A New Lifeform Takes Root on the ISS
 
Apr. 26, 2014: It's spring, and all around the northern hemisphere gardeners
are planting seeds, tilling soil, and watering crops. Imagine a gardener's
surprise, however, if water from the hose, instead of hitting the soil and
sinking in, floated up to the sky. Or if the soil itself rose up from the
ground and fled the garden. That's exactly the kind of dilemma astronauts
onboard the ISS have faced for years.  Without gravity, how do you make your
garden grow?
 
The situation is even more confusing for plants.  In a weightless environment,
up and down has no meaning, so roots grow in odd, chaotic directions. Shoots
that emerge from the soil in search the sun find, instead, a cold metallic
lamp that never rises or sets.  And needless to say, it never rains onboard
the space station.
 
On April 18th, SpaceX-3 blasted off from Cape Canaveral with a possible
solution to these problems.
 
"We call it 'Veggie'," says Gioia Massa of the Kennedy Space Center. "It's a
plant growth chamber designed to make gardens thrive in weightlessness."
 
http://www.youtube.com/watch?v=YFdwv9yrxD0
 
A new ScienceCast video explains how it is possible to grow plants in the
weightlessness of space.  Play it
assa, who leads the Veggie science team, has been working on the project for
years.  Veggie's heritage traces back decades to experiments with plants on
board the Russian space station Mir and NASA's space shuttle.  In all that
time, NASA astronauts have never tasted home-grown food in space-but that
could soon change.
 
"Our first crop will be a variety of lettuce called 'Outredgeous,'" says
Massa.  "It is delicious."
 
Veggie solves the problems of weightlessness using 'plant pillows.'
 
"Basically, these are bags of 'space dirt' and slow-release fertilizer,"
explains Trent Smith, the project manager from KSC. "Wicks inserted into the
bags draw water into the soil where it cannot float away."
 
In addition to guiding water, the wicks act as a kind of gardening stake.
 
"The wicks are where we glue the seeds," continues Massa.  "We have to be very
careful to orient the seeds so that roots grow 'down' into the soil and shoots
pop out of the bag."
 
When the shoots emerge, they find an array of LEDs shining overhead, providing
light for photosynthesis and a sense of direction to keep the shoots moving
"up."  The bellows-like walls of the chamber allow it to expand to make room
for the growing crop.
 
SpaceX's Dragon delivered Veggie to the ISS. Pictures of Veggie often show the
chamber flooded with a mixture of red and blue light.  That's the color of
light plants use most for photosynthesis.  "We're just giving them what they
want," says Smith.
 
Under a purplish light, plants appear gray and unappetizing. "Who wants to
look at that?" asks Massa.  Astronaut gardeners can switch on green LEDs as
well. Adding that color to the red-blue mix produces white light and displays
the garden to better effect.
 
The appearance of the garden is important because, as Massa points out,
gardening has psychological as well as nutritional benefits.  Compared to
Earth, spaceships are a relatively lifeless environment, cold, metallic and
sterile. "Plants allow astronauts to form a connection to living things," she
says.  "There could be a huge psychological benefit."
 
Chalking up another success for commercial space flight, SpaceX's Dragon
capsule delivered Veggie to the ISS on Sunday, April 20th.  Massa says the
first crop of Outredgeous should be ready for harvesting in late May, but
astronauts won't be allowed to taste-test.
 
"First, we have to bring the lettuce home for analysis," she explains. Is it
safe to eat?  Are there any bacteria growing on the leaves? "These are some of
the questions we'll be looking at. If everything checks out, future crops may
be eaten."
 
Salad anyone?
 
Credits:
Author: Dr. Tony Phillips | Production editor: Dr. Tony Phillips | Credit:
Science@NASA
 
Web Links:
Veggie Fact Sheet
 
SpaceX-3 Launches Science Cargo to Station
 
 
Regards,
 
Roger

--- D'Bridge 3.99
 * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)