By 2020, moon cukes and other crops?
Fresh lettuce or a vine-ripened tomato may seem routine dinner fare to many people. But for future astronauts spending a year or more on the moon or Mars, those simple earthly pleasures become mouth-watering delicacies.Skip to next paragraph
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Greenhouses in space hold promise for making astronauts more self- sufficient and cutting costs for long missions. Less freeze-dried food, water, and even oxygen would need to be hauled aboard future spaceships.
Although fresh veggies grown in self-sufficient space greenhouses are at least 15 years away, scientists already are testing experimental greenhouses in laboratories on Earth and in harsh environments like Devon Island in the Canadian high Arctic.
"For a mission of a year, it's possible to pack enough food and water," says Rob Ferl, director of the NASA-affiliated Space Agriculture Biotechnology Research and Education center at the University of Florida in Gainesville. "But for a Martian mission we're compelled to take along a recycling or bio- regenerative life-support system so plants can reproduce food from our waste and vice versa. And in the process of making food, we're also making oxygen and purifying water."
President Bush unveiled a plan in January 2004 to send a manned mission to the moon as early as 2015, and to use the moon after 2020 as a launch point for missions to Mars or beyond.
Mars presents tough challenges for both greenhouses and their plant inhabitants. The Red Planet's temperature extremes - which can range from 50 degrees F. in the day to more than negative 200 degrees F. at night - could crack the shell of a greenhouse, and could make the internal environment too cold to sustain the plants.
The thin Martian atmosphere does not screen out deadly ultraviolet radiation. Also, the atmospheric pressure on the planet's surface is less than 1 percent of that on Earth, a situation that causes plants to react as if they were dehydrated and can affect the structural stability of greenhouses. Mars has only about half the light of Earth, so costly artificial light might be needed for plants to grow.
But scientists remain undaunted as they pursue cutting-edge research in genetically modified plants, such as crops that are tolerant of shade or drought, and new materials for flexible greenhouses in extreme environments.
"One thing is absolutely certain. We're not getting off this planet without plants and the microbial systems that do a lot of the recycling for us," says Michael Dixon, director of the Controlled Environment Systems Research Facility on Devon Island and chair of environmental biology at the University of Guelph in Ontario. "We've got to resolve the management issues, and the mass and energy requirements of the plant production system to give us all the food, water, and oxygen we need, and to consume our carbon dioxide."
The Devon facility, running in its third season and growing mainly hydroponic lettuce that uses a nutrient-rich solution instead of soil, comprises more than 20 different chambers of varying sizes and pressures to study plant growth. Other plants that will be studied include beets, soybeans, tomatoes, and peppers.
In fact, food researchers at Cornell University in Ithaca, N.Y., already have come up with a 10-day menu cycle of vegetarian meals for a crew of six.
While much is known about the lunar surface, no Martian soil has been tested yet, so it's not known whether the soil is dangerous or whether it can grow plants. There also is evidence that water once existed on Mars.
"Whether it's still there ... and in significant quantities that can be easily had is another issue," Dr. Dixon says. "If it isn't, life support on Mars is going to be a very tricky thing indeed."