The Orbiting Carbon Observatory-3 (OCO-3) was launched on 04 May 2019 and provides a new perspective to the important task of studying atmospheric carbon dioxide (CO2) as well as solar-induced chlorophyll fluorescence (SIF), a bonus product, from space. The flight spare three-channel grating spectrometer instrument built for OCO-2 has been adapted for use on the International Space Station (ISS) as OCO-3 by modifying the entrance optics, using a new calibrator assembly, incorporating a two-axis pointing mirror assembly (PMA), and adding two context cameras. The ISS’ recessing orbit allows measurements to be collected from dawn to dusk in the equatorial to northern & southern mid-latitude regions and the PMA enables a new snapshot area mapping mode where ~80 km x ~80 km areas can be examined in more detail. The OCO-3 payload underwent an extensive ground test and calibration program in a 3 m diameter thermal vacuum chamber. The chamber has a port/window that allowed optical ground support equipment, including a heliostat, to illuminate the instrument under operating environmental conditions. The payload’s performance in space during the in-orbit checkout (IOC) period compares favorably with ground test results. Initial and not-yet-fully-calibrated retrieved estimates of the column-averaged dry air mole fraction of CO2 (XCO2) are reasonable when compared to ground-based measurements. SIF estimates show clear contrast between areas of high and low vegetation. There is high confidence that the three-year prime mission will deliver the data needed for science/research, data applications, and informed decision-making.
OCO-2 (Orbiting Carbon Observatory-2) is the first NASA (National Aeronautics and Space Administration) mission dedicated to studying atmospheric carbon dioxide, specifically to identify sources (emitters) and sinks (absorbers) on a regional (1000 km x 1000 km) scale. The mission is designed to meet a science imperative by providing critical and urgent measurements needed to improve understanding of the carbon cycle and global climate change processes. The single instrument consisting of three grating spectrometers was built at the Jet Propulsion Laboratory, but is based on the design co-developed with Hamilton Sundstrand Corporation for the original OCO mission. The instrument underwent an extensive ground test program. This was generally made possible through the use of a thermal vacuum chamber with a window/port that allowed optical ground support equipment to stimulate the instrument. The instrument was later delivered to Orbital Sciences Corporation for integration and test with the LEOStar-2 spacecraft. During the overall ground test campaign, proper function and performance in simulated launch, ascent, and space environments were verified. The observatory was launched into space on 02 July 2014. Initial indications are that the instrument is meeting functional and performance specifications, and there is every expectation that the spatially-order, geo-located, calibrated spectra of reflected sunlight and the science retrievals will meet the Level 1 science requirements.
The objective of the OCO (Orbiting Carbon Observatory) mission was to make the first space-based measurements of atmospheric carbon dioxide with the accuracy needed to quantify sources and sinks of this important greenhouse gas. Unfortunately, the observatory was lost as a result of a launch vehicle failure on 24 February 2009. The JPS (Jet Propulsion Laboratory) was directed to assess the options for the re-flight of the OCO instrument and recovery of the carbon-related measurement, and to understand and quantitatively asses the cost, schedule, and technical and programmatic risks of the indentified options. The two most likely solutions were (1) a shared platform with the TIRS (Thermal Infrared Sensor) instrument and (2) a dedicated OSC(Orbital Sciences Corporation) LEOStar-2 spacecraft bus similar to the utilized for the original OCO mission. A joint OCO-TIRS mission study was commissioned and two specific options were examined. However, each presented technical challenges that would drive cost. It was determined that the best option was to rebuilt the OCO observatory to the extent possible including another LEOStar-2 spacecraft bus. This lower risk approach leverages the original OCO design and provides the shortest path to launch, which is targeted for no later than February 2013 timeframe.
CloudSat is a NASA ESSP (Earth System Science Pathfinder Mission) that provides from a space the first global survey of cloud profiles and cloud physical properties, with seasonal and geographical variations. The data obtained will allow for clouds and cloud processes to be more accurately represented in global atmospheric models leading to improved climate change predictions, and eventually, weather forecasting. To achieve this ambitious goal, JPL (Jet Propulsion Laboratory) in collaboration with CSA (Canadian Space Agency) designed, developed, and tested a 94.05 GHz, W-band, microwave cloud profiling radar system derived from current ground-based and airborne systems. The CloudSat Project team is witnessing how well the instrument performs during in-flight operations with the recent successful launch. Although Level 1 (i.e. radiometric-corrected and geo-located) and Level 2 (i.e. retrieved geophysical parameters) science data products will not be released until the January 2007 timeframe, the yet uncalibrated and unvalidated "quick look" products, available to the general public on the CloudSat Data Processing Center website, provide every indication that the mission objectives will be met.
OSTM (Ocean Surface Topography Mission) will provide continuity of ocean topography measurements that began with TOPEX/Poseidon and are currently being carried out by Jason. Measurements made by the three missions will allow scientists to better understand ocean circulation, climate change processes, and sea level rise on a multi-decadal scale. While CNES (Centre National d'Etudes Spatiales) will provide the primary satellite instrument, a nadir-pointed altimeter, and a precision orbit determination system, NASA (National Aeronautics and Space Administration) will provide an instrument suite to provide the necessary measurement accuracy. The AMR (Advanced Microwave Radiometer) will measure atmospheric water vapor content to determine how it affects the accuracy of the altimeter readings. The GPSP (Global Positioning System Payload) will be used to accurately pinpoint the position of the satellite above the ocean surface. Finally, there is the LRA (Laser Retroreflector Array), a passive, supporting instrument that will allow ground-based laser ranging stations to also pinpoint the position of the satellite. Both the GPSP and LRA will be used to enhance the precision orbit determination system performance. The instruments are now undergoing ground test. In conjunction with in-flight calibration and validation activities these efforts will help to ensure mission success.