NASA craft to head for the sun

Scientific probe will reach the speed of nearly 700,000 km/h

TAMPA, Florida－NASA is poised to launch a $1.5 billion spacecraft on a brutally hot journey toward the sun, offering scientists the closest view of our strange and mysterious star.

After the Parker Solar Probe blasts off from Cape Canaveral, Florida on Saturday, it will become the first spacecraft to fly through the sun's scorching atmosphere, known as the corona.

Understanding how the corona works will help scientists anticipate dangerous space weather storms, which can disrupt the power grid on Earth.

"It's of fundamental importance for us to be able to predict space weather much the way we predict weather on Earth," said Alex Young, a solar scientist at NASA.

The corona is a "very strange, unfamiliar environment for us".

'Touch the sun'

The unmanned probe is named after Eugene Parker, the 91-year-old pioneering solar astrophysicist, and the US space agency has coined it as the first mission to "touch the sun".

It will actually skim by at a distance of 6.3 million kilometers above the sun's surface.

Mission managers said that may sound like a lot but is really quite a close shave, given the sweltering conditions out there.

The sun-facing side of the probe will endure temperatures of about 1,370 C.

The spacecraft is protected by a heat shield that will keep it closer to room temperature, about 29 C.

Speeding by at a pace of nearly 700,000 km/h will make it "the fastest human-made object", said project scientist Nicky Fox of the Johns Hopkins University Applied Physics Lab.

Over the course of its seven-year mission, the spacecraft aims to pass through the corona 24 times, which Fox said makes for an "incredibly daring journey".