Parachute fragility

[Rmack]

I usually try to re-enter on training missions, but I seemed to loose my main chute half the time.  Even if I seem to be doing everything right, it still can get destroyed.  The drogue chute, when there, hasn't survived yet.

Is this normal?  Am I doing something wrong?

[Plusck]

I haven't done the training missions, but frm what I've gathered you are directed to alter the pressure settings for semi-deploy so that you can stage the parachute while it is still "dangerous" to do so, and it'll only start to deploy low enough to be sure to be going slow enough.

In many ways this is the "correct" way to do things, but for any of us who have had significant gaming time under 1.0.5 it sounds like sheer madness ; )

In 1.0.5, chutes were made too fragile and the main ones could only be opened at under 250m/s or so. That speed was commonly reached only at very low altitudes.

1.1 has made parachutes much more resilient, so if you've followed the instructions about right-clicking the chute and setting semi-deploy pressure to a very high (the highest?) setting, then it would seem that you're simply coming in at too steep an angle.

The obvious solution is to do it the 1.0.5 way: do not stage your chutes at all until the background to the icon turns a greeny-grey, or for safety a light grey, colour. This is actually very fast for the drogue chutes, like nearly mach 2 iirc.

The more tutorial-friendly way is simply to ensure that you've set the pressure stting right, and make sure that you are coming in a sufficiently shallow angle to slow enough at that pressure-related height.

Finally, concerning incoming angle, you need to find the happy medium. Re-entering with too high a Pe makes you slow with virtually no vertical velocity at a very high altitude, then you drop more and more like a stone. Re-entering too low, and your vertical velocity will just rise and rise constantly. In the middle there, there is a point where your vertical velocity is relatively low while you are quite close to the thicker lower atmosphere, but you still have a decent horizontal velocity, so you will slow down enormously before reaching parachute height.

[FullMetalMachinist]

52 minutes ago, Rmack said:

I usually try to re-enter on training missions, but I seemed to loose my main chute half the time.  Even if I seem to be doing everything right, it still can get destroyed.  The drogue chute, when there, hasn't survived yet.

Is this normal?  Am I doing something wrong?

I hate to sound like I'm implying that you're dumb, but I just want to get the obvious out of the way. Are you sure that the parachutes are being destroyed? 

The reason I ask is because there's a color scheme for the parachute icons in the staging list that newer players might not know. 

So are the chutes actually deploying and being destroyed, accompanied by a message something along the lines of "parachute was destroyed by heat and aero forces"?

If not, and the staging icon is red background with a gray icon, then your chutes are fine. That just means that if they  deployed at that moment, then they would be destroyed. 

[Rmack]

No, they are getting destroyed and I'm getting that message.  The chute itself turns red, not the background.

 

[FullMetalMachinist]

11 minutes ago, Rmack said:

No, they are getting destroyed and I'm getting that message.  The chute itself turns red, not the background.

 

Hmm, yes that is very odd. Are you running any mods? 

[Rmack]

No.  I usually have this problem trying to re-enter the vehicle from the orbital tutorial.   It says to go ahead and ride it down, or something, just don't forget to separate the capsule.

 

It directs you to get your Pe below 20,000km, and I get it real close.  I seem to come in at a angle that is not too steep.

[FullMetalMachinist]

Well that reentry profile sounds like it should work for regular chutes, and certainly should work for drogues. 

If it's not a mod messing things up, about the only thing I can think of is that your physics.cfg somehow got messed up. You could delete it, which forces the game to make a new one with the default values when you restart the game. 

I'll try the orbital tutorial in a bit for myself and see if I have any trouble. 

[Rmack]

1 hour ago, FullMetalMachinist said:

Well that reentry profile sounds like it should work for regular chutes, and certainly should work for drogues. 

If it's not a mod messing things up, about the only thing I can think of is that your physics.cfg somehow got messed up. You could delete it, which forces the game to make a new one with the default values when you restart the game. 

I'll try the orbital tutorial in a bit for myself and see if I have any trouble. 

Above my pay grade.

[FullMetalMachinist]

Well, I just tried the "Go for Orbit" and "Orbiting 101" tutorials, reentered at the end of both, and had no problems.  However, I did notice that neither of those two crafts have drogue chutes, so I'm not sure when you've tried using those. 

29 minutes ago, Rmack said:

Above my pay grade.

Nonsense, it's not that hard.  It's in the main KSP folder/directory, just a few lines below the KSP executable.  After you've quit the game, just delete it ("it" being the physics.cfg, not the KSP application) and the next time you start the game it'll make a new one with all the correct numbers.  If you're using Steam and not sure where to find the KSP directory, it's pretty simple. Right click on KSP in your library, go to properties, then the "Local Files" tab, then click on "Browse Local Files" and it'll take you right to it.

Although, as I'm typing this, I remembered that there is a bug in 1.1.2 where none of the parts are making body lift. Claw's Stock Bug Fix Modules fixes it, but if you don't want mods then you'll just have to deal with the bug until they fix it in the stock game.  However, the game that I just tried the tutorials in is a clean stock game, so I don't think that's your problem either. 

If none of these suggestions work, then maybe a couple of screenshots will help diagnose?  Maybe one in map view showing your orbit, with the AP and PE numbers showing as you start reentry, and another one or two of your craft when you try to deploy your parachutes.

[Rmack]

18 hours ago, FullMetalMachinist said:

Well, I just tried the "Go for Orbit" and "Orbiting 101" tutorials, reentered at the end of both, and had no problems.  However, I did notice that neither of those two crafts have drogue chutes, so I'm not sure when you've tried using those. 

Nonsense, it's not that hard.  It's in the main KSP folder/directory, just a few lines below the KSP executable.  After you've quit the game, just delete it ("it" being the physics.cfg, not the KSP application) and the next time you start the game it'll make a new one with all the correct numbers.  If you're using Steam and not sure where to find the KSP directory, it's pretty simple. Right click on KSP in your library, go to properties, then the "Local Files" tab, then click on "Browse Local Files" and it'll take you right to it.

Although, as I'm typing this, I remembered that there is a bug in 1.1.2 where none of the parts are making body lift. Claw's Stock Bug Fix Modules fixes it, but if you don't want mods then you'll just have to deal with the bug until they fix it in the stock game.  However, the game that I just tried the tutorials in is a clean stock game, so I don't think that's your problem either. 

If none of these suggestions work, then maybe a couple of screenshots will help diagnose?  Maybe one in map view showing your orbit, with the AP and PE numbers showing as you start reentry, and another one or two of your craft when you try to deploy your parachutes.

The only thing I could find that was close to a 'library' didn't have anything to do with KSP.  If you mean all programs, I found the KSP folder there in the Steam folder.  When I right clicked, and selected 'properties', there was no 'local files' tab.  I'm running windows 7, btw.

Sorry for being so ignorant, but I haven't done anything like that for a decade or so, and I had step by step instructions then.

And I tried another training mission.  The one I'm having problems with is the Docking one.  I've gotten much better at rendezvous and docking, but when I set up a re-entry from the orbit of the target ship, with a 20,000 Pe, both parachutes fail.  My mistake about the drogue chute, that might be another training mission or something.  This ship has two side mounted chutes.

 

Is it possible that 20,000 meters is not a good Pe for coming in from that high of an orbit?  I seem to recall having the same problem trying to return to Kerbin from Mun.

Oh, OK, you meant in the steam program itself.  I'll go try to delete that file there.

[Rmack]

OK, the file is deleted, and I'm starting up the game.

 

[Rmack]

OK, I deleted that Physic.cfg file through Steam, started up the game and loaded that same training mission Docking.  I went up to the same (or very close) orbit of the target just to have the same conditions, and set up a re-entry.

I made real sure I set my Pe at 20,000 meters, and the same thing happened.  I lost both chutes during the re-entry.

[Rmack]

23 hours ago, Plusck said:

 

1.1 has made parachutes much more resilient, so if you've followed the instructions about right-clicking the chute and setting semi-deploy pressure to a very high (the highest?)

Wait a minute, I have been raising the altitude, but the pressure was default at 0.  I thought the chute wouldn't deploy anyway till it hit the set altitude.  Could that be what I'm doing wrong?

 

[Rmack]

30 minutes ago, Rmack said:

Wait a minute, I have been raising the altitude, but the pressure was default at 0.  I thought the chute wouldn't deploy anyway till it hit the set altitude.  Could that be what I'm doing wrong?

 

That was It!  I was forgetting the small matter of the pressure on the chutes.  In other training missions, the chute is set at max pressure.

Thanks for all the help, guys.

Edited May 19, 2016 by Rmack

[Warzouz]

The pressure parameter was very useful in 1.0.4, your could auto deploy chutes around specific altitude. But in 1.0.5, several things where changed and chutes were much more fragile. Now chutes must be open very near the ground.

It's true that in 1.1 chutes were fixed, but I don't know if i't safe to auto-deploy them using pressure parameter. Safety is based on speed.

[Loren Pechtel]

On 5/20/2016 at 4:09 AM, Warzouz said:

The pressure parameter was very useful in 1.0.4, your could auto deploy chutes around specific altitude. But in 1.0.5, several things where changed and chutes were much more fragile. Now chutes must be open very near the ground.

It's true that in 1.1 chutes were fixed, but I don't know if i't safe to auto-deploy them using pressure parameter. Safety is based on speed.

Yeah, when are we going to get a speed setting on chutes?  They should be safe to stage during re-entry and then pop at their safety limit.  I haven't even seen a mod for this.