Jump to content

Does the 1.25 heatshield matter anymore?


Recommended Posts

2 hours ago, Firemetal said:

that is majorly in-efficient

"Inefficient" means you are able to do it one way, but you choose another way that uses more resources. If you can't do it any other way, then the way you are calling "inefficient" is actually the opposite.

That said, as others have pointed out the Mk1 capsule and a heat shield is remarkably robust, making that the more efficient route. However if that did NOT work and a larger heat shield DID work, then the larger heat shield - as painful as it would be to bring along - would still be the most efficient route.

Link to comment
Share on other sites

6 minutes ago, 5thHorseman said:

"Inefficient" means you are able to do it one way, but you choose another way that uses more resources. If you can't do it any other way, then the way you are calling "inefficient" is actually the opposite.

That said, as others have pointed out the Mk1 capsule and a heat shield is remarkably robust, making that the more efficient route. However if that did NOT work and a larger heat shield DID work, then the larger heat shield - as painful as it would be to bring along - would still be the most efficient route.

Ok it seems that I mis-understood the meaning of inefficient but for some reason my heat shield and capsule burns up faster than anyone else's. I have tried to go at 30km and 15km and all in between but I always get the thermometer and nobody else does? Either I'm doing something wrong or I have a glitch. (probably the first one) Anyway guys you've been helpful but there is nothing else you can do. :D Go do something more interesting that trying to figure out how to fix my problem which solution is probably right in front of me.

Link to comment
Share on other sites

12 minutes ago, Firemetal said:

Ok it seems that I mis-understood the meaning of inefficient but for some reason my heat shield and capsule burns up faster than anyone else's. I have tried to go at 30km and 15km and all in between but I always get the thermometer and nobody else does?

"Getting the thermometer" is not always a big deal. Having part of a ship get up to "kinda hot" happens to me fairly often if there's something sticking out a little from behind the shield but if it doesn't actually blow up I don't worry about it.

 

I'll add to the general consensus here. If something blows up on re-entry behind a 1.25 HS it is, every single time,  because I did something wrong. Too heavy, too steep, unbalanced loading or some combination of the three when I'm really thumb-fingering the design. Usually, though, I find the HS far too generous and it ends up being jettisoned with 80% or more ablator left.

Link to comment
Share on other sites

Mark 1 Lander Can: Max Temp 2000k; not completely covered by 1.25m heat shield

Mark 1 Capsule: Max Temp 2400k; completely covered by 1.25m heat shield

Stop using a Lander Can to return to Kerbin.

 

Link to comment
Share on other sites

5 minutes ago, ibanix said:

Mark 1 Lander Can: Max Temp 2000k; not completely covered by 1.25m heat shield

Mark 1 Capsule: Max Temp 2400k; completely covered by 1.25m heat shield

Stop using a Lander Can to return to Kerbin.

Don't tell him that. It's more fun to see him complain in the next update how it "broke his save" because his exploitive ships now all of a sudden cannot survive re-entry and they're all stuck in orbit.

Link to comment
Share on other sites

I wouldn't call it an exploit... just "fixed" in 1.1 =)

4 hours ago, Nathair said:

Usually, though, I find the HS far too generous and it ends up being jettisoned with 80% or more ablator left.

Off topic, but this is my major complaint about the stock heat shields. They're so over full of ablator that I always strip off 80%; if I get into a situation where my heat shield might actually use most of the ablator, I'm almost certainly likely to explode from overheating due to bad re-entry planning. 

Hm, now I'm considering a Module Manager patch to change the heat shields....

Link to comment
Share on other sites

35 minutes ago, ibanix said:

I wouldn't call it an exploit... just "fixed" in 1.1 =)

Off topic, but this is my major complaint about the stock heat shields. They're so over full of ablator that I always strip off 80%; if I get into a situation where my heat shield might actually use most of the ablator, I'm almost certainly likely to explode from overheating due to bad re-entry planning. 

Hm, now I'm considering a Module Manager patch to change the heat shields....

@Nathair @ibanix Heat shields were designed with Jool aerobraking in mind, no wonder they seem too durable for Kerbin reentries. Mind my words, Apollo capsule heat shields never used more than a third of their ablative material when returning from the Moon, NASA overengineered them for safety.

Link to comment
Share on other sites

32 minutes ago, Enceos said:

@Nathair @ibanix Heat shields were designed with Jool aerobraking in mind, no wonder they seem too durable for Kerbin reentries. Mind my words, Apollo capsule heat shields never used more than a third of their ablative material when returning from the Moon, NASA overengineered them for safety.

Sure, that works for NASA, but the only thing I ever over-engineer is for dV on a mission I've never done before. 

The heat shield thing for Jool might make more sense, but IIRC, trying to aerobrake in Jool was more-or-less a death trap. Did that change?

Link to comment
Share on other sites

1 minute ago, ibanix said:

Sure, that works for NASA, but the only thing I ever over-engineer is for dV on a mission I've never done before. 

The heat shield thing for Jool might make more sense, but IIRC, trying to aerobrake in Jool was more-or-less a death trap. Did that change?

As I stated before, it's a matter of the vessel weight. My Jool sentinel sats had a nice weight/drag ratio to survive the Jool aerobraking in 1.1.2

Link to comment
Share on other sites

14 hours ago, Firemetal said:

Ok it seems that I mis-understood the meaning of inefficient but for some reason my heat shield and capsule burns up faster than anyone else's. I have tried to go at 30km and 15km and all in between but I always get the thermometer and nobody else does? Either I'm doing something wrong or I have a glitch. (probably the first one) Anyway guys you've been helpful but there is nothing else you can do. :D Go do something more interesting that trying to figure out how to fix my problem which solution is probably right in front of me.

Check the options and see if your reentry heating slider is > 100%.

Link to comment
Share on other sites

I still want confirmation that he understands the difference between the Mk1 capsule and the lander can. If he's using the capsule, nothing but the heat shield should ever get a temperature gauge. 

Link to comment
Share on other sites

5 hours ago, DChurchill said:

Check the options and see if your reentry heating slider is > 100%.

I'll do that but I doubt that is the case since I am on normal difficulty and I wouldn't make the heat slider anything more than that so that isn't the problem.

 

15 hours ago, Kerbart said:

Don't tell him that. It's more fun to see him complain in the next update how it "broke his save" because his exploitive ships now all of a sudden cannot survive re-entry and they're all stuck in orbit.

:rolleyes: Yeah... Very fun... Yes I now have to use 2.5m heat shield + Command module for every mission to a planet that is beyond Duna or Eve. Hilarious!

14 hours ago, ibanix said:

Sure, that works for NASA, but the only thing I ever over-engineer is for dV on a mission I've never done before. 

The heat shield thing for Jool might make more sense, but IIRC, trying to aerobrake in Jool was more-or-less a death trap. Did that change?

Problem is that almost no one uses heat shields for Jool since everyone does moon gravity assists.

Link to comment
Share on other sites

5 hours ago, ibanix said:

You still haven't confirmed if you're using the Lander Can or Command Module. If you're using the Lander Can, then you have no right to complain....

I swear, if he was ignoring the pertinent information any harder, I'd think it was intentional.

Edited by Jarin
Link to comment
Share on other sites

On 14/6/2016 at 2:06 AM, Nathair said:

"Getting the thermometer" is not always a big deal. Having part of a ship get up to "kinda hot" happens to me fairly often if there's something sticking out a little from behind the shield but if it doesn't actually blow up I don't worry about it.

 

I'll add to the general consensus here. If something blows up on re-entry behind a 1.25 HS it is, every single time,  because I did something wrong. Too heavy, too steep, unbalanced loading or some combination of the three when I'm really thumb-fingering the design. Usually, though, I find the HS far too generous and it ends up being jettisoned with 80% or more ablator left.

My experience shows that it's better to reenter without dropping the last stage, that is with the empty tanks and the engine. This way I can survive steeper reentries, probably because the extra mass is able to store more heat. When I have decelerated enough, I drop the stage and do the final part with the pod and the heat shield.

Link to comment
Share on other sites

The Mk1 Lander Can will not be completely shielded by a 1.25m heat shield, because it's considerably bigger than said heat shield.

Either:

  • Use a heat shield that completely shields the Mk1 lander can. A 2.5m heat shield looks ridiculously big on the Mk1 lander can, but it works.
  • Use the Mk.1 capsule, which is completely shielded by the 1.25m heat shield.
  • Use a bigger capsule, and an appropriately sized heatshield.

Think of the reentry heating as being "light", and the heat shield as being an object that can stop the light and cast a shadow.

You want your whole craft to be in the shadow. 

Also, most craft will self-stabilize to have their heatshield pointing the right way on reentry before anything gets too hot with the SAS off.

Edited by DaMachinator
Link to comment
Share on other sites

26 minutes ago, miceliux said:

My experience shows that it's better to reenter without dropping the last stage, that is with the empty tanks and the engine. This way I can survive steeper reentries, probably because the extra mass is able to store more heat. When I have decelerated enough, I drop the stage and do the final part with the pod and the heat shield.

Also, that big heavy engine keeps your craft pointing correct-side into the wind.

Link to comment
Share on other sites

On ‎6‎/‎14‎/‎2016 at 6:44 PM, ibanix said:

You still haven't confirmed if you're using the Lander Can or Command Module. If you're using the Lander Can, then you have no right to complain....

I have trouble with both.

Link to comment
Share on other sites

36 minutes ago, Firemetal said:

I have trouble with both.

Then you are a) coming in at too steep an angle; b) coming in at too shallow an angle; c) coming in too fast; d) not using enough heatshield abalator.

Players here do re-entry from Mun or Minmus on a daily basis with a Mk1 Capsule, without issues.

(Edit: or, e) your install is f-ed up, delete the entire directory and re-install from scratch). 

Link to comment
Share on other sites

For a and b, I use 30km re-entry which is what everyone here suggests, c is pretty much the same every time unless you burn prograde or retrograde and d I use the max ablator amount. I have just turned off sas and just pointed retrograde and survived but that is the only way. Its either that or I have a problem with installation. Thanks!

Link to comment
Share on other sites

On 11.6.2016 at 3:10 AM, Firemetal said:

Ugh I tried again and unfortunately I cannot triumphantly show you how my heat shield malfunctioned and my space craft exploded.

I lowered the mass by adding a smaller parachute and removing half the ablator.

It was close but Jeb made it. My critical thermal percentage was over 90% when I turned off SAS and the atmosphere took over.

Thanks guys! Helped me a lot. :)

Nice, note that the landing can is not supposed to be used during reentry, they are tin cans designed to operate in vacuum, to reenter with them is to use an tiny city car in an hard offroad track designed to tanks :)
 

Edited by magnemoe
Link to comment
Share on other sites

This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...