space, these ones conducted on the International Space Station in the twenty-first century.

The seeds tested were tobacco, Arabidopsis and morning glory. Groups of seeds were placed in conditions that would expose them to various levels of radiation for long periods of time – between 18 months and two years – and then, back on Earth, they were tested to see whether they’d germinate.

Seeds that were kept inside the ISS for long periods, shielded from radiation, did well, and the majority germinated when they were tested back on Earth. Seeds that had been stored on the outside of the space station, exposed to solar ultraviolet radiation, were almost uniformly incapable of developing; only 3% of them germinated, and those that did germinate did not survive when they were moved to soil.

As these experiments demonstrate, there are a lot of problems to tackle if we want to grow plants in space. The AstroPlant project can help to answer some questions: what are the best conditions for growing certain plants without normal Earth conditions? What would be the ideal humidity level, the right temperature, the right balance of light? However, there are other issues, such as solar radiation, that are harder to tackle on Earth and will need to be addressed through different research projects.

Astrobotany is a broad and fascinating subject, and we’re glad to be able to help out at Darwin.

Darwin Innovation Group is a UK-based company that provides services related to autonomous vehicles and communications. If you’re interested in working with us, take a look at our careers page. If you’d like to know how we can help your organisation make use of autonomous vehicles, contact us. You can also follow us on LinkedIn or Twitter.

For more about growing plants in space, return to our AstroPlant page.

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