Parker Solar Probe is a planned NASA robotic spacecraft to probe the outer corona of the Sun. It will approach to within 8.5 solar radii (5.9 million kilometers or 3.67 million miles) to the ‘surface’ (photosphere) of the Sun. The launch date will be the (Northern Hemisphere) summer of 2018.

NASA is now inviting people around the world to submit their names online to be placed on a microchip aboard NASA’s historic Parker Solar Probe mission. Submissions will be accepted until April 27, 2018. Learn more and add your name to the mission here: http://go.nasa.gov/HotTicket

the spacecraft and instruments will be protected from the Sun’s heat by a 4.5-inch-thick carbon-composite shield, which will need to withstand temperatures outside the spacecraft that reach nearly 1,370 C. This state-of-the-art heat shield will keep the four instrument suites at room temperature. These four are designed to study magnetic fields, plasma and energetic particles, and image the solar wind.

To compare distance with some familiar images, LASCO C3 images from 3.7 to 30 solar radii. LASCO C3 image below. So twice the inner radius of this.

mollwollfumble said:

Parker Solar Probe is a planned NASA robotic spacecraft to probe the outer corona of the Sun. It will approach to within 8.5 solar radii (5.9 million kilometers or 3.67 million miles) to the ‘surface’ (photosphere) of the Sun. The launch date will be the (Northern Hemisphere) summer of 2018.

NASA is now inviting people around the world to submit their names online to be placed on a microchip aboard NASA’s historic Parker Solar Probe mission. Submissions will be accepted until April 27, 2018. Learn more and add your name to the mission here: http://go.nasa.gov/HotTicket

the spacecraft and instruments will be protected from the Sun’s heat by a 4.5-inch-thick carbon-composite shield, which will need to withstand temperatures outside the spacecraft that reach nearly 1,370 C. This state-of-the-art heat shield will keep the four instrument suites at room temperature. These four are designed to study magnetic fields, plasma and energetic particles, and image the solar wind.

To compare distance with some familiar images, LASCO C3 images from 3.7 to 30 solar radii. LASCO C3 image below. So twice the inner radius of this.

Nobody asked. Given that the Corona’s temperature is 1 to 3 million degrees C, how come the spacecraft only has to withstand 1,370 degrees C?

Also nobody asked. Given that the epoxy of an epoxy carbon composite shield can only withstand 177 degrees C, the higher temperature phenolic resin can only withstand 350 degrees C. How do they expect a carbon-composite shield to withstand 1,370 degrees C?

same way sats dont burn up in the thermosphere? ;-)

Have you got your name down, Moll?

Yep, that’s the ticket above. Didn’t want to put in my real name julian mollwollfumble so gave them an alias instead.

mollwollfumble said:

Yep, that’s the ticket above. Didn’t want to put in my real name julian mollwollfumble so gave them an alias instead.

They probably wouldn’t accept my name.

Peak Warming Man said:

mollwollfumble said:

Yep, that’s the ticket above. Didn’t want to put in my real name julian mollwollfumble so gave them an alias instead.

They probably wouldn’t accept my name.

Nothing wrong with “Peak Man”.

This spell checker is awful. It autochanged “man” to “many”, “probe” to “problem”, “shield” to “shielding”, “fibre” to “fibreglass”. I’d write a new spellchecker if I knew how.

Back to the solar probe, I previously had two ideas for a heat shield. Based on lunar dust. One was a tangle of tungsten threads, like steel wool made out of tungsten. A second was made of three thin layers using carbon, tungsten and molybdenum with the shiny side out and matte side in.

A new one that occurs to me is a cheap forest of carbon nanotubes. This is made in the standard way by methane decompostion on metal dots. It’s oodles cheaper than single nanotubes.

I’m far from sure how successful the selected carbon fibre composite would be. How would it work?