WingNews logo WingNews GitHub [2]
top | item 29561885

NASA spacecraft ‘touches’ the Sun for the first time ever

266 points| perihelions | 4 years ago |nature.com | reply

83 comments

order
[+] remarkEon|4 years ago|reply
Since getting that close takes a lot of DeltaV and I was curious:

>The Parker Solar Probe mission design uses repeated gravity assists at Venus to incrementally decrease its orbital perihelion to achieve a final altitude (above the surface) of approximately 8.5 solar radii, or about 6×106 km (3.7×106 mi; 0.040 au).[35] The spacecraft trajectory will include seven Venus flybys over nearly seven years to gradually shrink its elliptical orbit around the Sun, for a total of 24 orbits.[1] The near Sun radiation environment is predicted to cause spacecraft charging effects, radiation damage in materials and electronics, and communication interruptions, so the orbit will be highly elliptical with short times spent near the Sun.[34]

https://en.wikipedia.org/wiki/Parker_Solar_Probe

[+] marcodiego|4 years ago|reply
> 6×106 km

Please... 6×10^6 km

[+] dmurray|4 years ago|reply
Highly elliptical orbits are cheaper to achieve anyway, right? You can get into one directly from your Venus gravity assists, and not have to keep precious fuel to transfer to a circular orbit later on.
[+] djxfade|4 years ago|reply
Why not just write 636 km?
[+] threefour|4 years ago|reply
If you’re curious why it won’t melt: https://www.nasa.gov/feature/goddard/2018/traveling-to-the-s...
[+] Aachen|4 years ago|reply
Relevant part: the capturing cups are of metals with high melting points, plus

> The corona through which Parker Solar Probe flies, for example, has an extremely high temperature but very low density. Think of the difference between putting your hand in a hot oven versus putting it in a pot of boiling water

And for the rest of the craft there is a highly reflective heat shield.

[+] lordnacho|4 years ago|reply
Basically not much heat is transferred because there's not many particles to do the transfer, like a hot oven.

What I didn't understand was the coolant. It's got to dump whatever heat it picks up somewhere? Just a big radiator?

[+] l0b0|4 years ago|reply
From the article:

  > A NASA spacecraft has entered a previously unexplored region of the Solar System — the Sun’s outer atmosphere, or corona. 

  > The mission’s closest approach is scheduled for 2025 at a distance of just 6.2 million kilometres from the solar surface, well within the orbit of Mercury.
From the paper, it looks like the closest approach was

  > 18.4 solar radii (R⊙ ≡ 6.95 × 10⁵ km) from the center of the Sun
Wait, what? NASA says[1] the corona extends 5 million km, so 6.2 million km would be outside the corona. 18.4 × 6.95 × 10⁵ = 12.788 million km, which is more than twice the quoted number. And according to Wikipedia[2], Mercury's orbit is ~58 million km from the sun. So it's already well within that orbit. I've had a couple beers, but I didn't think I was that drunk already. What's going on?

[1] https://www.nasa.gov/content/goddard/nasas-stereo-maps-much-...

[2] https://en.wikipedia.org/wiki/Mercury_(planet)

[+] steventharlow|4 years ago|reply
For one, the NASA article says 5 million miles (12 solar radii), not kilometers. So it's actually about 2/3 the quoted number.
[+] dataflow|4 years ago|reply
I think the 5 million km figure is just an order-of-magnitude/ballpark estimate, not something precise.

"The corona starts at 10,000 kilometers and extends out to about 10 million kilometers, where the gas finally escapes the sun's gravity and becomes part of the solar wind." [1]

[1] https://www.scientificamerican.com/article/i-read-that-the-s...

[+] heyoni|4 years ago|reply
I haven’t read any of this cause I’m on my phone but wouldn’t the closest approach occur in 2025? And isn’t the 6.95 quoted the closest distance so far?
[+] ivanhoe|4 years ago|reply
I get the heat part (well, after reading the explanations in the article that is), but how do they send the data back to Earth, considering the amount of EM noise that close to the Sun?
[+] bisRepetita|4 years ago|reply
For metric system people, if the Sun and the Earth were 1 meter apart, the probe would get as close as 11cm from the Sun.

(site writes: "If Earth was at one end of a yard-stick and the Sun on the other, Parker Solar Probe will make it to within four inches of the solar surface.")

[+] kitd|4 years ago|reply
But it's getting closer with each pass, and that distance will be down to 4cm by 2025.
[+] mcv|4 years ago|reply
But that's not really touching the sun, is it?
[+] omegalulw|4 years ago|reply
The original phrasing is more accurate. "Earth and sun being ... apart" doesnt tell you if you are measuring from the center or surface.
[+] spookthesunset|4 years ago|reply
11cm is still a long ways away. It's crazy how close yet so far everything is.
[+] cableshaft|4 years ago|reply
I didn't even know this was possible to get something that could withstand this much heat and still take valid measurements. This is incredible. Congratulations to the team that made this happen.
[+] tacocataco|4 years ago|reply
Icarus, consider yourself avenged.
[+] HPsquared|4 years ago|reply
That would have been a great name for this probe.
[+] hbcondo714|4 years ago|reply
> The Parker probe crossed into the Sun’s atmosphere at 9:33 a.m. Universal Time on 28 April of this year. It took several months for mission scientists to download and analyse the data it collected, and to be sure that the spacecraft had indeed crossed the much-anticipated boundary

What an achievement this is! I can't imagine the build up and anticipation the team members endured for months on end to finally get to this point.

[+] kolla|4 years ago|reply
If the Moon was 10x as far away from the Earth as it is now then that would still be closer to Earth than this probe ever was to the Sun.
[+] kitd|4 years ago|reply
And your point is?

The moon doesn't have a million-degree corona.

[+] Pxtl|4 years ago|reply
Please tell me this mission ends with the Venera/Cassini treatment of "let's drop the sucker into the atmosphere and see how long it lasts"
[+] thehappypm|4 years ago|reply
It’s not possible sadly. In order to crash into the sun you’d need to get out of orbit, counter-intuitively. The orbital speeds here are crazy high so the spacecraft would need either a gigantic amount of gravity assists or a gigantic rocket.
[+] perihelions|4 years ago|reply
Inconveniently, the sun is a loud radio emitter, so it isn't possible to communicate with this probe when it's at a low phase angle with the sun.
[+] codezero|4 years ago|reply
This is huge. It’s fun seeing people I worked with mentioned in a news article on a project that seemed so far off when I left the field in 2012.
[+] duxup|4 years ago|reply
Are there any photos from the spacecraft just to get an idea how close it is?

I am wondering why the sun looks like from there.

[+] lucideer|4 years ago|reply
Does anyone know what the differences in intent and mission scope are between this and the Solar Orbiter?

This obviously seems to go a lot closer, but both missions seem similar length and NASA is involved in both.

[+] gereshes|4 years ago|reply
They're complementary. Parker Solar Probe (PSP) carries a smaller, less capable payload than Solar Orbiter (SO) but it goes closer to the Sun, allowing for direct sampling of the corona. PSP cannot carry cameras for observing the Sun because of how close it gets (heat shield reasons), but SO can. This allows SO to observe the Sun's corona on a large scale, while PSP can validate those measurements with local sample collection.