The Sun makes people living on Earth at a distance of about 149 million kilometres go sweating with its scorching heat. People in their wildest imagination never dare to even think about going near the Sun. But NASA is going to do the impossible.
The US space agency has plans to send its first robotic spacecraft to the Sun in 2018. The spacecraft will hover around within six million kilometres of the blazing Sun and will probe its atmosphere.
Sending spacecraft to the Moon, Mars and distance interstellar space is nothing new, humans have been involved in space activities for long. But, launching the Solar Probe Plus mission to the hottest star is something which is going to be happened for the first time.
“This is going to be our first mission to fly to the Sun,” said Eric Christian, a NASA research scientist at Goddard Space Flight Centre.
“We can’t get to the very surface of the Sun,” but the mission will get close enough to answer three important questions, Christian said. The Sun’s surface is known as photosphere, while its atmosphere is called the corona. The NASA solar mission will try to find out why the surface of the Sun is not as hot as its atmosphere.
NASA says the surface temperature of the Sun is only about 5,500 degrees Celsius. But the atmosphere above it is two million degrees Celsius.
“You would think the farther away you get from a heat source, you would get colder. Why the atmosphere is hotter than the surface is a big puzzle,” Christian said.
The scientists also want to know how solar wind gets its speed, ‘Live Science’ reported.
“The Sun blows a stream of charged particles in all directions at a million miles an hour. But we do not understand how that gets accelerated,” he said.
The mission may also ascertain why the Sun occasionally emits high-energy particles that are a danger to unprotected astronauts and spacecraft.
NASA has designed a 11.4 centimetres carbon-composite shield, which is designed to withstand temperatures outside the spacecraft of 1,370 degrees Celsius.
The unmanned probe will have special heat tubes called thermal radiators that will radiate heat that permeates the heat shield to open space, “so it does not go to the instruments, which are sensitive to heat,” Christian added.
(With inputs from PTI)