INTERVIEWER: This is a 2015 video of International Space
Station astronauts Scott Kelly, Kjell Lindgren, and Kimiya Yui,
enjoying a simple salad.
Except it's not simple.
It's actually the most important salad in human history.
Why?
Because these ISS astronauts aren't just eating lettuce.
They're dining on the first lettuce
to be grown and eaten in space.
And it's all thanks to this creatively
named unit, the Vegetable Production System,
otherwise known as Veggie.
Now trying to grow plants in space isn't exactly a new idea.
There have been many attempts in the past.
In 1997, bean seedlings were grown on the Mir Space Station.
And in 2012, ISS astronaut Don Pettit
grew a zucchini plant for a year.
He even wrote a blog about it called
"Diary of a Space Zucchini."
And NASA has been looking into crop support
systems for over 30 years.
But Project Veggie is the first large-scale effort
to produce food crops in space, an idea that
is going to be critical if we want astronauts
to make long duration missions to places like Mars a reality.
GIOIA MASSA: In space, if you can get those environmental
conditions right-- the light, the temperature,
the atmosphere, the nutrients, and the water--
if you can get those right, plants
grow pretty well and pretty similarly
as they grow on earth.
INTERVIEWER: That was Dr. Gioia Massa,
who leads the Veggie team at the Kennedy Space Center,
the group responsible for tackling the challenges
of growing plants in space.
So far, the biggest of which has been coming up with a way
to water plants in a microgravity environment.
GIOIA MASSA: You don't think about how difficult it
is to water in microgravity, or to wash your vegetables
or things like that, until you start
to watch some of these videos of just how water behaves
in space.
INTERVIEWER: In order to tackle the problem of providing water,
nutrients, and light to plants within a space environment,
the Kennedy Space Center teamed up
with Orbital Technologies Corporation
to design and build the Veggie unit.
The hardware uses a passive watering system
supported by plant pillows.
These pillows are single-use pockets
filled with soil substrate and control released fertilizer.
Embedded into the pillow is a moisture wicking material
where seeds can be glued and carefully
orientated to ensure that the roots grow down
and the shoots grow up.
The LED light bank provides red, blue, and green light
to help plants generate energy.
And the walls of the whole system
can be extended upward, allowing room for growth.
It was this low mass modular system
that was sent to the ISIS in 2014,
where an astronaut set the unit up and started to grow lettuce
as a test species.
The crew also grew zinnia flowers
to test the long-term survival of flowering crops,
like tomatoes.
Initially, it was a success.
The first group of lettuce grown in Veggie
was sent back to Earth for analysis.
After those samples were deemed edible,
the ISS astronauts were given the green light
to tuck into the second crop of leafy greens, which
of course, they did.
The zinnias, however, were a different story.
Shortly after nurturing this bright orange flower,
Scott Kelly sent this tweet from the ISS.
"Our plants aren't looking too good.
Would be a problem on Mars.
I'm going to have to channel my inner Mark Watney."
Despite channeling Mark Watney, Scott's flowering zinnias
were dying, and there was nothing he could do about it.
GIOIA MASSA: We did get fungus growing on the zinnia.
And we were kind of estimating water volumes
for the astronauts to give to the plants.
And our estimates were not right.
And so there was excess water in the plant chamber.
And this led to fungus.
INTERVIEWER: Now you'll be relieved
to know that Scott did manage to save some of his zinnias.
And the moldy ones?
They were sent back to Massa's team
at the Kennedy Space Center, who eagerly started analyzing them.
GIOIA MASSA: We've been doing a lot of research
here on the tissue that was brought back,
to try and understand where this fungus came from
and how it infected these plants,
so that we will learn for the future.
INTERVIEWER: So far, five Veggie crops
have been harvested on the ISS.
And each time, the team have learned
how to tweak the hardware to support healthy space produce.
And aside from fine tuning Veggie to optimize plant health
and growth, the team are also experimenting
with different levels and intensities
of red, blue, and green LED light
to make space crops more nutritious and delicious.
Now chlorophyll, the pigment involved in generating plant
energy via photosynthesis, absorbs red and blue light
best.
Essentially, these wavelengths help space crops
to grow without sunlight.
Recent studies have also shown a small amount of green light
could be important for dense plant growth,
particularly in poor light conditions like in deep space.
However, getting the light balance just right
is still a work in progress.
GIOIA MASSA: It's a really fun puzzle
to figure out, what different plants are doing.
You might get higher levels of certain vitamins
under blue light.
Red light tends to make leafy crops expand more.
But it's not, it's not a universal thing.
For the most part, these light experiments
seem to be yielding delicious results.
In early 2017, astronauts Peggy Whitson and Shane Kimbrough
grew a Chinese cabbage on the ISS.
And it was considered the best tasting veggie crop so far.
It was a proud moment for those astronauts.
And that speaks to another strength
of Project Veggie, its ability to boost morale
among those stationed on the ISS for long periods of time.
GIOIA MASSA: It's just been incredible to watch them work
and to watch them grow the plants.
We're actually very interested in the human factors
and the psychological aspects of this.
And so that's one of the components
of the Veg-04 and Veg-05 experiment
will be to do some assessments trying
to quantify how much the plants might
impact the experience of living in space.
INTERVIEWER: Next year, NASA is set
to launch the Advanced Plant Habitat, the largest plant
chamber built so far.
The APH shares similar technology to Veggie,
but will be able to hold larger crops.
So who knows?
Perhaps the idea of astronauts growing potatoes on Mars
might not seem so far fetched after all.
NASA may have plans to make Mars habitable
using a giant space magnet.
To find out more, watch this episode now.
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