Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Traveling to the Sun: Why Won’t Parker Solar Probe Melt?

nasa.gov

Post reply on HN
Print view View original

11–20 of 128 posts

Re: Traveling to the Sun: Why Won’t Parker Solar Probe Melt?

#11

Post by Aaargh20318 »

JonoW wrote: post #10

>This all has to happen without any human intervention, so the central computer software has been programmed and extensively tested to make sure all corrections can be made on the fly. I'd love to get some deeper insight into how NASA writes and tests software, I can only guess it's a million miles from how most of us work. Anyone know of any good talks, articles from engineers there?

Here's an article about it I read a while back, interesting read: https://www.fastcompany.com/28121/they-write-right-stuff

Re: Traveling to the Sun: Why Won’t Parker Solar Probe Melt?

#12

Post by 1ste »

guidedlight wrote: post #5
hliyan wrote: post #2

As I understand, temperature is a measure of how fast atoms and molecules are vibrating, and not a measure of how much energy per unit area of contact can be transferred in a unit time.

Exactly. Stick your hand into an oven at 100 celsius ...OR... Stick your hand into into a pot of water at 100 celsius. The difference is that the water molecules are more tightly packed, than the air molecules in the oven. In space, they are quite far apart.

The article's video described this

Re: Traveling to the Sun: Why Won’t Parker Solar Probe Melt?

#13

Post by thedancollins »

chiph wrote: post #4

Dad joke: "They'll go at night" But really, it's cool that they're using carbon-carbon protection similar to that which was originally developed for the leading edges of the Space Shuttle. And I really want to know how they built foamed carbon for the interior. I'm guessing that they're using white ceramic paint on top instead of a reflective foil shield (like the Webb uses) because the foil would be shredded by the…

Texas A&M, represent!

Re: Traveling to the Sun: Why Won’t Parker Solar Probe Melt?

#14

Post by austincheney »

http://earthsky.org/space/heat-shield-parker-solar-probe

It appears the heat shield is a carbon sheet sandwich. At first I was guessing some form of tungsten-carbine, but that is the traditional material of NASA heat shields.

> Why is the solar wind a breeze closer to the sun but a supersonic torrent farther away? Why is the corona itself millions of degrees hotter than the surface?

I suspect the answer to all those questions is simply gravity, but it will be nice to verify such things with data.

Re: Traveling to the Sun: Why Won’t Parker Solar Probe Melt?

#16

Post by mi3law »

JonoW wrote: post #10

>This all has to happen without any human intervention, so the central computer software has been programmed and extensively tested to make sure all corrections can be made on the fly. I'd love to get some deeper insight into how NASA writes and tests software, I can only guess it's a million miles from how most of us work. Anyone know of any good talks, articles from engineers there?

There was a discussion on HN a while back RE NASA's software safety guidlines. Here is the link to the discussion: https://news.ycombinator.com/item?id=12014271

The PDF linked to in the discussion is no longer there, but I found it on standards.nasa.gov here: https://standards.nasa.gov/standard/nasa/nasa-gb-871913

There are also some interesting product management related guidelines from NASA, like this from 2014: https://snebulos.mit.edu/projects/reference/NASA-Generic/NPR...

Re: Traveling to the Sun: Why Won’t Parker Solar Probe Melt?

#17

Post by ComputerGuru »

close04 wrote: post #9

Any reason why they're using water for cooling? There's no other liquid with lower density and perhaps better thermal properties? I imagined they would try to save weight in some places if it allows them more freedom in others. Although I have no idea how much water is used in the first place so it might be a moot point.

> The coolant used for the system? About a gallon (3.7 liters) of deionized water. While plenty of chemical coolants exist, the range of temperatures the spacecraft will be exposed to varies between 50 F (10 C) and 257 F (125 C). Very few liquids can handle those ranges like water. To keep the water from boiling at the higher end of the temperatures, it will be pressurized so the boiling point is over 257 F (125 C).

Re: Traveling to the Sun: Why Won’t Parker Solar Probe Melt?

#18

Post by implements »

MichaelMoser123 wrote: post #8

>Another challenge came in the form of the electronic wiring — most cables would melt from exposure to heat radiation at such close proximity to the Sun. To solve this problem, the team grew sapphire crystal tubes to suspend the wiring, and made the wires from niobium. are these wires on the outside of the spacecraft? but what about the silicon of all the electronic stuff that this thing must be keeping? The cooling…

Not a scientist, but I assume using "radiative heat transfer" ie a hot surface shielded from the sun emitting thermal radiation away from the spacecraft.

Re: Traveling to the Sun: Why Won’t Parker Solar Probe Melt?

#19

Post by hutzlibu »

austincheney wrote: post #14

http://earthsky.org/space/heat-shield-parker-solar-probe It appears the heat shield is a carbon sheet sandwich. At first I was guessing some form of tungsten-carbine, but that is the traditional material of NASA heat shields. > Why is the solar wind a breeze closer to the sun but a supersonic torrent farther away? Why is the corona itself millions of degrees hotter than the surface? I suspect the answer to all those…

"Why is the corona itself millions of degrees hotter than the surface?

I suspect the answer to all those questions is simply gravity, but it will be nice to verify such things with data"

Can you explain your hypothesis a bit?

Post reply on HN