It may not be widely known that Landsat 5 is the longest operating Earth-orbiting satellite. Launched in 1984, Landsat 5 has downlinked over five million images to the USGS and international ground stations throughout the world. The archive of observations derived from the Landsat 5 provides our international community with a strong foundation of unbiased information on global land-surface features.
If you are curious about the Earth and how it has changed, Landsat 5 is for you. Questions that have been asked of the archive relate to: forests, farming, city expansion, natural disasters, coral reefs, glaciers, international borders, national parks, geology, biology, and the list goes on and on. And all these questions can be answered with an eye on change over the last 27 years – what did Atlanta, Georgia look like in 1984 compared to today? How much more land is used in Africa today for growing food than 20 years ago? Are the glaciers really receding? How has the region around Chernobyl changed? And so forth.
As Landsat 5 has aged, while continuously imaging the Earth day after day for 27 years, it has exhibited numerous problems, some predicted and others unforeseen. Landsat 5 has survived many setbacks, forcing flight engineers to switch on back-up components or find workarounds. Lots of fuel, the design and workmanship of the satellite, innovative workarounds and problem-solving, and finally, a bit of luck have all helped Landsat 5 keep working, monitoring the Earth, and providing an unparalleled archive of images for all humankind.