How to make Re-entry more deadly?

[Desperado34]

I love KSP and I love more realism. Thats why I played 0.90 with DRE, FAR, Remote Tech, TAC life support and a bunch of other stuff. Returning from orbit used to be something that needed some thought and some proper engineering if you wanted to bring back more then just a capsule. With 1.0 I got excited about the implementation of aero and re-entry into stock.

However now Im playing in 1.0.2 I find it near impossible to BBQ my crew on re-entry. Meaning that all my missions can safely return my crew guaranteed...no fun in that!

Goal: Burn up an MK1-2 capsule on re-entry

Settings: DRE, re-entry heat 120%, Aero heat production maxed at 5.000 (default is something like 3.250)

Attempted re-entry orbit: 500kmx30km no heatshield, 500km 90 degrees straight down no heatshield, 1000kmx5km no heatshield

The capsule survived all re-entry attempts. The crew died from excessive G-forces on the last 2 attempts, but the goal of capsule BBQ still failed.

Does anyone have tips on settings, mods etc to make re-entry more deadly again. Pretty much like how it was in .90?

Edited May 16, 2015 by Desperado34

[TheCanadianVendingMachine]

Step 1: Go into your save game's settings (persistent.sfs)

Step 2: Find ReentryHeatScale

Step 3: Turn this up to 2.0, instead of 1.2

Step 4: ???

Step 5: Profit (or burn)

[Gaarst]

Or you can download and install Deadly Reentry updated to 1.0.x

[Sokar408]

Or you can download and install Deadly Reentry updated to 1.0.x

Deadly Reentry doesn't make any sense to me anymore. My craft, even the simplest imaginable breaks apart on reentry. The Ablator doesn't even start getting used before parts explode. Seems very counter intuitive to me.

[Desperado34]

Step 1: Go into your save game's settings (persistent.sfs)

Step 2: Find ReentryHeatScale

Step 3: Turn this up to 2.0, instead of 1.2

Step 4: ???

Step 5: Profit (or burn)

Thanks will try that.

Or you can download and install Deadly Reentry updated to 1.0.x

I did that, however for some reason DRE (v7.0.3) went soft with 1.0.2

Some other weird occurance: when I launch a high TWR rocket the fuel tanks will explode around 5km@400m/s. Compared to the effort I have to go through to BBQ a capsule this seems odd.

Update: changing ReentryHeatscale to 2 makes the above occurance even more absurd. I flew up a test rocket rather carefully and the fuel tanks exploded at 6km@320m/s. Rockets should be able to break the sound barrier, even at lower altitudes.

Edited May 16, 2015 by Desperado34

[panzer1b]

1.0 was WAY more fun imo, both in atmo and in reentry heat (which was a MAJOR threat in 1.0, not in 1.0.2 though).

I feel that 1.0.2 was a rushed decisuion based on a few complaints (some of them justified, most of them just coming from people who didnt like the new aero and didnt actually think it through as to why it was good/bad, just hated that old craft nolonger worked). 1.0.2 is in my opinion a step backwards more towards the souposphere, and its almost IMPOSSIBLE to overheat/burn unless you make some uber streamlined vessel and come in at interplanetary velocities. I did some aerobraking at jool, laythe and kerbin in 1.0, it was difficult but my SSTO made it to laythe and returned to kerbin ALIVE, this is reasonable, despite the fact that i needed multiple aerobrake passes at jool to save myself the fuel itd take to burn normally otherwise.

The new aero just feels almost like it was back in 0.90, drag values are so high the only way to burn up (even in a crappy craft) is to come in at outright stupid angles, or have some lucridious velocity that more likely then not cant even be achieved without using mods or cheating with inf fuel (you aint gonna get 20km/s velocities in any encounter without some cheaty mods/inf fuel). Pretty much 1.0.2 made overheating a very minor nuissance at best, ive yet to actually TOUCH a heat shield for anything as they are just unnecessary mass right now. With a SSTO that has wings you can just brake by pointing wings perpendicular to velocity, with anything else slap on 2-4 airbrakes and those will slow you down enough that even parachutes are redundant.

Basically the more i think about it the more i see how nobody though 1.0.2 through, and honestly im STILL using 1.0 physics configs given how much more fun, balanced, and just tested the values were there. Reentry heat is now useless with the new souposphere mk-II, and while i wont go all out and say 1.0.2 is another 0.90 (which it isnt, its still better), i think 1.0's drag/aero made a more fun and difficult but not annoying gameplay.

[tater]

Kerbin is too small.

That is the problem.

The result is that orbital velocities are tiny, and the craft decelerate to safe speeds very quickly. Danger requires longer duration in the atmosphere at high velocities. This is why upping the heating kills spaceplanes. THEY have to fly longer at high speed in the atmosphere, so they can see way more heating than capsules.

The thing to do is to text scaled up Kerbin when that is available, and see what reentry looks like with a 2X kerbin, 3X kerbin, etc. (this is why those of us in the "err on the side of realism" camp think the way we do---when yo make an arbitrary planet that breaks physics like kerbin, things don't work as one would expect. The real test of the aero model is to try it on a 10X Kerbin and see what it looks like.

Edited May 16, 2015 by tater

[Aerindel]

which was a MAJOR threat in 1.0, not in 1.0.2 though).

What are you talking about? in 1.0 re-entry was even easier than in previous versions. Parachutes where indestructible and instantly slowed you from any speed before heating could ever be an issue.

I agree that re-entry heating is utterly broken but it wasn't any better in 1.0 either.

[tater]

Reentry heating is not necessarily broken. Unless you have tested in a 10X Kerbin, you cannot say it is broken. Alternately, hit the kerbin atmosphere at 9 km/s, and report back how that works (hard, I know, since to get any sort of slice of the atmosphere you'll need to set periapsis near sea level, lol).

Kerbin has the rough stats of Earth---except for its tiny size.

If you jack up shock heating such that 1500m/s is nasty, what will happen to aircraft and spaceplanes?

The obvious solution is rescaling.

- - - Updated - - -

OK, just tested a mk1-2 with periapsis on Kerbin at ~20 km, speed 8500. Heat shield blew, but craft survived. Of course it was not an unreasonable reentry.

Same happened at 11 km/s, the heat shield blows in 2-3 seconds, then the pod happily reenters at 8+ km/s and doesn't overheat. Temp of mk1-2 got to 1374.

That's a lunar reentry kind of speed.

Edited May 16, 2015 by tater

[Desperado34]

Could it be that we are on to a bug that makes crew capsules invincible to re-entry heat? Or is it just not tested properly by Squad?

[tater]

Anyone suffering from reentry has to be trying REALLY hard. 11km/s, no problem. I didn't test with no heat shield, but honestly, I don't think they are needed at all.

I still think the scale needs to be larger, because LKO reentry likely cannot be made dangerous without unwanted consequences, still, it's pretty terrible as it stands.

Shuttle was built to withstand just under 2000 K (hottest it got was apparently actually under 1800), via the RCC portion looks like. The craft itself, however was not. The Columbia disaster had a failure in the HRSI section, which was for temps under 1533 K. So the crafts need to have acceptable heat reduced substantially, IMO. instead of 200, or 2400, maybe 1000 k. Then the heat shields are required.

DRE includes g forces, which should also be in the system.

Edited May 16, 2015 by tater

[Fuzzy Dunlop]

It's the 1.02 atmosphere, compared to 1.0 it's a step back to the old soup-o-sphere. The higher drag means that pods tend to slow down in the upper atmosphere and so avoid much heating later on. In 1.0 pods punched straight through the upper atmosphere then got fried lower down.

[Xavven]

Wow, you guys are right. At first I thought that there was at least some gameplay value in the threat of re-entry heat, in that players would be encouraged to use capsules to re-enter and be unable to re-use their, say, Mun lander as a Kerbin reentry vehicle. So I ran some tests. I set re-entry heat to 100%, built a Mun lander that is totally not aerodynamic, slapped a parachute on it, launched past Minmus, set my periapsis to 25k altitude and grabbed some popcorn.

The only things that exploded were some externally mounted batteries. Everything else survived. Girders, radially attached tanks, exposed engines, landing gear, lights, etc.

Then I repeated the test, but this time went past Minmus and burned TOWARDS Kerbin to simulate an interplanetary re-entry. My orbital velocity was 3000 m/s at Minmus.

Still nothing. In fact, my lander even freaking flipped headfirst because of center of mass issues, and I thought "ok, surely Jeb's toast now." Nope. Batteries exploded, flames died down. Deployed parachutes at 10k and landed.

I'm not even going to bother trying 120% re-entry heat. I already have my answer. This is insane.

[Aerindel]

Or is it just not tested properly by Squad?

Probably this. Their QA system for 1.0 seems virtually none existent.

[cicatrix]

Will FAR + DRE help in any way now?

[asmi]

This is what happens when you break some laws of physics - other laws of physics starts breaking down as well as they are all interrelated.

[tater]

So I tested in the SKY mod, which ups a Kerbin (and some other worlds) by 3.7X.

LKO reentry was uneventful at 4100 m/s (used some heat shield, as one would expect).

I tried an 11 km/s reentry as well. Burned off the heat shield on the mk1-2 pod, and then dangerously heated the remaining spacecraft. Without the shield it would have been toast for sure, it ha dthe little heat bars come up about 80% full, and the chute started to overheat. I think a nominal direct Mun return in that mod is around 10km/s, so it actually looks pretty decent for a scaled up Kerbin as this is basically our Apollo CM. I think with a scaled up Kerbin, there would actually be a non-zero chance of reentry failure.

[Archgeek]

Just what were the re-entry heat settings for 1.0? I've been messing around with a minimalistic test rig and the worst I've been able to do to a mk1 pod was 472k coming down from a 950.6km x 1.8km orbit, and just under 411k from a 76km x -400m orbit.

Sadly, 1.02 happened when I was at work so I didn't get a chance to save a 1.0 copy and so lack a reference to the old config, and I miss having setting my ablator being part of the design considerations for a mission.

EDIT: I see it's even worse than I thought -- an unshielded mk2 pod coming down from a 1000km x 20km orbit only pulled a max temp of 228.0k... 'turns out the heating's weak enough that starting temperature has a greater effect. Even rampaging down from 1000 x -495km only got a max temp of 457.8k.

Edited May 17, 2015 by Archgeek
New observations

[Fire-Dragon-DoL]

I'm a bit concerned, I have basically no part exploding except for the "connectors" between a small tank and a larger tank, they explode as soon as they hit any sort of atmosphere.

I thought they were meant to be quite resistent. Is this a bug?

[DanEklund]

I don't have the same experience. I am playing un-modded in career mode and find that parts explode and parachutes, especially radial parachutes, are destroyed pretty much every time.

[tater]

I've lost a few things hanging off the sides, like solar panels, that's it.

[Archgeek]

I don't have the same experience. I am playing un-modded in career mode and find that parts explode and parachutes, especially radial parachutes, are destroyed pretty much every time.

Yeah, I've just been testing bare pods with top-mounted chutes. Exposed bits and bobs will still blow if you don't pull them up high enough to be occluded by the pod's base. Also for some reason, kerbals in lawn chairs on heat shields will take convection flux like they're dangling out the side while everything near them is untouched.

In 1.0, you see, a bare pod couldn't easily make it down inact, and you were likely to use half of the ablator on a shield. Losing chutes is minor in comparison, unless you're in career and there are kerbals on board.

[Gerandar]

Yeah, I've just been testing bare pods with top-mounted chutes. Exposed bits and bobs will still blow if you don't pull them up high enough to be occluded by the pod's base. Also for some reason, kerbals in lawn chairs on heat shields will take convection flux like they're dangling out the side while everything near them is untouched.

In 1.0, you see, a bare pod couldn't easily make it down inact, and you were likely to use half of the ablator on a shield. Losing chutes is minor in comparison, unless you're in career and there are kerbals on board.

i dunno about you but in 1.0 you just hit the space bar to deploy your chutes and they would stop you instantly from anyspeed from just about anywhere in the atmo. 1.0.2 at least fixed that.

[Archgeek]

i dunno about you but in 1.0 you just hit the space bar to deploy your chutes and they would stop you instantly from anyspeed from just about anywhere in the atmo. 1.0.2 at least fixed that.

Eh, that was super easy to ignore. One just chose to not open chutes until doing so was reasonable. What troubles this thread is how a change other than the parachute fix neutered the ability of the atmosphere to melt an unprotected command pod.

[Xavven]

... What troubles this thread is how a change other than the parachute fix neutered the ability of the atmosphere to melt an unprotected command pod.

or pretty much anything except radially mounted batteries and parachutes.