LANDSAT 8

Landsat 8 is an American Earth observation satellite operated by the United States Geological Survey (USGS) and built at NASA's Goddard Space Flight Center. Carrying the NORAD catalog identifier 39084 and the international designator 2013-008A, it was launched on February 11, 2013, continuing a program of systematic, long-term land surface monitoring that stretches back to the early 1970s. As of the time of writing, the satellite remains active in a sun-synchronous orbit, continuing to acquire imagery of Earth's land surface on a regular basis.

Mission and Purpose

Landsat 8 is the eighth satellite in the Landsat series and the seventh to successfully reach orbit, continuing a legacy of uninterrupted Earth observation data that spans more than five decades. Before its launch, the mission was developed under the name Landsat Data Continuity Mission (LDCM), a designation that reflects the primary goal driving its creation: ensuring that the long, consistent record of moderate-resolution land imaging established by earlier Landsat satellites would not be broken.

The satellite resulted from a collaborative effort between NASA and the USGS. NASA's Goddard Space Flight Center in Greenbelt, Maryland, took responsibility for the engineering and development of the satellite itself and for procuring the launch vehicle, while the USGS oversaw the development of the ground systems needed to receive, process, and archive data, and assumed operational responsibility for the mission once it reached orbit. This division of labor reflects a broader institutional pattern in the Landsat program, in which NASA's technical expertise and USGS's mandate for long-term land monitoring are combined.

The satellite carries two primary science instruments. The Operational Land Imager, known as the OLI, is a push-broom imager that collects data across multiple spectral bands covering wavelengths from the visible through the shortwave infrared. This allows it to capture detailed information about vegetation cover, land use, urban development, water bodies, bare soil, and other surface characteristics. Alongside the OLI sits the Thermal Infrared Sensor, or TIRS, which operates in the thermal infrared portion of the spectrum. TIRS enables the satellite to measure the thermal emission from Earth's surface, which corresponds broadly to surface temperature. This capability makes Landsat 8 a useful tool not only for traditional land-cover mapping but also for monitoring heat patterns, studying evapotranspiration in agricultural regions, and contributing to scientific understanding of surface temperature trends and global warming. Together the two sensors provide a comprehensive view of the land surface that supports a wide range of scientific, governmental, and commercial applications.

Because the Landsat archive is freely and openly accessible, imagery from Landsat 8 has been used in thousands of scientific publications covering subjects from deforestation monitoring and glacier retreat to urban heat islands, drought assessment, and post-disaster damage evaluation. Governments, researchers, land managers, and humanitarian organizations around the world draw on this data regularly.

Orbit and Tracking

Landsat 8 occupies a sun-synchronous orbit, a type of near-polar orbit designed so that the satellite passes over any given point on Earth at approximately the same local solar time on each revisit. This consistency is essential for land observation missions: by keeping the solar illumination angle roughly constant from one pass to the next, sun-synchronous orbits reduce the variability in image brightness and shadowing that would otherwise complicate comparisons of imagery acquired at different times.

The orbital parameters recorded in the satellite catalog describe a nearly circular orbit with an apogee of 708 km and a perigee of 706 km, giving the orbit a near-perfect circular shape. The inclination is 98.2°, which is the slight retrograde tilt—just past 90°—that characterizes all sun-synchronous orbits and enables the orbital plane to precess at a rate that keeps pace with Earth's movement around the Sun. At this altitude and inclination, Landsat 8 completes one orbit every 98.8 minutes, meaning it circles Earth roughly 14 to 15 times per day.

The ground track of the satellite, combined with the swath width of its instruments, allows it to image the entire Earth's land surface over a repeating cycle. The revisit interval allows researchers to detect seasonal and year-over-year changes in surface conditions. Tracking data for Landsat 8 is maintained by the United States Space Force's Space Surveillance Network and published through the NORAD catalog under identifier 39084. The satellite launched under the international designator 2013-008A, meaning it was the first cataloged object from the eighth launch of 2013.

Design and Operator

Landsat 8 was manufactured at NASA's Goddard Space Flight Center and has a launch mass of 3,085 kg, making it a substantial Earth observation platform by the standards of government science satellites. Goddard has long served as the engineering hub for the Landsat program, providing the technical infrastructure to design, build, and test the spacecraft before handing off operational control.

Day-to-day operation of the satellite falls to the USGS, which manages the mission through its Earth Resources Observation and Science (EROS) Center in Sioux Falls, South Dakota. From there, the USGS coordinates the collection of imagery, the downlinking of data, and its processing and distribution to users worldwide. The USGS has maintained this operational role for Landsat satellites since the early phases of the program, ensuring continuity in ground-based handling and data management across successive spacecraft generations.

The satellite is classified as a payload in the orbital catalog—it is a functional spacecraft serving a defined scientific and operational mission, as opposed to a rocket body or debris object. Its orbit class is sun-synchronous, consistent with the mission requirements described above. The spacecraft was designed with sufficient propellant to maintain its orbit over a planned operational lifetime, allowing for periodic maneuvers to counteract atmospheric drag at its operating altitude and to keep the satellite within its assigned ground-track corridor.

Significance and Legacy

The Landsat program as a whole represents one of the longest-running Earth observation efforts in history, and Landsat 8 has played a central role in sustaining that record into the twenty-first century. When earlier Landsat satellites experienced instrument failures or mission endings, gaps in the data record created difficulties for scientists who rely on consistent time-series analysis. The development of Landsat 8—carefully engineered to produce imagery compatible with the archive of its predecessors—was intended specifically to prevent such a gap from opening again.

By maintaining radiometric and geometric consistency with earlier Landsat sensors, Landsat 8 allows researchers to place contemporary imagery in direct comparison with observations stretching back decades. This is particularly valuable for studies of slow-moving or long-term processes such as forest degradation, coastal change, agricultural intensification, and the retreat of mountain glaciers. The thermal capability provided by TIRS adds a dimension not available from all earlier Landsat instruments, broadening the mission's scientific utility.

Landsat 8 has also been significant from a policy and institutional standpoint. The USGS's decision to make the entire Landsat archive available free of charge, implemented before Landsat 8's launch, transformed the user community for Landsat data. Imagery that had previously been expensive enough to limit use to well-funded institutions became available to any researcher, government body, or organization with an internet connection. Landsat 8's data has flowed into this open archive continuously since its commissioning, contributing billions of observations across its instrument bands.

The satellite's continued presence in orbit also provided a foundation for planning its successor. Landsat 9, built on a similar design philosophy, was launched in September 2021, and the two satellites now operate in coordinated orbits that together increase the frequency with which any given location can be imaged. This tandem operation represents a maturation of the program's approach to ensuring data continuity and density.

How to Spot It

At an orbital altitude of approximately 707 km and with a mass of over three metric tons, Landsat 8 is a reasonably large object in low Earth orbit, but it is not among the brightest satellites visible to the naked eye. Like most Earth observation platforms, it lacks the large reflective solar arrays of communications satellites or the International Space Station that make those objects strikingly visible. Under favorable conditions—a dark sky, the satellite passing overhead at low solar elevation, and the observer positioned such that the satellite is in sunlight while the ground is in shadow—Landsat 8 may be visible as a slowly moving point of light. Dedicated satellite-tracking tools, including the real-time tracking features available on this site, can generate precise pass predictions based on the satellite's current two-line element set, allowing observers to plan sighting attempts. The NORAD ID 39084 can be used to look up Landsat 8 specifically in any catalog or tracking application.