The US space agency NASA is planning to send its first ever unmanned robotic probe to observe Sun in 2018. The spacecraft will get within four million miles of the extremely hot Sun atmosphere. The major challenge for the NASA scientists is to make a spacecraft that can withstand such high temperature and prevent it from evaporating.
The American space agency has sent probes to the moon and different planets; farthest being the New Horizons spacecraft to explore dwarf planet, Pluto. However, it will be the first attempt to send a probe to the Sun located nearly 100 million miles far from earth.
Unlike landing probes on Mars and Moon, scientists cannot land a probe on the Sun, but they will try to make the closest approach to the Sun while keeping the spacecraft alive.
“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.”
It is to be noticed that scientists once sent a spacecraft to Mercury which is the hottest planet and the spacecraft evaporated and stopped responding to commands within few minutes after reaching Mercury. Temperature near Sun will be even more violent which can destroy the spacecraft even before it reaches the planned orbit.
NASA scientists say that surface temperature of Sun is pretty low at 5,500 degrees Celsius; however, solar atmosphere is very hot at two million degrees Celsius. The farther we get from the solar surface, the hotter it becomes for millions of miles. Also, solar flares coming from Sub are very hot and can go up to millions of miles dissipating a large amount of heat in the surrounding making it scorching.
Researchers at NASA are developing material that can withstand such extreme temperature. As per the reports, they have designed a 1.4 centimetres carbon-composite shield that can survive at 1,370 degrees Celsius. However, the material is not enough and scientists are working to improve the endurance capability and also designing a new heat shield to protect the spacecraft.