In order to study the Earth as a whole system and understand how it is changing, NASA develops and supports a large number of Earth observing missions. These missions provide Earth science researchers the necessary data to address key questions about global climate change.

Missions begin with a study phase during which the key science objectives of the mission are identified, and designs for spacecraft and instruments are analyzed. Following a successful study phase, missions enter a development phase whereby all aspects of the mission are developed and tested to insure it meets the mission objectives. Operating missions are those missions that are currently active and providing science data to researchers. Operating missions may be in their primary operational phase or in an extended operational phase.

The table below lists all Earth missions in all phases.