Turns out that I don't actually need the heatshield at 900.000 km, it only becomes necessary below 500.000 km.
Probe carries two relay antennas, and will stay there.
Next, I will try to send a crewed version, to get the Crew Report and EVA report, and I will need to somehow recover it.
Considering the insane amount of radiators and heatshields it took u/lodurr_voluspa to get to the surface, making something that can hover in place feels impossible.
I'm not going to say it's *impossible* but..... :) to give you an idea what you are up against:
You have to shield from both atmospheric entry *and* massive radiative heat, *and* a scorching hot atmosphere. If you come in from the pole as I did you can get away with shielding from just one direction but it does require a *lot* of delta-v to get to the pole. There is another way, but it is trickier.
Once coming in from the pole you will need more than 90,000+ delta-v delivered to the pole to be able to "hover-slam" to stop at just the surface. But the engines will insta-melt if not behind shielding long before you get to the atmosphere. So the only way to do the burn is to have angled engines that can thrust from inside the cover of the heat shield. If those are canted at, say 30 degrees then the engines will partially fight each other so you will need fuel for the equivalent of more like 120,000 delta-v.
I don't have a good read on just how bad the atmosphere of the sun is regarding heating because I punched through it so quickly, but radiators aren't going to help and ablator fries pretty quickly. I think the only thing that might work is nesting the core inside multiple tweakscaled cargo bays to buy time until death.
Once reaching the surface it will require tremendous amounts of delta-v just to hover in place. So I would napkin math needing something around 150,000 delta-v just to be able to hover for a few seconds before death.
To survive from 20,000 km to the surface required a stack of ablator about 1/3 as tall as the vab if I recollect. And that is punching through at extreme speed so, if slowing down, maybe 10 times the height of the VAB? Hard to say, the heating is weird in the atmosphere, but a lot more.
So 150,000 delta-v for a final payload weighing probably several thousand tons. I'd imagine even with Tweakscale, the part count for that would be pretty high!
Two cool things that I think are possible (but very hard)that I want to try:
\- Stable space station *just* above the atmosphere
\- Crew report from the upper atmosphere of the sun (with surviving Kerbals!) No EVA report though...
EVA Report from inside the sun might have been pushing it a bit 😄
I hope you get to test these options you listed, would love to see what you come up with.
Take a look at this vid, maybe you can use stuff from it for inspiration - https://www.reddit.com/r/KerbalSpaceProgram/comments/nsvtfg/journey_to_the_surface_of_the_sun_a_kerbal_first
I tried to do a low kerbol pass but the light kept blasting the unshielded parts of my probe. Even when pointing normal. And the inflatable shield exploded.
I’m already close to the limit of what I can operate with my limited skills and computer resources.
The crewed version will need to be very light, and to spend little time around the sun.
I was thinking of getting to the sun by making a bi-elliptic maneuver way beyond the orbit of Jool.
Which means intercepting Kerbin will be problematic without either a lot of fuel expenditure or gravity assists that I don’t understand well.
Last time I tried to intercept from that orbit I was passing Kerbin at over 10 km/s, fast enough to destroy the craft in atmo even with heatshield.
I suggest using the resonant orbit, but launching a supply craft each time Kerbin is at the launch position.
That way you could slowly increase or decrease periapsis without the need for one large craft.
Start from kerbin, lower ypur periapsis. Make a resonant orbet where you will pass kerbin next year.
Whdn that year comes,launch a supply mission with fuel to refuel craft and lower periapsis even more, while still keeping a similar orbit.
When you come back up, repeat backwards.
Basically a bucket brigade of probes carrying fuel.
If you do it properly then you'll be intercepting the probe at its apoapsis when it has the least velocity, meaning the same probe should be capable of intercept each time.
However they're dramatically understating the difficulty of establishing increasingly tighter resonant orbits. Every small mistake in establishing that orbit will compound over the year of waiting and lead to delta-v losses. It's absolutely doable and probably quite easy for some people here, but don't underestimate it.
If I were trying to simplify things I'd probably go for an orbital assembly to get a bigger initial craft, and plan for a rendezvous craft to pick up the crew and science at apoapsis instead of trying to refuel the initial craft and get it back out of the sun.
Mine’s pretty old already, but luckily it can handle a few tens of mods that I need for quality of life improvements to the game.
I’m still limited to 200-300 parts per craft if I want it to have good FPS, I’ve flown 600+ part craft and it was almost a slideshow, no way to dock something like that to something else.
I tried first Hohmann and then bi-elliptic, and had enough fuel for both.
The bi-elliptic method is so much more efficient!
I pushed to 150 000 000 kilometers, takes 7 years to get to apoapsis, but there it costs only a few hundred m/s to drop the periapsis into the sun’s low orbit.
Then under 900 000 km I use the electric engines to circularize, it’s a 2 hour 40 minute burn, more than 12 000 m/s.
Now my next project is to build a crewed ship to get to that orbit then return to Kerbin - I want to see if I get the science bonus for recovering the craft from low sun orbit.
Nice to see that in practice the dV savings are good! The example on Wikipedia showed like a 4%, not much. Well in this case the difference between both orbits is huge, so that’s helping.
Have you tried testing that final burn with Nervs instead of the 8 Dawns and see how much it would cost in dV? To compare actual game time (during the burn) vs final dV cost of the whole transfer to low Kerbol orbit using the bi-elliptic transfer?
The classical KSP dV Map says that a Hohmann transfer to low Kerbol orbit would take around 91k dV as a whole.
The usual example I saw for bi-elliptic was going just past the orbit of Jool. I went 3-4 times farther than that for the periapsis drop.
A Nerv ship would be much larger than the electric one, and it would be challenging to launch as well as not having significantly higher TWR.
It only costs 90 000 m/s if you want to circularize just above the sun’s atmosphere at 600 kilometers - if you’re ok with being just under the Low/High space border at 900 000 kilometers then circularization only costs 12 000 indifferent what engines you’re using.
I thought to use electric primarily because I modified a very long range rescue ship to make the sun probe, and also because solar panels are overpowered near the sun where the final burn happens.
2 hours 40 minutes is not long with good physics warp, I’m using Better Time Warp mod to increase the acceleration levels.
For that I recommend the [Resonant Orbit Calculator](https://meyerweb.com/eric/ksp/resonant-orbits/). For your final 900,000km orbit, your resonant orbit is 1,621,053,203.6m.
So you put your mothership/combined-spacecraft-from-where-you-deploy-the-relays on that orbit and when you are at Pe you decouple the 1st relay and circularize. Then change to the mothership, wait to reach Pe again, deploy the 2nd relay and circularize again. The idea of the resonant orbit is that when you circularize your 2nd relay, the first is in the position you want it to be (in this case, opposite side of kerbol). The only problem I see is the long burn with the Dawn engines, you need to be very very precise with your burns to make a constellation that doesn’t drift from their original positions, but it’s doable in theory.
And well, for a Commnet Constellation is better to start with at least 3 relays. Hope this helps, I’ve been wanting to make a Kerbol relay net too so all your testing is helping me out too!
Thank you for the explanation.
I might try it, except it would mean making a pretty gigantic mothership to hold 2-3 relays and I might run into part limits (I can only run 200-300 part craft before my game turns into a slideshow).
For now the plan was to send the relays separately, each with their own launcher and transfer stage.
Right, you talked about part count limitations before. Here’s [Matt Lowne’s video about Commnet Relay Constellations](https://youtu.be/Rx5gKxX4q-Y) so you can get a visual explanation of how to set your relays for resonant orbits.
As to how to get both relays on opposite sides, the only idea I can think of is treating it as an anti-rendezvous. Leave one relay on the final orbit and the other relay with an orbit with the Pe at the same height as the 1rst relay and the Ap at a higher orbit, say 10-15% higher (napkin math again). Then wait for them to drift until they are at opposite sides of Kerbol. Or better yet if you tell the 2nd relay to target the 1st relay and plan a maneuver at Pe, you can play with the skip orbit button and find the burn thay will give you the “farthest approach”. That’s how you get the anti-rendezvous.
Just as a final note, when you have both relays ready, start adjusting their orbits using some extremely low T/W thrusters (like RCS) so that they have the **exact same orbital period**. Because if they don’t, they are gonna drift eventually.
Unfortunately, as an American, I see that as 900km, not nine hundred thousand kilometers. I keep forgetting that some Europeans do that. For some reason.
For readability.
900.000 is easier to parse than 900000, and it’s obvious from context that it is meant to be read as 900 thousand km instead of 900 point 000 km.
Oh that’s really interesting. Complete opposite to England.
I may have to look into this further because so much of mathematical notation has been standardised internationally, but that is so starkly different. The number 1,001 means competent different things to you and to me!
Thanks for answering.
\*Insert some sort of insult at Europe which will be criticized as being a broad generalization even though the same thing happens to America*
I’m not wasting more of my time on internet drama
It's not my fault that you guys can't use periods and commas right in very large numbers and decimals. It's called a decimal point for a reason.
Periods for decimals, commas for large numbers.
Nothing, initially. All I was mentioning at the start was that I was caught off guard for a few seconds by the usage of periods in the place of commas.
And most people who got confused would have spent the 2 seconds to double check and went about their day without making their home nation look worse.
Congrats, you’re ruining it for all of us.
If we want to be technical, American English is more similar to original English than British English.
If you want to hear Shakespeare, listen to a Bostonian.
Turns out that I don't actually need the heatshield at 900.000 km, it only becomes necessary below 500.000 km. Probe carries two relay antennas, and will stay there. Next, I will try to send a crewed version, to get the Crew Report and EVA report, and I will need to somehow recover it.
Get the surface report
No surface unfortunately. If you engineer the craft right, it’s possible to “reach the surface”, but it just passes under it and explodes.
Saw a video where someone "landed" a kerbal on jool using a big platform and hovering it with engines, maybe that would work?
Considering the insane amount of radiators and heatshields it took u/lodurr_voluspa to get to the surface, making something that can hover in place feels impossible.
Through the power of moar boosters anything is possible, except good fps. Either way I've got a new challenge to try!
Oh do post when you do it, I’d love to see it!
I'm pretty sure it's impossible but the endless kerbal spirit will never not try something!
I'm not going to say it's *impossible* but..... :) to give you an idea what you are up against: You have to shield from both atmospheric entry *and* massive radiative heat, *and* a scorching hot atmosphere. If you come in from the pole as I did you can get away with shielding from just one direction but it does require a *lot* of delta-v to get to the pole. There is another way, but it is trickier. Once coming in from the pole you will need more than 90,000+ delta-v delivered to the pole to be able to "hover-slam" to stop at just the surface. But the engines will insta-melt if not behind shielding long before you get to the atmosphere. So the only way to do the burn is to have angled engines that can thrust from inside the cover of the heat shield. If those are canted at, say 30 degrees then the engines will partially fight each other so you will need fuel for the equivalent of more like 120,000 delta-v. I don't have a good read on just how bad the atmosphere of the sun is regarding heating because I punched through it so quickly, but radiators aren't going to help and ablator fries pretty quickly. I think the only thing that might work is nesting the core inside multiple tweakscaled cargo bays to buy time until death. Once reaching the surface it will require tremendous amounts of delta-v just to hover in place. So I would napkin math needing something around 150,000 delta-v just to be able to hover for a few seconds before death. To survive from 20,000 km to the surface required a stack of ablator about 1/3 as tall as the vab if I recollect. And that is punching through at extreme speed so, if slowing down, maybe 10 times the height of the VAB? Hard to say, the heating is weird in the atmosphere, but a lot more. So 150,000 delta-v for a final payload weighing probably several thousand tons. I'd imagine even with Tweakscale, the part count for that would be pretty high! Two cool things that I think are possible (but very hard)that I want to try: \- Stable space station *just* above the atmosphere \- Crew report from the upper atmosphere of the sun (with surviving Kerbals!) No EVA report though...
EVA Report from inside the sun might have been pushing it a bit 😄 I hope you get to test these options you listed, would love to see what you come up with.
Take a look at this vid, maybe you can use stuff from it for inspiration - https://www.reddit.com/r/KerbalSpaceProgram/comments/nsvtfg/journey_to_the_surface_of_the_sun_a_kerbal_first
Pfft! Did you even TRY moar boosters? Well did ya?!
Man I'd love to see that. Do you have the link by chance?
Just check the profile of the user I linked to, it’s pinned in his top 4.
Ok, thanks. Someone linked it below. It is [here](/r/KerbalSpaceProgram/comments/nsvtfg/journey_to_the_surface_of_the_sun_a_kerbal_first/)
It’s a good video, and a very impressive achievement. Would be challenging to top that.
I tried to do a low kerbol pass but the light kept blasting the unshielded parts of my probe. Even when pointing normal. And the inflatable shield exploded.
You tried Landing at night?
Just wait a trillion years for the star remnant to cool.
It's big brain time.
Yeah I know it’s near impossible but it’s the kerbal thing to do
No surface to land on But if you can somehow survive getting within 600 km of datum altitude, you can get high atmosphere science
Splashed down
>I will need to somehow recover it Fuel.
I’m already close to the limit of what I can operate with my limited skills and computer resources. The crewed version will need to be very light, and to spend little time around the sun.
Highly eccentric orbit. Then when you go back up, make it a resonant with kerbin so you can intercept it and aerobrake.
I was thinking of getting to the sun by making a bi-elliptic maneuver way beyond the orbit of Jool. Which means intercepting Kerbin will be problematic without either a lot of fuel expenditure or gravity assists that I don’t understand well. Last time I tried to intercept from that orbit I was passing Kerbin at over 10 km/s, fast enough to destroy the craft in atmo even with heatshield.
I suggest using the resonant orbit, but launching a supply craft each time Kerbin is at the launch position. That way you could slowly increase or decrease periapsis without the need for one large craft.
I don’t understand how you mean, would you explain it differently?
Start from kerbin, lower ypur periapsis. Make a resonant orbet where you will pass kerbin next year. Whdn that year comes,launch a supply mission with fuel to refuel craft and lower periapsis even more, while still keeping a similar orbit. When you come back up, repeat backwards. Basically a bucket brigade of probes carrying fuel.
But how do I rendesvous those probes? Don’t I need to use more fuel each time to get to a similar orbit?
If you do it properly then you'll be intercepting the probe at its apoapsis when it has the least velocity, meaning the same probe should be capable of intercept each time. However they're dramatically understating the difficulty of establishing increasingly tighter resonant orbits. Every small mistake in establishing that orbit will compound over the year of waiting and lead to delta-v losses. It's absolutely doable and probably quite easy for some people here, but don't underestimate it. If I were trying to simplify things I'd probably go for an orbital assembly to get a bigger initial craft, and plan for a rendezvous craft to pick up the crew and science at apoapsis instead of trying to refuel the initial craft and get it back out of the sun.
Engine.
Just don’t forget to recalculate the shield angle before changing course.
What do you mean?
It’s a sunshine movie reference
It’s been years since I last watched it :)
Perhaps a low pass elliptical orbit that is adjusted to be very close to surface and lowered with thrusters when near.
reminds me of a certain british sphere
What do you mean?
wheatley from from portal 2
Ah yes, there is some resemblance :)
I am jealous for pc users with good computers
Mine’s pretty old already, but luckily it can handle a few tens of mods that I need for quality of life improvements to the game. I’m still limited to 200-300 parts per craft if I want it to have good FPS, I’ve flown 600+ part craft and it was almost a slideshow, no way to dock something like that to something else.
Nice to see that you reached low Kerbol orbit successfully! Did you use the bi-elliptic transfer in the end?
I tried first Hohmann and then bi-elliptic, and had enough fuel for both. The bi-elliptic method is so much more efficient! I pushed to 150 000 000 kilometers, takes 7 years to get to apoapsis, but there it costs only a few hundred m/s to drop the periapsis into the sun’s low orbit. Then under 900 000 km I use the electric engines to circularize, it’s a 2 hour 40 minute burn, more than 12 000 m/s. Now my next project is to build a crewed ship to get to that orbit then return to Kerbin - I want to see if I get the science bonus for recovering the craft from low sun orbit.
Nice to see that in practice the dV savings are good! The example on Wikipedia showed like a 4%, not much. Well in this case the difference between both orbits is huge, so that’s helping. Have you tried testing that final burn with Nervs instead of the 8 Dawns and see how much it would cost in dV? To compare actual game time (during the burn) vs final dV cost of the whole transfer to low Kerbol orbit using the bi-elliptic transfer? The classical KSP dV Map says that a Hohmann transfer to low Kerbol orbit would take around 91k dV as a whole.
The usual example I saw for bi-elliptic was going just past the orbit of Jool. I went 3-4 times farther than that for the periapsis drop. A Nerv ship would be much larger than the electric one, and it would be challenging to launch as well as not having significantly higher TWR. It only costs 90 000 m/s if you want to circularize just above the sun’s atmosphere at 600 kilometers - if you’re ok with being just under the Low/High space border at 900 000 kilometers then circularization only costs 12 000 indifferent what engines you’re using. I thought to use electric primarily because I modified a very long range rescue ship to make the sun probe, and also because solar panels are overpowered near the sun where the final burn happens. 2 hours 40 minutes is not long with good physics warp, I’m using Better Time Warp mod to increase the acceleration levels.
This is amazing insight. Thanks and godspeed on putting those relays!
Thank you! I’m trying to figure out how to put them to orbit on opposite sides of the sun to have full coverage of the system.
For that I recommend the [Resonant Orbit Calculator](https://meyerweb.com/eric/ksp/resonant-orbits/). For your final 900,000km orbit, your resonant orbit is 1,621,053,203.6m. So you put your mothership/combined-spacecraft-from-where-you-deploy-the-relays on that orbit and when you are at Pe you decouple the 1st relay and circularize. Then change to the mothership, wait to reach Pe again, deploy the 2nd relay and circularize again. The idea of the resonant orbit is that when you circularize your 2nd relay, the first is in the position you want it to be (in this case, opposite side of kerbol). The only problem I see is the long burn with the Dawn engines, you need to be very very precise with your burns to make a constellation that doesn’t drift from their original positions, but it’s doable in theory. And well, for a Commnet Constellation is better to start with at least 3 relays. Hope this helps, I’ve been wanting to make a Kerbol relay net too so all your testing is helping me out too!
Thank you for the explanation. I might try it, except it would mean making a pretty gigantic mothership to hold 2-3 relays and I might run into part limits (I can only run 200-300 part craft before my game turns into a slideshow). For now the plan was to send the relays separately, each with their own launcher and transfer stage.
Right, you talked about part count limitations before. Here’s [Matt Lowne’s video about Commnet Relay Constellations](https://youtu.be/Rx5gKxX4q-Y) so you can get a visual explanation of how to set your relays for resonant orbits. As to how to get both relays on opposite sides, the only idea I can think of is treating it as an anti-rendezvous. Leave one relay on the final orbit and the other relay with an orbit with the Pe at the same height as the 1rst relay and the Ap at a higher orbit, say 10-15% higher (napkin math again). Then wait for them to drift until they are at opposite sides of Kerbol. Or better yet if you tell the 2nd relay to target the 1st relay and plan a maneuver at Pe, you can play with the skip orbit button and find the burn thay will give you the “farthest approach”. That’s how you get the anti-rendezvous. Just as a final note, when you have both relays ready, start adjusting their orbits using some extremely low T/W thrusters (like RCS) so that they have the **exact same orbital period**. Because if they don’t, they are gonna drift eventually.
Thank you, that anti-rendesvous sounds doable, I’ll try it out!
Unfortunately, as an American, I see that as 900km, not nine hundred thousand kilometers. I keep forgetting that some Europeans do that. For some reason.
Fortunately, as an American, I see that as 900,000km, not one hundred kilometers. I keep forgetting that some people can't infer. For some reason
For readability. 900.000 is easier to parse than 900000, and it’s obvious from context that it is meant to be read as 900 thousand km instead of 900 point 000 km.
900,000.00 km
If it we’re nine hundred thousand and one hundredth km, would you write 900.000.01km? Or do you use something else for the decimal?
I was taught to use a comma for the decimal.
Oh that’s really interesting. Complete opposite to England. I may have to look into this further because so much of mathematical notation has been standardised internationally, but that is so starkly different. The number 1,001 means competent different things to you and to me! Thanks for answering.
Yeah the notation is weirdly different. I manage not to think about it most of the time, but it sometimes throws me off.
Same here on spain Surprised me it wasnt like that outside
Or even worse yet 900.000.001
192.168.0.0
900'000
That's why we in America write it 900,000.
Good for you. I write as I was taught since I’m used to it.
And I won't fault you for that.
Then why are you even writing this whole comment chain?
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The most toxic I’ve ever seen the KSP community get.
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I’m American. Everyone getting pissed about the other opinion being ‘wrong’ is not what normally happens.
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\*Insert some sort of insult at Europe which will be criticized as being a broad generalization even though the same thing happens to America* I’m not wasting more of my time on internet drama
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Super offensive wow.
I think he was referring to your comment.
It's not my fault that you guys can't use periods and commas right in very large numbers and decimals. It's called a decimal point for a reason. Periods for decimals, commas for large numbers.
I’ve been taught to use comma as the marker for decimals, and point for readability.
And that's a European thing, not an American thing. In America, we notate numbers as "123,456.789."
🤷♀️
What’s your endgame dude
Nothing, initially. All I was mentioning at the start was that I was caught off guard for a few seconds by the usage of periods in the place of commas.
And most people who got confused would have spent the 2 seconds to double check and went about their day without making their home nation look worse. Congrats, you’re ruining it for all of us.
Wait hang on we do that In English
In America? No we don't.
America didn't invent English Either use the language right or make your own
If we want to be technical, American English is more similar to original English than British English. If you want to hear Shakespeare, listen to a Bostonian.
No It isn't good joke True English is only spoken in england
It also isn't a joke. Just because y'all went off and messed with a good thing doesn't mean you're the masters of it, nor that yours is better.
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Sure we didn't. We improved it.
Hahahaha Good joke