A groundbreaking mission soared into space early Wednesday morning as a SpaceX rocket carried three vital spacecraft: two for NASA and one for the National Oceanic and Atmospheric Administration (NOAA).
These missions include NASA’s Interstellar Mapping and Acceleration Probe (IMAP) and the Carruthers Geocorona Observatory, alongside NOAA’s Space Weather Follow On-Lagrange 1 (SWFO-L1).
Together, these spacecraft are poised to deeply investigate the solar wind – a constant flow of charged particles from the sun – and its profound impact on Earth and the vast expanse of interstellar space. This energetic flow forms the heliosphere, a colossal magnetic bubble that envelops our solar system, acting as a crucial shield against harmful cosmic rays from beyond.
The NOAA spacecraft is particularly critical for safeguarding our planet, offering essential advance warnings of solar storms. These powerful eruptions from the sun can unleash torrents of high-energy particles capable of crippling orbiting satellites and disrupting electrical grids on Earth.
The launch itself was a spectacle, with the Falcon 9 rocket lifting off at 7:30 a.m. from NASA’s Kennedy Space Center in Florida, just as the sun began to rise. Roughly 90 minutes later, all three spacecraft successfully detached from the rocket’s second stage, beginning their individual journeys.
Their shared destination is Lagrange 1, a unique point nearly a million miles from Earth where the gravitational pulls of our planet and the sun perfectly balance. They are expected to reach this distant outpost by January.
Joe Westlake, director of NASA’s heliophysics division, emphasized the cost-effectiveness of this combined launch, stating during a recent news conference, “Having them fly together as one provides such an immense value for our American taxpayer.”
The Interstellar Mapping and Acceleration Probe (IMAP) project carries a total price tag of $782 million, which includes $109 million for its launch. The Carruthers Observatory is budgeted at $97 million, while the SWFO-L1 mission comes in at $692 million.
IMAP is equipped with ten specialized instruments designed to meticulously analyze the solar wind and the formation of the heliosphere’s magnetic bubble, providing unprecedented insights into these crucial solar phenomena.
This heliospheric shield is essential, diverting the majority of high-energy radiation originating from beyond our solar system.
Indeed, without the heliosphere’s safeguarding influence, the emergence of life on Earth might not have been possible.
David McComas, a Princeton University astrophysics professor and IMAP’s principal investigator, highlighted the mission’s importance: “Understanding that shielding, why it works, how it works, how much it can vary over time is obviously very important for human exploration beyond the near-Earth environment,” especially for future endeavors to places like Mars.
Among its many studies, IMAP will investigate charge exchange, a fascinating process where solar wind protons acquire an electron as they interact with the outer heliosphere. This transformation creates electrically neutral hydrogen atoms, which then journey back towards the inner solar system over several years, becoming detectable by IMAP.
While individually these ’10 billion-mile hole-in-one’ events are incredibly rare, as Dr. McComas puts it, the sheer abundance of solar wind particles ensures IMAP will gather ample data.
Furthermore, IMAP is designed to identify neutral particles that cross into the heliosphere from distant interstellar space.
The SWFO-L1 mission will effectively replace the Deep Space Climate Observatory (DSCVR), launched in 2015 as an earlier solar storm warning system. DSCVR has been plagued by persistent technical issues, going offline in July with no clear path to repair.
Currently, NOAA depends on two much older NASA spacecraft – the Advanced Composition Explorer (ACE), launched in 1997, and the Solar and Heliospheric Observatory (SOHO), launched in 1995 – for critical solar wind and solar storm data.
Fortunately, SWFO-L1 incorporates advanced, modernized versions of the instruments found on ACE and SOHO, promising improved data collection.
Originally known as GLIDE (Global Lyman-alpha Imager of the Dynamic Exosphere), the Carruthers Geocorona Observatory will focus on the Earth’s exosphere. This incredibly faint atmospheric layer stretches far beyond Earth, reaching at least halfway to the Moon’s orbit. By capturing images of the exosphere, scientists hope to gain a deeper understanding of its interactions with the solar wind.
In 1972 an ultraviolet camera deployed on the moon by astronauts during Apollo 16 revealed that the exosphere glows.
When sunlight hits hydrogen atoms in the exosphere, it often pushes electrons in the atoms into a higher-energy state. When the electrons fall back into their lowest-energy state, the hydrogen atoms emit a specific wavelength of ultraviolet light known as the Lyman-alpha line.
It was George Carruthers, the brilliant scientist behind the Apollo ultraviolet camera, who first named this atmospheric glow the ‘geocorona,’ meaning ‘Earth’s crown’ in Latin.
Following Dr. Carruthers’ passing in 2020, Paul Hertz, then director of NASA’s astrophysics program, recognized a strong link between the iconic Apollo 16 images and the planned studies of GLIDE. Dr. Hertz, who had worked with Dr. Carruthers — a pioneering Black scientist in the Apollo era space missions — championed the renaming.
Consequently, in 2022, NASA officially renamed the GLIDE mission to honor Dr. Carruthers.
Lara Waldrop, the principal investigator for the Carruthers observatory, explained that her team’s instrument utilizes the very same light-shifting process from ultraviolet to visible wavelengths that Dr. Carruthers originally devised. While the initial principle remains, the photographic recording has been updated from Apollo’s film to modern digital sensors.
Despite its significant reach, the exosphere is remarkably sparse. Dr. Waldrop noted that its densest region, approximately 300 miles above Earth, holds merely 30,000 to 100,000 atoms per cubic centimeter. While this might sound substantial, it’s thin enough that satellites, even the International Space Station, navigate through much denser atmospheric layers below.
Even further out, at an altitude of 50,000 miles, the density plummets to a mere 25 atoms per cubic centimeter, according to Dr. Waldrop, who is also a professor of electrical and computer engineering at the University of Illinois at Urbana-Champaign.
Remarkably, even with such a sparse atomic population, the exosphere plays a critical role in Earth’s atmospheric recovery after a solar storm. Electrons from its hydrogen atoms can occasionally transfer to high-speed protons within the solar wind, effectively dissipating the intense electrical currents that threaten orbiting satellites and ground-based power systems.
Dr. Waldrop concluded, stating, “This was underappreciated for a long time.”