NASA OCO-3 Spacecraft To Monitor How Plants Glow

NASA is talking up the spacecraft that will launch later this month to the ISS called the Orbiting Carbon Observatory 3 or OCO-3. The new instrument will work alongside its sibling, the OCO-2 and will work to measure solar-induced fluorescence (SIF) and carbon. SIF as a phenomenon that happens when plants take in more sunlight than they need for photosynthesis.

That excess sunlight doesn't make plants fat, as excess calories will do for humans, rather the excess sunlight is shed by the plants as a very faint glow. The glow is so faint that humans can't detect it. It can, however, be detected by OCO-3. NASA says that being attached to the ISS will allow OCO-3 to collect a denser data set than OCO-2 is capable of because OCO-2 orbits the Earth from pole-to-pole.

OCO-3 will be attached to the outside of the ISS and orbit at 52-degrees north and south latitude. Mounting the instrument to the ISS also means that the orbit of the station will bring the instrument over Earth at any given location at a different time on each orbit. That will allow dawn-to-dusk observations of SIF and how it varies during the day.

OCO-3 will also measure carbon dioxide concentrations around the globe. NASA scientist Nicholas Parazoo says that OCO-2 and OCO-3 together will allow the monitoring of carbon in uncertain regions, specifically the Arctic with lots of carbon in the ground and the tropics with lots of carbon in plants.

As OCO-3 orbits it will turn its sensor quickly to point at instrumented towers on the ground below the spacecraft. Those towers measure SIF and photosynthesis at the same time with a similar resolution that OCO-3 offers allowing for data validation. Averaged over a large area, the data suggest that there is a straightforward relationship between solar energy coming in and photosynthesis taking place according to NASA.