GeoCarb

GeoCarb (Geostationary Carbon Observatory) is a mission for measuring key greenhouse gases and vegetation health from space to advance our understanding of Earth’s natural exchanges of carbon between the land, atmosphere and ocean.

GeoCarb will build on the success of NASA’s Orbiting Carbon Observatory-2 (OCO-2) mission by placing a similar instrument on a hosted satellite flying in geostationary orbit. From a geostationary position above the Americas, GeoCarb will collect 10 million daily observations of the concentrations of carbon dioxide, methane, carbon monoxide and solar-induced fluorescence (SIF) at a spatial resolution of about 5 to 10 kilometers. The primary goals of GeoCarb, led by Berrien Moore of the University of Oklahoma in Norman, are to monitor plant health and vegetation stress throughout the Americas, and to probe, in unprecedented detail, the natural sources, sinks and exchange processes that control carbon dioxide, carbon monoxide and methane in the atmosphere. The NASA-directed mission will launch on a hosted satellite to make observations over the Americas from an orbit of approximately 35,800 kilometers above the equator.

The GeoCarb instrument views reflected light from Earth through a narrow slit. When the slit is projected onto Earth’s surface, it sees an area measuring about 2,800 kilometers from north to south and about 3.7 miles (6 kilometers) from east to west. In comparison, OCO-2’s swath is about 10 kilometers wide. GeoCarb stares at that area for about 4-1/2 seconds, then the slit is moved half a slit width -- 3 kilometers -- to the west, allowing for double sampling. With this technique, GeoCarb can scan the entire continental United States in about 2-1/4 hours, and from Brazil to South America’s West Coast in about 2-3/4 hours. It is not designed to observe the oceans, as reflectivity over the oceans is too low to provide useful data. The mission was competitively selected from 15 proposals submitted to the agency's second Earth Venture - Mission announcement of opportunity for small orbital investigations of the Earth system. GeoCarb is the second space-based investigation in the Earth Venture - Mission series of rapidly developed, cost-constrained projects for NASA's Earth Science Division.

GeoCarb was originally planned to be a hosted payload on a commercial communications satellite. Since no fitting launch opportunity could be found, NASA decided in February 2022 to procure a small dedicated satellite bus for the GeoCarb instrument, to be launched on a dedicated or ride-share launch. Launch is planned for not later than end of 2024.

NASA has canceled in November 2022 the mission after the mission lost its ride to orbit and suffered severe cost overruns. Also technical concerns with the mission and the availability of other sources of greenhouse gas monitoring data were given as reasons.