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The Parker Solar Probe will make its closest approach yet to the Sun
- pavel_lishin 2y ago> 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.
- zomg 2y agoi was thinking the same but with respect to this entire article -- feels like we're missing the second half and/or much more detail. feels like the article was due in to the editor by 11pm and the author forgot and started writing it at 10pm. :x either way, very fascinating experiment. i look forward to hearing about the results!
- Ancalagon 2y agowould a solar sail be a feasible - albeit long time scale - method of getting the delta-v to decrease the orbit? Just point it retrograde and wait a long time?
- tifik 2y agoI might be missing something, but here is my thinking... the radiation coming out of the sun would always be perpendicular to your direction of travel around the sun at any given moment, so it would only ever be able to add delta-V and increase your orbit, not reduce it. Unfortunately you can't do upwind sailing in a vacuum. That being said, you can still use it for the method described in parent post, but you'd still need a different propulsion method to slow you down at the apogee.
- floxy 2y agoYou should be able to tilt your mirror/sail at 45°, so that the reflected light heads off in the direction of your travel, so that the momentum it imparts works against your current velocity, slowing you down, and degrading your orbit. Right?
- emilamlom 2y agoThey can be used to decrease orbit as well. Since you just need to bleed off the speed from Earth's orbit, you could angle the sail diagonally so the the reflected light is pushing against your direction of orbit (sort of like how the fins on a pinwheel are angled). While I was googling, a couple places likened it to tacking into the wind, but that's a different kind of phenomenon that works because of friction and pressure differences.
- pavel_lishin 2y agoI think that if you're constantly being thrusted radially out, you don't actually gain delta-v or increase your orbit - you just shift it. Your apoapsis increases, but your periapsis decreases. (It's been awhile since I've played KSP, I could be wrong.)
- josho 2y agoSailors have figured this out centuries ago to travel against the wind (called tacking). Some of the same principles apply, like orienting the sail so that photons push against the sail reducing the angular momentum.
- happytoexplain 2y agoI absolutely hate that AI is the first thing I think of whenever I see things like this now. Yes, innocent mistakes happen in writing and editing all the time. But look at that whole paragraph you're quoting. It does exactly what sloppily-guided AI does: It's using words in an order that sounds relationally intuitive, but taken as a whole it's ping-ponging across completely unrelated concepts. It can't have come from a human, unless, like you said, parts were removed in editing without re-reading the result.
- GauntletWizard 2y agoI disagree. I have encountered tons of humans who do exactly that - Use "words in an order that sounds relationally intuitive, but taken as a whole it's ping-ponging across completely unrelated concepts". It's not unique to AI, it's fairly common across bullshitters of all stripes. But perhaps more tragically, it often happens to actually big thinkers whose brain is connecting dots so fast that they're eliding a bunch of important hops along the way, and while the former is more common, it's easy to confuse for the latter.
- pavel_lishin 2y agoHey, sometimes you get called on in standup when you're trying to do some work, and you just have to glue some words together. I'm just glad nobody's writing those words down and publishing them!
- adolph 2y agoThats improv, not standup; granted, one must be agile either way.
- Heliosmaster 2y agoScrum standup, not comedy...
- gosub100 2y agoI think this will be the greatest travesty of AI, that will hurt us beyond what any stolen+regurgitated content ever will. AI is going to steal our faith in each other, our faith in fellow humans. because you'll never know for sure, if you're talking/listening to a human or not. This will lead people to treat each other worse because of being jaded by talking to bots all the time.
- strongpigeon 2y agoYou would think Eric Berger (who's a pretty seasoned space writer) would have played Kerbal Space Program. That game took my understanding of orbital dynamics to a whole other level. I was immediately bothered by that paragraph as well.
- daveslash 2y agoI'm not a KSP pro, but I have tried and tried to fly into the sun and have yet to succeed. Even if I do my best to lose as much of the planet's orbital velocity as I can until I'm out of fuel, and I begin to fall towards the sun.... I still always miss and then just go into an elongated elliptical orbit. It's really hard.
- Filligree 2y agoYou'll want a bi-elliptic transfer orbit. And probably a larger rocket.
- LorenPechtel 2y agoI would suspect that a slingshot at Jool would do it but I've never tried.
- vikingerik 2y agoYes, Parker used gravity assists, several passes by Venus. The cheapest way in terms of delta-v in the real solar system is actually to use Jupiter, launch to there and slingshot against your incoming velocity to cancel it out and drop towards the sun. Parker considered this, but decided not to because it would complicate the spacecraft design to handle operations at Jupiter (cold) and at the sun (hot). And yes, without assists, it's harder to get from Earth to the sun than to anywhere else. Solar escape velocity is 42 km/s at the altitude of Earth's orbit. Earth's orbital speed is 30 km/s, closer to escape velocity than to the near-0 you would need to drop all the way to the sun.
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- imglorp 2y agoI'm not wild about the title either. In English, "fly into the sun" implies permanence and they exploited that for title bait. Better, "closest approach" or even "dip into" would say that Parker will keep doing its job afterwards, maybe even lower the next time!
- LorenPechtel 2y agoI don't think it has the delta-v to go lower. Anything it loses to the solar wind on the flyby comes off the apoapsis, not the periapsis. Really messed up mission to Eeloo, returning the capture burn for Kerbin would have been around 2,000m/s and I only had half of that. After many reloads I managed to make it work: I put the encounter distance in the upper atmosphere and waited until the burn would complete a bit past periapsis to light the engine. The booster was destroyed by the heat just after the engine shut down, a good portion of my heat shield burned off but I came out of the encounter slowed just barely enough for capture. I turned around and waited. Every time around my apoapsis would drop, the periapsis stayed almost constant through many orbits. When my apoapsis was low enough I didn't expect to get another orbit I turned back around and went in.
- hnuser123456 2y agoIt sounds like for large changes in orbit, a bi-elliptic transfer can beat Hohmann: https://news.ycombinator.com/item?id=42357272 https://news.ycombinator.com/item?id=42357272
- maximilianburke 2y agoPlane change maneuvers are expensive
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- buildsjets 2y agoSoundtrack for appropriate ambiance. https://music.youtube.com/watch?v=ZnIxWznakz8&si=jhjMURGD4S0T0-5O https://music.youtube.com/watch?v=ZnIxWznakz8&si=jhjMURGD4S0...
- Qem 2y agoI was thinking about Adagio in D Minor, because of Sunshine (2007).
- grecy 2y agoSoundtrack to "Sunshine" also seems very appropriate. https://www.youtube.com/watch?v=AXzqJucLae8 https://www.youtube.com/watch?v=AXzqJucLae8
- vardump 2y agoI was thinking about Red Dwarf theme: https://youtu.be/zV0hwZwNQZc?si=NcQULlVtqBX_V7wm https://youtu.be/zV0hwZwNQZc?si=NcQULlVtqBX_V7wm ”It's cold outside There's no kind of atmosphere I'm all alone More or less Let me fly Far away from here Fun, fun, fun In the sun, sun, sun”
- wormius 2y agoCame here looking for this. :)
- koops 2y agoYou could also go with this: https://www.youtube.com/watch?v=juq0_2Oj5qw https://www.youtube.com/watch?v=juq0_2Oj5qw
- amelius 2y agoOf course it is completely evaporated before hitting anything that remotely resembles a surface.
- detritus 2y agoIs there even a surface?
- amelius 2y agoYes, if you zoom out enough you see it. Like with ordinary objects.
- shwouchk 2y agoMost ordinary objects have the property that the density of object mass has a very sharp gradient near some 2d surface that encloses a compact domain, and outside that is close to 0. However not identically 0, since eg the object is constantly releasing vapor of atoms of itself. If you zoom out enough out out of anything it looks like that, depending on how sharp you wish the gradient to be to call it a "surface". For objects where the gradient at the boundary is not great relative to our size we would subjectively experience no surface when coming close eg to a cloud. Does a galaxy have a "surface"? We can often also "clearly see" the edge of it...
- amelius 2y agoHow do you define density?
- shwouchk 2y agoReally? I suspect this is a troll but, in the static case, roughly the ratio of volume of space to how much gravitational force said volume applies on other objects. Extrapolate correctly for qm/gr - thats an exercise left for the reader. Depending on your scales etc you may wish to group different things into the category of “object”, eg a car would likely be be selected as a valid grouping of atoms as an object by most people in conversation wheres it is mostly empty space at the micro level, and has a bunch of very different densities (many oom) at diff volumes even at the macro scale (eg the air in the trunk vs the engine block).
- alnwlsn 2y agoYeah, 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.
- blindriver 2y agoI 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?
- thisisbrians 2y agoyou're probably getting downvoted because there isn't really a temperature 4 million miles away from the Sun (it's mostly just empty space being bombarded by radiation) 2,500º F is merely the temperature the probe is expected to reach at that distance. if it were to stay at that distance indefinitely, it would grow much, much hotter as it absorbed more energy from the sun.
- tomnicholas1 2y agoNo not necessarily - it will keep growing hotter until the black body radiation emitted by the probe matches the power of the radiation hitting the probe. Then it will stay at constant temperature. It's a standard undergraduate problem to work out what this equilibrium temperature is for a flat plate at a distance from the sun equal to the Earth's orbital radius. Interestingly the result is only a few 10's of degrees less than the average temperature of the real Earth - the difference is due to the Greenhouse Effect. For the probe one could easily do the maths but I could believe that at 4 million miles that equilibrium temperature is 2,500F.
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- thisisbrians 2y agoi definitely can't do the math myself, but excellent retort. thank you for the nuance
- feoren 2y agoTemperature is so wibbly-wobbly. The probe will reach an equilibrium energy-in vs. energy-out temperature depending on its distance from the sun, its surface area facing the sun, and the materials being lit, vs. its surface area facing away, the thermal radiation rate of various materials, and other factors. You could give an aerospace engineer almost any temperature between the CMB and the surface of the sun and they could probably design a (at least theoretical) probe that would reach that temperature eventually* at almost any distance. My guess is that 2500 ºF probably is the equilibrium temperature of the probe at that distance. * With "eventually" being "assuming a stable state for infinite years" which is of course not how astrophysics actually works.
- FredPret 2y agoIf KSP is to be believed, this is shockingly difficult to do
- lizzas 2y agoThe same gravity that wants to pull you in keeps you in orbit. And any object we launch starts off in the suns orbit.
- FredPret 2y agoIt's only the v0 you start off with from being in orbit already that makes it hard. Earth (and Kerbin) orbit at a very high speed.
- feoren 2y ago> The same gravity that wants to pull you in keeps you in orbit I would say it's your velocity that keeps you in orbit. Without the velocity, you fall into the star. Without the star's gravity, you keep going away in a straight line. Any object we launch starts off with Earth's velocity.
- Terr_ 2y agoIt's like a joke I recall from Hitchhiker's Guide to the Galaxy: You are indeed falling towards the ground... but the trick is to miss. Your lateral velocity is what keeps you missing, whether you want to or not.
- beAbU 2y agoIn order to 'land' on the sun, or any celestial body, you need to get rid of your orbital speed. Higher orbital speed means higher orbit altitude. Landing on earth is comparatively easy, because you can use the atmospheric drag to slow down. It is so difficult to land on Mars because of it's thin atmosphere. Alternatively you need a shitload of fuel to burn to kill that velocity. Earth's orbital velcity is ~30km/s. So by extension, anything that comes from Earth will at least have that speed. So the probe needs to find 30km/s delta v in order to actually get close to the sun.
- kfogel 2y agoMost 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.
- verzali 2y agoPretty sure it's 0.064%, not sure why the article got it wrong, still impressive though
- caseyohara 2y agoStill. ~200,000 m/s (= ~430,000 mph) is unfathomably fast.
- jebarker 2y agoIt is, although I was still a little surprised it's on the order of a minute to go NYC to Tokyo at that speed. My intuition was it would be much less time.
- tehjoker 2y agoLight loops around the earth ~7.75x a second iirc so a few orders of magnitude less makes sense
- sandworm101 2y agoLight is fast, but it isn't imperceptible. The original experiments to measure it in a lab involved spinning rigs and mirrors between hills. When dealing with objects the size of continents, such as phone or other communication systems, the delays are well within our abilities to detect.
- gosub100 2y agoterrestrial phone / internet carried by undersea cables are gated by the relays more so than c. the ping time from US to Australia (one way) is about 115 ms (rounding down, using most optimistic data. Light can travel over 34,000km in that time. The great arc distance from LA to Sydney is just over 12,000km. In all likelihood the fiber line connecting them doesn't follow that arc, but it shouldn't be too far out of limits. So about 2/3 of the latency is caused by relays and switching equipment. it gets even worse for satellite, because (until starlink) communications satellites are in geosynchronous orbit, 35,000km above the equator. so talking on one means a 70km round trip, which causes its path to take over 5x more distance than the linear distance (across the surface) between those 2 cities.
- verzali 2y agoThis 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.
- curtisblaine 2y agoThis 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!"
- abecedarius 2y agohttps://www.poetryfoundation.org/poems/43914/the-walrus-and-the-carpenter-56d222cbc80a9 https://www.poetryfoundation.org/poems/43914/the-walrus-and-...
- rufus_foreman 2y agoSet the controls.
- adregan 2y agoOut 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?
- bc569a80a344f9c 2y agoApparently, full impulse is relative to the engine spec. For the Voyager, it is 0.25c, so about 167 million mph. Edit: https://memory-alpha.fandom.com/wiki/Impulse_engine https://memory-alpha.fandom.com/wiki/Impulse_engine
- lqueenan 2y agoReminds me of this far side comic, https://static1.srcdn.com/wordpress/wp-content/uploads/2023/04/the-far-side-mr-sun.jpg https://static1.srcdn.com/wordpress/wp-content/uploads/2023/...
- throwaway657656 2y agoI don't get the Far Side. Could a Cliff Clavin chime in ?
- danparsonson 2y agoYeah I'm generally a big fan but that one is a bit obscure - according to this [0], it's just the incongruity of trained professionals in mortal danger using a childish nickname for the thing that's about to destroy them. [0] https://www.cbr.com/the-far-side-confusing-comics-like-cow-tools/ https://www.cbr.com/the-far-side-confusing-comics-like-cow-t...
- tgv 2y agoI think it's simply out of fashion. E.g., "Don't mess with Mr. In-between" is a line from the 1940's song "Ac-Cent-Tchu-Ate the Positive." It's addressing abstract entities in a personalized form, which --I assume-- is a style convention commonly understood at the time. https://www.youtube.com/watch?v=5Qk9o_ZeR7s https://www.youtube.com/watch?v=5Qk9o_ZeR7s https://en.wikipedia.org/wiki/Ac-Cent-Tchu-Ate_the_Positive https://en.wikipedia.org/wiki/Ac-Cent-Tchu-Ate_the_Positive I learnt of this song through the fantastic series "The Singing Detective."
- QuantumGood 2y agoThose only smart enough to think of our local star as "Mr Sun" perhaps should not be piloting craft in its vicinity.
- nick3443 2y agoChildren's song lyrics I heard growing up. Sun, sun, Mr. Golden sun, sun shine down on me.
- fortran77 2y agoCan’t they just go at night?
- ordu 2y agoAt night there is no corona, nothing to look at.
- dreamcompiler 2y agoImagine 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.
- ozim 2y agoI would argue that is also most “into the sun” we can reasonably get.
- tedd4u 2y agoI think NASA is saying it's already gone well inside the Alfvén surface and so that qualifies as basically "into the suns atmosphere." [1] https://en.wikipedia.org/wiki/Alfvén_surface https://en.wikipedia.org/wiki/Alfvén_surface
- dang 2y agoRelated. Others? What NASA's Parker Solar Probe discovered in its first 5 years looping the sun - https://news.ycombinator.com/item?id=37128838 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 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 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 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 https://news.ycombinator.com/item?id=17569741 - July 2018 (86 comments)
- mmooss 2y agoLook at this NASA animation of two solar probes orbiting the Sun (thanks ostacke and DiggyJohnson): https://svs.gsfc.nasa.gov/3966/ 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?
- Hextinium 2y agoThe Parker solar probe gets much closer than the solar orbiter, 0.046 AU vs 0.28 AU respectively. The successive Venus flybys are to drop it increasingly further into the sun's orbit to take solar atmospheric data on quick flybys while the Solar orbiter is more for spectrograph measurements of the sun's corona, just different mission sets.
- rplnt 2y agoYou can't "just drop", it requires energy (fuel) and that's probably the answer why.
- spacesanjeet 2y agovery cool indeed, looking forward to see how the results pan out from this project.
- ballooney 2y agoRather frustrating to read - as if intentionally written for nine year-olds. I was surprised to see it was Eric Berger, I don’t recall this affected style from him before, though I’ve not paid close attention.
- everdrive 2y agoFor those of you that are worried the ship is going to burn up, the team does have a plan: they’re going to do the mission at night.
- d754903977 2y agoIt's not very hot if you go at night.
- MR4D 2y agoYour comment gives me faith in humanity. Well played!
- webdoodle 2y agoIt would be nice if the public could see the data/images directly in real time, not this curated drivel they feed us.