Thus began a relationship that begat the Landsat Program and the Earth Resources Observation and Science (EROS) Center. The mutual benefits continue today for NASA and for EROS, which is celebrating 51 years of imagery stewardship in the South Dakota countryside.

Early Years of the Landsat Program

In 1966, two USGS scientists and USGS Director William Pecora proposed to Interior Secretary Stewart Udall that the Department of the Interior (DOI) develop its own satellite program with the aim of collecting data on the Earth’s geography, geology, hydrology and natural resources for research and mapping.

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Udall agreed and announced a new DOI program, Earth Resources Observation Satellite (EROS), that would launch satellites and be managed by the USGS. With no money to fund a satellite program, the DOI turned to NASA to build a satellite to suit the department’s needs.

However, the DOI was happy to manage the thousands, and eventually millions, of satellite scenes that needed to be stored and distributed to people around the world. The USGS set up the EROS Center as a satellite data processing center that was the first of its kind, just as Landsat 1—originally called Earth Resources Technology Satellite, or ERTS-1—was the first dedicated Earth observation satellite.

NASA successfully launched Landsat 1 from Vandenberg Air Force Base on July 23, 1972. The two sensors aboard started sending back imagery to several ground receiving stations within two days, and the electronic imagery was transferred to NASA’s Goddard Space Flight Center in Maryland. There, it was converted to photographic film and flown to EROS’ temporary location in Sioux Falls.

The next year, the new EROS facility’s dedication on August 7, 1973, included remarks from USGS, DOI and NASA officials. Afterward, more imagery flowed into EROS from Goddard and out of EROS to fulfill orders as scientists, mineral seekers and the public appreciated the value and fascination of satellite scenes.

NASA, now convinced of the satellite program’s usefulness, launched Landsat 2 on January 22, 1975. In 1979, a year after the launch of Landsat 3, a 30-foot antenna was installed in front of the EROS building to receive digital Landsat data directly from Goddard, improving the data quality and reducing the imagery turnaround time.

In 1978, then EROS Director Al Watkins emphasized in a USGS memo that EROS played a key role in the Landsat Program. “(EROS Data Center) has become a respected and full partner in the Landsat satellite program, with meaningful inputs to policy formulation.”

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Shifting Landsat Responsibilities

During the era of commercialization, when the Landsat Program was gradually transferred to the private sector, EROS worked with other agencies. The National Oceanic and Atmospheric Administration (NOAA), under the Department of Commerce, became involved. NASA still built and launched Landsat 4 in 1982 and its twin, Landsat 5, in 1984, but then turned their operations over to NOAA.

In 1985, the Earth Observation Satellite Company (EOSAT) received a 10-year contract to own and operate the Landsat program, with the understanding that EROS would continue its work for a few years until EOSAT was ready to assume processing, distribution and storage of data from Landsat 4 and Landsat 5. However, funding issues eventually darkened plans for future Landsat satellites and the entire commercialization effort. The Land Remote Sensing Policy Act of 1992 ultimately ended commercialization of the Landsat Program, and EOSAT’s Landsat 6 satellite failed to achieve orbit in 1993.

Extending a Thriving Partnership 

By 1998, the USGS and NASA were the sole agencies responsible for all of the Landsat missions, starting with Landsat 7. NASA placed an antenna at EROS to serve as that satellite’s primary ground station. After NASA launched Landsat 7 on April 15, 1999, EROS successfully processed the first imagery April 18, making full use of its new ground station capabilities. In 2001, NASA handed over flight operations of Landsat 5 and Landsat 7 to EROS and Goddard Space Flight Center.

In 2008, the USGS and NASA agreed to a momentous policy that changed the world of land remote sensing data. Barb Ryan of the USGS and Michael Freilich of NASA signed the Landsat Data Distribution Policy, which opened the Landsat archive to free distribution over the internet. The policy kept EROS busy facilitating the transition and led to an explosion in research using the data.

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At the same time, USGS and NASA were working together to develop Landsat 8 and its instruments, which NASA launched on February 11, 2013, and later the similar Landsat 9, which launched September 27, 2021. Landsat 9 was the first mission launched under the 2015 USGS-NASA Sustainable Land Imaging partnership, designed to ensure continuity by extending the Landsat Program collaboration between the agencies for at least two decades, including Landsat Next, which is expected to launch in 2030.

At the August 2022 ceremony that marked the transition of Landsat 9’s ownership and operations from NASA to the USGS, NASA Deputy Director of Flight Projects Directorate Cathy Richardson reflected on the Landsat collaboration.

“We are tremendously proud to have had the long history and opportunity to build Landsat satellites and to be part of the program and the organizations contributing to Landsat now and in the future. Our partnership with USGS is extremely important,” Richardson said.

The USGS is still operating Landsat 7 as it continues to collect imagery in an orbit slightly below Landsat 8 and 9, but NASA has another mission in mind for the aging satellite. In a first-of-its-kind attempt, NASA is preparing to robotically refuel Landsat 7, which was not designed to be serviced, to test the ability to extend the life of satellites in orbit. The On-orbit Servicing, Assembly and Manufacturing 1 (OSAM-1) mission is planned for launch around 2026.

Helping inform user needs for instruments on pending Landsat satellites, among other tasks, are five-year Landsat Science Teams, co-chaired by the Landsat Project Scientists at NASA and USGS EROS. Members bring a wide breadth of expertise, backgrounds and geographic locations to the teams to represent the vast global community of Landsat users.

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Calibration and Commitment

Calibration and validation of Landsat data ensures the quality of currently collected Landsat data and enhances the quality of archive data. Other satellite systems also use Landsat as a benchmark for calibrating their own data. The Landsat Cal/Val Team is led by EROS and the Goddard Space Flight Center and includes the NASA Jet Propulsion Laboratory and several universities, and their efforts have become more important through time.

One key maneuver the Landsat Cal/Val team performed for each new satellite starting with Landsat 5 involved flying it in an orbit below its predecessor for a few days before moving it into its lifetime operational orbit of 438 miles above Earth. This exercise, called an underfly, helps the new satellite to be calibrated as closely as possible to the other one. The Landsat 9 underfly included field measurements for comparison taken in Canada and Australia, in addition to the United States.

The international partners for the underfly were a natural fit, being part of the longstanding network of International Cooperators with Landsat ground stations established in their countries.

Many partners have helped along the way, but throughout its 51-year history and some tumultuous times, the Landsat Program had two distinct mainstays: the USGS and NASA. Without the level of commitment from NASA to build and launch the satellites and from USGS EROS to preserve every scene possible for global distribution, the unbroken record of Earth observations likely would not exist. 

With a long-term agreement in place to carry this invaluable partnership through the design, assembly and launch of the new and improved Landsat Next and beyond, the Landsat Program has bright prospects. Scientists, land managers and the public can trust that the long-term record of land change will continue to help them respond to the world’s increasing changes and challenges.