Plants are resilient, simple to maintain and can produce clean air, clean water and food for astronauts. It should be a no brainer to bring them into space and onto the International Space Station—except for that gravity problem.
Unlike other organisms, plants count on gravity for growth and respiration and researchers in plant biology at N.C . State are sending experiments with the space shuttle program’s final mission July 8 to study how micro-gravity environments influence plant growth.
Heike Sederoff , assistant professor in plant biology, has worked on cultivating plants in environments of little gravity for the past three years and she said like humans, plants sense stimuli like drought, stress and the force of gravity.
“Plants will react to these stimuli,” Sederoff said. “They use a sugar called inositol phosphitase . It’s generated in the cell membrane, which reacts to the cells’ environment.”
IP3 , which scientists prefer referring to the cellular messenger, is responsible for plants’ reaction to gravity acting on them, signaling roots to grow down, towards the force, and shoots and leaves to grow up. In space, with little or no gravity, plants will grow erratically, according to Sederoff .
Chris Brown, associate vice chancellor of research and development and professor of plant biology, said the species of plant, Arabidopsis thaliana , will be the subject of the experiment, but previously wheat, lettuce, radishes and tomatoes have been tested to the space station.
“Growing plants in space is incredibly important when thinking about supporting and sustaining life in space in the future,” Brown said. “Plants give us food, they convert carbon dioxide to oxygen and then can filter water through transpiration. To take the idea of habitation in space seriously, we will need plants.”
In collaboration with Sederoff , Imara Perera , research associate professor in plant biology, is in Florida to oversee the packaging of the experiments supplies.
According to Brown, the primary investigators chose Arabidopsis due to its simple genetic structure and ease to grow.
“You walk on it very day,” Sederoff said. “It’s a little wheat grass, that only grows a few inches.”
Arabidopsis only has five chromosomes, making it an ideal subject for experiments, according to Sederoff . The chemical messenger IP3 is an enzyme linked to a gene. Scientists have already decoded the short genome of Arabidopsis , making it easy to isolate the IP3 gene.
Sederoff and Brown said the crew of Atlantis would transport the experiment to the International Space Station for station-resident astronauts to conduct.
“We are hoping the next flight of Russians bring the experiment back to Earth,” Sederoff said.
The retirement of the shuttle program will close a 30-year era of space exploration, including scientific milestones like the first satellite rescue, the deployment of the Hubble telescope and construction of the space station, totaling 135 missions.
N.C . State has been involved with NASA and the shuttle program before Columbia’s first launch in 1981, according to Fred DeJarnette , campus director of North Carolina Space Grant.
“The University first got involved with development for the shuttle program in 1970, when I just arrived to the State,” DeJarnette , professor of mechanical and aerospace engineering, said. “Though the program is ending, we still continue to develop and expand our research to apply it to other vehicles that NASA is considering, following the shuttle program.”
DeJarnette started his work developing a system to protect the shuttle upon reentry to the atmosphere. The friction of reentry is so tremendous it destroyed the malfunctioned Columbia and killed its crew of seven. DeJarnette was involved in designing a thermal protection system including heat resistant ceramic plates and a computer system that protect the interior of the shuttle from the hot exterior.
In light of the termination of the shuttle program, DeJarnette said the project was a success.
“The shuttle program allowed us to ferry humans and equipment between earth and the space station and their research will have an important role in our scientific advancements and further exploration of space,” DeJarnette said. “The program did not live up to its predictions or expectations, but it was the best we could do.”
The end of the shuttle program won’t limit NASA, or the plant biology research team, in future missions to space. According to Sederoff , NASA will start to send American astronauts and equipment to space via Russian missions or flights on private spacecraft, like the Space Exploration Technologies Corporation soon-to-come rocket, the Dragon.
The controversy of the termination of the shuttle program has erupted into debate after the Obama administration asked Congress to scale back affairs at NASA in 2010.
Sederoff said the U.S . should work to collaborate with the international community to develop an international shuttle system, basing off the International Space Station.
“We should look at science with a long term approach, not a 4-year election-cycle timeframe,” Sederoff . “We have come so far in space exploration and advancing research beyond the frontiers of Earth and we need to keep on focusing.”
DeJarnette said NASA is working for a replacement for the shuttle, but he said the future craft will need to operate same way the shuttle program did in effectively transporting crew and equipment.
N.C . State experiments won’t be the only local good Atlantis will carry to the space station.
Ted Bateman, associate professor in the UNC / NCSU Biomedical Engineering department, will send his experiment studying bone loss in mice on the Atlantis flight.
Similar to the confused growth of plants in zero gravity, animals experience bone density loss and muscle loss due to the lack of gravity. Bateman’s research will focus on singling out the protein, sclerostin , which controls bone formation, to see if the mice have reduced levels of this bone precursor, according to a report by UNC Health Care.
However, according to Brown, the research is bigger than weeds and mice.
“It is important we develop this research so we can employ it for future missions to space,” Brown said.
