[Credit: NASA]
Since its launch on February 11, 2015, NOAA’s Deep Space Climate Observatory (DSCOVR) has played a crucial role in protecting power grids, telecommunications, aviation, and navigation systems such as GPS from the disruptive effects of space weather.
Stationed at Lagrange Point 1 (L1)—approximately one million miles from Earth, between the Earth and the sun—DSCOVR provides real-time solar wind data that enables NOAA’s Space Weather Prediction Center (SWPC) to issue timely alerts and forecasts. These warnings help mitigate the risks posed by coronal mass ejections (CMEs), powerful solar eruptions, and the resulting geomagnetic storms that can interfere with all kinds of technological infrastructure.
The importance of these warnings was emphasized in a March 2020 report from the Congressional Budget Office. It noted that a large enough solar disturbance could create strong electric currents along long-distance transmission lines, which could potentially overload and disable large power transformers. If enough transformers are affected, regional power outages could occur. The report also noted that since large power transformers can take considerable time to manufacture and replace, portions of the grid could remain vulnerable if they need to be replaced.
Accurate warnings based on data from DSCOVR and similar satellites have helped mitigate these risks and reduce costs. NOAA has been increasingly able to distinguish between dangerous storms and those that ultimately have little effect on Earth.
DSCOVR’s Impact on Space Weather Forecasting
DSCOVR has proven to be an invaluable asset for space weather monitoring. For example, during a severe geomagnetic storm on May 10, 2024, DSCOVR detected the arrival of energy from a CME with high precision, enabling forecasters to issue accurate warnings. The storm, which reached G5 on NOAA’s space weather scale (G1-G5), was the strongest in 21 years.
This graph shows data from the solar wind, including the CME shock front traveling past the DSCOVR spacecraft, in the first five panels, and the resulting geomagnetic storm on the ground in the last panel. The strong interplanetary magnetic field (black line in the top plot) which was mostly oriented downward toward the Earth (red line in the top plot) which caused coupling with the Earth's magnetic field (dark red bars in the bottom plot), maximizing the impact on the power grid, GPS systems and spacecraft in Earth orbit. The solar wind speed (purple line in the third plot from the bottom) almost doubled in a period of less than 20 seconds, to a speed of over 1.5 million MPH.
Observational data from DSCOVR revealed that the solar wind speed nearly doubled in less than 20 seconds, reaching over 1.5 million miles per hour. The interplanetary magnetic field (IMF) magnitude and orientation, measured by DSCOVR, showed strong coupling with Earth’s magnetic field, increasing the storm’s impact on power grids, GPS systems, and satellites.
Richard Ulman, Acting Director of Space Weather Observations at NOAA, shared that "DSCOVR has long surpassed its design life, continuing to serve as NOAA's warning buoy to characterize space weather shocks before they impact Earth. While its resilience has been remarkable, it's critical that we maintain continuity with a new fleet of instruments and satellites to take its place. The first being the SWFO-L1 observatory which launches in September of this year."
The Future of NOAA’s Space Weather Missions
The satellites currently monitoring CMEs and solar wind at L1, including NOAA’s DSCOVR, NASA’s ACE launched in 1997 and NASA-ESA’s SOHO launched in 1995, are operating well beyond their intended service lives. While these missions have provided invaluable data, NOAA is ensuring continuity by launching SWFO-L1. This next-generation satellite will be NOAA’s first satellite dedicated solely to space weather observations and will sustain and enhance NOAA’s ability to monitor solar wind, energetic particles, and the interplanetary magnetic field, while also continuing the Large Angle and Spectrometric Coronagraph (LASCO) observations previously conducted by SOHO.
The SWFO-L1 project will use a suite of instruments to make real time measurements of the solar wind, thermal plasma, and the magnetic field. In addition, SWFO-L1 will have a Compact Coronagraph (CCOR), a special solar telescope used to detect CMEs while they are still in the Sun's upper atmosphere, typically 1 or 2 days before they reach Earth.
Taking us into the late 2020s and early 2030s, NOAA’s Space Weather Next program will place additional observatories at L1, creating a series to ensure that if one satellite fails, the other can take over its functions, maintaining continuous coverage and reducing the risk of disruption. Together, SWFO-L1 and Space Weather Next will ensure the necessary resiliency to equip SWPC operations with 24x7 observations.