RSS+RP-0. My heatshields are so hot...

[aMaestro]

Hello everyone.

Let me introduce myself. My name is Maestro,. I'm 43, wearing a beard and started KSP at 0.24. Well, I'm not a newbie.

 

Inspired with Scott Manley's videos "Serious Business", I've started a new career 'RSS+RP-0' and everything went well. until I first time tried to return the Moon vehicle to Earth. I've escaped Moon SOI, planned my Earth Pe. to 60-55... and... KA-BOOM! Heatshield exploded due to overheating. Well-well, I do know the physics and I do realize that heatshield isn't a panacea. So I've made the couple of experiments and realized that safe Pe. is ~ 70 Km. But when I try to land with this "safe Pe." I'm expecting dozens of re-entries.

 

As far as I know, LUNA-16 and Apollos landed without this "flying fish"-style, they did it into single entry. So it seems to me that something is wrong in configuration files. Maybe mod "RealHeat", or something like that.

I'll really appreciate any help or/any advice.

 

Sincerely,

Maestro

1 minute ago, aMaestro said:

Hello everyone.

Let me introduce myself. My name is Maestro,. I'm 43, wearing a beard and started KSP at 0.24. Well, I'm not a newbie.

 

Inspired with Scott Manley's videos "Serious Business", I've started a new career 'RSS+RP-0' and everything went well. until I first time tried to return the Moon vehicle to Earth. I've escaped Moon SOI, planned my Earth Pe. to 60-55... and... KA-BOOM! Heatshield exploded due to overheating. Well-well, I do know the physics and I do realize that heatshield isn't a panacea. So I've made the couple of experiments and realized that safe Pe. is ~ 70 Km. But when I try to land with this "safe Pe." I'm expecting dozens of re-entries.

 

As far as I know, LUNA-16 and Apollos landed without this "flying fish"-style, they did it into single entry. So it seems to me that something is wrong in configuration files. Maybe mod "RealHeat", or something like that.

I'll really appreciate any help or/any advice.

 

Sincerely,

Maestro

PS. Excuse me for mistakes if any - English isn't my native.

[GluttonyReaper]

Hmm, you might want to consider the effects of the lifting body of the Apollo capsule. If you right-click on the command module, it should give you the option to offset the center of mass in-flight, allowing you to better control rate of descent.

[legoclone09]

I think only some heatshields are lunar-rated, look for that in description of the parts.

[Hodo]

I think the biggest problem is, if you are running a RO, RSS scale Earth.  You are hitting the atmosphere at a pretty steep angle from the moon.   That is a deep re-entry approach.  

 

Seeing as the Earth in RSS has an atmosphere of around 180km, you are setting your PE for 60-70KM that is about 2/3rds of the way in, while coming from the moon, which will give you a VERY VERY fast approach speed.   The Apollo would do a high altitude skip to bleed off energy and speed then do the finale dip to splash-down.

[NathanKell]

60 is about right for a ballistic entry. 50 or so for lifting. Do remember to right-click on your capsule and enable descent mode so you fly a lting reentry (you want your navball crosshairs to be directly above the retrograde marker, i.e. stay rolled level with the horizon).

As @legoclone09 says, though, not all heat shields are rated for lunar reentry. If you don't have a lunar-rated shield, then you'll have to slow down over many, many passes.

[MaxL_1023]

You need the bronze-colored heatshield with a max temp of 3600 degrees - the silver/grey ones are LEO only (2600 degrees). It also makes a big difference what pod you are using and how much extra mass you have attached - in general the heavier your ship the tougher a safe re-entry is. 

I would recommend trying to save 1000m/s of delta-V, and burn slightly above retrograde just before atmospheric entry. If you angle it right, you can take 90% of that delta-v off your entry velocity while maintaining the same Perigee. An entry at 10 km/s is a lot easier than 11 km/s - heat scales with the cube of velocity AFAIK. 

[NathanKell]

Convective heat does. Radiative heat is worse (radiative heating can essentially be ignored for LEO reentry, whereas in the first minute or two of a lunar reentry it's like 50+% of the heat load).

[aMaestro]

Thanks to everyone for good answers!

Really, heatshields differs. I've simulated "direct fall from the Moon" with the bronze shield (3600K) and this was much better.

But then I've decided to go another way. After successful launch of probes to Mercury, Mars and Venus I've got enough science to go directly to discover of atomic engines, especially RE-N4 "Nova". After this my first manned Moon mission was very smooth and comfortable - with habitat, plenty of delta-V, blackjack and Bender  So, I've just dropped dV to enter LEO and landed easily.

 

Thanks again to everyone!

[Teilnehmer]

Oh thank you guys! I’ve had the same problem with my Moon journey in RO.