Reentry Problem.

[Fr8monkey]

Haven't really played 1.0.5 much... medical stuff. Is there a reason why my capsule is still speeding up at 20,000M? I can't open the chutes until 1,000M or so and I am still hitting the surface at 300MpS.

[Choctofliatrio]

Where are you reentering from?

[Goody1981]

Basically the atmosphere has been reworked :)

If you're re-entering from orbit, try a higher Pe maybe? Also, others have suggested (Slashy I think) that if you just have a Mk1 capsule plus heat shield, it's pretty 'slippy' through the atmosphere. You could put a decoupler to stage the heat shield away once the heating effects are over. Also, if you have access to drogue chutes, you could definitely use them.

If you're going straight up, then coming straight back down...that's a paddling.

[ZooNamedGames]

You can add airbrakes to add drag. That always helps.

[Venusgate]

Basically, you're going to have to spend more time horizontal in the atmosphere. 1.0.5 atmo was spread out more instead of all scrunched up toward the bottom (Which is probably a good thin considering they made re-entry heating practically deadly)
from 75x75, anything (and I mean commandpod+.625 chute) with an entry Pe below, say 15km, is going to be going too fast to deploy the chutes in time.

[Fr8monkey]

I reentry like usual. I always wound up being under 250MpS at 6,000M. Guess I'll have to change something.

[Xyphos]

[quote name='Venusgate']Basically, you're going to have to spend more time horizontal in the atmosphere. 1.0.5 atmo was spread out more instead of all scrunched up toward the bottom (Which is probably a good thin considering they made re-entry heating practically deadly)
from 75x75, anything (and I mean commandpod+.625 chute) with an entry Pe below, say 15km, is going to be going too fast to deploy the chutes in time.[/QUOTE]

more horizontal time is also going to cause overheating problems, the longer you stay in thin atmospheres.
the real trick is to get into dense zones quickly before heat becomes a problem, and increase your drag as much as possible.
on spaceplanes that means going belly-first instead of nose-first because the wings would give more drag than AIRBRAKES.

[ZooNamedGames]

[quote name='Fr8monkey']I reentry like usual. I always wound up being under 250MpS at 6,000M. Guess I'll have to change something.[/QUOTE]

Try rocking the pod, that can increase drag *just* enough sometimes to bring you within parachute safe deployment ranges. While coming down, try to yaw or pitch in one direction as far as it will let you, and maybe even swing with it. When you go as far as you can in one direction, go in the opposite direction and do the same.

[GoSlash27]

Fr8monkey,
This is a known bug. The fix is to attach your heat shield with a decoupler and detach it once reentry heating subsides.
Best,
-Slashy

[jf0]

[quote name='GoSlash27']Fr8monkey,
This is a known bug. The fix is to attach your heat shield with a decoupler and detach it once reentry heating subsides.
Best,
-Slashy[/QUOTE]

how is it a bug? heating and aerodynamics simulation has improved (more accurate). I dont think that it 'being more difficult' means it counts as a bug. you just need to be more careful about you trajectory. You can still successfully reenter from low orbit with a command pod+heatshield, and heating is not even a problem really, you can do it easily with 20 ablator. If your going too fast by the time you are too low, then your trajctory was too steep, if running out of heatshield a problem, your too shallow.

[MaxL_1023]

If you have a strong RCS system or a lot of torque, try pointing your pod's nose about 15 degrees above retrograde. Your pod should generate some lift during re-entry and follow a shallower profile in the lower atmosphere.

If you wanted to be hilarious, put a 2.5m shield under your 1.25m pod. 4 times the surface area with less than twice the overall pod mass = twice as much deceleration.

[Starwaster]

[quote name='GoSlash27']Fr8monkey,
This is a known bug. The fix is to attach your heat shield with a decoupler and detach it once reentry heating subsides.
Best,
-Slashy[/QUOTE]

Having extra mass that increases your ballistic coefficient is not a bug and there's other things you can try besides decoupling the shield. For instance you can use the tweak slider to decrease the amount of ablator on the shield, which will lighten it.


You can also try flying a lifting reentry by orienting the nose at an angle, giving your capsule some lift and giving you more time to shed velocity.


(not strictly necessary; it IS possible to land a Mk1 pod + full shield depending on where you bring it down and how you configure the chute's opening parameters)

[Hannu]

[quote name='Fr8monkey']I reentry like usual. I always wound up being under 250MpS at 6,000M. Guess I'll have to change something.[/QUOTE]

What is the problem? You can open parachute at 260 m/s (at least small one and side mounted one). There is no large tolerances, but I have lost only one Mk-1 pod when I learned a new behavior of parachutes by a hard way (RIP Jeb). I have used to open them at below 300 m/s. I do not separate the heat shield. I try to decrease ablative mass to 100 kg but do not always remember that. I have only tried MK-1 with 1.0.5 yet.

Re-entry with 3300 m/s maximum speed (at about 40 km) and 15 km Pe (return from Minmus) seems to go flawlessly. It burns about 40 kg ablative mass (Mk-1, small parachute and heat shield). However, it may be that highest mountains are fatal. I can open parachute at 2000-3000 m.

[Alshain]

[quote name='jf0']how is it a bug? heating and aerodynamics simulation has improved (more accurate). I dont think that it 'being more difficult' means it counts as a bug. you just need to be more careful about you trajectory. You can still successfully reenter from low orbit with a command pod+heatshield, and heating is not even a problem really, you can do it easily with 20 ablator. If your going too fast by the time you are too low, then your trajctory was too steep, if running out of heatshield a problem, your too shallow.[/QUOTE]

Apparently some people are getting an almost phantom force when re-entering. To the point they barely slow down, even in thick atmosphere. I've not seen it myself but there have seen several reports. As Slashy said, those who do have the problem fix it by decoupling the heat shield.

[Majorjim!]

[quote name='Alshain']Apparently some people are getting an almost phantom force when re-entering. To the point they barely slow down, even in thick atmosphere. I've not seen it myself but there have seen several reports. As Slashy said, those who do have the problem fix it by decoupling the heat shield.[/QUOTE]

Unless proven otherwise it is not a bug. Heatshields are heavy, on a small pod it is just too slippy and heavy. Use drogue chutes, that is what they are there for. I have re-entered with pod and HS with zero issues. you just have to do it correctly. If you don't know how, just experiment.

[Frozen_Heart]

I've been finding that with just pod + chute + heatshield, I can deploy fine at about 3000m. The heating is more deadly than before and you don't slow nearly as quickly but I haven't had any problems now that I've adjusted.

I think some people must be having a bug if their pod isn't slowing down enough to deploy chutes. My re-entry is pretty crude and I manage it fine.

[moogoob]

I just did a test - LKO to 30km periapsis with the size 1 pod w/ heat shield and 2 goo canisters bolted to it. Ablator reduced to 75. Skimmed through the highest layers of the atmo until hitting the stratosphere, then decelerated as normal until I could pop chute (size 0) at 5km altitude. Still had 40 or 50 ablator remaining. Goo canisters didn't even get hot, unlike my last suborbital flight.

Mun return might be a different beast, however!

[sal_vager]

It's a known [I]issue[/I], rather than a bug, [U][URL="http://forum.kerbalspaceprogram.com/threads/138802-Kerbal-Space-Program-1-0-5-New-Issues-Repository#heatshield_drag"]which you can find more info on here.[/URL][/U]

Though even with dropping your heatshield I'd not reenter too low, a Kerbin periapsis of about 30km works for me for most situations.

[Majorjim!]

[quote name='sal_vager']It's a known [I]issue[/I], rather than a bug, [U][URL="http://forum.kerbalspaceprogram.com/threads/138802-Kerbal-Space-Program-1-0-5-New-Issues-Repository#heatshield_drag"]which you can find more info on here.[/URL][/U]

Though even with dropping your heatshield I'd not reenter too low, a Kerbin periapsis of about 30km works for me for most situations.[/QUOTE]

I don't see any issue at all, it is as intended. If you account for this improved behavior there is no issue at all. It is just people not used to the new changes.

Also, you stated to do what real life pods do and stage the heat-shield. No pods in current or past use staged the heat-shield. Edited November 20, 2015 by Majorjim

[obsidian_x]

Every time I stage the heatshield, it immediately crashes back into the pod and explodes the shield and sep. (I guess I need to turn down the separation force, so it doesn't move that far away before bumping back into the pod)

[A_name]

I think the reason it's being called a bug or an issue is because the un-shielded capsule has more drag than the shielded one. Of course it makes sense that the weight of the heat shield will make you drop a bit faster, but the problem is drag.

[sal_vager]

[quote name='obsidian_x']Every time I stage the heatshield, it immediately crashes back into the pod and explodes the shield and sep. (I guess I need to turn down the separation force, so it doesn't move that far away before bumping back into the pod)[/QUOTE]

I find if I tilt a bit it's fine, the Apollo command module was tilted a little due to its offset CoM, so when it dropped its heatshield it wouldn't hit it.

[URL="https://en.wikipedia.org/wiki/Apollo_Command/Service_Module#Command_Module_.28CM.29"][quote name='en.wikipedia.org/wiki/Apollo_Command/Service_Module#Command_Module_.28CM.29']At 24,000 feet (7.3 km) the forward heat shield was jettisoned using four pressurized-gas compression springs. The drogue parachutes were then deployed, slowing the spacecraft to 125 miles per hour (201 km/h).[/QUOTE][/URL]

[quote name='A_name']I think the reason it's being called a bug or an issue is because the un-shielded capsule has more drag than the shielded one. Of course it makes sense that the weight of the heat shield will make you drop a bit faster, but the problem is drag.[/QUOTE]

Actually this is incorrect, it really is just the difference in mass.

The combined pod+heatshield has a slightly larger drag cube from the sides of the pod, the pods top and the heatshield on the base.

The heatshields only occlude heat, while a detached heatshield has a lot of drag from the flat rear side which the pod doesn't have due to its taper. Edited November 20, 2015 by sal_vager

[MrOsterman]

[quote name='A_name']I think the reason it's being called a bug or an issue is because the un-shielded capsule has more drag than the shielded one. Of course it makes sense that the weight of the heat shield will make you drop a bit faster, but the problem is drag.[/QUOTE]

Weight yes but it's also, potentially, more aerodynamic. You do want it cutting through the air a little better in order to help minimize the compression heat of the high speed re-entry. It's possible that the model they're using for drag gives the heat shield a break compared to the bottom of the stock capsule. Drag force is based on mass, but also area and current velocity, iirc, so maybe the issue is our current understanding of the actual physics?

[Majorjim!]

[quote name='obsidian_x']Every time I stage the heatshield, it immediately crashes back into the pod and explodes the shield and sep. (I guess I need to turn down the separation force, so it doesn't move that far away before bumping back into the pod)[/QUOTE]

Use drogue chutes then stage the heatshield.

[BenCushwa]

[quote name='Venusgate']from 75x75, anything (and I mean commandpod+.625 chute) with an entry Pe below, say 15km, is going to be going too fast to deploy the chutes in time.[/QUOTE]

I re-enter in 1.0.5 from 80x80 with Pe of zero or less all the time. The trick is to have a high enough drag to weight ratio and sufficient heat shielding. A simple Mk1 pod/heat shield/chute would probably crash on my descent profile because it wouldn't slow down in time, but a ship that's three Mk1's wide with three Mk1 shields and not a lot of extra weight slows down very nicely, even with only 20% max ablator to start.