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The Parker Solar Probe will make its closest approach yet to the Sun

https://arstechnica.com/space/2024/12/were-about-to-fly-a-spacecraft-into-the-sun-for-the-first-time/
144pseudolus | | 114 | HN
kfogel | parent | next
Most of the comments so far are about the temperature and the closeness to the sun, and, hey, I get it: those are both amazing to think about. But to me even more amazing is... 0.16% of the speed of light?? Yikes.
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blindriver | parent | next
I don't know if I'm shocked or not shocked that the temperature is 2500F 4 million miles away from the Sun. Part of me expected it to be much much hotter than that, but I guess it is 4 million miles. Considering we are 90 million miles away, and the temperature still gets up to 120F on the Earth, maybe that makes sense?
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FredPret | parent | next
If KSP is to be believed, this is shockingly difficult to do
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pavel_lishin | parent | next
> Now, you might naively think that it's the easiest thing in the world to send a spacecraft to the Sun. After all, it's this big and massive object in the sky, and it's got a huge gravitational field. Things should want to go there because of this attraction, and you ought to be able to toss any old thing into the sky, and it will go toward the Sun.

Yes, yes, speak orbital dynamics to me!

> The problem is that you don't actually want your spacecraft to fly into the Sun or be going so fast that it passes the Sun and keeps moving. So you've got to have a pretty powerful rocket to get your spacecraft in just the right orbit.

What?! No! I mean, yes, you don't want your spacecraft going right into the sun itself, but that's not the major reason why it's difficult! It's that at launch, the spacecraft is already in orbit around the sun - since it came from the Earth. And left to its own devices, it won't want to "fall" into the sun any more than it already is, any more than the Earth is falling into it. Changing orbital parameters that much is expensive in terms of delta-V!

As I recall, the "cheap" way of getting into a low-enough orbit to get that close to the sun is to counterintuitively first expand your orbit massively, and then do a retrograde burn at the highest point. (But I'm guessing the Parker Solar Probe used gravity assists.)

I wonder if some editor cut a large part of this paragraph.

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buildsjets | parent | next
Soundtrack for appropriate ambiance.

https://music.youtube.com/watch?v=ZnIxWznakz8&si=jhjMURGD4S0...

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grecy | parent | next
Soundtrack to "Sunshine" also seems very appropriate.

https://www.youtube.com/watch?v=AXzqJucLae8

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dreamcompiler | parent | next
Imagine the Sun as a ball 1 mile in diameter. If you flew a probe by the Sun that never got closer than 4 miles away (4 diameters) would you describe it as "into the Sun?"

Neither would I.

Sure, it's close enough to get very hot. But it's not into the sun.

dang | parent | next
Related. Others?

What NASA's Parker Solar Probe discovered in its first 5 years looping the sun - https://news.ycombinator.com/item?id=37128838 - Aug 2023 (1 comment)

A NASA probe has touched plasma and gas that belongs to the sun - https://news.ycombinator.com/item?id=29965805 - Jan 2022 (31 comments)

NASA’s Parker Solar Probe Is Unlocking the Sun’s Mysteries - https://news.ycombinator.com/item?id=21709598 - Dec 2019 (2 comments)

Traveling to the Sun: Why Won’t Parker Solar Probe Melt? - https://news.ycombinator.com/item?id=17743599 - Aug 2018 (121 comments)

Traveling to the Sun: Why Won't Parker Solar Probe Melt? - https://news.ycombinator.com/item?id=17569741 - July 2018 (86 comments)

mmooss | parent | next
Look at this NASA animation of two solar probes orbiting the Sun (thanks ostacke and DiggyJohnson):

https://svs.gsfc.nasa.gov/3966/

One probe, Parker I assume, goes through all the planetary flybys to achieve its solar orbit. The other just drops into an even closer solar orbit. Why not do that for both probes?

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adregan | parent | next
Out of curiosity, what is the relationship between 430,000 mph and the speed of impulse power on Star Trek? I assume Parker Solar Probe is way slower, but what are we talking?
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verzali | parent | next
This article is about 3 years late, Parker first flew through the Sun's atmosphere in 2021. This is its closest approach but definitely not the first time it's doing it.
alnwlsn | parent | next
Yeah, it's going to get pretty hot. Scientists estimate that the probe's heat shield will endure temperatures in excess of 2,500° Fahrenheit (1,371° C) on Christmas Eve, which is pretty much the polar opposite of the North Pole.

That's the South Pole. I wasn't aware global warming has gotten that bad yet.

fortran77 | parent | next
Can’t they just go at night?
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spacesanjeet | parent | next
very cool indeed, looking forward to see how the results pan out from this project.
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amelius | parent | next
Of course it is completely evaporated before hitting anything that remotely resembles a surface.
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curtisblaine | parent | next
This reminds me of an old joke about a guy known for being particularly foolish (often a member of a specific group, like a military unit). He tells someone he plans to travel to the Sun in a spaceship. When the other person points out, "You can’t do that - you’d die from the extreme heat before even getting close" the first guy replies, "I'm not stupid! I'll go at night!"
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