What is the max speed that a heat shield can protect from?

[Kerminator K-100]

The title is a little confusing so here is some context. I have a ballistic craft that I'm using for the Quest for Hypersonic challenge (link in my sig!). I've just done a Jool gravity assist and am speeding toward Kerbin at 8000 m/s but before I hit the SRBs and boost up to 10000, I want to see if anyone knows what the max survivable reentry speed with a heat shield.

[Guest]

It’s 9999 

No I’m not sure. I know you can stack heat shields but not sure whether they’d count as one or get destroyed in order?

[Mythos]

"Reentry" just means entering the atmosphere, not necessarily that you stay within 

So if you only dive into the atmosphere a few meters for a few seconds, then the speed to survive that is pretty high. But you only get close to zero deceleration from that  But still, if you come with a little bit over escape velocity and aerobrake just below escape velocity then this maneuver has got you captured and enables a second run, and a third, etc 

So then the question is about heat management in general and depends on your overall ship design.

If you aim for a single shot to land immediately, and worst case come in straight vertically, then that speed is very low.

There certainly is a distance where you can have 0 relative velocity to kerbin, and still won't survive because gravity will accelerate you too much on the rest of your journey. So you even need to specify your idea of speed a little more (what's your reference?)

 

[Kerminator K-100]

2 hours ago, Mythos said:

"Reentry" just means entering the atmosphere, not necessarily that you stay within 

So if you only dive into the atmosphere a few meters for a few seconds, then the speed to survive that is pretty high. But you only get close to zero deceleration from that  But still, if you come with a little bit over escape velocity and aerobrake just below escape velocity then this maneuver has got you captured and enables a second run, and a third, etc 

So then the question is about heat management in general and depends on your overall ship design.

If you aim for a single shot to land immediately, and worst case come in straight vertically, then that speed is very low.

There certainly is a distance where you can have 0 relative velocity to kerbin, and still won't survive because gravity will accelerate you too much on the rest of your journey. So you even need to specify your idea of speed a little more (what's your reference?)

I was talking about a vertical entry, the point of the challenge is to get as much speed, not so much, lose the speed. But I'm thinking a conventional might be a better idea. At the very least a periapsis of 45 km.

[king of nowhere]

with a conventional reentry, a small simple capsule made of a Mk3 command pod with 2 parachutes and its thermal shield, I survived a reentry at almost 8.5 km/s, braking all the way to full stop. i also tried 10.5, and i exploded. the limit is somewhere in between. it is possible that more heat shields may withstand even harsher braking, but in my case i had activated g forces, and i got close to 40 g as top deceleration. more than that, and it would have killed the crew and smashed the ship anyway

[JcoolTheShipbuilder]

In terms of hitting an atmosphere at a high speed, don’t try skimming Duna at 40km periapsis at 15km/s, I tried it once, and it burned through like four heat shields in two seconds lol...