NASA’s Earth Observatory is a government-funded project managed within the Goddard Space Flight Center in Maryland. They provide us with an in-depth perspective from the hundreds of satellites launched and maintained by the United States that are working 24/7, tracking the weather, redirecting voice and data communications, and sending GPS information to and from anywhere on the globe.
“The Earth Observatory’s mission is to share with the public the images, stories, and discoveries about the environment, Earth systems, and climate that emerge from NASA research …”
Tasking a Satellite
A satellite’s “place in space” is determined by three things: its distance from the surface of the earth (the farther away, the slower the orbit), the eccentricity of its orbit (either circular or elliptical) and its inclination (whether it orbits parallel to the equator or at an angle).
For instance, a weather satellite might be positioned in a geosynchronous circular orbit to constantly monitor cloud cover, precipitation, and storm systems in a particular area of the globe, while communication satellites that cover regions over the north and south poles would follow a highly elliptical orbit inclined at a 90-degree angle.
- Low Earth Orbit (LEO) the ISS, Hubble, earth observation satellites
- Medium Earth Orbit (MEO) GPS satellites
- Geosynchronous Orbit (satellite and the earth have same orbital speed)
- High Earth Orbit (HEO) weather satellites
A cool website Stuff in Space has located thousands of satellites, both active and non-functioning, as well as large pieces of space debris that are carefully monitored by NASA’s initiative Astromaterials Research and Exploration.
Read Instride: Earth