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Re-entry made impossible now for most missions.


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Its been a while since I last played but I ran into a huge issue...

It takes about 2,400 miles an hour to get a basic orbit around Kerbal. You NOW have to get below 1,700 miles an hour just to not burn up and die. This requires me to use a whole other tank of fuel just to get under 1,700 miles an hour when in re-entry from an orbit. Does anyone know how to fix this back the the way it was? 

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@EvolutionLovesU what version did you last play? Re-entry heat was added in 1.0 along with a new, realistic aerodynamics model, so if you were playing before that, you'll have to adjust to the new aerodynamics.

Some other things you should be aware of: parachutes and antennas now rip off if they are deployed at too high of a speed, the atmospheres are more realistic (meaning that they won't slow you down as much in the first 10,000 meters), water now works properly, probes require a direct connection to the KSC to function, you can mine for resources and convert it to fuel, female Kerbals were introduced, jet engines were overhauled, asteroids sometimes glow in the dark...the list goes on. 

Also, it's not necessary to completely rework the aerodynamics to stop your ships from exploding. Simply add heatshields and/or radiators to your ships; (and keep the heatshield pointing :prograde: during re-entry) they'll keep heat away from the explosion-prone parts. Both are under the Thermal tab in the VAB/SPH. I've found that a periapsis of about 30,000 meters is effective enough to slow down my ships without overheating (again, these are ships with heatshields.)

Hope this helps!

P.S. I think you mean meters per second, not miles per hour...

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2 hours ago, EvolutionLovesU said:

Does anyone know how to fix this back the the way it was?

When starting a new save, you can adjust a slider for re-entry heating. Just moving it to zero should bring back the old days.

However... have you already found the heat shields? Devs not only added heat but also means to cope with it. You can still enter almost anything at nearly any speed as long as it has a heatshield pointed into the wind.

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2 hours ago, EvolutionLovesU said:

 

Its been a while since I last played but I ran into a huge issue...

It takes about 2,400 miles an hour to get a basic orbit around Kerbal. You NOW have to get below 1,700 miles an hour just to not burn up and die. This requires me to use a whole other tank of fuel just to get under 1,700 miles an hour when in re-entry from an orbit. Does anyone know how to fix this back the the way it was? 

It's meters per second (m/s), not miles per hour.

Reentry is pretty trivial, still. Set periapsis to maybe 20km. BTW, does your craft have heat shields?

Edited by tater
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If you are using Lifting body/Shuttle/SSTO, and you are coming in from Mun or any high orbits, you will need to use airbrakes, by lowering Pe to about 55km to lower some speed. Once that's sufficent, you will need to enter it liek shuttle, staying at around 30 degreess to enter Kerbin.

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There may be an issue with your install.

A simple command pod should be able to reenter from orbit on its own, without a heatshield, without any problems. I'm not sure about reentry coming from the Mun or Minmus: I tend to play safe and add a heatshield anyway.

For planes, I haven't had any serious difficulites other than the Mk2 cockpit. And that's on medium difficulty with reentry heating turned up.

So maybe you've got some kind of problem with your install/configs, which is massively overdoing the reentry heat. At normal levels this should not be a problem.

 

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If anything, I'd say reentry is considerably EASIER now than it has been in the last few versions since I started playing, mostly due to the improvements to SAS.  As long as you don't come in MUCH too steeply and you use a heatshield for anything beyond LKO, you should be fine.

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12 hours ago, EvolutionLovesU said:

You NOW have to get below 1,700 miles an hour just to not burn up and die.

Screenshot, please?

Reentry, when done "right", is easy and doesn't require retro-thrust or other fancy shenanigans.  Reentry at over 3000 m/s is easily doable.

However, when done "wrong", it can be a problem.  Furthermore, there are many different ways to be "wrong"-- these include your trajectory, whether you have heat shields or not, the mass and shape of your ship.  Without more detailed information, it's hard for anyone to give you specific helpful advice.  There's a good chance that your difficulties are because you're doing one simple thing wrong, and fixing that one thing will clear up all your problems.

A screenshot of your ship would be very helpful, along with knowing what its mass is, and how steep your reentry is (e.g. what is your Pe set to before you hit atmosphere?)

In general, here are the ways to be survivable:

  • Have a heat shield.  If you have a low-ballistic-coefficient ship (i.e. lightweight & draggy) in LKO, you can generally enter without a heat shield with no problem.  But for higher speeds, and/or ships with higher ballistic coefficient, a heatshield is a lifesaver.
  • Build the ship to have a low ballistic coefficient.  You want something that is lightweight relative to the amount of drag.  Best case is a lightweight pancake; worst case is a heavy javelin.  For example, a Mk1 command pod entering by itself, blunt end first, has a nicely low coefficient and can generally reenter just fine even without a heat shield.
  • Don't enter too steep or too shallow.  If you just dive straight at the ground, you're still going too fast when you hit the "charbroil zone."  On the other hand, if you're too tentative about it and set your Pe way up in the upper atmosphere, you end up generating scads of heat without actually slowing yourself down much.  The sweet spot will vary depending on your ballistic coefficient, but in general, aim for a Pe of around 30 km or a bit less, and that seems to work pretty well.
  • Use lift.  This applies especially to spaceplanes, which have all that wing surface to play with... but it also applies to wingless reentry vehicles, if they've got a cylindrical profile.  Angle the ship to take advantage of body lift (i.e. so that the incoming airstream strikes the underside of the ship and is deflected downwards, generating lift).  This provides a great way to increase your drag and bleed off a lot of speed, while still keeping your altitude relatively high.  If you're flying a ship with heat shields, lift generally isn't a factor (you don't need it, and using it is tricky because angling the ship for lift would expose non-heat-shielded surfaces to the blowtorch).  However, if you're reentering without a heat shield, you should try to use lift for maximum advantage.
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I have a challenge for you.

Make a reentry vehicle consisting of exactly one MK1 pod, one M16 parachute, have a kerbal pilot on board, and SAS set to retrograde.

Make it burn up in the atmosphere, on stock 100% reentry heat.

 

I managed to do it, by bringing it below 21km at some 7500m/s. That's the kind of speed you get returning from Eeloo. It didn't actually overheat following the standard heat mechanics, just a built-in game override that automatically kills everything that moves below 21km at certain (excessive) speed, regardless of its heat tolerance. Normally, that setup is about impossible to overheat.

Edited by Sharpy
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