NASA probe launching on solar voyage
CAPE CANAVERAL, Fla. — A red-hot voyage to the sun is going to bring us closer to our star than ever before.
NASA’s Parker Solar Probe will be the first spacecraft to ‘‘touch’’ the sun, hurtling through the sizzling solar atmosphere and coming within 3.8 million miles of the surface.
It’s designed to take solar punishment like never before, thanks to its revolutionary heat shield that’s capable of withstanding 2,500 degrees Fahrenheit.
Liftoff is set for the pre-dawn hours of Saturday for this first-of-its-kind mission to a star.
‘‘The coolest, hottest mission, baby, that’s what it is,’’ said Nicola Fox, the project scientist at Johns Hopkins University.
Roughly the size of a small car, Parker will get nearly seven times closer to the sun than previous spacecraft. To snuggle up to the sun, it will fly past Venus seven times over seven years. Each flyby will provide an orbit-shaping gravity boost, drawing it ever closer to the sun and straight into the corona — the sun’s outermost atmosphere.
Scientists hope such close encounters will help them figure out why the corona is hundreds of times hotter than the sun’s surface. Another mystery scientists hope to solve: What drives the solar wind? That’s the steady, supersonic stream of charged particles blasting off the corona and into space in all directions.
‘‘There are missions that are studying the solar wind, but we’re going to get to the birthplace,’’ Fox said.
Scientists expect the $1.5 billion mission to shed light not only on our own dynamic sun, but the billions of other yellow dwarf stars — and other types of stars — out there in the Milky Way and beyond. While granting us life, the sun also has the power to disrupt spacecraft in orbit, and communications and electronics on Earth.
‘‘This is where we live,’’ said NASA solar astrophysicist Alex Young. ‘‘We have to understand and characterize this place that we’re traveling through.’’
The project was proposed in 1958 to a brand-new NASA, and ‘‘60 years later, and it’s becoming a reality,’’ said project manager Andy Driesman, also of Johns Hopkins, which designed and built the spacecraft. The technology for surviving such a close solar encounter, while still being light enough for flight, wasn’t available until now.
Parker’s 8-foot heat shield is just 4 ½ inches thick. Sandwiched between two carbon sheets is airy carbon foam. The front has a custom white ceramic coating to reflect sunlight; it’s expected to glow cherry red when bombarded by the extreme solar heat.
Almost everything on the spacecraft will be behind this and thus in room-temperature shade while ducking through the jagged edges of the corona.
This is the first NASA spacecraft to be named after someone still alive.
Eugene Parker, 91, professor emeritus at the University of Chicago, predicted the existence of solar wind 60 years ago. He plans be at Cape Canaveral for the launch.
‘‘This is a journey into never-never land, you might say, where it’s too hot for any sensible spacecraft to function,’’ Parker told Johns Hopkins’s Fox in a recent interview. ‘‘But some very clever engineering and construction have succeeded in making what looks like a very workable instrument.’’