Since 1972, the Landsat program has been continually monitoring the Earth, to now provide 50 years of digital, multispectral, medium spatial resolution observations. Over this time, Landsat data were crucial for many scientific and technical advances. Prior to the Landsat program, detailed, synoptic depictions of the Earth's surface were rare, and the ability to acquire and work with large datasets was limited. The early years of the Landsat program delivered a series of technological breakthroughs, pioneering new methods, and demonstrating the ability and capacity of digital satellite imagery, creating a template for other global Earth observation missions and programs. Innovations driven by the Landsat program have paved the way for subsequent science, application, and policy support activities. The economic and scientific value of the knowledge gained through the Landsat program has been long recognized, and despite periods of funding uncertainty, has resulted in the program's 50 years of continuity, as well as substantive and ongoing improvements to payload and mission performance. Free and open access to Landsat data, enacted in 2008, was unprecedented for medium spatial resolution Earth observation data and substantially increased usage and led to a proliferation of science and application opportunities. Here, we highlight key developments over the past 50 years of the Landsat program that have influenced and changed our scientific understanding of the Earth system. Major scientific and programmatic impacts have been realized in the areas of agricultural crop mapping and water use, climate change drivers and impacts, ecosystems and land cover monitoring, and mapping the changing human footprint. The introduction of Landsat collection processing, coupled with the free and open data policy, facilitated a transition in Landsat data usage away from single images and towards time series analyses over large areas and has fostered the widespread use of science-grade data. The launch of Landsat-9 on September 27, 2021, and the advanced planning of its successor mission, Landsat-Next, underscore the sustained institutional support for the program. Such support and commitment to continuity is recognition of both the historic impact the program, and the future potential to build upon Landsat's remarkable 50-year legacy.

自 1972 年以来，Landsat 计划一直在持续监测地球，到现在提供 50 年的数字、多光谱、中等空间分辨率观测。在此期间，Landsat 数据对许多科学和技术进步至关重要。在 Landsat 计划之前，地球表面的详细天气描述很少见，获取和使用大型数据集的能力有限。Landsat 计划的早期实现了一系列技术突破，开创了新方法，展示了数字卫星图像的能力和能力，为其他全球地球观测任务和计划创造了模板。Landsat 计划推动的创新为后续的科学、应用和政策支持活动铺平了道路。通过 Landsat 计划获得的知识的经济和科学价值早已得到认可，尽管存在资金不确定性时期，但该计划已经持续了 50 年，以及有效载荷和任务性能的实质性和持续改进。2008 年颁布的免费和开放获取 Landsat 数据对于中等空间分辨率地球观测数据来说是前所未有的，并大大增加了使用量，并导致科学和应用机会的扩散。在这里，我们重点介绍过去 50 年 Landsat 计划的关键发展，这些发展影响并改变了我们对地球系统的科学理解。在农作物测绘和用水、气候变化驱动因素和影响、生态系统和土地覆盖监测，并绘制不断变化的人类足迹。Landsat 采集处理的引入，再加上免费和开放的数据政策，促进了 Landsat 数据使用从单一图像向大面积时间序列分析的转变，并促进了科学级数据的广泛使用。Landsat-9 于 2021 年 9 月 27 日发射，其后续任务 Landsat-Next 的提前规划强调了对该计划的持续机构支持。这种对连续性的支持和承诺是对该计划的历史影响以及未来在 Landsat 50 年非凡遗产的基础上发展的潜力的认可。再加上免费和开放的数据政策，促进了 Landsat 数据使用从单一图像转向大面积时间序列分析的转变，并促进了科学级数据的广泛使用。Landsat-9 于 2021 年 9 月 27 日发射，其后续任务 Landsat-Next 的提前规划强调了对该计划的持续机构支持。这种对连续性的支持和承诺是对该计划的历史影响以及未来在 Landsat 50 年非凡遗产的基础上发展的潜力的认可。再加上免费和开放的数据政策，促进了 Landsat 数据使用从单一图像转向大面积时间序列分析的转变，并促进了科学级数据的广泛使用。Landsat-9 于 2021 年 9 月 27 日发射，其后续任务 Landsat-Next 的提前规划强调了对该计划的持续机构支持。这种对连续性的支持和承诺是对该计划的历史影响以及未来在 Landsat 50 年非凡遗产的基础上发展的潜力的认可。其后续任务 Landsat-Next 的提前规划强调了对该计划的持续机构支持。这种对连续性的支持和承诺是对该计划的历史影响以及未来在 Landsat 50 年非凡遗产的基础上发展的潜力的认可。其后续任务 Landsat-Next 的提前规划强调了对该计划的持续机构支持。这种对连续性的支持和承诺是对该计划的历史影响以及未来在 Landsat 50 年非凡遗产的基础上发展的潜力的认可。