[0.20] Deadly Reentry 2.3 - reentry heat, plus thermal and g-force damage to parts

[rifter]

Option 2 sounds more fun to me.

[Zapmunk]

While I understand your argument, the purpose of including acceleration to the "deadliness" is because reentry must consider heat and acceleration. Otherwise, you can survive nearly any reentry just by nose diving straight down. This mod is meant to provide realistic, challenging reentry, which makes the inclusion of deadly G forces a must, lest an inaccurate heat model be introduced.

Perhaps some people would like a challenging but not necessarily realistic reentry.

I would certainly like the added challenge of heat management, but having g-forces spontaneously deconstruct my ship in the atmosphere is something that happens often enough to me without the aid of your mod.

Furthermore, the buggy and ironically inaccurate calculation of this makes exacerbates the problem- a pair of lightweight radial parachutes on my capsule somehow managed to be destroyed despite having a very low mass, and ought not to be affected by such forces as much. (Someone please give me a physics lesson if I've made a terrible error here.) The system needs to be significantly improved before it approximates accuracy- at the moment it's less accurate than before.

Perhaps the solution would be to leave g-forces as a togglable option? Let those who want the realism play with it enabled, and those who want fewer arbitrary explosions can disable it.

[Spoo]

It's fun for me when my plane or rocket explodes for a reason that was obvious in retrospect. Explosions for no discernible reason aren't fun. So that said, high g-forces should be deadly when re-entering or tumbling, but not for otherwise normal launches.

[taniwha]

My problem with g-force based damage is a ship than can survive 3g thrust when full (ie, TWR is 3) should be able to survive 15g thrust when empty because the actual forces are exactly the same.

I am not against acceleration damage, I'm against only the implementation of basing the damage on "a" rather than "F" (of F=ma).

I would rather acceleration damage be separate (mostly as a programmer, actually), but I understand the desire to have it integrated.

[Tinweasele]

Can anyone help me out with surviving reentry? i can make it through the atmosphere but my parachute blows off due to G forces before i hit the ground:(

[taniwha]

I think the g-force code is borked because I'm getting things breaking at 3-4g :/

However, first make sure you're not physical time warping when your chute opens.

[Tinweasele]

I think the g-force code is borked because I'm getting things breaking at 3-4g :/

However, first make sure you're not physical time warping when your chute opens.

im doing a 100% no warp play-through so definitely not

[asmi]

My problem with g-force based damage is a ship than can survive 3g thrust when full (ie, TWR is 3) should be able to survive 15g thrust when empty because the actual forces are exactly the same.

I am not against acceleration damage, I'm against only the implementation of basing the damage on "a" rather than "F" (of F=ma).

I would rather acceleration damage be separate (mostly as a programmer, actually), but I understand the desire to have it integrated.

Nope, that's not the way it works. Acceleration effectively increase mass, so things break more easily. It never is that force does something - it's always acceleration.

[rhoark]

It's not uncommon or specific to this mod for the parachute to snap if you have anything more than a pod attached. Use a drogue first in that case.

[Tinweasele]

It's not uncommon or specific to this mod for the parachute to snap if you have anything more than a pod attached. Use a drogue first in that case.

My setup was mk1 pod mk16 parachute made it through reentry, popped the chute and it snapped shortly after it fully deployed. How should i modify my build to survive reentry?

[Malsheck]

Here's what I've been doing to keep the ole G-meter low. When I set up my command module I take an octagonal strut and place it on top. Next I put 2 radial chutes and attach them to the sides of the strut and add them to command group 2 to deploy. Next I take a drogue chute and slap it on top and add it to command group 1 to open and again to group 2 to cut the drogue chute lines. Afterwards I take the strut with the chutes attached and flip it upside down and clip in into the command pod so that the top attachment node uses the node on top of the pod. Then I surface attach a docking port on top of it all. If done right you should only see the capsule and the docking port. You might want to confirm on the pad that you didn't block the hatch with drogue chute. If you are then you might need to add a small strut between the octagonal strut and the drogue chute.

How to use: Do your normal re-entry but dont pop your drogue chute (group 1) until your speed has slowed to <200m/s. This should slow you down quite a bit. Next wait until you are at or below 500m and hit group 2 to cut the drogue chute and pop the 2 main chutes. This should bring you down nice and soft. Doing this I've done whole flights from launch to touchdown without going over 4.5G's

[rhoark]

Perhaps the derivative of acceleration ("snap") would be a better proxy for mechanical stresses.

[taniwha]

asmi: acceleration does /not/ affect mass. It affects force. Remember, F=ma: F:force, m:mass, a:acceleration. And the current system /is/ bogus: I can put a pancake tank between a mainsail and an orange tank and everything is fine. Remove the orange tank and the pancake tank explodes due to acceleration. This is completely backwards as the pancake tank will be under slightly more stress with the orange tank than without.

(simple ship: probe, tanks, mainsail (actually, it was probe, tank, skipper, separator, tank, mainsail, both tanks were pancakes)

[asmi]

asmi: acceleration does /not/ affect mass. It affects force. Remember, F=ma: F:force, m:mass, a:acceleration. And the current system /is/ bogus: I can put a pancake tank between a mainsail and an orange tank and everything is fine. Remove the orange tank and the pancake tank explodes due to acceleration. This is completely backwards as the pancake tank will be under slightly more stress with the orange tank than without.

(simple ship: probe, tanks, mainsail (actually, it was probe, tank, skipper, separator, tank, mainsail, both tanks were pancakes)

Nope. Example - put human on top of rocket engine and start it up - he will be dead. Put him on top of heavy fuel tank and the same engine - and he survives Acceleration is everything.

Breakdowns in rigid bodies are caused by stress caused by uneven acceleration in different parts of that body. More acceleration - more acceleration differential (initially only the layer that is directly affected by the force moves, while the rest of the body stays at the same place - remember, mass is measure of inertia, so there is greater strain between that layer and the rest of the body).

Edited June 11, 2013 by asmi

[C159123]

Love it! Thanks and keep up the great work!

[Sleipnir]

so when is the finalized version coming out?

[Spoo]

Nope. Example - put human on top of rocket engine and start it up - he will be dead. Put him on top of heavy fuel tank and the same engine - and he survives Acceleration is everything.

Breakdowns in rigid bodies are caused by stress caused by uneven acceleration in different parts of that body. More acceleration - more acceleration differential (initially only the layer that is directly affected by the force moves, while the rest of the body stays at the same place - remember, mass is measure of inertia, so there is greater strain between that layer and the rest of the body).

You're saying "acceleration" and describing "force."

[MonkeyLunch]

Im looking forward to this. I was using it before the last update, but now im waiting for a .20 updated version. I hope ones in the works. Ill be happy to test it plenty.

[taniwha]

asmi: Your example is the opposite of mine. A human lying on the ground can survive 1g no problem (funny that, we've been doing so for at least a million years). However, put a car on top of that person, and 1g will mean a squished person. A tank that can handle being between a mainsail producing 1500kN of thrust and a 36t jumbo tank (plus a 0.1t probe module) certainly should be able to survive being between a mainsail producing 1500kN of thrust and a 0.1t probe module, despite the acceleration being radically different (3.28g vs .14.4g). Of course, a human on top of the latter would be having a very bad day (but would likely survive if lying down) while on top of the former would be not even uncomfortable (when lying).

So, why is it that a tank that can handle 1306kN from below and 1162kN from above cannot handle 650.9kN from below and 14.15kN from above? That does not make sense because in the first case, the tank is under 2468.9kN of compressive force (but only 144.8kN of accelerative force), while in the second case it is under 665.1kN of compressive force (but 636.8kN of accelerative force). Note that accelerative force will not cause any damage as it is spread evenly across all particles in the tank (as a first approximation, anyway). But even then, the stresses in the second tank (with higher acceleration) are less than the first (with lower acceleration).

(mainsail: 1500kN thrust, 6t mass. pancake tank: 4.5t full mass. jumbo tank: 36t full mass. probe module: 0.1t)

[ialdabaoth]

Good news everyone! DRE2.2 is out! Check the first post in this thread for the link.

[betaking]

this might be a petty complaint, as it is purely cosmetic, but would it be possible to make a sort of fairing or something so I don't see a gap between the heatshield and a lower layer?..

I'm unsure why it bothers me but it does for some reason.

[ialdabaoth]

yeah, it bugs me a little too; unfortunately I'm not a modeller.

[Moon Goddess]

Good news everyone! DRE2.2 is out! Check the first post in this thread for the link.

Seriously, I just downloaded 2.1 like 2 hours ago

[ialdabaoth]

Seriously, I just downloaded 2.1 like 2 hours ago

Heh. Well, 2.2 is pretty cool. There's now a "Repair damage" EVA feature, but note that you may have to click it multiple times if the damage is substantial. Each click will repair between 0 and 10% of the current damage, so on average light damage will take 1 click, moderate damage will take 2-3, heavy damage will take 4-5, and critical damage will take 6-10.

[gunnyfreak]

link isn't working for me... can someone post mirror?