The Landsat program is the longest-running enterprise that has acquired satellite imagery of Earth. It is a joint NASA / USGS program. On 23 July 1972, the Earth Resources Technology Satellite was launched. This was eventually renamed to Landsat 1 in 1975. The most recent, Landsat 9, was launched on 27 September 2021.
The instruments on the Landsat satellites have acquired millions of images. The images, archived in the United States and at Landsat receiving stations around the world, are a unique resource for global change research and applications in agriculture, cartography, geology, forestry, regional planning, surveillance, and education, and can be viewed through the U.S. Geological Survey (USGS) "EarthExplorer" website. Landsat 7 data has eight spectral bands with spatial resolutions ranging from ; the temporal resolution is 16 days.The Landsat Program – Technical Details Landsat images are usually divided into scenes for easy downloading. Each Landsat scene is about 115 miles long and 115 miles wide (or 100 nautical miles long and 100 nautical miles wide, or 185 kilometers long and 185 kilometers wide).
History
In 1965, William T. Pecora, the then director of the United States Geological Survey (USGS), proposed the idea of a remote sensing satellite program to gather facts about our planet's natural resources. Pecora stated that the program was "conceived in 1966 largely as a direct result of the demonstrated utility of the Mercury and Gemini orbital photography to Earth resource studies."
While weather satellites had been monitoring Earth's atmosphere since 1960 and were largely considered useful, there was no appreciation of terrain data from space until the mid-1960s. So, when Landsat 1 was proposed, it met with intense opposition from the Bureau of Budget and those who argued that high-altitude aircraft would be the fiscally responsible choice for Earth remote sensing. Concurrently, the Department of Defense feared that a civilian program such as Landsat would compromise the secrecy of its reconnaissance missions. Additionally, there were geopolitical concerns about photographing foreign countries without permission. In 1965, NASA began methodical investigations of Earth remote sensing using instruments mounted on planes.
In 1966, the USGS convinced the Secretary of the Interior, Stewart Udall, to announce that the Department of the Interior (DOI) would proceed with its Earth-observing satellite program. This savvy political stunt coerced NASA into expediting the building of Landsat. However, budgetary constraints and sensor disagreements between application agencies (notably the Department of Agriculture and DOI) again stymied the satellite construction process. Finally, by 1970, NASA had a green light to build a satellite. Remarkably, Landsat 1 was launched within only two years, heralding a new age of remote sensing of land from space.
The Hughes Aircraft Company from the Santa Barbara Research Center initiated, designed, and fabricated the first three Multispectral Scanners (MSS) in 1969. The first MSS prototype, designed by Virginia Norwood, was completed within nine months, in the fall of 1970. It was tested by scanning Half Dome at Yosemite National Park. Norwood was called "The Mother of Landsat" for this design work.
Working at NASA's Goddard Space Flight Center, Valerie L. Thomas managed the development of early Landsat image processing software systems and became the resident expert on the Computer Compatible Tapes, or CCTs, that were used to store early Landsat imagery. Thomas was one of the image processing specialists who facilitated the ambitious 'Large Area Crop Inventory Experiment', known as LACIE — a project that showed for the first time that global crop monitoring could be done through remote sensing with Landsat satellite imagery.NASA Landsat Science, A Face Behind Landsat Images: Meet Dr. Valerie L. Thomas
The program was initially called the Earth Resources Technology Satellites Program, which was used from 1966 to 1975. In 1975, the name was changed to Landsat. In 1979, Jimmy Carter's Presidential Directive 54 transferred Landsat operations from NASA to the National Oceanic and Atmospheric Administration (NOAA), recommended development of a long-term operational system with four additional satellites beyond Landsat 3, and recommended transition to private sector operation of Landsat. This occurred in 1985 when the Earth Observation Satellite Company (EOSAT), a partnership of Hughes Aircraft Company and RCA, was selected by NOAA to operate the Landsat system with a ten-year contract. EOSAT operated Landsat 4 and Landsat 5, had exclusive rights to market Landsat data, and was to build Landsats 6 and 7.
In 1989, this transition had not been fully completed when NOAA's funding for the Landsat program was due to run out (NOAA had not requested any funding, and the U.S. Congress had appropriated only six months of funding for the fiscal year), and NOAA directed that Landsat 4 and Landsat 5 be shut down.
The head of the newly formed National Space Council, Vice President Dan Quayle, noted the situation and arranged emergency funding that allowed the program to continue with the data archives intact.
Again in 1990 and 1991, Congress provided only half of the year's funding to NOAA, requesting that agencies that used Landsat data provide the funding for the other six months of the upcoming year.
In 1992, various efforts were made to procure funding for follow-on Landsats and continued operations, but by the end of the year, EOSAT ceased processing Landsat data. Landsat 6 was finally launched on 5 October 1993, but was lost in a launch failure. Processing of Landsat 4 and 5 data was resumed by EOSAT in 1994. NASA finally launched Landsat 7 on 15 April 1999.
Congress recognized the value of the Landsat program in October 1992 when it passed the Land Remote Sensing Policy Act (Public Law 102-555), authorizing the procurement of Landsat 7 and assuring the continued availability of Landsat digital data and images, at the lowest possible cost, to traditional and new users of the data.
By the turn of the century, the emergence of a viable U.S. commercial remote sensing industry, newly stabilized by its support to the national intelligence community, raised questions about the continued viability of a publicly managed land remote sensing satellite system. As a result, White House plans shifted to possible adoption of an MSS-like instrument onboard the NPOESS platform and, concurrently, cancellation of future Landsat satellites by the U.S. Office of Science and Technology Policy. These actions were subsequently cancelled by OSTP and the White House, causing the production of a new, national policy for Land Remote Sensing. The OSTP Plan for a National Land Imaging Program was published in 2007 following Landsat 8 re-authorization. Subsequently, the Landsat satellite system was recognized as foundational to U.S. space, earth observation, and geospatial management and policy.
Satellite chronology Instrument Picture Launched Terminated Duration Notes Landsat 1 23 July 1972 6 January 1978 Originally named Earth Resources Technology Satellite 1. Landsat 1 carried two vital instruments: a camera built by the Radio Corporation of America (RCA) known as the Return Beam Vidicon (RBV); and the Multi spectral Scanner (MSS) built by the Hughes Aircraft Company. Landsat 2 22 January 1975 25 February 1982 Originally named Earth Resources Technology Satellite B. Nearly identical copy of Landsat 1. Payload consisting of a Return Beam Vidicon (RBV) and a Multi spectral Scanner (MSS). The specifications of these instruments were identical those of Landsat 1. Landsat 3 5 March 1978 31 March 1983 Nearly identical copy of Landsat 1 and Landsat 2. Payload consists of a Return Beam Vidicon (RBV) and a Multi spectral Scanner (MSS). Included with the MSS was a short-lived thermal band. By this point in the program the MSS was considered more scientifically applicable than the RBV, which was omitted from future missions. Landsat 4 16 July 1982 14 December 1993 Landsat 4 carried an updated Multi Spectral Scanner (MSS) used on previous Landsat missions and a Thematic Mapper. Landsat 5 1 March 1984 5 June 2013 Nearly identical copy of Landsat 4. Longest Earth-observing satellite mission in history. Designed and built at the same time as Landsat 4, this satellite carried the same payload consisting of a Multi Spectral Scanner (MSS) and a Thematic Mapper. Landsat 6 5 October 1993 5 October 1993 0 days Failed to reach orbit. Landsat 6 was an upgraded version of its predecessors. Carrying the same Multi spectral Scanner (MSS) but also carrying an Enhanced Thematic Mapper, which added a 15m resolution panchromatic band. Landsat 7 15 April 1999 4 June 2025 Operating with the scan line corrector disabled since May 2003. The main component of Landsat 7 was the Enhanced Thematic Mapper Plus (ETM+). It still consists of the 15m-resolution panchromatic band and includes a full aperture calibration. This allows for 5% absolute radiometric calibration. Landsat 8 11 February 2013 Active Originally named Landsat Data Continuity Mission from launch until 30 May 2013, when NASA operations were turned over to the United States Geological Survey (USGS). Landsat 8 has two sensors with its payload, the Operational Land Imager (OLI) and the Thermal InfraRed Sensor (TIRS). Landsat 9 27 September 2021 Active Landsat 9 is a rebuild of its predecessor Landsat 8.
Timeline
Spatial and spectral resolution Landsat 1 through 5 carried the Landsat Multispectral Scanner (MSS). Landsat 4 and 5 carried both the MSS and Thematic Mapper (TM) instruments. Landsat 7 uses the Enhanced Thematic Mapper Plus (ETM+) scanner. Landsat 8 uses two instruments, the Operational Land Imager (OLI) for optical bands and the Thermal Infrared Sensor (TIRS) for thermal bands. The band designations, bandpasses, and pixel sizes for the Landsat instruments are: +Landsat 1–5 Multispectral Scanner (MSS)Landsat 1–3 MSSLandsat 4–5 MSSWavelength (micrometers)Resolution (meters)Band 4 – GreenBand 1 – Green0.5 – 0.660*Band 5 – RedBand 2 – Red0.6 – 0.760*Band 6 – Near Infrared (NIR)Band 3 – NIR0.7 – 0.860*Band 7 – NIRBand 4 – NIR0.8 – 1.160* * Original MSS pixel size was 79 x 57 meters; production systems now resample the data to 60 meters. +Landsat 4–5 Thematic Mapper (TM)BandsWavelength (micrometers)Resolution (meters)Band 1 – Blue0.45 – 0.5230Band 2 – Green0.52 – 0.6030Band 3 – Red0.63 – 0.6930Band 4 – NIR0.76 – 0.9030Band 5 – Shortwave Infrared (SWIR) 11.55 – 1.7530Band 6 – Thermal10.40 – 12.50120* (30)Band 7 – SWIR 22.08 – 2.3530 * TM Band 6 was acquired at 120-meter resolution, but products are resampled to 30-meter pixels. +Landsat 7 Enhanced Thematic Mapper Plus (ETM+)BandsWavelength (micrometers)Resolution (meters)Band 1 – Blue0.45 – 0.5230Band 2 – Green0.52 – 0.6030Band 3 – Red0.63 – 0.6930Band 4 – NIR0.77 – 0.9030Band 5 – SWIR 11.55 – 1.7530Band 6 – Thermal10.40 – 12.5060* (30)Band 7 – SWIR 22.09 – 2.3530Band 8 – Panchromatic0.52 – 0.9015 * ETM+ Band 6 is acquired at 60-meter resolution, but products are resampled to 30-meter pixels.
+Landsat 8 Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS)BandsWavelength (micrometers)Resolution (meters)Band 1 - Ultra Blue (coastal/aerosol)0.435 – 0.45130Band 2 - Blue0.452 – 0.51230Band 3 - Green0.533 – 0.59030Band 4 – Red0.636 – 0.67330Band 5 – NIR0.851 – 0.87930Band 6 – SWIR 1 1.566 – 1.65130Band 7 – SWIR 22.107 – 2.29430Band 8 – Panchromatic0.503 – 0.67615Band 9 – Cirrus1.363 – 1.38430Band 10 – Thermal 110.60 – 11.19100* (30)Band 11 – Thermal 211.50 – 12.51100* (30) * TIRS bands are acquired at 100 meter resolution, but are resampled to 30 meter resolution in the delivered data product.