New Spacecraft Will Come Closer To The Sun Than Ever Before

Astronomers expect to get the closest look at the sun after the scheduled Solar Orbiter launch in 2017. The European Space Agency and NASA plan to finance the $400 million satellite that will pass within 29 million miles (46 million kilometers) from the sun -- closer than Mercury, officials announced in April.

The Solar Orbiter will aim to better understand how solar winds affect radio signals and satellites. The planned satellite will also examine the sun's atmosphere, called the heliosphere, which expands outward into space as a bubble over 10 billion miles (17 million kilometers), according to the ESA.

We don't really know how (the sun's atmosphere is) formed and how it varies with time, but Solar Orbiter will get really deep into that atmosphere to see where on the surface the emissions are coming from, to ultimately understand how the great bubble is made, Lucie Green, a solar physicist from University College London, told BBC News.

The orbiter will carry a heat shield as the sun reaches over 10,000 degrees Fahrenheit (5,600 degrees Celsius).

If it were not protected, the face of the spacecraft would get as hot as 500 degrees - - which would be disastrous, Ralph Cordey, head of science at Astrium U.K., the organization that will build the orbiter, told BBC News. We will use a thick heat shield to reduce the temperature within the spacecraft and its systems down to about room temperature so that all the electronics can operate comfortably.

NASA has launched several probes to study the sun in the past.

Between 1960 and 1969, NASA launched five probes as part of its Pioneer mission to study the sun. The spacecraft ventured within 90 million miles (150 million kilometers) of the sun and studied the magnetic fields and analyzed its cosmic radiation.

In 2006, NASA launched two STEREO spacecraft that for the first time monitored the far side of the sun. In February 2011, the two spacecraft reached exactly 180 degrees from each other and allowed astronomers to view the entire sun at once.

In addition to taking images of the sun, the STEREO spacecraft are monitoring coronal mass ejections -- massive bursts of charged particles -- that could interfere with radio communications, airlines, power grids and satellites.

The orbiter mission will create a better understanding of the sun's influence on our planet, Alvaro Gimenez Canete, director of science and robotic exploration for the ESA, told the Agence France-Presse.

It will help us understand how the Sun, essential to almost all life on Earth, forms the heliosphere and the origin of space weather, which can have an enormous influence on our modern civilization, he said.