Projects

JPL has begun developing a new instrument for the International Space Station to study how effectively plants use water. The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) will offer clues about how Earth’s water and carbon cycles affect plant growth and how ecosystems adapt to changes in climate by measuring evapotranspiration, or the loss of water from leaves and soil.

“By measuring evapotranspiration, we get an early indicator of what plants are experiencing,” said Simon Hook, a research scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California and the project’s principal investigator. “Just like when a person is sweating, if they get enough water, they can keep exercising. But if they cannot get enough water, they will show signs of stress and eventually collapse. If we can detect that stress, we can do something about it. Similarly, if plants do not have enough water to transpire, or sweat, we can detect that stress and do something about it before the plants collapse.”

ECOSTRESS will provide crucial information about heat and water stress in plants by taking the temperature of plants, like looking for a fever. When plants open pores in their leaves, they take in carbon dioxide for photosynthesis but lose water vapor. Without enough water, plants close their pores and these processes shut down.

“Evapotranspiration operates like sweat to cool plants down,” said Josh Fisher, a research scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California and the science lead for ECOSTRESS. “If we measure a plant’s temperature and find it’s hot, it’s not getting enough water to cool itself down. To make matters worse, if there’s not enough water, there’s no photosynthesis to make the sugars it needs to function. These are two ways a plant can die – hydraulic failure and carbon starvation.” 

The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) addresses how Earth’s water and carbon cycles affect plant growth and how ecosystems adapt to changes in climate by measuring evapotranspiration, or the loss of water from leaves and soil.

ECOSTRESS’s science instrument works like a thermometer to measure the temperature of plants and the amount of heat radiating from Earth’s surface. The thermal infrared radiometer measures the Earth’s electromagnetic radiation at five different wavelengths.

Scientists use these data to calculate the amount of water plants lose through transpiration.