# OCO-3 (Orbiting Carbon Observatory 3)
*missions*

NASA carbon-monitoring instrument deployed on ISS in May 2019; SIF at 757 nm and 740 nm demonstrated; target-mode and snapshot area mode provide hundreds to thousands of SIF retrievals per overpass at biologically diverse sites.

## Specifications
- **operator**: nasa
- **current status**: operational
- **actual launch**: 2019-05-04
- **orbit type**: ISS orbit 408 km 51.6-degree inclination
- **tasking supported**: false
- **launch vehicle**: spacex-falcon-9
- **entity type**: mission
- **last verified date**: 2026-06-11
- **verified by**: agency-doc
- **claim status**: unclaimed
- **provider**: nasa
- **attributes**: {"operator":"nasa","current_status":"operational","actual_launch":"2019-05-04","orbit_type":"ISS orbit 408 km 51.6-degree inclination","tasking_supported":false,"summary":"NASA carbon-monitoring instrument deployed on ISS in May 2019; SIF at 757 nm and 740 nm demonstrated; target-mode and snapshot area mode provide hundreds to thousands of SIF retrievals per overpass at biologically diverse sites.","launch_vehicle":"spacex-falcon-9"}
- **relevance**: in-scope

## Editorial
OCO-3 (Orbiting Carbon Observatory 3) is a NASA carbon-monitoring instrument deployed on the International Space Station in May 2019, attached to the Japanese Experiment Module Exposed Facility (JEM-EF).[^eoport-oco3][^jpl-oco3]

OCO-3 shares the same three-channel grating spectrometer design as OCO-2, covering the oxygen A-band, the weak CO2 band, and the strong CO2 band. The spacecraft carries a Pointing Mirror Assembly (PMA) that enables two observing modes beyond the nadir-only geometry of OCO-2: Target Mode, which tracks a specific surface site across the overpass, and Snapshot Area Map (SAM) mode, which collects hundreds to thousands of SIF retrievals across a 80x80 km area at biologically and ecologically diverse sites in a single pass.[^eoport-oco3]

Because OCO-3 orbits on the ISS at 408 km altitude and 51.6-degree inclination, it observes at varying times of day rather than at the fixed sun-synchronous crossing time of OCO-2. This variable local solar time sampling provides a different temporal context for CO2 and SIF measurements compared to sun-synchronous orbits with fixed crossing times. Sun-induced fluorescence retrieval at 757 nm and 740 nm has been demonstrated from OCO-3 data.[^jpl-oco3]

## Compositional position
- oco-2 (missions) --[successor]--> OCO-3 (Orbiting Carbon Observatory 3)

## Sources
- [eoport-oco3] | ISS OCO-3 mission overview, eoPortal | https://www.eoportal.org/satellite-missions/iss-oco-3 | tier=agency-doc | accessed=2026-06-11
- [jpl-oco3] | OCO-3 mission site, NASA JPL | https://ocov3.jpl.nasa.gov/mission/ | tier=operator-marketing | accessed=2026-06-11

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Source: https://eo-atlas.org/missions/oco-3
Maintainer: SpectraWorks B.V. (CC-BY 4.0)