From Madison to Mars

UW lab plants seeds for deep space travel

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“Three…two…one…engine ignited, and we have liftoff of SpaceX Falcon 9 Rocket and Dragon.”

On Dec. 15, 2017, Simon Gilroy listened to that countdown as he gazed across a river separating a mass of scientists from the launch pad at the Kennedy Space Center in Titusville, Florida. He was a couple of miles from the site, but as close as you could get without being inside the rocket.

Even farther away, tourists gathered at the visitor complex, thrilled to see the supply shuttle blast beyond the Earth’s atmosphere. But Gilroy had a more personal stake in the operation.

Exactly 260 Arabidopsis — or rockcress — seeds from his lab at UW-Madison were on the rocket, beginning their journey to the International Space Station.

“You have your experiment on there, so you kind of have an investment in that rocket, and there is a potential that it can blow up on the pad,” says Gilroy, imitating the sound of an explosion in his bright, but cluttered office. “So, you watch the rocket launch and they really are spectacular.… The rockets rise much more slowly than you would imagine, they’re not like fireworks going off, they just rumble up.”

And like lightning before thunder, Gilroy saw the launch before hearing it.

“You have to be a pretty long way away so there’s a gap between seeing it launch and the sound. Because of the way the Kennedy Space Center is set up there’s a big wide piece of water between you and the launch pad and you can see the sound coming across the surface of the water,” he says. “They are pretty awesome.”

In two days’ time, the seeds would dock at the International Space Station (or ISS), where they would sprout and grow for experiments overseen remotely by Gilroy at his lab in Madison. Growing plants in space isn’t just a curiosity, but a necessary step in expanding humans’ ability to reach beyond the moon. Gilroy’s research could also help humans grow food more efficiently down on earth, as climate change takes hold and the weather becomes more harsh and erratic. But the more exciting prospect is what might happen in outer space.

“The space station is 200 miles away straight up, but in space terms it’s right next door,” Gilroy says. “Once we start getting a little bit farther away...the ability to resupply by sending a rocket becomes harder and harder, and so being able to provide fresh food — which is going to be vegetables — is gonna be a big deal.”

Under Gilroy’s lead, UW-Madison has become the epicenter for calculating just how that food will be cultivated.

Born in the United Kingdom, Gilroy grew up in a small town just outside the city of Winchester. Fascinated by the intricacies of living things from a young age, Gilroy feels that he’s always been a biologist. But it wasn’t until he was an undergraduate at the University of Cambridge that he became interested in plants.

“I really wasn’t going to be botanist…but the plant biologists could just tell you why it was cool,” Gilroy says. “If you have really good, inspirational teachers who can just tell you why they are excited and interested in whatever it is they’re interested in — everything is interesting.”

Gilroy says a class taught by professor David Hanke had a lasting impact on him. The class, much like his research today, dove into the science behind plant hormones, the chemicals that aid in the growth and development of plants. After studying under Hanke, Gilroy was determined to be a plant biologist.

Gilroy went on to get his doctorate in Scotland, and was then a postdoc at the University of California-Berkeley. He spent the next 14 years teaching at Penn State, and has been at UW-Madison since 2007.

A year ago, Gilroy helped shepherd in a new chapter in plant biology as he nervously watched his 260 Arabidopsis seeds go where few humans have ever gone before.

Preparing the seeds for the experiment involved some trickery on Gilroy’s part. With days between preparation and arrival, the botanists needed to stall the germination of the seeds so that they wouldn’t begin to grow until they were on the space station.

“There’s lots of things that will happen to them as they’re being launched,” Gilroy says. “We want them to germinate and grow while they’re in space. So somehow these seeds which are now sitting on this great nutrient gel with lots of water around them, we have to stop them from germinating.”

To delay growth, the scientists shone “far red light” onto the seedlings (a signal that tricks them into thinking they don’t need to sprout) and wrapped them in aluminum foil to shield them from any light.

The seeds arrived still dormant, ready for astronaut Scott Tingle to unwrap and place each one into the space station’s growth chamber, fittingly dubbed the “VEGGIE.” The 2-by-2-foot metal box was designed and built by ORBITEC, a subsidiary of the Sierra Nevada Corporation in Middleton.

In videos and photographs of the experiments, Tingle’s face glows a pinkish purple as he places petri dish after petri dish of Arabidopsis seeds into the VEGGIE. The seeds sprouted in about a day, leaving Tingle to plot their growth for the next eight days through photos and observations.

“It was very precise,” Tingle says of the experiment. The astronaut was aided by the Advanced Plant Experiment program, or APEX, which is run by NASA. The fifth in a series, the project was dubbed APEX-05.

“When we got up there, APEX was one of the groups that actually provided enough time to do the experiment properly...They really did a nice job figuring out how much time they would need and scheduled it properly. And their procedures were very squared away too so that we didn’t waste a whole lot of time trying to figure out what to do.”

After eight days — during which several photos of the plants’ had been collected and transmitted to Earth — Tingle prepared the plants for their trip home.

“At the end of the whole process we want to get those samples back because we want to analyze what genes were switched on and off,” Gilroy explains. “[To do that] Scott Tingle has to open up a petri dish and with a pair of [tweezers], pick up all of these plants and then put them into a [test] tube.”

Tingle harvested 26 petri dishes for Gilroy, who watched through a live feed at his lab in Madison. The task took hours. “It’s a little bit nerve racking,” Gilroy says.

The lack of gravity makes the task difficult, Tingle says. “When you’re in a lab on Earth if you’re doing an experiment and a little piece falls off or gets away from you, you just have to look down and you’ll find it. In space you don’t know where it is, it could just disappear,” Tingle says. “If you had old growth and it was old and crusty like an old leaf or an old root and it broke apart when you were going to harvest it or take it as a sample, all those pieces would scatter and it could get in somebody’s eye, it could get in somebody’s food, it could go into somebody’s sleeping quarters and then come out later and get in somebody’s eye, so it’s really a whole new ballgame when you’re talking about doing this stuff in space.”

Once the test tubes were filled they were frozen and packed into what Gilroy calls a “magic bag” that can maintain a constant temperature for days without power. They were then loaded back onto the capsule they arrived in and shot back to Earth, to be recovered by NASA after splashing into the ocean.

“They get access almost instantaneously to the capsule and they pull out all of the samples which have to be maintained frozen and they keep them in a freezer and they fly them to Kennedy Space Center and at that point we’re like ‘phew,’” Gilroy says.

Sarah Swanson, an assistant scientist in the Gilroy Lab, flew down to the Kennedy Space Center to prepare the samples to be shipped via FedEx to Madison.

“We FedEx them up on dry ice…it’s incredibly reliable,” Gilroy says. “They come in a thing called a custom critical van, so it’s gonna get here. We get the samples and then it’s up to us.”

It’s a lot of effort to answer a question that’s been gnawing at Gilroy since the beginning of his career: How does a plant know up from down?

It’s a process Gilroy says plants must understand, much like he says they can tell when the lights are on, if they’re being touched, or if they’re being eaten. “We’ve worked on that for a long time, like decades, with lots of different questions,” Gilroy says. “But the one that’s really the fascinating one, and the one that links to astrobotany, is how do they know up from down?”

Even Charles Darwin, known for his groundbreaking evolutionary theories, pondered the question in a book called The Power of Movement in Plants, where he described how plants respond to external stimuli.

“He wrote it in 1880 and it’s still as good as anything,” Gilroy says. “He totally nails the description of how plants grow in response to gravity. But we still don’t know how it works.”

In animals, the concept is clear. “I can tell you where the sensor is in your ear, I can tell you how it works, I can tell you genes that are involved and all that good stuff — and for plants, we don’t know.”

The Gilroy Lab’s partnership with NASA is one attempt to solve the centuries-old mystery, while at the same time figuring out the more practical question of how to grow and harvest plants in space.

According to NASA, the next space station will be the Deep Space Gateway, which will be somewhere near the moon. It will give astronauts the chance to “begin testing the systems needed for challenging missions to deep space destinations including Mars.”

But the farther away from Earth we get, the less possible it is to do routine resupply missions, like the ones that bring fresh food and new experiments to the ISS.

“If we’re going to go to long distance, deep space in long duration we need to learn how to feed ourselves,” Tingle says. “We need to know what the correct nutrients are, how much soil we need, how roots actually propogate and grow, and how plants can actually survive in a zero-G environment so that we can optimize and maximize our output and feed ourselves in the long-term.”

Tingle, who was aboard the space station for 168 days, helped grow and sample a harvest of red leaf lettuce.

“The lettuce tasted great, it tasted just like it does on Earth,” Tingle recalls. “We were able to harvest it and include it in with some of our meals and it was a nice, different thing to do. We usually have food that’s bagged and thermally stabilized and dehydrated and this was pretty much straight from the farm.”

Growing and cultivating plants in an otherwise sterile environment can have a psychological benefit, Gilroy argues. “Even if you didn’t grow them for food, just having a growing living thing out there stops [astronauts] from going crazy,” Gilroy says. “Because it’s a really hard place to live.”

Gilroy points to two astronauts who benefitted from growing plants: Don Pettit and Scott Kelly.

In 2012, before there was high-tech growing equipment on the ISS, Pettit took zucchini seeds to space. He made compost from the astronaut’s food waste and grew his zucchini in the window, all the while blogging the experience from the perspective of the zucchini to millions of people.

On Jan. 5, 2012, Pettit’s “zucchini” wrote: “I sprouted, thrust into this world without anyone consulting me. I am not one of the beautiful; I am not one that by any other name instills flutters in the human heart. I am the kind that makes little boys gag at the dinner table thus being sent to bed without their dessert. I am utilitarian, hearty vegetative matter that can thrive under harsh conditions. I am zucchini – and I am in space.”

Kelly — the first NASA astronaut to spend an entire year in space — also gardened in space. While on board the ISS the team grew both lettuce and zinnias, but one day Kelly noticed the plants had taken a turn for the worse.

So he cleaned fungus off of the leaves, figured out a watering schedule and technique, and nursed them back to health.

“Eventually he gets them to flower and he makes a bouquet for Valentine’s Day for his girlfriend,” Gilroy says. “It was clear that being a gardener in space, the psychology of it, is a huge, huge thing.”

The research on growing plants in space may also provide clues that will help humans grow food on Earth as climate change takes hold, causing extreme shifts in temperature and precipitation.

During a tour of the Gilroy Lab in UW-Madison’s Birge Hall, Richard Barker, an assistant scientist, points to various contraptions — low oxygen chambers, heat shock machinery, vertical gardens, centrifuges and flood gardens — that simulate environmental stressors and enable scientists to record the plants’ genetic responses.

“It gives us an opportunity to study responses to climate change — it’s true, it’s real — and understanding how plants will respond to heat shock is actually really important,” Baker says. “Flooding is going to increase in response to climate change and so although we’re focused on doing astrobiology, we’re creating data and tools that will provide insights that will help agriculture adapt to more extreme and variable environments.”

Tingle sees how vital the space experiments are for both agriculture on Earth and in space.

“It really helps us get a different perspective on how the plants work and they’re looking at all kinds of different hybrids of plants — which ones are stronger, which ones seem to survive, which ones adapt and can actually have a great probability of being successful in space,” Tingle says. The Gilroy Lab is preparing for another project and launch scheduled for 2019. The project, sponsored by Target and organized by the nonprofit Center for the Advancement of Science in Space, will look into how to reduce the environmental footprint of growing cotton.

“Cotton is a very, very environmentally impactful crop, it uses a tremendous amount of water and when it’s grown intensively it uses a lot of agrochemicals as well,” Gilroy says. “We’re not going to improve cotton by growing it on the space station but we’ll know more about how it works and especially in relation to how it gets and uses water, and how it deals with drought and environmental stresses.”

Gilroy sees a Mars landing on the horizon for humans, although it is not clear whether we’ll get there in one direct journey or by incremental steps.

According to Gilroy, a stepping-stone approach would involve building more space stations and a moon base first. The other approach — often referred to as Mars Direct — is more straightforward.

“Just build a rocket and go there,” Gilroy says. “Don’t try to do the stepping stones because where you want to be is Mars, so just fly to Mars and develop all the strategies so that you can come home again.”

Gilroy notes that commercial space flights — like Jeff Bezos’ Blue Origin and Elon Musk’s SpaceX — are becoming viable, evidence that humans are making progress in space exploration.

The commercial activity, says Gilroy, “is freeing up NASA to do the big, big projects which are things like the deep space gateway, taking Orion capsules out past the moon, with the idea of developing a really long reach into space.

“Somebody is going to step foot on Mars and not so far in the future that it’s science fiction.”