It’s human nature to get excited by novelty in science…to gravitate to the sexy headlines and the tales of new discoveries and the flashy imagery. But so much of science is a slow slog, an anonymous labor in ordinary looking labs and cinderblock office buildings. Most scientists know that the fundamental advances do not often come in “Eureka!” moments or get announced at press conferences. They get made in the background by the unsung worker bees, both human and technological.
And so it is for NASA’s Wind spacecraft. You probably have never heard of it. Most of my colleagues around NASA have never heard of it. And yet it has quietly made fundamental contributions to our understanding of the electric space around Earth.
Wind studies a dark and mostly desolate netherworld between Earth and the Sun, a region that doesn’t quite fit into solar science (heliophysics) nor does it have a home in Earth science. The Wind spacecraft has no cameras and its data are rarely turned into images for public consumption. With particle counters and antennas and magnetometers, it studies how Earth’s sphere of space — geospace — interacts with the energy and particles Sun flying off of the Sun. The field is often referred to as space weather, but the analogies sort of fall apart when you learn that the most potent solar wind couldn’t ruffle the hair on your head. (It could wipe out your satellite, though.)
This solar wind, the namesake of the spacecraft, stretches and pulls the Earth’s magnetic aura (the magnetosphere) like a windsock. The magnetic field occasionally snaps back to energize the Van Allen radiation belts and to create the cascade of atmospheric particles that we know as aurora borealis and aurora australis (the northern and southern lights). Click on this link to a 1997 vintage computer model showing how the solar wind stirs up the magnetosphere. (Seventeen year-old GIFs below, with credit to Ramon Lopez, Chuck Goodrich, and their former science team at the University of Maryland).
In November 2014, Wind celebrated its 20th birthday in space. After observing our magnetic and plasma environment from several angles, it has moved back to where it started its work at the L1 Lagrange point, where the gravitational pull of the Earth and Sun cancel each other out and provide a stable orbit. Engineers say there is enough fuel to keep the spacecraft there until 2074, so Wind will keep working until the batteries or money run out.
I have a special affection for Wind, as it is one of the missions that first brought me to work at NASA. In 1997, the scientists leading the International Solar Terrestrial Physics program and the Global Geospace Science hired a young science writer to help them tell their story, and I am grateful to have had the chance. If you want to spy a bit of ancient history on the web, take a look at this old web site.
My colleague in NASA’s heliophysics division, Karen Fox, has written a great roundup of where Wind has been and all that has been accomplished with this mostly anonymous spacecraft. Go here to read her article. If you want to dig through nearly 3,000 scholarly references to Wind data, click here.