Earth Observing System
Program overview
CountryUnited States
PurposeObserve Earth to improve understanding of climate, weather, land and atmosphere
Program history
Cost$33 Billion USD
Uncrewed vehicle(s)All

The Earth Observing System (EOS) is a program of NASA comprising a series of artificial satellite missions and scientific instruments in Earth orbit designed for long-term global observations of the land surface, biosphere, atmosphere, and oceans. Since the early 1970s, NASA has been developing its Earth Observing System, launching a series of Landsat satellites in the decade. Some of the first included passive microwave imaging in 1972 through the Nimbus 5 satellite.[1] Following the launch of various satellite missions, the conception of the program began in the late 1980s and expanded rapidly through the 1990s.[2] Since the inception of the program, it has continued to develop, including; land, sea, radiation and atmosphere.[1] Collected in a system known as EOSDIS, NASA uses this data in order to study the progression and changes in the biosphere of Earth. The main focus of this data collection surrounds climatic science. The program is the centrepiece of NASA's Earth Science Enterprise.

History and development

TIROS-1 Satellite displayed at National Air and Space Museum in Washington

Prior to the development of the current Earth Observing System (EOS), the foundations for this program were laid in the early 1960s and 1970s. TIROS-1, the very first full-scale, low Earth orbit weather satellite.[3] The primary objective of TIROS-1 was to explore television infrared observation as a method of monitoring and studying the surface of Earth. Critical to the development of the satellites currently in use, TIROS-1 was a program that allowed NASA to use experimental instruments and data collection methods to study meteorology worldwide. Crucially, this new information gathered by TIROS-1 would allow meteorologists and scientists to observe large-scale weather events. In doing so, they would be able to answer questions such as  "should we evacuate the coast because of the hurricane?".[3] Following TIROS, the experimental Applications Technology Satellite (ATS) program was developed. The main objective of these satellites were weather predictions and the study of the environment of space. Significantly, this program focused on launching satellites to orbit geosynchronously and evaluate the effectiveness of this orbit pattern in observing the Earth.[1] ATS-3, the longest-lasting mission, saw a life span of over 20 years. It was the first satellite to capture colour images from space and acted significantly as a medium of communications.[1]

After the success of TIROS-1 and ATS-3, NASA in conjunction with United States Geological Survey (USGS), progressed forward in Earth observation through a series of Landsat satellites launched throughout the 1970s and 1980s. The Nimbus 5 satellite launched in 1972 used passive microwave imaging; a highly successful method to observe changes in sea ice cover.[1]  Observation was furthered by succeeding missions such as Nimbus 7, fitted with a coastal zone colour scanner (CZCS) for detailing colour changes in the Earth's oceans, and a Total Ozone Mapping Spectrometer (TOMS) to measure solar irradiance and the reflected radiance from the Earth's atmosphere.[1] The early satellites of these programs have paved the way for much of the EOS program today. The TIROS satellites were extremely important in the testing and development of not only the Earth observing instruments such as spectrometers, but much was also learnt from the various sensors used in order to maintain these satellites in orbit for sustainable periods of time. Sensors such as horizons sensors were tested on these early satellites and have been adapted to produce more advanced methods of observation and operating configurations.[1]

Operation and technology - Logistics

According to NASA's Earth Observing System mission page, there are over 30 missions that remain active.[4] As an evolving program, the EOS can collect a variety of data through various instruments that have been developed. Below outlines various sensors on different EOS missions and the data they collect.
Mission / Satellites Technology Uses
Landsat Program
Landsat 5-8 Operational Land Imager (OLI) [5] Developed by Ball Aerospace & Technologies Corporation, the OLI is a crucial aspect of modern LandSat vehicles. Using 7000 sensors per band (Spectrum band), the OLI on NASA's most recent LandSat (LANDSAT 8) Satellite, will image/view the entire earth every 16 days.
Enhanced Thematic Mapper + (ETM+) [6][7] Used in conjunction with OLI, the ETM + images the Earth in 30m Pixels. To ensure quality, each scan has a correction due to Scan-Line correcting.
A-Train Program
CloudSat Cloud Profiling Radar (CPR) [8] Operates at 96 GHz. Crucially, the CPR is used to detail cloud-sized particles. These can be in the form of snow, cloud ice, water and light rains.
CALIPSO Lidar [9] Similarly to Radar, Lidar measures by the time a light (Laser) source takes to return to the sensor. CALIPSO, fitted with Lidar Level 2, mainly focused with measuring condensable vapours such as water and nitric acid.  Collects Polar Stratific cloud data.
AURA Microwave Limb Sounder (MLS) [10] Used to measure microwave emissions (Thermal) that naturally occurs. The name Limb refers to the "edge" of Earth's atmosphere. This data collected includes atmospheric gas profiles and atmospheric temperature and pressure.
Tropospheric Emission Spectrometer (TES) [11] TES is an infrared sensor aboard AURA used to investigate the troposphere of Earth's Atmosphere. Crucially, it helps scientists understand the impact of Carbon dioxide in the atmosphere and the OZONE layer and its changes.
AQUA Advanced Microwave Scanning Radiometer  (AMSR-E) [12] AMSR-E, a critical instrument used to measure physical properties occurring on Earth. Rain precipitation, various sea and land temperatures, snow and ice cover, and water vapour from the ocean are just some properties that are measured using microwave scanning radiometer. Detecting microwave emissions, the data is evaluated to determine various characteristics about each geophysical property.
Moderate Resolution Imaging Spectroradiometer (MODIS) [13] Measuring in 36 different spectral bands, the MODIS system is critical on AQUA. Used to increase understanding of global properties and dynamics, MODIS helps Scientists to predict changes on Land, water and lower atmosphere.

Data collection and uses

Since the inception of the program, the aim overall has remained the same: "monitor and understand key components of the climate system and their interactions through long-term global observations."[4] Through the use of various programs such as LandSat and the A-Train programs, scientists are gaining a greater understanding of Earth and its changes. Currently, the data collected by the satellites in EOS is digitised and collated by the Earth Observing System Data and Information System. Scientists then use this data to predict weather events, and more recently to predict the effects of climate change for treaties such as Paris Climate agreements, with data mainly being collected by EOS and then analysed.

Intergovernmental agencies and partnerships

In a broader sense of Earth observing and all missions that impact EOS, there have been a variety of intergovernmental partnerships and international partnerships that have helped fund, research and develop the complex array of satellites and spacecraft that make the Earth Observing System successful in its role. In total, intergovernmental partnerships account for almost 37% of all missions while 27% of the missions also involve international partnerships with other countries and international companies.

As of 2022, there have been nine LandSat satellites with LandSat 7, 8, and 9 orbiting the Earth. The LandSat program has involved many organisations since its inception, particularly the United States Geological Survey (USGS). Other intergovernmental agencies that have been a part of the Earth Observing program include the Environmental Science Services Administration (ESSA), US Department of Defence (USDOD), United States Department of Energy (USDOE) and the US National Oceanic and Atmospheric Administration (NOAA). These intergovernmental agencies cooperating allow for greater funding for the program along with collaboration of government resources from various agencies. Often these partnerships begin with another governmental agency wanting a specific instrument as a part of a payload included on a mission.[14]

Similarly, international partnerships with countries have either resulted from a specific payload (instrument) accompanying an existing mission that NASA has developed or NASA collaborating and requiring the use of facilities of another Space agency such as the European Space Agency. A partnership like this was observed in 2000 when the ERS-1 satellite was launched from the Guiana Space Centre; a spaceport in French Guiana, South America. International agencies that have assisted or collaborated with NASA include CONAE (Argentinian Space Agency), CNES (French Space Agency), DLR (German Aerospace Centre), the state space federation Roscosmos of the Russian Federation, and JAXA (Japanese Space Agency; previously NASDA).[2]

Over the program's life, there have also been various corporate and organisational partnerships with companies both based in America and internationally. In 2002, the SeaWIFS missions saw a collaboration with GEOeye, an American satellite imaging company. Similarly, organisations such as the International Council for Science (ICSU), International standards Organisation (IOS), World Data System (WDS) and the committee on Earth Observing Satellites (CEOS) have been involved in the planning, data collection, and data analysis of missions. As mentioned, funding, instrumental additions and over assistance in coordination and data analysis are all benefits of these partnerships.[15]

Mission list with launch dates

NASA Earth Science Division Operating Missions as of 2 February 2015
This animation shows the orbits of NASA's 2011 fleet of Earth remote sensing observatories
Active mission Completed mission
Satellite Launch date Designed mission duration Completion date Launch site Agency Mission description
ACRIMSAT 20 December 1999 30 July 2014 Vandenberg NASA Study Total Solar Irradiance
ADEOS I 17 August 1996 30 June 1997 Tanegashima NASA / NASDA Study wind scattering and map the ozone layer
ADEOS II (Midori II) 14 December 2002 24 October 2003 Tanegashima JAXA  / NASA Monitor the water and energy cycle as a part of the global climate system
ATS-3 7 December 1966 3 years 1 December 1978[16] Cape Canaveral NASA Weather observation
ATLAS-1 24 March 1992 2 April 1992 Cape Canaveral NASA Unravel man's impact on the environment
CHAMP 15 July 2000 5 years 19 September 2010 Plesetsk 132/1 GFZ Atmospheric and ionospheric research
CRRES 25 July 1990 3 years 12 October 1991 Cape Canaveral NASA Investigate fields, plasmas, and energetic particles inside the magnetosphere
DE 1 and DE 2 3 August 1981 28 February 1991 and 19 February 1983 Vandenberg NASA Investigate the interactions between plasmas in the magnetosphere and those in the ionosphere
ERBS 5 October 1984 2 years 14 October 2005 Cape Canaveral NASA Study the Earth's radiation budget and stratospheric aerosol and gases
ESSA program 1966–1969 Cape Canaveral ESSA / NASA Provide cloud-cover photography
ERS-1 17 July 1991 March 2000 Kourou ESA Measure wind speed and direction and ocean wave parameters
SeaWiFS 1 August 1997 1 August 2002 11 December 2010 Vandenberg GeoEye / NASA Provide quantitative data on global ocean bio-optical properties
TRMM 27 November 1997 27 November 2000 9 April 2015 Tanegashima NASA / JAXA Monitor and study tropical rainfall
Landsat 7 15 April 1999 27 September 2021 Vandenberg NASA Supply the world with global land surface images
QuikSCAT 19 June 1999 19 June 2002 19 November 2009 Vandenberg NASA / JPL Acquire global radar cross-sections and near-surface vector winds
Terra (EOS-AM) 18 December 1999 18 December 2005 Active Vandenberg NASA Provide global data on the state of the atmosphere, land, and oceans
NMP/EO-1 21 November 2000 30 March 2017 Vandenberg NASA Demonstrate new technologies and strategies for improved Earth observations
Jason 1 7 December 2001 1 July 2013 Vandenberg NASA / CNES Provide information on ocean surface current velocity and heights
Meteor 3M-1/Sage III  10 December 2001 6 March 2006 Baikonur Roscosmos Provide accurate, long-term measurements of ozone, aerosols, water vapor, and other key parameters of Earth's atmosphere
GRACE 17 March 2002 27 October 2017 Plesetsk Cosmodrome NASA / DLR Measure Earth's mean and time-variable gravity field
Aqua 4 May 2002 4 May 2008 Active Vandenberg NASA Collect water information in the Earth system
ICESat 12 January 2003 14 August 2010 Vandenberg NASA Measuring ice sheet mass balance, cloud and aerosol heights, and land topography and vegetation characteristics
SORCE 25 January 2003 25 February 2020 Cape Canaveral NASA Improve understanding of the Sun
Aura 15 July 2004 15 July 2010 Active Vandenberg NASA Investigate questions about ozone trends, air-quality changes and their linkage to climate change
CloudSat 28 April 2006 28 April 2009 Active Vandenberg NASA Provide the first direct, global survey of the vertical structure and overlap of cloud systems and their liquid and ice-water contents
CALIPSO 28 April 2006 Active Vandenberg NASA / CNES Improve understanding of the role aerosols and clouds play in regulating the Earth's climate
SMAP 31 January 2015 31 May 2018 Active Vandenberg NASA Measure surface soil moisture and freeze-thaw state
OCO-2 2 July 2014 2 July 2019 Active Vandenberg NASA Provide space-based global measurements of atmospheric carbon dioxide
Aquarius 10 June 2011 3 years 17 June 2015 [17] Vandenberg NASA  / CONAE Map the spatial and temporal variations of sea surface salinity
Landsat 8 11 February 2013 11 February 2018 Active Vandenberg NASA / USGS Supply the world with global land surface images
ICESat-2 15 September 2018 3 years Active Vandenberg NASA Measuring ice sheet mass balance, cloud and aerosol heights, and land topography and vegetation characteristics
Landsat 9 27 September 2021 5 years Active Vandenberg NASA / USGS Global land surface images, continuation of the Landsat program

Future missions

Illustration of Sentinel 6B

Sentinel 6B

As the Earth Observing System becomes more crucial in studying the Earth's climate and changes, the program will continue to evolve. NASA along with other government agencies such as the European Space Agency and NASDA (Japan), have planned many future missions. Sentinel 6B is one such mission with the aim of continued water and ocean observations. A key objective of the sentinel missions is to monitor sea level rise, a primary indicator of climate change and global warming. As Paris Agreement policy and more countries aim for a carbon neutral world, the data collected by Sentinel missions will assist in the continued understanding of the Earth's changing climate. It is also expected that one of the sentinel satellites will test a new experiment with regards to weather prediction. As a part of its payload, it will use Global Navigation Satellite System Radio Occultation (GNSS-RO), a method to detail changes and information of different layers in the atmosphere.[18]

JPSS-3 and 4

JPSS or Joint Polar Satellite systems are expected to launch in 2027. This project will be an  intergovernmental collaboration between NASA and National Oceanic and Atmospheric Administration (NOAA) and will observe a new generation of Polar Orbiting environmental satellites. Crucially, these polar orbiting satellites are non-geosynchronous meaning these two satellites will have an inclination angle of close to 90 degrees to the equator. Crucially this project is continuing and is the third and fourth satellite in the JPSS series. The payload for this type of satellite will include Visible Infrared imaging Radiometer, Advanced Technology Microwave Sounder and Ozone Mapping and Profiler Suite. The data collected by these variety of instruments will included numerical weather prediction to be used for modelling and forecast prediction.[19]


Cumuionimbus INCUS clouds over Poland. The aim of EVM-3 INCUS is to investigate the formation of these clouds and thunderstorms often associated.

A branch of the Earth Venture Missions, the Investigation of Convective Updrafts missions is planned to have three small satellites. The three satellites will orbit in tight coordination and will have the aim of understanding the formation of convective storms and heavy precipitation. It aims to know not only how, but know exactly where and when they will form. Although still in planning and development stages, the first of the three satellites in EVM-3 in 2027. After deliberation between 12 proposals of EVM in 2021, the INCUS mission was selected after a review by panellists. NASA's Earth Science Director Karen St. Germain stated, "In a changing climate, more accurate information about how storms develop and intensify can help improve weather models and our ability to predict risk of extreme weather." As the effects of climate change are ever more increasing with increasing sea level temperatures globally, it is predicted that storms will have a greater intensity and occur more often. This is a result of increased water vapour moving upwards creating the convection currents. INCUS will help scientist understand these currents and help predict the likelihood and location of major storms when fully operational.[20]

Key personnel

Personnel Qualifications Role
Steven Platnick B.S & M.S Electrical Engineering

Ph.D. Atmospheric Sciences

EOS Senior Project Specialist

A Train project Scientist

Claire L.Parkinson B.A. Mathematics

Ph.D. Climatology

AQUA Project Scientist
Bryan N.Duncan B.S Chemistry

M.S & Ph.D. Earth & Atmospheric Sciences

AURA Project Scientist
James Butler B.S Physical Chemistry

Ph.D. Physical Chemistry

EOS Calibration Scientist
Christopher S.R. Neigh B.A Geography

Ph.D. Geography

LandSat 9 Project Scientist
Ernesto Rodriguez *Not Found QuickSCAT project Scientist
Kurtis Thome B.S Meteorology

M.s & Ph.D. Atmospheric Sciences

TERRA Project Scientist

See also


  1. ^ a b c d e f g Platnick, Steven (22 March 2022). "Historical Missions". NASA's Earth Observing System.
  2. ^ a b Platnick, Steven (5 April 2022). "Earth Observing System". NASA's Earth Observing System.
  3. ^ a b "TIROS | Science Mission Directorate". Retrieved 11 May 2022.
  4. ^ a b Platnick, S (2022). "Current Missions | NASA's Earth Observing System". NASA EOS.
  5. ^ Masek, G (2022). "Operational Land Imager | Landsat Science | A joint NASA/USGS Earth Observation Program". NASA Landsat Science. Retrieved 2 November 2022.
  6. ^ "Explore Enhanced Thematic Mapper Plus (ETM+) - Earth Online". Retrieved 11 May 2022.
  7. ^ Smith, A. M. S.; Drake, N. A.; Wooster, M. J.; Hudak, A. T.; Holden, Z. A.; Gibbons, C. J. (June 2007). "Production of Landsat ETM+ reference imagery of burned areas within Southern African savannahs: comparison of methods and application to MODIS". International Journal of Remote Sensing. 28 (12): 2753–2775. Bibcode:2007IJRS...28.2753S. doi:10.1080/01431160600954704. ISSN 0143-1161. S2CID 1507458.
  8. ^ "CloudSat - eoPortal Directory - Satellite Missions". Retrieved 11 May 2022.
  9. ^ "NASA - Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations". Retrieved 11 May 2022.
  10. ^ Froidevaux, Lucien; Kinnison, Douglas E.; Santee, Michelle L.; Millán, Luis F.; Livesey, Nathaniel J.; Read, William G.; Bardeen, Charles G.; Orlando, John J.; Fuller, Ryan A. (12 April 2022). "Upper stratospheric ClO and HOCl trends (2005–2020): Aura Microwave Limb Sounder and model results". Atmospheric Chemistry and Physics. 22 (7): 4779–4799. Bibcode:2022ACP....22.4779F. doi:10.5194/acp-22-4779-2022. ISSN 1680-7324.
  11. ^ "Tropospheric Emission Spectrometer - Earth Instruments - NASA Jet Propulsion Laboratory". NASA Jet Propulsion Laboratory (JPL). Retrieved 11 May 2022.
  12. ^ "Advanced Microwave Scanning Radiometer (AMSR) SIPS | Earthdata". 3 February 2022. Retrieved 11 May 2022.
  13. ^ "MODIS Web". Retrieved 11 May 2022.
  14. ^ "Relevant Organizations". Resources for the Future. Archived from the original on 24 September 2022. Retrieved 19 May 2022.
  15. ^ Ramapriyan, Hampapuram K.; Murphy, Kevin J. (13 November 2017). "Collaborations and Partnerships in NASA's Earth Science Data Systems". Data Science Journal. 16: 51. doi:10.5334/dsj-2017-051. ISSN 1683-1470. S2CID 65241888.
  16. ^ "ATS | Science Mission Directorate". Retrieved 27 October 2016.
  17. ^ Team, Lisa Taylor, Aquarius EPO. "NASA Aquarius Mission – Mission Status & Event Report". web)): CS1 maint: multiple names: authors list (link)
  18. ^ Platnick, S (2022). "Sentinel-6B | NASA's Earth Observing System". NASA EOS.
  19. ^ Platnick, Steven. "Future Missions Earth Observing System". NASA's Earth Observing System.
  20. ^ Potter, Sean (5 November 2021). "NASA Selects New Mission to Study Storms, Impacts on Climate Models". NASA. Retrieved 19 May 2022.