The Landsat 7 and Landsat 8 satellites orbit the Earth at an altitude of 705 kilometers (438 miles) in a 185-kilometer (115-mile) swath, moving from north to south over the sunlit side of the Earth in a sun synchronous orbit, following the World Reference System (WRS-2). Each satellite makes a complete orbit every 99 minutes, completes about 14 full orbits each day, and crosses every point on Earth once every 16 days.
The satellite orbits are offset to allow 8-day repeat coverage of any Landsat scene area on the globe. Between the two satellites, more than 1,500 scenes are added to the USGS archive each day.
Traveling on the descending (daytime) node from north to south, the satellites cross the equator on each pass at a time that provides the maximum illumination with minimum water vapor (haze and cloud build-up). Landsat 7 crosses the equator at 10:00 a.m. +/- 15 minutes (mean local time) while Landsat 8 crosses the equator at 10:00 a.m. +/- 15 minutes (mean local time).
The Landsat 7 and Landsat 8 satellites each acquire data in accordance with their respective Long Term Acquisition Plan (LTAP) using parameters such as seasonality, land definition, historical cloud cover, gain settings, and sun angle.