NASA's Parker Solar Probe is attempting its closest approach to the Sun

A NASA spacecraft is attempting to make history with the closest approach to the Sun in history.

The Parker Solar Probe plunges into the outer atmosphere of our star, enduring brutal temperatures and extreme radiation.

It has been out of communication for several days during this scorching hot flyby, and scientists will wait for a signal, expected on December 27, to see if it survived.

The hope is that the probe can help us better understand how the Sun works.

Dr Nicola Fox, Head of Science at NASA, told BBC News: 'For centuries people have studied the Sun, but you don't get a sense of the atmosphere of a place until you visit it.

“And so we can't really experience our star's atmosphere unless we fly through it.”

The Parker Solar Probe launched in 2018, heading toward the center of our Solar System.

It has already passed the Sun 21 times, getting ever closer, but the Christmas Eve visit is a record.

At its closest approach, the probe is 3.8 million miles (6.2 million kilometers) from the surface of our star.

That might not sound that close, but NASA's Nicola Fox puts it into perspective: “We're 93 million miles from the Sun, so if I put the Sun and Earth a meter apart, the Parker Solar Probe is four centimeters from The sun – so it's close.”

The probe will have to withstand temperatures of 1400C and radiation that can damage the electronics on board.

It is protected by an 11.5 cm (4.5 in) thick carbon composite shield, but the spacecraft's tactic is to get in and out quickly.

In fact, it will travel faster than any man-made object, flying at 430,000 miles per hour – the equivalent of flying from London to New York in less than 30 seconds.

So why go to all this effort to “touch” the Sun?

Scientists hope that as the spacecraft passes through our star's outer atmosphere – its corona – it will solve a long-standing mystery.

“The corona is really, really hot, and we have no idea why,” explains Dr. Jennifer Millard, an astronomer at Fifth Star Labs.

“The surface of the Sun is about 6000C or so, but the corona, that tenuous outer atmosphere that you can see during solar eclipses, reaches millions of degrees – and that's further away from the Sun. So how does this atmosphere get hotter?”

The mission should also help scientists better understand the solar wind, the constant stream of charged particles erupting from the corona.

When these particles interact with Earth's magnetic field, the sky lights up with dazzling auroras.

But this so-called space weather can also cause problems by knocking out power grids, electronics and communications systems.

“Understanding the Sun, its activity, space weather, the solar wind is so important to our daily lives on Earth,” says Dr. Millard.

NASA scientists face an anxious wait at Christmas while the spacecraft is out of touch with Earth.

Nicola Fox says that as soon as a signal is sent home, the team will text her with a green heart to let her know the probe is OK.

She admits she is nervous about the daring attempt, but she believes in the probe.

“I'll worry about the spaceship. But we really designed it to withstand all these brutal, brutal conditions. It's a sturdy, sturdy little spacecraft.''