NASA to Send Craft to the Sun

NASA is preparing for an unprecedented mission to visit and study the sun closer than ever before.

A few weeks ago, I wrote about several past and future missions for space probes. One probe, Juno, is gearing up for a trip to Jupiter, where it will be exposed to extreme heat and radiation. But those conditions are nothing compared with the conditions of the sun. NASA recently announced its Solar Probe Plus mission, an unprecedented project to send a spacecraft to the sun by 2018.

The Solar Probe Plus will mark mankind's first visit to a star. Despite decades of careful research about the sun, many mysteries still exist about aspects like its atmosphere (the corona) and winds. Unfortunately for Earth-bound astronomers and scientists, these mysteries can only be unlocked through up-close measurements and observations. The Solar Probe Plus is being designed to undertake these experiments.

The Solar Probe Plus probe will get closer to the sun than any spacecraft before it (source: NASA).

"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?" says Dick Fisher, director of NASA's Heliophysics Division in Washington, D.C., in a NASA press release. "We've been struggling with these questions for decades, and this mission should finally provide those answers."

The spacecraft will enter into the sun's atmosphere at a distance of about 6.4 million kilometers (4 million miles) from the star's surface. No other craft has ever visited this region of space, where temperatures exceed 1,400 degrees Celsius (2,550 degrees Fahrenheit). The car-sized machine has a revolutionary carbon-composite heat shield to protect it from this heat and frequent blasts of intense radiation.

In 2009, NASA invited research proposals for the craft's objectives. Among a total of 13, five proposals were chosen by a team of NASA researchers and outside scientists. Total funding of approximately $180 million will be awarded to the projects for preliminary analysis, design, development and tests.

The craft will count and capture the most abundant particles in solar winds—electrons, protons and helium ions. Measurements and analysis of these particles will provide keys to the structure and origins of the sun. A wide-field telescope will take 3D pictures of the sun's corona, including winds, clouds and solar shocks. The images will allow scientists to take measurements of solar qualities like plasma.

The probe will measure electric and magnetic fields, radio emissions, and shock waves that pulse throughout the sun's atmospheric plasma. It will also detect any dust particles passing by its antennae.

Using mass spectrometry, two separate instruments will weigh and sort ions in the vicinity of the spacecraft. This will allow scientists to take an inventory of the specific elements in the sun's atmosphere.

All data collected by the probe will be transmitted back to scientists on Earth, where it can be processed and analyzed.

"This project allows humanity's ingenuity to go where no spacecraft has ever gone before," says Lika Guhathakurta, Solar Probe Plus program scientist at NASA Headquarters in Washington, D.C. "For the very first time, we'll be able to touch, taste and smell our sun."

The mission is part of NASA's Living with a Star Program, which aims to understand the sun and Earth's space environment. NASA'S Goddard Space Flight Center in Greenbelt, Md., manages the program, with supervision from NASA's Science Mission Directorate's Heliophysics Division. The Johns Hopkins University Applied Physics Laboratory, in Laurel, Md., is the prime contractor for the space probe.