At long last, here comes the sun (mission).
Never mind NASA’s numerous observatories; never mind the unmanned Pioneer 10 and Voyager probes careening toward the far reaches of the solar system—no craft has ever gone to the center of the solar system, the sun. This decade that will change. NASA is in the process of selecting the instruments for its Solar Probe Plus, a mission to launch by 2018 that will get closer to then sun than ever before, and hopefully find some answers to the open questions that remain about our life-giving star.
“The experiments selected for Solar Probe Plus are specifically designed to solve two key questions of solar physics: why is the Sun’s outer atmosphere so much hotter than the Sun’s visible surface, and what propels the solar wind that affects Earth and our Solar System,” said Dick Fisher, director of Nasa’s Heliophysics Division in Washington DC. [BBC News]
The probe isn’t quite setting the controls for the heart of the sun, Pink Floyd-style, but it will draw dangerously close.
Eight weeks after launch, Solar Probe Plus will arrive at the sun to begin the first of 24 orbits using flybys of Venus to gradually shrink its distance to the sun. Eventually, it will come as close as about 4 million miles, which is inside the orbit of Mercury and about eight times closer than any previous spacecraft. [Discovery News]
At that distance the spacecraft must be able to withstand temperatures of about 2,600 degrees Fahrenheit, at least long enough for the instruments it carries to conduct their study. NASA’s press release counts out the five experiments chosen for this suicide mission, which include:
counting the most abundant particles in the solar wind: electrons, protons, and helium ions
imaging the corona in 3D
directly measuring the magnetic and electric fields in the sun’s atmospheric plasma
taking stock of all the elements in the sun’s atmosphere
an independent overview of the mission
All this was a long time coming. Physicists who study the sun have wanted to go there since the dawn of the space age more than a half-century ago, but were thwarted by the problem of getting close enough to conduct meaningful studies without burning up in an instant.
Now, finally, we’re getting to know our home star. This year NASA launched the Solar Dynamics Observatory, which has beamed home some stunning views of solar splendor. It won’t be the only one staring at the sun once the billion-dollar Solar Probe Plus takes flight. However, SPP’s mission is still nearly a decade away: The launch was intended for 2015, but NASA delayed the mission three years to spread out its cost.
Image: JHU/APL
