Space biology research in the Shuttle-Mir program focused on studying how microgravity influences and affects the growth and development of plants and animals. Specifically, this area of research involves studying (1) the fundamental growth and development of plants and animals during extended durations in microgravity, (2) facilities for growing plants in a space station environment, and (3) the radiation environment in low Earth orbit.
All life is influenced by the pull of Earth's gravity. For example, plants respond to gravity (called gravitropism) by showing a downward growth of roots even when placed on their sides. Plants also respond to light (called phototropism) and will bend toward any light source placed near them. Researchers have developed experiments that will add to the understanding of how plants develop and use these gravity responses by comparing and studying how they react in space, without the presence of Earth's gravity.
The effects of space flight on crop plants is an important area of research, since plants could eventually be a major contributor to life support systems in long term space flight. Plants produce oxygen and food while eliminating carbon dioxide and excess humidity from the environment. These functions would contribute greatly to sustaining life in the closed environment of a spacecraft.
The ways in which animals may be affected by microgravity was also investigated in the Shuttle-Mir program. Researchers studied how gravity influences the development of embryos, since it is believed that normal embryonic development relies heavily on the ability of the embryo to maintain a genetic program. If a disturbance, such as microgravity, interferes with this program, developmental abnormalities could occur.
Plant growth was also studied as part of the Fundamental Biology research program. A Russian/Slovakian-developed plant growth facility called the "Svet" was used throughout the program for growing plants. The U.S. added new lighting and watering systems to enhance plant growth conditions, as well as an instrumentation system to gather information on how microgravity affects the gas exchange process in plants. The scientific data collected on Mir will be used to build better plant growth facilities on the International Space Station. It is hoped that one day, astronauts can grow their own food on the space station.
Space radiation, often considered the primary hazard associated with space flight, is also important to study since it can have a great impact on human health. In space, crewmembers are subjected to greater amounts of natural radiation than they receive on Earth, exposing them to possible immediate and long-term risks. There are three major sources of radiation in space. The first, trapped belt radiation, occurs from particles found in the Earth's magnetic field. A second type, called galactic cosmic rays (GCRs), consists of particles that originate outside the solar system. The third type results from a solar particle event (SPE), which sometimes accompanies solar flares, and may be the most potent space radiation hazard to lightly shielded spacecraft. Regardless of the source, large amounts of radiation exposure can lead to radiation sickness and have the potential to damage the body's chromosomes.
Experiments List:
Active Dosimetry of Charged Particles
Biorack Experiments
Cellular Mechanisms of Space Flight-Specific Stress to Plants (BRIC)
Developmental Analysis of Seeds Grown on Mir
Effective Dose Measurement at EVA
Effects of Gravity on Insect Circadian Rhythmicity
Environmental Radiation Measurements on Mir Space Station
Greenhouse - Integrated Plant Experiments on Mir (Phase 1A)
Greenhouse - Integrated Plant Experiments on Mir
Incubator - Integrated Quail Experiments on Mir (Phase 1A)
Incubator - Integrated Quail Experiments on Mir
Standard Interface Glovebox Operations (SIGB)
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Curator:
Julie Oliveaux Responsible NASA Official: John Uri |
Page last updated: 07/16/1999
