Heatshields

[stildawn]

Hi All

I tried looking for a quick answers thread for this but no luck.

So I played the game heaps back in .24 I think, then I went on holiday and when I came back I had lost the enthusiasm to get back into the often times fustrating (in a good way) game.

Anyway, steam main page advertised that its been officially released so I have downloaded again and I'm back into it.

So heat shields, back in my day they werent needed but now re-entries are deadly as hell (at least for me).

So assume I have no knowledge of space or KSP, how do I use these heat shields correctly and to prevent burn up.

I put one on my Mun explorer, and this morning I managed to get it back to Kerbin, but only after multiple attempts (quicksaves lol) using air breaking to get the speed down and down, was still a close call when it finally did make it.

This is how I set it up:

^ - Aerodynamic Cone (top of initial rocket)

---- - Heat shield

/ \

/ \ - This is my one man capsule

| | - Science Module

So I was going nose down on the reentry.

Would love some professional insight into it all.

[Savage117]

Think of the Heat shield as a windscreen, everything you want to protect from the wind has to be behind the windscreen right? So that means anything you want to protect from re-entry has to be behind the heat shield and the heat shield has to be facing into the "wind" or towards the retrograde marker.

So, Your heat shield should be pointed towards the way you are going and the nose of your craft should be pointed backwards, unless its an SSTO(Space Shuttle) then its a whole different ballgame.

^ - Nosecone

/ \ - Command pod of your choice

| | - Science module

--- - Heat shield, this should cover everything behind it, or above it in this case, if it sticks out past the edge of the heat shields shadow, or occlusion zone, it will probably explode.

^ -Direction the wind is coming from

Hope this helps,

Savage

[stildawn]

Ah ok yeah I thought I was doing it wrong (mainly due to the shape of the part).

So it should be right next to my decoupler so that its the rear of the rocket on the way down. And it should protect everything behind it in this orientation?

Does this one heat shield work for all re-entries as long as things don't stick out? Or do I need better ones etc for more high speed entries? Or should I just use Kerbin to air break a few times round before actually going for the landing?

[SRV Ron]

Reentry has totally changed that you should aim for a window of 30,000 meters for the sake of the heat shield and your Kerbals. There is an easy fix to fix the COM causing the pods to flip nose first which is now fatal. Do expect a long reentry heating as the updated physics of the atmosphere now takes much longer to slow down your pod. Small parts attached high on the pod will be protected by the heat shield.

[stildawn]

When you say "aim for a window of 30,000 meters"

What do you mean exactly? I don't know much about space terminology, in the old versions it was simple as nothing ever happened on re-entry, so I would just decelerate until the Pe hit the earth then coast on down lol.

In the past I have used air breaking (might be the wrong term) to reduce speeds/bring Ae down from inter planet/moon returns, where you "dip" into the Kerbin atmosphere to lower your Ae to either slow down or get a stable low orbit with no fuel used (useful for when I wanted to link back up with a space station).

But what is this window you talk about?

I read about the fix in regards to the physics for the heat shield part, will be doing that tonight, though I still read that getting a science module down is still hard?

[Tex]

When you say "aim for a window of 30,000 meters"

What do you mean exactly?

This means that when you burn retrograde, when you're coming back down from an orbit, bring your periapsis (the lowest point in your orbit) down to just under 30,000m. I normally use a periapsis of 25,000m even in old pre-1.0 aerodynamics and it worked perfectly fine even then.

[stildawn]

Ah ok got it so the air will break you enough at 30km to do the actual landing.

I have to say I'm liking the added difficulty even though I was late for work this morning getting my craft safely back on the ground.

If I read the notes on the release correctly, then adding nose cones etc actually matters now correct?

[stildawn]

Man this is hard now lol

Sorted the heat shield problem but now I have two more:

1. With the side mounted parachutes, one of them I get this message when deploying: "Cannot deploy while stowed" and it wont open

2. I'm trying to get the Stayputnik into polar orbit, but the thing just explodes all the time the log says overheating, but its ages away from any engines? I have even tried putting a heat shield in between but nothing works?

[andruszkow]

Man this is hard now lol

Sorted the heat shield problem but now I have two more:

1. With the side mounted parachutes, one of them I get this message when deploying: "Cannot deploy while stowed" and it wont open

2. I'm trying to get the Stayputnik into polar orbit, but the thing just explodes all the time the log says overheating, but its ages away from any engines? I have even tried putting a heat shield in between but nothing works?

StayPutnik isn't really happy about heat. You get lots of heat taking off now as well. With the new aerodynamics, plunging through the atmosphere at 1000 m/s generates A LOT of heat. If your StayPutnik is on top of your rocket on take-off, you should put it inside a fairing.

[magnemoe]

StayPutnik isn't really happy about heat. You get lots of heat taking off now as well. With the new aerodynamics, plunging through the atmosphere at 1000 m/s generates A LOT of heat. If your StayPutnik is on top of your rocket on take-off, you should put it inside a fairing.

I use the octo probe most and tend to just put an nosecone over it then put batteries and science in its shadow.

[John FX]

Man this is hard now lol

Sorted the heat shield problem but now I have two more:

1. With the side mounted parachutes, one of them I get this message when deploying: "Cannot deploy while stowed" and it wont open

2. I'm trying to get the Stayputnik into polar orbit, but the thing just explodes all the time the log says overheating, but its ages away from any engines? I have even tried putting a heat shield in between but nothing works?

You may have to put it inside a fairing to stop the overheating.

E : Ninja'd

[KSK]

Think of the Heat shield as a windscreen, everything you want to protect from the wind has to be behind the windscreen right? So that means anything you want to protect from re-entry has to be behind the heat shield and the heat shield has to be facing into the "wind" or towards the retrograde marker.

So, Your heat shield should be pointed towards the way you are going and the nose of your craft should be pointed backwards, unless its an SSTO(Space Shuttle) then its a whole different ballgame.

^ - Nosecone

/ \ - Command pod of your choice

| | - Science module

--- - Heat shield, this should cover everything behind it, or above it in this case, if it sticks out past the edge of the heat shields shadow, or occlusion zone, it will probably explode.

^ -Direction the wind is coming from

Hope this helps,

Savage

Some centre of gravity care needed here. Depending which science module you're using you might find it's a bit light, which means that the heavy part of your re-entry vehicle (the pod) is furthest away from the heat shield. Unless you're very careful, the vehicle ends up flipping heavy side down, which means you end up doing a nose first re-entry, making that heat shield useless. At which point Bad Things happen.

I found that out the hard way with the Science Junior. Ended up retrieving the science results in orbit, flying a very very twitchy re-entry, having Junior explode on me and then keeping all fingers firmly crossed that I was low and slow enough that the naked pod could survive.

[stildawn]

Yeah it was just the Stayputnik, I changed to the hex ones and its been fine.

[Melcom]

I find that the new heatshields do not protect your craft enough. I added a retractable ladder on my shielded 2,5m lander pod. this thing just explodes in reentry - great. Ok, i tried somethings with fairings. Didn't the Devs hinted that fairings can be used as heatshields? i put a 2,5m heatshield and a 2,5m fairngbase under my pod. The fairings are extended around the lander. In reentry, the effects are great on the fairngs. And in the craft, temps are good. But *boom* the fairngbase explodes because of heat. Come on! How could you ever build complex landers when the heatshilds are to small, don't protect even a covered ladder and farings seems to do nothing... ?

ahh, and i also have problems with "stowed" items that won't activate. Not nice!

[stildawn]

What are these fairings people are talking about? Where do I find them?

It would be better I think if the heat shields were slightly more wider at each size point, so that they actually create a "shadow" for externally mounted parts to hide in.

In regards to the parachute, I just activate them manually now, it seems that the staging thing some parts just don't stage right randomly.

[Melcom]

What are these fairings people are talking about? Where do I find them?

The new parts to cover a payload against drag and/or heat... under aerodynamics

[MajorThomas]

Ever since the new aerodynamics / deadly re-entry has been introduced in 1.0, I've lost so many Kerbals upon reentry. Kinda shocking, as I had not lost any Kerbals in the last year of gameplay.

Makes reentry a bit more agonizing--as it should be!

[CanOmer]

What happens if I use 1.25m heat shield with 2.5m Mk1-2 Command Pod for deorbit? (I'm asking because 2.5m heat shield is too heavy even with lowest ablator, 580kg.)

[FrostedShoe]

1 hour ago, CanOmer said:

What happens if I use 1.25m heat shield with 2.5m Mk1-2 Command Pod for deorbit? (I'm asking because 2.5m heat shield is too heavy even with lowest ablator, 580kg.)

I would suspect that your pod will overheat and explode, but I have never tried it.

[wumpus]

2 hours ago, CanOmer said:

What happens if I use 1.25m heat shield with 2.5m Mk1-2 Command Pod for deorbit? (I'm asking because 2.5m heat shield is too heavy even with lowest ablator, 580kg.)

Can't be good.  You are only protecting ~5 square meters of a ~20 square meter pod and presumably deflecting a significant amount of heat from the protected area to the unprotected area (I have no idea if KSP models this or not).

If mass is a problem (when *isn't* mass a problem), the first thing to do is stop using a Mk1-2 pod and switch to a Mk1 pod + Mk1 crew cabin.  You'll save over 2 tons of mass and can now use the 1.25 heat shield.  Another option is moving the slider *way* down on the amount of ablator on the heat shield.  It's presumably built for Eve aerobraking and overkill for nearly any Kerbin reentry.  Check out how much ablator is left on a working orbiter (presumably while slowly dangling from the parachutes) and notice that it barely uses 10%.  Of course, you might need a certain amount of ablator to make sure the CoM is low enough to have the whole contraption to reenter ablator-down.

For the OP, if you can spacewalk (in career mode this isn't unlocked until a couple buildings are upgraded: I think it is the astronaut complex and science center) there is no reason to attempt to return the science jr with a capsule.  Just take the data out and put it in the capsule and just bring the capsule home.  If you must bring it back, I would try mounting it on top of the capsule (expect explosions) and use side-mounted parachute as I wouldn't be at all confident that the science jr will survive (try putting center-mount parachute on top just for the aero), but I'm pretty sure this often works, just be careful about a good reentry (note I don't think I've used this method for anything beyond returning from Low Kerbin Orbit: you mileage may vary if attempting a Minmus or Duna return).  If you don't have a kerbal on board, make the whole thing as light as possible, yet still with a CoM low enough to keep the ablator pointing down (try using a full ablator for maximum ballast) and letting the low mass make rentry easier (don't bother with any aero reduction, just the ablator, science jr, probe core, and parachutes).

One final note about the Mk1 crew cabin.  Since it is the lightest way to bring kerbals to space (.5T/kerbal), I tend to abuse them a lot.  One nasty issue they have is that they have no external exits (not necessarily true if an end is exposed, but that is a pretty weird design).  You have to transfer crew between another exit (like a mk1 capsule) to perform any sort of spacewalk.

[Rocket In My Pocket]

This thread is pretty ancient.

However I'll add that you don't even need a heatshield for most returns from anywhere in Kerbins SOI, especially with the Mk1 command pod.

You shouldn't be going that terribly fast anyways when you de-orbit.

[Cpt Kerbalkrunch]

@Rocket In My Pocket is correct in that you don't really need a heatshield with the Mk1-2. The thing is a freakin' spacetank. Unless you're free-returning from out around Jool, the shield is a bit superfluous at Kerbin.

And @wumpus is definitely right about the passenger cabin. It's the smart way to go (especially early on), but I prefer the Mk1-2. It's insanely heavy and completely unnecessary, but I don't care. It's freakin' cool and I like it. 

 

[Jas0n]

7 hours ago, CanOmer said:

What happens if I use 1.25m heat shield with 2.5m Mk1-2 Command Pod for deorbit? (I'm asking because 2.5m heat shield is too heavy even with lowest ablator, 580kg.)

I don't really see how the heat shield is too heavy. i would follow the mantra of MOAR BOOSTERS.

 

[kahs007]

where to download ? This specialized shield cap protects the contents found In a Storage Shield's hollow space from the rigors of atmospheric entry.

Edited April 6, 2020 by kahs007