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

nasa.gov

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

#61

Post by close04 »

ComputerGuru wrote: post #17
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).

I just imagined that for an object sent to the Sun they'd want to... overdo it a little. Go for something synthetic that would behave even better or would save 1/2 Kg.

I'm just the inquisitive type. Explaining that something is used always makes me wonder "why not something else" :).

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

#62

Post by tgb »

kenjackson wrote: post #60
guidedlight wrote: post #5

Earlier quoted context omitted.

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.

Is that also a reason that you feel warmer in high humidity heat?

That's only part of it - sweat not being able to evaporate is another part. I'm not sure which is the bigger effect.

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

#63

Post by btrettel »

throwawaymath wrote: post #50
GimbalLock wrote: post #43

Earlier quoted context omitted.

Hello! I’m a FSW dev at NASA Langley. As others have said, the talks from the FSW workshop are a great start. If you want to see a well-used framework, check out CFS ( https://cfs.gsfc.nasa.gov )

Off topic, but I've always been interested by the way that government agencies almost exclusively choose acronyms for their software. Meanwhile private companies (especially in the last decade or two) almost always choose unrelated, single words. It initially seems kind of ridiculous to me that everything has an acronym, but I suppose it's no more ridiculous than choosing a name that sounds like a Pokemon. Maybe less…

https://ntrs.nasa.gov/search.jsp?R=20100024508

> The development and verification of the Charring Ablating Thermal Protection Implicit System Solver (CATPISS) is presented. [...]

Not sure industry would try this one either, though it is very memorable.

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

#64

Post by [deleted] »

kijin wrote: post #23
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…

I'm curious about the foam, too. Normally, foam contains a lot of air. But that kind of foam will blow itself apart in a vacuum. How do they make foam where all the air pockets are replaced with vacuum? Is vacuum-filled foam a better or worse insulator than air-filled foam?

[deleted]

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

#65

Post by cryoshon »

newscracker wrote: post #45

Towards the end, it says: > “After launch, Parker Solar Probe will detect the position of the Sun, align the thermal protection shield to face it and continue its journey for the next three months, embracing the heat of the Sun and protecting itself from the cold vacuum of space.” What a phenomenal piece of engineering! The article was not only fascinating to read as a non-astronomer/lay person, but it also makes it…

>The article was not only fascinating to read as a non-astronomer/lay person

yeah, this article was a masterpiece of science writing. all of the difficult concepts were boiled down into very fruitful analogies and metaphors which clarified things succinctly.

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

#66

Post by netfire »

The article makes it sound like there is no possible way for the probe to melt. Is this actually the case? Is there no possibility that manufacturer defects or a solar anomaly that could cause unexpected problems?

I don’t want to downplay the good design and engineering that went into this, but should we be so confident without actually having done something like this thousands of times?

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

#67

Post by Nokinside »

jccooper wrote: post #57

The part of the answer here that NASA always seems to skip (perhaps because it's not as fun as talking about all the cool heat-resistant technology) is that the vehicle is in an orbit that will only take it into the corona for a short time. While the closest approach is very close, its aphelion is (at closest) about the orbit of Venus. This gives it time to cool down after each corona encounter. https://www.youtube.c…

Thank you. I was wondering just this.

Heat resistant material will eventually reach equilibrium where the back side is almost as hot as the front side unless it's cooled somehow.

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

#68

Post by noir_lord »

dghughes wrote: post #48
kijin wrote: post #23

Earlier quoted context omitted.

I'm curious about the foam, too. Normally, foam contains a lot of air. But that kind of foam will blow itself apart in a vacuum. How do they make foam where all the air pockets are replaced with vacuum? Is vacuum-filled foam a better or worse insulator than air-filled foam?

And if the foam cells have a vacuum in them (in? lack of?) how does it not implode when on earth.

The difference between Vacumn and 1atm is 14psi, bike tires pumped to between 50-120psi (on my road bike for example), 14 psi isn't that large a pressure for a reasonably strong/stiff material.

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

#69

Post by Nokinside »

ofrzeta wrote: post #26
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…

Speaking of jokes, I guess this is how they make the foamed carbon: https://www.youtube.com/watch?v=Wex_yKfrTo4

I wonder how much carbon foam insulation costs.

http://carbonfoam.com/

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

#70

Post by lifeformed »

Nokinside wrote: post #67
jccooper wrote: post #57

The part of the answer here that NASA always seems to skip (perhaps because it's not as fun as talking about all the cool heat-resistant technology) is that the vehicle is in an orbit that will only take it into the corona for a short time. While the closest approach is very close, its aphelion is (at closest) about the orbit of Venus. This gives it time to cool down after each corona encounter. https://www.youtube.c…

Thank you. I was wondering just this. Heat resistant material will eventually reach equilibrium where the back side is almost as hot as the front side unless it's cooled somehow.

Also, the cool side of the craft will stay cool by radiating its heat away into space.
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