(Space Weather Observations at L1 to Advance Readiness 1, SWFO-L1, Space Weather Follow On-Lagrange 1)
(NOAA space-weather warning satellite)
SOLAR-1 (for Space Weather Observations at L1 to Advance Readiness 1)
is an NOAA (National Oceanic and Atmospheric Administration)
spacecraft to monitor space weather from solar events,
particularly to detect coronal mass ejections (CMEs) that pose a danger
to technology on Earth and in Earth orbit.
SOLAR-1 is located at Earth-Sun Lagrangian point L1.
It was launched in September 2025 (on the same launch vehicle as IMAP),
reached L1 in January 2026, and became fully operational in June 2026.
Among the instruments:
SOLAR-1 was previously called SWFO-L1,
for Space Weather Follow On-Lagrange 1.
The phrase follow on refers to the notation that it
improves upon and/or replaces some monitoring capabilities
of the existing satellites, DSCOVR and Advanced Composition Explorer (ACE).