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Best way to land on kerbin?


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6 hours ago, JHadden123 said:

Aw dude you've been missing out. The pod shape (Assuming you're using a pod/heat shield combo with nothing crazy hanging off of it!) Points you softly in the right direction the whole way down. SAS makes you stiff as a board. Good for stable flight, but SAS isn't very useful on the way back down unless your aerodynamic shape prevents you from pointing in the right direction in the first place.

Meh, Having tried it both ways now I don't see much of a difference. The pod lands no problems with either method.

Having SAS on stability assist the whole way down won't even drain the command pods built in battery so there really isn't any harm in it.

To each his own I suppose, that little SAS light glowing just makes me feel better I suppose lol.

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Yeah man. I know the feeling. At least you did some investigating of your own before deciding either way. Just make sure your pod doesn't run out of juice or you'll be sending your least senior Kerbal to deploy the chutes EVA.

 

Edit: I mistook you for the OP... There's an extremely good chance you don't need my helpful tips lol.

Edited by JHadden123
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12 hours ago, Madrias said:

drogue chutes and an action group to cut them free

use the stack drogues attached to a decoupler and a cubic strut; you can stage them off instead and save yourself an action group for something else.

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1 hour ago, Xyphos said:

drogues attached to a decoupler and a cubic strut

I never thought of that!  Now I'm gonna have to start doing that because I've had my share of running out of action groups because of those bloody chutes.

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33 minutes ago, Madrias said:

I never thought of that!

 

also, for large carrier-type crafts, you can turn a cargo ramp upside down and clip it, then put it on the BRAKES action group,
and you've got yourself Mk3 sized AIRBRAKES without using TweakScale.

 

EeZTK7m.jpg

Edited by Xyphos
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35 minutes ago, Xyphos said:

cargo ramp upside down and clip it, then put it on the BRAKES

That actually works!?  I'll have to consider it for other craft I typically use, but consider that one written down.  Cargo Ramp as Airbrake.

I suppose the only thing I can mention is that I like placing things like RTG's and batteries clipped inside the Structural Fuselage (MK1) because it de-clutters the ship and makes sense.  It is, after all, a big hollow tube.  I've got one or two saved as sub-assemblies that can just be picked up and attached on the fly, containing a number of RTG's and a number of batteries.  (For example, a Power Tube with 8 RTG's and 4 batteries with 100 charge each is a PT 8-400.  A power tube with 4 RTG's and 1600 EC total is a PT 4-1600.  If I ever make one that exceeds 10,000 EC, it'll be a PT x-10k (or equivalent charge rating) because I try to keep subassemblies from being cluttered)

Another thing I used to do, before the 1.1 updates, was trying to build rovers into the service bays.  Took lots of mods, but I had one or two self-contained folding rovers that could stack-detach from under my landing craft and slowly wander around a planet.

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All my reentry vehicles are built like little spaceplanes. So I just reenter them that way. A Pe around 59k, and slowly bleed off my first 200 m/s in pancake mode in the stratosphere before trying to do the full reentry thing. If I have fuel left, I burn it retrograde one sea ahead of KSC. I never just reenter a capsule. I like getting almost all my launch money back, so I land my little spaceplanes on the KSC runway for full credit. If I need to do a few aerobraking passes coming back from the Mun, so be it.

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41 minutes ago, Madrias said:

That actually works!?

yeah. cargo ramps have a really high amount of drag, even more when deployed.
what is being shown in the photo is being positioned towards the rear of the craft so the door lies flat when closed and causes the craft to nose-up when deployed during re-entry, so the vessel doesn't go head-on and burn up.

Edited by Xyphos
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If you want to go for drama (and a really speedy reentry)... it's kinda fun to put the inflatable heatshield on a craft that's not a giant.

As long as the ship is relatively lightweight (say, under 20 tons), you can slam into Kerbin's atmosphere going 3500 m/s straight down.

It's... dramatic.  You'll pull several dozen gees of deceleration near the end, but you'll come through unscathed.

Yes, it's overkill.  But fun.  :)

On a more practical note:  I find that I virtually never need to use drogue chutes on Kerbin.  (Duna, yes.)  One thing that helps a lot is to make maximal use of body lift; it's incredibly helpful.  For example, a very common reentry vehicle I use a lot is Mk1 command pod, 2-ton LFO tank, and Terrier.  No heatshield.  I enter engine-first, with the pod tipped downward about 30 degrees below retrograde.  This generates lots of body lift and slows it down plenty before it gets down into the charbroil zone.  In fact, the body lift is so effective that often I can get it down to 10 km altitude, cancel out the dive, and actually climb a kilometer or two before it runs out of steam-- at which point it's moving much slower than the speed limit for a standard parachute.

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On July 5, 2016 at 4:36 PM, Rocket In My Pocket said:

Meh, Having tried it both ways now I don't see much of a difference. The pod lands no problems with either method.

Having SAS on stability assist the whole way down won't even drain the command pods built in battery so there really isn't any harm in it.

To each his own I suppose, that little SAS light glowing just makes me feel better I suppose lol.

Sooooo. You are playing with heat at 100%?

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9 hours ago, Firemetal said:

You are playing with heat at 100%?

Everything is at 100%

I prefer to play my games vanilla if possible, normal difficulty, default settings, as few mods as possible.

I want to experience the game the way the Devs intended. Also, that way when I'm discussing something about said game with someone on a forum or in real life we've both been playing the same game and thus are on the same page.

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Just to try what NOT to do : Kill you horizontal surface velocity above 70km then let you fall down to the surface. You will probably not survive. The fall is too short to slow you down and you may not be able to safely open your chute, even above water. It's doable with drogues though. The high atmosphere is too thin to let you open you chutes when you speed is low (even though that may no save you either ***)

As for my usual design for reentry vehicle : as many, it's the simplest I can. Usually a pod and one chute. I add a heat shield only for interplanetary reentry. It's not useful for Mun and Minmus. Stock Kerbal-X don't have any heat shield and can safely reenter from Mun, Minmus and even Duna (I've not tested Eve, But I think it's good to go too)

As for trajectory, I aim for PE at 30 to 34km. I keep SAS in high atmosphere then remove it around 45km.

*** Well, I remembered landing on Duna with Chutes (no drogues). My ship wasn't slowing fast enough, and I slowed down with engines to let my speed be under the chute safe deploy. Then I deployed the chutes. But even with the chutes, the ship was still gaining speed and as soon as the speed went over the safe speed, the chutes were destroyed, even they were safely deployed... Hope fully I could do an emergency landing on engines, but that cost me the return home :wink: 

EDIT : And I agree with @Snark, Drogues are note really useful for Kerbin for a regular reentry. I used them to land very heavy vehicles though back in 1.0.5 (like a 500T first stage recovery...). But they are great for Duna to allow you to open your regular chutes without burning fuel.

Edited by Warzouz
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1 minute ago, Firemetal said:

Hmm then I must have a problem with heat. I set my pe to 30km and burn up unless I turn off SAS. Strange.

I usually go for 35km but I can't see that making a huge difference.

I'm not sure how or why you would burn up with SAS on? Does the craft wobble or spin out of control or something?

With or without SAS as long as you keep your heat shield pointed retrograde it shouldn't make a difference.

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I use KER thermal. At 60km my critical thermal percentage is already at 50%. Turning of SAS allows for the atmosphere to steer me in the right direction but if I don't, it heats up fast and blows up.

Idk.

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19 minutes ago, Firemetal said:

Hmm then I must have a problem with heat. I set my pe to 30km and burn up unless I turn off SAS. Strange.

oh and this happens only with mk1 parts.

I should say I'm not really sure about MK1 parts, but I'm quite sre about MK1-2 command pod (the silly heavy one)

I usually add a partially filled heat shield on "custom" vehicles such as those stacked MK1 pods (sometimes 6 of them...) designs we nearly all do to avoid using the heavy MK1-2 pod.

 

10 minutes ago, Firemetal said:

I use KER thermal. At 60km my critical thermal percentage is already at 50%. Turning of SAS allows for the atmosphere to steer me in the right direction but if I don't, it heats up fast and blows up.

Idk.

Well, that's strange. Again, I don't have KSP here and I don't have used MK1 for quite a while, but I don't think my heat level goes up to 50% critical at 60km.

I know that critical heat level is above 90% for MK1-2 when reentering from the Mun (3000m/s)

 

Edited by Warzouz
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12 minutes ago, Firemetal said:

I use KER thermal. At 60km my critical thermal percentage is already at 50%. Turning of SAS allows for the atmosphere to steer me in the right direction but if I don't, it heats up fast and blows up.

Idk.

Oh I see, I'm so used to tapping "W" every now and then to nudge the nose that I forget I even do it.

If you didn't touch the keyboard at all the SAS would eventually take you off retrograde as it's trying to keep you from changing direction.

I forget most people probably x4 warp through re entry. I've always rather enjoyed the trip down, taking in the sights of Kerbin and so on so I typically do it in real time. (Also, as my busy work schedule leaves me little time to play I only do a handful of launches per week so I'd imagine I have more patience for sitting through things and admiring them. If I got to play more often I'd probably be sick of watching it by now. Lol.)

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2 hours ago, Firemetal said:

Hmm then I must have a problem with heat. I set my pe to 30km and burn up unless I turn off SAS. Strange.

oh and this happens only with mk1 parts.

It matters a lot how massive your ship is-- more specifically, its ballistic coefficient, basically "how massive is it compared with how draggy is it."

A very low ballistic coefficient-- i.e. a lightweight pancake ship-- can reenter very easily.  This is the example I give above, of using the inflatable heat shield on a ship that's under 20 tons:  you can slam into atmosphere at 3500 m/s straight down and it brakes with no problems at all.

A very high ballistic coefficient-- i.e. a long, skinny, dense lawn dart-- will have a lot more problems with heating, and is much more likely to go kaboom.

When most people say "oh yeah, you can reenter from the Mun with a 30 km Pe with no problems", they're assuming you have a "typical" ship based on their idea of what their usual munar reentry vehicle looks like.  If your design is very different from that (denser, less draggy) then you could have problems.  Would help to see a screenshot of your reentry vehicle, along with what its mass is.

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33 minutes ago, Snark said:

It matters a lot how massive your ship is-- more specifically, its ballistic coefficient, basically "how massive is it compared with how draggy is it."

A very low ballistic coefficient-- i.e. a lightweight pancake ship-- can reenter very easily.  This is the example I give above, of using the inflatable heat shield on a ship that's under 20 tons:  you can slam into atmosphere at 3500 m/s straight down and it brakes with no problems at all.

A very high ballistic coefficient-- i.e. a long, skinny, dense lawn dart-- will have a lot more problems with heating, and is much more likely to go kaboom.

When most people say "oh yeah, you can reenter from the Mun with a 30 km Pe with no problems", they're assuming you have a "typical" ship based on their idea of what their usual munar reentry vehicle looks like.  If your design is very different from that (denser, less draggy) then you could have problems.  Would help to see a screenshot of your reentry vehicle, along with what its mass is.

I do what everyone else does and I still blow up if I don't turn off SAS. Do I have a glitch? I just use mk1 command pod, mk1 heatshield and the smallest parachute not counting drogues. :/

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2 minutes ago, Firemetal said:

I do what everyone else does and I still blow up if I don't turn off SAS. Do I have a glitch? I just use mk1 command pod, mk1 heatshield and the smallest parachute not counting drogues. :/

That's... really weird.  What does your reentry profile look like?  When you hit atmosphere, how fast are you going and what's your Pe?

(Trying to understand why SAS would matter at all, here, anyway.)

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Ok I come from the moon and I lower PE to 30km. I hit the atmosphere at 3200 m/s and turn off SAS. My critical thermal percentage peaks at around 70%.

If I don't turn off SAS, my CTP rises like an elevator and I blow up around 30-40 km.

*Shrugs*

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Like I was saying before with SAS on it'll want to keep you going the way you are going instead of letting the pod naturally rotate to keep the heat shield facing retrograde as the retrograde marker moves down.

You have to make a little adjustment to your pitch every now and then to keep it aligned correctly or eventually you will be off center and the heat will be getting past the shield and hitting the command pod directly.

I'd wager this is what's happening.

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