A NASA Spacecraft Will Head Straight For the Sun -- Farther Than Any Probe Before It (abc.net.au)

A US spacecraft will swoop inside the Sun's corona, its superheated outer atmosphere, on a pathfinding mission to learn more about how stars work. Nasa's $1.5bn Parker Solar Probe, which will be protected by a shield that can withstand temperatures of 1,400C, will journey within 6m km of the Sun's surface, seven times closer than any previous spacecraft. From a report: Set to kick off next July, the plan is to plunge the Parker Solar Probe into the Sun's corona -- the hazy bit you can see around the edges of the Sun during a total solar eclipse -- to study this phenomenon. The car-sized spacecraft will get closer to the Sun than any other mission ever has. Travelling at the dizzying speed of more than 720,000 kilometres per hour, the probe will eventually come within less than 6.4 million kilometres of the Sun's surface. We've been studying the Sun for thousands of years, and even though we now have remote sensing observatories and spacecraft that examine it in spectacular detail, many questions still remain. The two big ones are: 1. Why is the corona on the outside of the Sun at least 300 times hotter than the surface? 2. Why does the solar wind speed up?

Comments

The heat shield is much better than Plan B...

[wernst]

...which was to have the probe do its work close to The Sun at night.

Re:The heat shield is much better than Plan B...

[edxwelch]

Night is when you use an actual planet for the heat shield

since space is a vacuum

[Anonymous Coward]

it has no temperature... so the shield material will get that hot... but what's going to protect what's behind that shield from that temperature?

Since it can only cool by radiation, it'll have to sink to the cold side, behind the spacecraft, right?

Re:since space is a vacuum

[quenda]

it has no temperature...

Vacuum is far from empty. Even in deepest, darkest space you have a temperature of 2.7K from the cosmic background radiation.
Temperature is not just about conduction.

This probe is going into the sun's corona, which does have a particle temperature, but is so thin that the radiation temperature is far more important.

It's hard to hit the Sun

[jfdavis668]

Since the Earth is moving in solar orbit, so is the spacecraft launched from Earth. You have to lose quite a bit of energy to slow down enough to drop toward the Sun. There is a MinutePhysics video on the issue: https://www.youtube.com/watch?...

Re:Why does the solar wind speed up?

[MangoCats]

Because the electrons are all screaming "Charge!"

We're heading right for it

[Soft Filter]

Simon: My God! The sun.

Elaine: What is it, Simon?

Simon: A large, fiery ball at the center of our solar system, but that's not important now. We're heading right for it.

Re:This story and the Climate change story precedi

[slew]

The summary is very wrong. The sun's surface is ~5800K. The corona (above the surface) is ~500,000 K, or 100x hotter than that (or more; the temperature of the corona varies). This means if the probe is designed to burn up at ~1700K, it won't get to 5 km above the surface; in fact, it will burn up more than 2000 km above the surface.

Unless you define "surface" as the top of the corona... in which case maybe, but the temperature number is wrong at that point.

I guess we have to wait until 2369 for Dr. Reyga to develop metaphasic shielding to know for sure...

Required video...

[QuietLagoon]

Pink Floyd - Set The Controls For The Heart of the Sun...

https://www.youtube.com/watch?...

Re:This story and the Climate change story precedi

[FatdogHaiku]

It's OK, their going at night...