NASA Going to the Sun

Our Sun has been the focus of astronomers for many centuries, and humanity for much longer. So for the first time, NASA will be sending a mission, labeled as Solar Probe+ (Solar Probe plus) to study our star.

"We are going to visit a living, breathing star for the first time," says program scientist Lika Guhathakurta of NASA Headquarters. "This is an unexplored region of the solar system and the possibilities for discovery are off the charts."

The mission could launch as soon as 2015, and within the 7 years it will take to complete the mission, Solar Probe+ will have hopefully solved two of the greatest astrophysical mysteries; the high temperature of the Sun’s corona and the weird acceleration of solar winds.

At its closest approach, Solar Probe+ will be 7 million kilometers from the sun, witnessing the Sun at 23 times wider than what we see it from Earth. The vessel will have to withstand temperatures greater than 1400 degrees Celsius, and suffer radiation bursts that no other Earth vessel has ever encountered.

Johns Hopkins' Applied Physics Lab (APL) will be designing and building the spacecraft, following on from their MESSENGER success. The MESSENGER, which this year made its first flyby of Mercury, is made up of similar heat protection, considering how close it travels to the Sun. The “plus” part of the missions name comes from the improved design of APL’s earlier 2005 design called Solar Probe.

The two main mysteries that Solar Probe+ is hoping to answer are puzzles that have baffled scientists for a long time. In the case of the Sun’s corona, if you were to take the Sun’s surface temperature, it would read somewhere around the 6,000 degrees Celsius mark. However, if you move further out, the heat rises, instead of intuitively dropping.

The second mystery, that of the solar winds, focuses on the fact that, even though all objects in a system suffer from solar winds, there are no organized winds close to the surface of the Sun. So just what gives the solar winds their massive velocity?

Solar Probe+ will likely launch May 2015, and spend the next 7 years hopefully answering these mysteries, and making new discoveries. It will encounter the end of Solar Cycle 24, as well as hopefully finish near the predicted maximum of Solar Cycle 25. "Solar Probe+ is an extraordinary mission of exploration, discovery and deep understanding," says Guhathakurta. "We can't wait to get started."

Posted by Josh Hill.