SOLAR-1

​SOLAR-1 is the new name for the U.S. space weather monitoring satellite formerly known as SWFO-L1 (Space Weather Follow-On L1). It is described as America’s first satellite designed exclusively for continuous, operational space weather observations, positioned about 1.5 million kilometers from Earth near the Sun–Earth L1 Lagrange point to monitor the solar wind and solar activity in real time.  These data support forecasting of solar storms that can affect power grids, communications, navigation systems, and spacecraft operations.
 
Before the rename to SOLAR-1, SWFO-L1 was the name of a NOAA spacecraft mission dedicated to continuous operational monitoring of space weather from the Sun–Earth L1 point. It was launched into orbit on September 23, 2025 and was conceived as the deep-space element of NOAA’s Space Weather Follow On program, designed to ensure continuity of critical measurements as older missions like ACE, DSCOVR, and SOHO age.  SWFO-L1 carries a suite of instruments (including a compact coronagraph, magnetometer, supra-thermal ion sensor, and solar wind plasma sensor) to observe coronal mass ejections, solar wind, energetic particles, and magnetic fields in real time.  
 
References
(2026, January 27). SWFO-L1, Renamed SOLAR-1, Reaches Final Destination One Million Miles from Earth. National Evironmental Satellite, Data, and Information Service. https://www.nesdis.noaa.gov/news/swfo-l1-renamed-solar-1-reaches-final-destination-one-million-miles-earth
 
(2026, January 22). Space Weather Follow On-Lagrange 1. In Wikipedia, https://en.wikipedia.org/wiki/Space_Weather_Follow_On-Lagrange_1
 
(2025, September 25). SWFO-L1. NASA. https://science.nasa.gov/mission/swfo-l1/