After a dry, dusty day exploring Mars, it's easy to imagine how delicious a fresh baked potato or steamed carrots might taste to a hardworking astronaut.
Homegrown vegetables would not only be a nice alternative to freeze dried meals, but they'd help provide a constant supply of food for exploration crews while on the planet.
At NASA's Space Life Sciences Lab at Kennedy Space Center in Florida, a team of engineers are devising ways to keep an astronaut's pantry stocked by designing greenhouses to grow vegetables on barren Mars.
A round-trip to Mars will take more than a year and a half, requiring more food than a spacecraft can hold. Vegetables are the best candidate for feeding astronauts because the seeds are easy to carry, can be germinated in space, and then planted upon reaching the surface of Mars.
At the Space Life Sciences Lab, an inter-disciplinary team of scientists are using their green thumbs and sharp minds to create a reliable system for growing vegetables in space.
Erin Wilkerson, an agricultural engineer from the University of Florida, is trying to figure out if plants will survive or wither and die in a greenhouse on Mars.
She's answering this question by taking a close look at the speed at which plants expel or retain moisture in atmospheres that range from thick and moist like Earth to conditions wispier and drier than Mars. "Can plants sense pressure or do they just lose their water faster?" asked Wilkerson.
The radish plants Wilkerson is using for her experiment are grown in conditions of varying air pressure, humidity, carbon dioxide concentration and light. "Really, what I'm after is a mathematical model to see if I can understand the steady evaporation rate and calculate it."
"It's exciting to work on the project because it's really stretched my imagination," said Wilkerson. Individual radish plants are grown inside capsule-shaped containers stored in a climate-controlled room.
Wilkerson called on her hefty engineering skills to construct the specialized capsules that are sealed tight and equipped with sensors capable of controlling the internal environment. The talented engineer even created software to track the experiment from a computer cart sitting just outside the room. "I wrote this program to monitor everything," she said.
Wilkerson's work to determine how plants behave in low pressure is critical in designing a Mars greenhouse. If plants can grow well in lower air pressure, this means explorers won't have to build immensely heavy and expensive structures to raise crops in a high-pressure, Earth-like atmosphere.
In fact, it's possible the first human visitors may grow food inside spacious and lightweight, inflatable greenhouses.
On the red Martian plains, inflatables offer an efficient use of materials and space. "You can bring something to Mars with a low mass and get a large volume," said Phil Fowler, a scientist with the space Life Sciences Lab. While Wilkerson determines the tolerance of plants for lower pressures, Fowler is testing the equipment to be used in the greenhouses.
"The interesting thing Erin and I dug up is the affect of gravity on these systems. It's really significant," said Fowler. Equipment like sensors, heaters and lights built on Earth can have problems operating correctly on other worlds. Differences in gravity and atmospheric density between planets can affect how heat spreads and air moves around.
In the low pressure and gravity of Mars, lights and heaters may quickly overheat because of reduced air flow to cool them. "It was one of those things that never dawned on me until she came up with an equation and there was this gravity function in it. I thought, 'What's that doing in there,' " said Fowler. "There are all of these little details that we have to work out."
Just what an inflatable greenhouse is made of could hinge on research conducted by Jim Clawson from the University of Colorado. "I'm looking at the materials you would use for a greenhouse on Mars," said Clawson. The greatest threat to a greenhouse and its plants is the planet's intense ultraviolet radiation.
"Mars' UV (ultraviolet rays) will harm most plants quite readily," said Clawson. The materials scientist is focusing on transparent plastics in an effort to find a balance between something that lets in a healthy amount of light while protecting plants from lethal UV. "If we go transparent, that gives us light, and any light we don't have to produce is good," added Wilkerson.
When the final design of the Mars greenhouse is finished, it's likely to be one of the most cleverly engineered units in technological history. Thanks to the Space Life Sciences Lab's diverse group of scientists, astronauts can be sure the greenhouse is up to the task and just what they need to keep food on the table.
Subscribe To SpaceDaily Express
Huntsville AL (SPX) Aug 11, 2005
Have you ever walked across a wool carpet in leather-soled shoes on a dry winter day, and then reached out toward a doorknob? ZAP! A stinging spark leaps between your fingers and the metal knob.
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.|