NASA to install Ecostress instrument on space station to determine Earth's plant water

Ecostress instrument will provide new insights into water usage and plant health on Earth

NASA has developed an instrument that will enable researchers to determine plant water use and to study how drought conditions affect plant health.

Soon to be installed on the International Space Station, the instrument is called Ecostress (an abreviation for 'ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station') and will measure the temperature of plants from space.

"Plants draw in water from the soil and, as they are heated by the Sun, the water is released through pores on the plants' leaves through a process called transpiration. This cools the plant down, much as sweating does in humans.

"However, if there is not enough water available to the plants, they close their pores to conserve water, causing their temperatures to rise," NASA explained in a news release today about the project.

It continued: "Plants use those same pores to take up carbon dioxide from the atmosphere for photosynthesis - the process they use to turn carbon dioxide and water into the sugar they use as food. If they continue to experience insufficient water availability, or 'water stress', they eventually starve or overheat, and die."

Ecostress data will therefore show these changes in plants' temperatures, providing insight into their health and water use while there is still time for water managers to correct agricultural water imbalances.

Simon Hook, Ecostress' principal investigator at NASA's Jet Propulsion Laboratory in Pasadena, California, said that when a plant is so stressed that it turns brown, it's often too late for it to recover.

"But measuring the temperature of the plant lets you see that a plant is stressed before it reaches that point," he said.

These temperature measurements are also considered an early indicator of potential droughts, so when plants in a given area start showing signs of water stress through elevated temperature, its likely an agricultural drought is likely underway.

Having this data in advance will therefore give the agricultural community a chance to prepare and respond accordingly, NASA said

"Ecostress will allow us to monitor rapid changes in crop stress at the field level, enabling earlier and more accurate estimates of how yields will be impacted," added Martha Anderson, an Ecostress science team member. "Even short-term moisture stress, if it occurs during a critical stage of crop growth, can significantly impact productivity."

Ecostress will hitch a ride to the space station on a NASA-contracted, SpaceX cargo resupply mission scheduled to launch from Cape Canaveral Air Force Station in Florida on 29 June. Once it arrives, NASA said it will be robotically installed on the exterior of the station's Japanese Experiment Module Exposed Facility Unit.

Over the next year, the new instrument will use the space station's unique low Earth orbit to collect data over multiple areas of land at different times of day, producing detailed images of areas as small as 40 by 70 metres, or around the size of a small farm, every three to five days.