SpaceX just sent three space weather probes to the final frontier.
A Falcon 9 rocket lifted off from NASA’s Kennedy Space Center in Florida today (Sept. 24) at 7:30 a.m. EDT (1130 GMT), carrying NASA’s IMAP mission and and two other spacecraft.
Each probe has its own objectives, but all three will work toward the same larger goal: help scientists better understand space weather and its effects on Earth.
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They’re also all headed to the same place — the sun-Earth Lagrange Point 1, a gravitationally stable spot about 930,000 miles (1.5 million kilometers) from Earth, in the direction of our star.
IMAP (short for “Interstellar Mapping and Acceleration Probe”) is the primary payload on today’s flight. The roughly $600 million spacecraft carries 10 different science instruments, which it will use to monitor solar activity as well as study interstellar dust and the solar wind, the stream of charged particles flowing continuously from our sun.
The mission’s data will also help scientists map the outer boundary of the heliosphere, the vast bubble around our solar system that’s dominated by the sun’s solar wind and magnetic field.
IMAP will also provide radiation warnings for astronauts — for example, those with NASA’s Artemis program, which aims to establish a sustained human presence on and around the moon over the next decade or so.
“Radiation exposure is a real threat to our astronauts traveling to the moon and beyond,” Nicky Fox, associate administrator of NASA’s Science Mission Directorate, said during a news conference on Sunday (Sept. 21).
“Humanity has only ever existed inside our protective magnetosphere, and as we travel beyond that protective shield, whether it be to the moon or to Mars, the actionable information from missions like IMAP will keep our astronauts safe,” she added.
The other two spacecraft that went up today are NASA’s Carruthers Geocorona Observatory (CGO) and the U.S. National Oceanic and Atmospheric Administration’s Space Weather Follow-on (SWFO-L1) spacecraft.
CGO will investigate the exosphere, the wispy outermost reaches of Earth’s atmosphere. The small satellite “will image the faint glow of ultraviolet light from this region, called the geocorona, to better understand how space weather impacts our planet,” NASA officials said in a mission description. “The Carruthers mission continues the legacy of the Apollo era, expanding on measurements first taken during Apollo 16.”
SWFO-L1 will track solar storms, providing an early warning system for space weather, which can pose a threat to satellites, astronauts in orbit and some infrastructure on the ground, such as power grids.
If all goes according to plan today, the Falcon 9’s upper stage will deploy IMAP into an interplanetary transfer orbit about 84 minutes after launch. SWFO-L1 and CGO will follow suit about 6.5 minutes and 13 minutes after that, respectively.
The rocket’s first stage came back to Earth as planned today, landing a little less than nine minutes after liftoff on the SpaceX droneship “Just Read the Instructions,” which was stationed in the Atlantic Ocean. It was the second flight for this particular booster, according to a SpaceX mission description.
Today’s launch was the 120th Falcon 9 flight of 2025 already. Most of these missions — more than 70% of them — have been dedicated to building out SpaceX’s Starlink satellite-internet constellation in low Earth orbit.
