NOAA-21, NOAA-20, and Suomi NPP satellite orbits

The Joint Polar Satellite System (JPSS) is the nation’s advanced series of polar-orbiting environmental satellites. JPSS satellites circle the Earth from pole-to-pole and cross the equator 14 times daily in the afternoon orbit—providing full global coverage twice a day. Polar satellites are considered the backbone of the global observing system.

The operational JPSS constellation currently consists of the NASA-NOAA Suomi National Polar-Orbiting Partnership satellite, the technology pathfinder mission for JPSS launched in 2011, and NOAA-20, previously called JPSS-1 and launched in 2017. The third satellite in the series, NOAA-21 (formerly JPSS-2), launched November, 10, 2022. Once it reached its polar orbit JPSS-2 was renamed NOAA-21.

Once NOAA-21 is fully commissioned and science products are provisional, notionally a year after launch, NOAA-20 will transition a quarter orbit ahead of S-NPP. NOAA-21 will then become the primary satellite, NOAA-20 will become the backup satellite, and Suomi-NPP will become the tertiary satellite in the JPSS constellation, as shown in this animation.

JPSS represents significant technological and scientific advancements in observations used for severe weather prediction and environmental monitoring. These data are critical to the timeliness and accuracy of forecasts three to seven days in advance of a severe weather event. JPSS is a collaborative effort between NOAA and NASA.