NASA's epic mission to 'touch the Sun'

NASA is launching a spacecraft to 'touch the Sun' for the first time. The $1.4 billion Parker Solar Probe mission will aim to edge within 6.4 million km of the searing hot star — close enough to study its atmosphere, solar winds, and other properties. The launch takes place from Cape Canaveral in Florida on Saturday. However, NASA has through August 23 to fire off its probe, which is expected to reach the Sun a few months after launch. The probe will ride atop a United Launch Alliance Delta IV Heavy rocket, one of the most powerful operational launch vehicles on Earth. To withstand the sunlight — 3,000 times more powerful than on Earth — it will be equipped with a special heat shield called the Thermal Protection System, which will absorb and deflect solar energy that might otherwise roast the probe.