The Orbiting Carbon Observatory-3 (OCO-3) is a NASA-

JPL The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, United States. Founded in the 1930s by Caltech researchers, JPL is owned by NASA ...

instrument designed to measure carbon dioxide in Earth's atmosphere. The instrument is mounted on the Japanese Experiment Module-Exposed Facility on board the

International Space Station The International Space Station (ISS) is the largest modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA ( ...

(ISS). OCO-3 was scheduled to be transported to space by a

SpaceX Dragon American private space transportation company SpaceX has developed and produced several spacecraft named Dragon. The first family member, now referred to as Dragon 1, flew 23 cargo missions to the ISS between 2010 and 2020 before being retired. ...

from a

Falcon 9 Falcon 9 is a partially reusable medium lift launch vehicle that can carry cargo and crew into Earth orbit, produced by American aerospace company SpaceX. The rocket has two stages. The first (booster) stage carries the second stage and pay ...

rocket on 30 April 2019, but the launch was delayed to 3 May, due to problems with the space station's electrical power system. This launch was further delayed to 4 May due to electrical issues aboard Of Course I Still Love You (OCISLY), the barge used to recover the Falcon 9’s first stage. OCO-3 was launched as part of CRS-17 on 4 May 2019 at 06:48 UTC. The nominal mission lifetime is ten years. OCO-3 was assembled using spare materials from the Orbiting Carbon Observatory-2 satellite. Because the OCO-3 instrument is similar to the OCO-2 instrument, it is expected to have similar performance with its measurements used to quantify to 1 ppm precision or better at 3 Hz.

History and timeline

* 24 February 2009 -

Orbiting Carbon Observatory The Orbiting Carbon Observatory (OCO) is a NASA satellite mission intended to provide global space-based observations of atmospheric carbon dioxide (). The original spacecraft was lost in a launch failure on 24 February 2009, when the payload ...

was launched on a Taurus XL rocket but failed to achieve orbit when the fairing failed to separate from the satellite. * 1 February 2010 - The 2010 President's budget included funding for development and re-flight of an OCO replacement. * October 2010 - The Orbiting Carbon Observatory-2 project went into implementation phase. * 2 July 2014 - OCO-2 was successfully launched from

Vandenberg Air Force Base Vandenberg may refer to: * Vandenberg (surname), including a list of people with the name * USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in Key West, Florida * Vandenberg Spa ...

with a

Delta II Delta II was an expendable launch system, originally designed and built by McDonnell Douglas. Delta II was part of the Delta rocket family and entered service in 1989. Delta II vehicles included the Delta 6000, and the two later Delta 7000 v ...

rocket. * 2015 - Funding for the OCO-3 project cancelled. * 22 December 2015 - OCO-3 project authorized to proceed. Funding was included in the 2016 spending bill. * 16 March 2017 - OCO-3 was not included in the proposed FY2018 presidential budget. * 23 March 2018 - Funding for the OCO-3 project was restored. * May 2018 - Instrument underwent

TVAC TVAC (The Vehicle Application Centre) was a British company based in Leyland, Lancashire that performed chassis conversions and assembled bodies for commercial vehicles, refuse trucks and fire engines. History In 1996 TVAC approached Plastiso ...

testing. * 4 May 2019 - Launched using a

rocket from

Cape Canaveral Air Force Station Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida. Headquartered at the nearby Patrick Space Force Base, the stat ...

. The delivery was part of

SpaceX CRS-17 SpaceX CRS-17, also known as SpX-17, was a Commercial Resupply Services mission (CRS) to the International Space Station that was launched aboard a Falcon 9 rocket on 4 May 2019. The mission was contracted by NASA and was flown by SpaceX. Lau ...

, which also included delivery of STP-H6 and a cargo resupply. * After arrival - Robotic installation onto Exposed Facility Unit 3 (EFU 3) on the JEM-EF.

Instrument design

OCO-3 is constructed from spare equipment from the

OCO-2 Orbiting Carbon Observatory-2 (OCO-2) is an American environmental science satellite which launched on 2 July 2014. A NASA mission, it is a replacement for the Orbiting Carbon Observatory which was lost in a launch failure in 2009. It is the seco ...

mission. Thus its physical characteristics are similar, but with some adaptations. A 2-axis pointing mirror was added, which will allow targeting of cities and other areas on order of for area mapping (also called "snapshot mode"). A resolution context camera was also added. An onboard

cryocooler A refrigerator designed to reach cryogenic temperatures (below ) is often called a cryocooler. The term is most often used for smaller systems, typically table-top size, with input powers less than about 20 kW. Some can have input powers as lo ...

will maintain detector temperatures of around . Entrance optics were modified to maintain a similar ground footprint to OCO-2. Similar to OCO and OCO-2, the main measurement will be of reflected near-IR sunlight. Grating spectrometers separate incoming light energy into different components of the

electromagnetic spectrum The electromagnetic spectrum is the range of frequencies (the spectrum) of electromagnetic radiation and their respective wavelengths and photon energies. The electromagnetic spectrum covers electromagnetic waves with frequencies ranging from b ...

(or wavelengths or "colors"). Because and molecular oxygen absorb light at specific wavelengths, the signal or absorption levels at different wavelengths provide information on the amount of gases. Three bands are used called Weak (around 1.6 μm), Strong (around 2.0 μm), and Oxygen-A (around 0.76 μm). There are 1,016 spectral elements per band, and measurements are made simultaneously at 8 side-by-side locations or "footprints" each about or smaller, 3 times per second.

Expected data use

Overall measurements from OCO-3 will help quantify sources and sinks of carbon dioxide from terrestrial ecosystems, the oceans, and from anthropogenic sources. Due to the ISS orbit, measurements will be made at latitudes less than 52°. Data from OCO-3 are expected to significantly improve understanding of global emissions from human activities, for example, using measurements over cities. Near simultaneous observations from other instruments onboard the

such as

ECOSTRESS ECOSTRESS (Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station) is an ongoing scientific experiment in which a radiometer mounted on the International Space Station (ISS) measures the temperature of plants growing in specific lo ...

(measuring plant temperatures) and Global Ecosystem Dynamics Investigation lidar (measuring forest structure) may be combined with OCO-3 observations to help improve the understanding of the

terrestrial ecosystem Terrestrial ecosystems are ecosystems which are found on land. Examples include tundra, taiga, temperate deciduous forest, tropical rain forest, grassland, deserts. Terrestrial ecosystems differ from aquatic ecosystems by the predominant presence ...

. Similar to OCO-2, OCO-3 will also measure Solar Induced Fluorescence which is a process that occurs during plant

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in ...

References

{{Satellite and spacecraft instruments Kibo (ISS module) * Satellite meteorology SpaceX payloads contracted by NASA Spacecraft instruments Spectrometers Spacecraft launched in 2019

History and timeline

Instrument design

Expected data use

See also

References