Atmosphere entry challenges ahead

[dellcom1800]

Hello All

So I have noticed quite a few landers I have seen posted here land without any heatshield/thermal protection. With the current version this is not an issue but with the listed item to have heat damage count during atmosphere interface I think it will present new design challenges. I have tried to have all my landers that will go through an atmosphere utilize a shield, basically one of the circle adapters attached to a mounting strut and a de-coupler to release it after re-entry and the parachutes deploy. I find the shield adds a design challenge in that it add mass (not a lot usually) and requires some thought on placement and how the craft will enter an atmosphere but also be oriented at launch. You also have to make sure the shield diameter covers everything behind it.

But I think the bigger challenge will be on larger craft and aero-braking/aero-capture maneuvers. It would be bad if your comms tower burnt off or an exposed fuel tank blew up while trying to aerobrake at Eve or Jool.

[gtmattz]

Look up Deadly Reentry for a taste of things to come. Dealing with atmospheric friction makes aerobraking a lot more interesting!

[Sirrobert]

I don't think we'r going to get something as thorough as deadly reentry though. That would make your first orbit impossible to land, and we do need to keep an eye out of the newbys

[Hodo]

Dealing with atmospheric friction makes aerobraking a lot more interesting!

That's one way of putting it.

And I can't agree more.

I don't think we'r going to get something as thorough as deadly reentry though. That would make your first orbit impossible to land, and we do need to keep an eye out of the newbys

Why, when I started, I downloaded FAR and DRE the first day. My first pod recovery was a success. It was the third, forth and fifth that failed.

Honestly I find DRE and FAR make the game easier if you have any idea how the real world works.

Granted they are simplified versions of the KIDS mod, which makes life REAL hard in KSP and with the Planet rescaler it becomes a nightmare.

Edited November 5, 2013 by Hodo

[Eric S]

The devs have said that they're not planning on having reentry heat something you'd need a heat shield for. After all, we're reentering at a third the velocity of real life reentries. They said that they wanted it to be something you had to keep in mind, but not something that required extra parts.

As a side note, very little of reentry heat comes from friction, most of it comes from the compression that the atmosphere in front of the craft undergoes.

[Sirrobert]

That's one way of putting it.

And I can't agree more.

Why, when I started, I downloaded FAR and DRE the first day. My first pod recovery was a success. It was the third, forth and fifth that failed.

Honestly I find DRE and FAR make the game easier if you have any idea how the real world works.

Granted they are simplified versions of the KIDS mod, which makes life REAL hard in KSP and with the Planet rescaler it becomes a nightmare.

And that's exactly why. Most people have NO IDEA how orbits work

[Hodo]

And that's exactly why. Most people have NO IDEA how orbits work

But that makes for a perfect time to learn.. lol

[Sirrobert]

I think this has enough homework as it is...

[annallia]

That's one way of putting it.

And I can't agree more.

Why, when I started, I downloaded FAR and DRE the first day. My first pod recovery was a success. It was the third, forth and fifth that failed.

Honestly I find DRE and FAR make the game easier if you have any idea how the real world works.

Granted they are simplified versions of the KIDS mod, which makes life REAL hard in KSP and with the Planet rescaler it becomes a nightmare.

How wonderful for you. However in the end this is a game, as such you will have people of varying levels of skill. Not everyone will be an out of the box kerbalnaut, not everyone will want to spend hours watching other people have fun on youtube instead of figuring it out for themselves.

Also unless I am mistaken, though I don't think I am what Sirrobert said is true in respect to career mode, as it currently stands that is.

[csanders]

Little known fact: all Kerbal parts are coated with ablative paint.

[dellcom1800]

The devs have said that they're not planning on having reentry heat something you'd need a heat shield for. After all, we're reentering at a third the velocity of real life reentries. They said that they wanted it to be something you had to keep in mind, but not something that required extra parts.

As a side note, very little of reentry heat comes from friction, most of it comes from the compression that the atmosphere in front of the craft undergoes.

It doesn't have to be exact but a reasonable approximation would be good. What would be the point of being aware of the re-entry heat if you don't really have to do anything to protect your craft? I feel that going through an atmosphere is a pretty big part in landing something from space, aside from actually getting it there. Just something I would like to see.

And you are correct " When air is processed by a shock wave, it is superheated by compression and chemically dissociates through many different reactions (Direct friction upon the reentry object is not the main cause of shock-layer heating. It is caused mainly from isentropic heating of the air molecules within the compression wave. Friction based entropy increases of the molecules within the wave also account for some heating.)"http://en.wikipedia.org/wiki/Atmospheric_entry.

[bludy]

having to figure a reentry trajectory and add some shield here and there wouldn't be such a problem. maybe it will take a bit longer to build stations on eve, or to use a shuttle for missions, but something you must be aware of doesn't mean you cannot deal with it. i'd like to fly something damaged..even if i'm a noob ;-)

[zxczxczbfg]

I think simply slapping a heatshield on the bottom of the payload would be enough for most designs for landers and stuff. For returns, the capsules and fuselages appear to already have heat shields anyway.

[Eric S]

It doesn't have to be exact but a reasonable approximation would be good. What would be the point of being aware of the re-entry heat if you don't really have to do anything to protect your craft? I feel that going through an atmosphere is a pretty big part in landing something from space, aside from actually getting it there. Just something I would like to see.

Heat shields are hardly the only way to have to react to reentry heat. Given that the heat is less than you'd see in reality, heat shields could be overkill. The solution could be as simple as making sure that any heat-sensitive parts are occluded by parts that aren't as heat sensitive.

I seriously doubt that the lander cans are going to have the heat tolerance of the capsules once heat is an issue, so you might have to avoid using lander cans on craft that will be reentering, or at least make sure that the lander can stays occluded. Other solutions could be "just don't aerobrake at high velocity and low altitudes, take more than one orbit to slow down."

It's quite possible that we may wind up in a position of having multiple ways of dealing with reentry heat, and as long as we pick one of them, we're good.

For what it's worth, I've played with Deadly Reentry, including the versions that were actually deadly back when the heat was higher than the physics would suggest. I'm not saying that we shouldn't have to deal with reentry heat, just that that's not the only way to have to deal with it, and I'll wait until I see what the devs are thinking before saying something has to be done a certain way.

[annallia]

I think simply slapping a heatshield on the bottom of the payload would be enough for most designs for landers and stuff. For returns, the capsules and fuselages appear to already have heat shields anyway.

Certain payloads would have to be redesigned completely to make them more stable as well. Wouldn't do you any good to slap a heat shield on the bottom of a payload that has trouble keeping the correct vector.

[hobbsyoyo]

The game already has a lot of features and variables to keep track of, both in its present state and as far as what is planned yo be added. Adding yet another variable to keep track of and make the game more difficult to play and do successful missions doesn't sound fun to me. If I wanted ultra-realism I would play Orbiter. At some point KSP will stop being a fun game with a side of realism and start being a game of realism with a side of fun if we go down that path.

[Merinsan]

I'd like to experience re-entry heat at some point, I think it'd add to the challenge. But at the same time, I think it should be optional - as in a difficulty setting - since not everyone would be able to handle it.

Also, before anyone tells me to get deadly reentry, I know about it, but I like to stay mod free.

[katateochi]

Has re-entry heat been announced as a 0.23 thing? I didn't think I saw it mentioned anywhere.

I was actually going to start a thread asking if anyone bothered with atmospheric skips when re-entering kerbins (or any) atmo. After watching a very old skool but v informative documentary (which someone posted here a while back) about the Apollo re-entry I've been trying to do atmo skips as I come back in with command pods. It's quite strangely satisfying when you do get it to work and you experience much less re-entry effect. It's been totally a trial an error thing thou. I've found that with the 1 man pod returning from Mun, hitting the atmo at around 34km is about right and from Minmus at about 28km but I've not tried doing it from interplanetary transfer or with the 3 man pod yet.

That being said, I do hope that it is implemented in such a way that doesn't stop some of the more insane designs. Fun game before simulator and all that.

From what I've read the shuttle has a re-entry speed of 17500 mph[1] (7823ms) which is way faster than most things I de orbit. I hope that I still will be able to deorbit my 20 man LKO crew transport craft and that some of the more fun super fast jet craft will still be viable. I don't mind having to learn to take a more gradual descent, I would mind if I have to totally re-do a load of nice designs.

[soranno]

after playing with a bugged install of deadly reentry for quite a while, that often saw ships spontaneously explode among other thing, I learned to be extremely careful on reentry. That install effectively rendered heatshields inactive and magnified the heating effects of atmospheres

anyway, I learned how to do it, and since correcting the deadly reentry install reentry has been a walk in the park. In an engine powered controlled descent, an engine`s own standard heat resistance is plenty enough to see you through, and it doesn`t often need a large amount of fuel.

In short, don`t be afraid of it, it`s just one more thing to figure out, like rendevous or docking or landing itself. And once you have it figured out it won`t be a problem again.

[Clouds]

That would make your first orbit impossible to land, and we do need to keep an eye out of the newbys

Well, there's a pretty simple middle ground: make certain pods (eg. both conical pods) able survive re-entry heating on their own - describe them as having an integrated heat shield on their bottom. Make them relatively heavy (which they already are, somewhat). The 1-man capsule would be the starter.

The lander-cans could, and IMO should, be even lighter weight than they are, for landing on nonatmospheric targets and would need separate heat shields to survive re-entry (like their description says). Likewise, other constructions (eg. rovers, science probes) would need shields built below them.

[Eric S]

Has re-entry heat been announced as a 0.23 thing? I didn't think I saw it mentioned anywhere.

Hasn't been mentioned recently, and the devs have even gone back and forth on whether or not they want to do it at all. I think the last mention I heard of it was as an optional setting.

[FlamedSteak]

Yeah I think an option to turn it off would be the best route. I'm not keen on downloading the mod, but I probably will learn how to deal with it if it gets added in future versions.

[magnemoe]

I think simply slapping a heatshield on the bottom of the payload would be enough for most designs for landers and stuff. For returns, the capsules and fuselages appear to already have heat shields anyway.

Yes, the only issues is that we would need heat shields of various properties and sizes, it would also requre an better aerodynamic model like FAR as drag would be dependent on direction you are facing.

With properties I mostly think how much heating they withstand, Duna aerobrake would be mild heating, you would only need to protect sensible parts.

Dropping an probe into Jool would require an very strong heat shield.

[Don Quixote]

To be honest I don't like the idea of reentry heat being added to the game. Don't get me wrong, I play with FAR and Deadly Reentry, both of which are among the best, and most important mods in my opinion. However, it does require a major change in craft design, and I undestand that new players could be turned off by it. So if something gets implenented into stock KSP, it will most likely be a watered-down version with far less consequences than FAR & DRE. The result would be "realism" players who are unhappy because reentry isn't deadly enough, and the "fun" players being unhappy because they don't want to be forced to change their designs. Not to mention new players who are already challenged by the other mechanics of the game. Imagine a new player who has just managed to get his craft into orbit for the first time - having it burn up on reentry at the end of the mission would be extremely frustrating.

In other words, personally I'd rather see improvement on existing features in KSP than having added something likely to displease many players, and which can already be achieved through mods for those who want it.

Besides, reentry heat is one thing. Even more deadly are excessive g-forces, which would again require major redesigns...

[tobjv]

I only plan to look forward to it if they can make it fun to deal with and not a burden.