How two video
meetings, two online purchases, and a kitchen counter led to what could be
“one small step” for future astronauts to grow food on the Moon.
While others have
perfected sourdough starter or whipped up chocolate chip cookies during the
pandemic, NASA scientist Max Coleman has been toiling in his kitchen over
containers of baby radishes – all in the name of science.
been used before in space, and they germinate very, very fast,” Coleman
researchers had sent radishes to the International Space Station, and now,
Coleman and his colleagues hope to help the quest for astronauts to eventually
grow their own food on the lunar surface.
The team of 13 is
trying to simulate – physically and chemically – lunar surface soil, or
regolith, here on Earth, including such details as how quickly water is
absorbed between lunar soil grains, how big the particles are, and what
proportions of minerals are ideal.
Video Meetings Plant the Seed
Coleman and team
spent over a year doing their research at NASA’s Jet Propulsion Laboratory in
Southern California and were about to start hands-on tests of sensors that
might eventually be used on the Moon. Mandatory telework in response to the
coronavirus interrupted those plans.
Then, one day in
April during a video team meeting from home, an idea sprouted in Coleman’s head
for a homemade radish lab. They were discussing how they could, hypothetically,
try growing some radishes with no nutrients and some with a small amount of
theorize about this; why don’t we just do it!” was Coleman’s battle cry.
And before the virtual meeting had ended, he had bought a batch of radish seeds
online to be delivered to his home. A subsequent video meeting prompted another
impulse buy. “Video chats clearly stimulate me,” Coleman jokes. This
time, it was desert sand, which is often sold to be used as a top layer to make
indoor potted plants look pretty.
Armed with the
radish seeds and desert sand, Coleman was ready for serious business.
to show astronauts can use horticulture to grow their own food on the
Moon,” he explains. “We want to do one tiny step in that direction,
to show that lunar soil contains stuff which can be extracted from it as
nutrients for plants. This includes getting the right chemical elements to
allow plants to make chlorophyll and grow cell walls.”
Because the Moon
always faces Earth as it orbits our planet every month, it is essentially
turning on its axis once a month. The lunar timeline (one Moon day equals 28
Earth days, 14 days of daylight) makes quick-sprouting radishes a good bet for
relatively rapid experiment results. It will be possible to complete the
experiment in one lunar day, starting just after dawn.
Research in the Home Kitchen
Coleman started his
first radish experiment by cutting paper towels into small squares, adding
water, stuffing them into a container, then tucking in three radish seeds at a
depth of half an inch. Only one sprouted – apparently the one that somehow got
enough oxygen to germinate. Once the sand arrived, Coleman ditched the paper
towels and started using it in a four-compartment deli container.
He put varying
amounts of water in the four sections. The result: Radishes in the section with
the least water germinated first and best, which was interesting because, he
says, “we want to see how little water we can get away with.” Coleman
adds, “This immediately had an impact on how we would do the experiment
with water and lunar soil if we get it to the Moon.” He considers this an
example of serendipity in research.
Coleman also raided
the kitchen for chopsticks to make holes in the soil surface for each seed. And
at one point, he added kitchen-counter “electrodes” to measure
moisture levels and track evaporation in the desert sand: He folded aluminum
foil four or five times to make a strip, then used his battery tester to
measure electrical resistance from the water.
The team’s research
is aimed at biological in-situ resource utilization – tackling such challenges
as where to get food as opposed to how to get water and oxygen. Coleman
explains that, for future astronauts, “the more you can use what’s already
there, the more efficient you can be because you don’t have to carry that much
with you.” Their specific work is to develop a small payload on a
commercial spacecraft going to the Moon, which, if selected, would be delivered
to the lunar surface through the NASA
Commercial Lunar Payload Services (CLPS) initiative. The team planned to
develop the experiment as a suitable payload for a CLPS spacecraft in terms of
size, mass, power requirement, and communication needs.
By going to the Moon, the radish experiment would complement plant
predecessors tested under microgravity conditions on the space station. For
example, the currently flying Vegetable Production System, or Veggie, features plants growing in specially prepared soil,
with the goal of eventually providing food for space station astronauts.
properly test here on Earth with perfect lunar soil, but we’re doing as much
here as we can. Then we want to show that it actually does work on the
Moon,” Coleman says.
Investigator Pamela E. Clark leads the JPL radish research team, which includes
John Elliott, who started the project, and Gerald Voecks, who works with
Coleman on measurements. Together, they’re designing the potential Moon
experiment and a payload that would put lunar soil in a chamber, where water and air would be
added in an attempt to raise radishes. JPL’s Human/Robotic and Emerging Capabilities
Office is funding the current work.
Growing Young Minds
Coleman has been
documenting the sprouting radish experiment with his smartphone and sharing the
progress with his 7-year-old granddaughter, Lillibette, in England. He even
ordered a second radish-seed purchase for her. Her response to her grandfather?
“I could plant them and eat radishes, or I could plant them and do what
Coleman says that
if the lunar payload concept were to fly someday, Lillibette and other children
might be able to follow the mission. The team plans to include a small, simple
camera, and make images and other data available so that, as he envisions it,
“kids of Earth can watch radishes grow on the Moon.”
News Media Contact
Jet Propulsion Laboratory, Pasadena, Calif.
Written by Jane Platt
Source: Jet Propulsion Laboratory