[1.12.*] Deadly Reentry v7.9.0 The Barbie Edition, Aug 5th, 2021

[chrisl]

Ok, I just successfully made a reentry using RSS/RO and did not experience what you described. I'm still looking over your files. (and NP++ is being a female dog about it right now...)

Edit:

The only thing that *might* make a difference is FAR. The version I used is different from yours. AFAIK I have the latest official so I'm guessing you have a dev version. (0.15.5 vs 0.15.3)

But I'm just not seeing that as a factor. I don't think FAR is really doing anything with that affects heat except that how it calculates area is/has been different. But that's not going to spike the temperature.

I'm using 0.15.5 which is the version shown on the main FAR page: http://forum.kerbalspaceprogram.com/threads/20451 I had been using 0.15.4.1. Think I upgraded beginning of the month so it's possible that's where the difference is. I can easily check, though. I'll just put the older version on and refly my save and see what happens.

EDIT: FAR 0.15.5 seems to be the culprit. I removed it and reinstalled the older FAR 0.15.4.1 I had been using, then reloaded that save. This time skin temp rose steadily to about 1690 which didn't happen until I was closer to 52km. Then skin temp started to drop and didn't spike again. Not sure what is going on there but I'll post over on the FAR thread. Thanks for helping me narrow this down, Starwaster.

Edited September 6, 2015 by chrisl

[Enceos]

Hi Starwaster, I haven't played with DRE for a while, has it become SSTO friendly in the latest patch?

[Starwaster]

Hi Starwaster, I haven't played with DRE for a while, has it become SSTO friendly in the latest patch?

I'm not sure how to answer that.... I'm not aware it was ever SSTO unfriendly given that SSTO just means 'single stage to orbit'

Unless you're really maybe asking about spaceplanes but then my answer would be the same. Over the past couple of days I've flown a number of spaceplanes either to orbit or suborbital successfully and then returned from space safely.

(with the exception of a fairly complex OPT spaceplane that had one its engine nacelles explode on a suborbital hop, but I successfully recovered and made an emergency landing. Not sure what happened there)

If you've had trouble in the past, give me more info and I'll see if I can help.

In general though, if you're approaching Mach 2 then you better be at or near 25km altitude and if your ascent is shallow then you might need to steepen it a bit... but I've done both, where I ascended shallow and then at 25km I pitched up 10 deg to gain some altitude. But I prefer to go steep as soon as I leave the runway. (my favorite OPT design was going vertical by the time it reached the middle of the runway, at which point I just kicked in MechJeb's ascent guidance autopilot)

[Enceos]

I see, thanks for the answer! The magic number of 25km is all I need to make my trajectories safe then

[Starwaster]

I see, thanks for the answer! The magic number of 25km is all I need to make my trajectories safe then

One thing though about the reentry portion of it. You do want that shallow. Your skin is very low thermal mass, high emissions factor. They'll heat up a lot quickly and it's honestly a little scary to behold all the red temp gauges lighting up.

Start reentry from halfway across the planet with a Pe of 50-55

[Enceos]

One thing though about the reentry portion of it. You do want that shallow. Your skin is very low thermal mass, high emissions factor. They'll heat up a lot quickly and it's honestly a little scary to behold all the red temp gauges lighting up.

Start reentry from halfway across the planet with a Pe of 50-55

Does it mean that a safe spaceplane reentry from orbits beyond Mun is impossible?

[Starwaster]

Does it mean that a safe spaceplane reentry from orbits beyond Mun is impossible?

I haven't tried it, but that would probably be a bad idea.

A reentry that relied entirely on aerobraking means that you'd have to dip at least 35 km into the atmosphere (it really depends on your mass. On the ballistic coefficient if it were calculated)

That's too steep and you'd be coming in a lot faster.

I gave spaceplane parts thermal properties equivalent to the shuttle's tile system.

[NathanKell]

You could do multiple passes. It's not a problem unless you're going fast enough that you can't aerocapture on the first pass.

[Starwaster]

You could do multiple passes. It's not a problem unless you're going fast enough that you can't aerocapture on the first pass.

It also just occurred to me that the guy who is doing the stork delivery parts is also doing a ballute... people have been asking for those for awhile now.

[Jobadiah]

I am playing with the RO/RP-0/RSS mods (and their dependencies and recommended supporting mods). I seem to be having the opposite problem of most people here; my heat shields hardly lose any ablator during reentry. For example, I just returned a payload from 250 km orbit with a 43 km reentry perapsis and my remaining heat shield is 77.61 of the original 80 using the 1.25m LEO heat shield. Are my settings for DRE way off somehow? (using DRE 7.2.2)

Thanks!

[Starwaster]

I am playing with the RO/RP-0/RSS mods (and their dependencies and recommended supporting mods). I seem to be having the opposite problem of most people here; my heat shields hardly lose any ablator during reentry. For example, I just returned a payload from 250 km orbit with a 43 km reentry perapsis and my remaining heat shield is 77.61 of the original 80 using the 1.25m LEO heat shield. Are my settings for DRE way off somehow? (using DRE 7.2.2)

Thanks!

Apparently, in real life, shields were overengineered (because we weren't sure how much they had to withstand) and didn't lose very much material. So, Realism Overhaul (note the 'real' there, heh) tones down the ablation quite a bit and DRE probably is chewing away at your shields more than is realistic.

For the time being I've elected to keep DRE's original shield behavior to keep things challenging and players on their toes. If RO customers would prefer more challenging shields then in the future I'll figure something out. Probably an in-game slider that scales ablation on the fly. That way, the various configs that control behavior wouldn't have to be changed anywhere. But yeah, in the meantime: Status Quo.

[XxDARKWOLF67Xx]

Does this work with atmospheric trajectories?

[Starwaster]

Does this work with atmospheric trajectories?

No. But it doesn't not work with it. They really don't have anything to do with each other.

[Wuwuk]

Somebody please give a link

to the latest version of DRE for KSP 0.90.

[Starwaster]

Somebody please give a link

to the latest version of DRE for KSP 0.90.

Last version for KSP 0.90 was DRE 2.5.3.

https://github.com/Starwaster/DeadlyReentry/releases/tag/v6.5.3-beta

Edited September 14, 2015 by Starwaster

[Wuwuk]

Last version for KSP 0.90 was DRE 2.5.3.

https://github.com/Starwaster/DeadlyReentry/releases/tag/v6.5.3

Thank You.

[Starwaster]

Thank You.

Oops, one caveat: It was tagged as beta and due to the chaos in moving to DRE 7.0 (for the KSP 1.0 update) it was never marked as full release. I tried to remove the beta tag when I linked to it for you, but that caused some other issues where Github was saying that 6.5.3 was the very latest update so I put the beta tag back.

Correct link (for anyone who might find this in the future and need the download) is https://github.com/Starwaster/DeadlyReentry/releases/tag/v6.5.3-beta

If you already downloaded it, you're fine. If for some reason you didn't and try the old link, use the new link above.

[Jovus]

Reentering on a 75x25 profile with a mk1 pod, a Science Jr. and a 1.25m heat shield causes the pod to explode at about 50km.

Is this intended behaviour? That's a real question; it's been a while since I last used DRE - before the stock skin temp support change. If so, what would you recommend as a reentry profile nowadays?

If not, I can do some more digging to figure out the actual problem; I've already re-installed DRE twice. Before I do are there any known mod conflicts/funny interactions? I'm using FAR, RealChute and KSPI, too, along with a bunch of informational mods.

[Starwaster]

Reentering on a 75x25 profile with a mk1 pod, a Science Jr. and a 1.25m heat shield causes the pod to explode at about 50km.

Is this intended behaviour? That's a real question; it's been a while since I last used DRE - before the stock skin temp support change. If so, what would you recommend as a reentry profile nowadays?

If not, I can do some more digging to figure out the actual problem; I've already re-installed DRE twice. Before I do are there any known mod conflicts/funny interactions? I'm using FAR, RealChute and KSPI, too, along with a bunch of informational mods.

FAR was implicated as a culprit in this post: http://forum.kerbalspaceprogram.com/threads/54954-1-0-4-Deadly-Reentry-v7-2-2-update-July-24-2015-%28The-Melificent-Edition%29?p=2180893&viewfull=1#post2180893

I haven't kept up on the issue so I don't know what you need to do. (drop back a version, get the dev version, etc...)

[Sampa]

Apparently, in real life, shields were overengineered (because we weren't sure how much they had to withstand) and didn't lose very much material. So, Realism Overhaul (note the 'real' there, heh) tones down the ablation quite a bit and DRE probably is chewing away at your shields more than is realistic.

For the time being I've elected to keep DRE's original shield behavior to keep things challenging and players on their toes. If RO customers would prefer more challenging shields then in the future I'll figure something out. Probably an in-game slider that scales ablation on the fly. That way, the various configs that control behavior wouldn't have to be changed anywhere. But yeah, in the meantime: Status Quo.

Which,reminds me...i need to reinstall this!

[Jovus]

Thanks Starwaster; I'll go see if they've found a solution with FAR or if I should just drop back a version.

Found this over on the FAR thread:

I originally posted this on the DRE forum thinking my heating issue was related to that mod. But with some assistance from Starwaster, it looks like the problem is actually with FAR. Here's what I'm experiencing. I'm playing with RO/RSS/RP0, all their respective required mods and most of their suggested mod (plus FASA). I recently upgraded from FAR 0.15.4.1 to 0.15.5. Prior to the upgrade, I had successfully launch and recovered 6 Mercury Atlas rockets. After upgrading to 0.15.5, however, I launched a 7th and have been experiencing issues during recovery. Reentry seems to be going initially fine. Skin temp will slowly increase from space to around 1600 at 62km (speed: 7km/s, vert speed: -238m/s, 2.1375g). At this point, skin temp starts to slowly drop until its down to under 1350 at just over 50.5km (speed: 5.6km/s, vert speed: -305m/s, 5.1374g). But as soon as I hit 50.5km, skin temp immediately jumps back up to over 1950 and begins climbing. Without the "Ignore Max Temperature" cheat turned on, the Mercury capsule explodes moments after falling below 50.5km do to overheating. With the cheat turned on, skin temp continues to climb until it peaks at about 2550 at 45.6km. Obviously, the issue is this phantom +600 in skin temp that seems to be added as soon as I hit 50.5km.

If I remove FAR and reinstall the older 0.15.4.1 version (and Starwaster was using 0.15.3 which worked for him), then reload the exact same save that resulted in the failed reentry above, the reentry works just fine. The Mercury pods skin temp slowly increases to just shy of 1700 but that doesn't happen until I'm already below 15.5km. And when skin temp starts to fall, it never has any sudden increase and makes it all the way down to the ground. I don't know enough about modding to have the first clue as to what changed between 0.15.4.1 and 0.15.5 that might be causing this strange heating issue, but I wanted to report it so it can be investigated.

Just wanted to report that 0.15.5.1 seems to resolve the issue I reported.

Note I'm not using RO or any of those things, and I am on the latest version of FAR (0.15.5.1). Also, as a point of interest, suborbital flights don't seem to be a problem; possibly because I don't stay in the 50-70km range anywhere as long?

I'll do some more digging and get back to you once I have more detail. At this point I'm just posting so you're aware, in case you get other reports.

ETA: Without FAR, reentry works fine, with skin temp on the capsule hovering around 450. The shield gets to a skin temp of around 1000.

With FAR, first the Science Jr starts heating, quickly. Facing absolutely dead on into the atmo stops the heating, but otherwise it continues receiving heat. Around 58km, the skin temp on the mk1 pod mirrors the phenomenon described above; viz. the skin temp begins to rise considerably, until the capsule blows with skin temp at about 1000 somewhere between 48-53km (depending on exact periapsis and careful flying).

If I had to guess, and I do because there's nothing in the debug log to indicate misfunction, I'd say FAR has an occlusion issue. I'll dig around some more and see if I can't replicate it with different parts - e.g. a payload bay instead of a Science Jr, the pod itself (sans ablative), etc.

Let you know what I find.

Edited September 18, 2015 by Jovus

[Herrkurt]

My craft keep exploding around 80km on re-entry in RSS. Using DR as part of RSS+RO+RP0. Just did a clean delete and reinstall of DR 7.2.2 and module manager 2.6.8. Weirdly in-game it seems to have no functionality and gives the version number as 7.0.5. I get heating on the pad (manageable) but during re-entry my heat shields seem to do no, or little good. Attempting my first re-entry in this career with a periapsis between 80 and 99 with a small probe using RCS and MJ retro hold to do as best it can. The heat shield itself starts to get a overheat bar, going up to around 60%, while losing little ablator. At the same time heat is radiating up from/through the shield. I made a tiny conic probe hidden behind a shield wider than itself. The probe fuel tank connected to the shield was the part that went critical near 80km alt and 7km/s velocity. Why is my DR version number in game wrong after I manually reinstalling the files? Could there be some related file I missed beside the DR folder and module manager dll? Are there manual adjustments that need to be made to aero-heating via the debug menu? All the posts I've turned up on this issue so far have been from a year or more ago before re-entry heat was stock.

[Starwaster]

ETA: Without FAR, reentry works fine, with skin temp on the capsule hovering around 450. The shield gets to a skin temp of around 1000.

With FAR, first the Science Jr starts heating, quickly. Facing absolutely dead on into the atmo stops the heating, but otherwise it continues receiving heat. Around 58km, the skin temp on the mk1 pod mirrors the phenomenon described above; viz. the skin temp begins to rise considerably, until the capsule blows with skin temp at about 1000 somewhere between 48-53km (depending on exact periapsis and careful flying).

If I had to guess, and I do because there's nothing in the debug log to indicate misfunction, I'd say FAR has an occlusion issue. I'll dig around some more and see if I can't replicate it with different parts - e.g. a payload bay instead of a Science Jr, the pod itself (sans ablative), etc.

Let you know what I find.

The mk1pod has a maxTemp of 2400 until its shield burns out (ablator depleted) and then it drops to 1200.

Other heat shields are going to be higher (stock shield keeps its maxTemp of 3800 until it depletes, not sure about other shields)

So I don't see any reason why they would burn up at 1000 no matter what issues FAR might bring to the table...what was the internal part temperature, do you know? (should be a lot lower.....)

My craft keep exploding around 80km on re-entry in RSS. Using DR as part of RSS+RO+RP0. Just did a clean delete and reinstall of DR 7.2.2 and module manager 2.6.8. Weirdly in-game it seems to have no functionality and gives the version number as 7.0.5. I get heating on the pad (manageable) but during re-entry my heat shields seem to do no, or little good. Attempting my first re-entry in this career with a periapsis between 80 and 99 with a small probe using RCS and MJ retro hold to do as best it can. The heat shield itself starts to get a overheat bar, going up to around 60%, while losing little ablator. At the same time heat is radiating up from/through the shield. I made a tiny conic probe hidden behind a shield wider than itself. The probe fuel tank connected to the shield was the part that went critical near 80km alt and 7km/s velocity. Why is my DR version number in game wrong after I manually reinstalling the files? Could there be some related file I missed beside the DR folder and module manager dll? Are there manual adjustments that need to be made to aero-heating via the debug menu? All the posts I've turned up on this issue so far have been from a year or more ago before re-entry heat was stock.

The in-game number is just because I forgot to change it. It's just a string that I set manually and it doesn't grab the dll's version at all. But that won't affect functionality

(line where menu version number is set)

https://github.com/Starwaster/DeadlyReentry/blob/master/Source/DRToolBar.cs#L139

I've tested DRE with RSS+FAR+RO and didn't experience what you're describing. (did not have RP0 but I'm not aware of any relevant changes it might make...)

Note above that some people have had trouble with FAR and DRE. Chrisl says that 0.15.5.1 fixed it for him (and that's the version I tested with) but Jovus says it did not.

A few things I should mention here...

1. DRE edits a few things like max temps, skin-internal conductivity, some minor changes to the stock heat shield (by way of extending the ModuleAblator class) but aside from that, all thermodynamic functionality is the stock code. So if there is some issue between FAR and thermodynamics, it's still stock. There's not a lot (that I can see) that I could do to resolve a FAR-DRE compatibility issue, because it's mostly stock

2. NathanKell has mentioned (and this isn't really news, but it seems to be frequently forgotten) is that capsules are too massive for their size. Or rather, are 64% smaller than they would be IRL while retaining the same mass, which means drag has less impact on them. Is maybe reducing stock capsule masses something that I should look into?

Edited September 19, 2015 by Starwaster

[Herrkurt]

From your first point about the stock code I'm suspecting it may be a problem with the parts from RO. I think they did an update recently which may have introduced the problem. Anything known about the pad heating in RSS+RO? I've noticed it in Scott Manley's recent RSS+RO videos.

Having watched an old NASA video I'm wondering now if even a small probe coming in shallow from low orbit would need to offset mass for lift?

Edited September 19, 2015 by Herrkurt

[Enceos]

I noticed that after installing DRE all of the pats became unstackable in KIS containers. What list of modules DRE adds to parts?