[0.90]NEAR: A Simpler Aerodynamics Model v1.3.1 12/16/14

[yohuan]

Not sure which mod to reply too but im using the MK2 lighting cockpit and the intakes have way too much drag so plane can barely get past 150 m/s, so i have to close those intakes and use another air intake which make the craft easily hit 300 m/s.

[ferram4]

Update the cockpit mod, it should have a fix.

[Sobanaut]

Hey guys,

I want to report issue with NEAR. Initially I had problem with parachutes (excessive heat damage) and then they just get ripped off. I have NEAR, Deadly Reentry and bunch of other mods installed, everything up to date. I skimmed through the thread and it looks like you need to be below 400m/s to deploy chutes (I am using RealChutes), fine.

However there is a problem, I cant slow down to that velocity...

Using Mk.1 pod going straight down from 100km I hit the ground at about 500-600 m/s.

I suspected it might be something to do with drag so I installed FAR and it worked perfectly, it slowed me down significantly, enough to deploy chutes safely at subsonic speed (at around 7km). So I believe it is safe to assume that there is an issue with drag in NEAR.

[yohuan]

Update the cockpit mod, it should have a fix.

Great thanks

[Pondafarr]

Similar effect, I have a basic spaceplane, and I used AtmosphericTrajectories to deorbit at an appropriate spot to land at the KSC. Didn't have quite enough dV, so i could only get my periapsis down to ~30. Used SVEL+ (with a few degrees up), intending to use aerobraking to slow. I found my orbital velocity would not drop below 2k, even with pitch of 45deg. The plane refused to slow down, so i circumnavigated the planet , power off, at about about 41k altitude. It was actually kinda cool. Then when it finally did slow down (RCS slowed me eventually), my craft spin out of control and crashed. THAT was clearly my fault, I had burned her dry, and was at COM=COL, therefore I didn't have enough control.

No way to show a log, and didn't video it, but it was very interesting.

Solution: Pack more dV to drop the periapsis lower, and download a drouge chute from somewhere

[biohazard15]

I have a question regarding the fairings.

The question is, why is my ship isn't shielded (by all logical means, it should be - there is no openings between fairing and LES) and how do I make it shielded? "Delete LES and use usual fairings" is not an option

I've tried to add a second ring between LES and ship to make fairings clip there, but that didn't work either - the payload is still labeled as unshielded.

Or I should go somewhere else with tht question (like PF thread)?

[Xenro66]

Reporting a problem. NEAR is disabling the SP+ control surfaces completely. They're just inert and won't move. I'm fairly certain that it is infact NEAR that's causing this.

I reinstalled KSP, tried it without any mods, control surfaces worked. added a batch of mods (not including NEAR), they still worked. Removed that batch and put another batch in (of 5) WITH NEAR, they stopped working. I removed NEAR and they began working again.

So I think that's enough evidence. I am not sure what is going on, I'm currently re-downloading this mod and trying it again. Will report back if the situation changes.

- Xenro66

[NathanKell]

Xenro66: are you using NEAR on an unsupported KSP? (i.e. not-25, or 25 Win x64?)

[FirstSecondThird]

ferram4, YOU ARE AWESOME!

[Pondafarr]

Come to think of it, I have the same problem, my control surfaces don't move at all, I assumed I was having a graphics problem, but it would explain why my planes are difficult to control, they must be relying on torque completely...which is bad. I just confirmed Xenro's assessment that removal of NEAR re-enables the new SP+ control surfaces.

I verified I'm using the x86 version of .25 KSP.exe.

Spaceplane operations are suspended by order of Jeb until this is independently confirmed.

Reporting a problem. NEAR is disabling the SP+ control surfaces completely. They're just inert and won't move. I'm fairly certain that it is infact NEAR that's causing this.

I reinstalled KSP, tried it without any mods, control surfaces worked. added a batch of mods (not including NEAR), they still worked. Removed that batch and put another batch in (of 5) WITH NEAR, they stopped working. I removed NEAR and they began working again.

So I think that's enough evidence. I am not sure what is going on, I'm currently re-downloading this mod and trying it again. Will report back if the situation changes.

- Xenro66

[ferram4]

@biohazard: I cannot reproduce the issue. I'm not sure what's wrong.

@Pondafarr & Xenro66: I've attempted to reproduce from a stock NEAR install, and cannot reproduce it. All SP+ control surfaces function properly; I suspect that you haven't installed NEAR correctly, do not have a copy of ModuleManager installed, or are using something that interferes with NEAR.

[AetherGoddess]

@Pondafarr & Xenro66: I've attempted to reproduce from a stock NEAR install, and cannot reproduce it. All SP+ control surfaces function properly; I suspect that you haven't installed NEAR correctly, do not have a copy of ModuleManager installed, or are using something that interferes with NEAR.

Are you using the SP+ surfaces that come with .25, or do you have left-over, possibly colliding parts from .24.2's version of SP+?

[FirstSecondThird]

This is what helped me learn to fly aircraft and spaceplanes using FAR. It is really quite the FAR for noobs.

[Pondafarr]

AHHA! I did not notice you had a 1.3(A) version, installed that, and everything works properly now...

@biohazard: I cannot reproduce the issue. I'm not sure what's wrong.

@Pondafarr & Xenro66: I've attempted to reproduce from a stock NEAR install, and cannot reproduce it. All SP+ control surfaces function properly; I suspect that you haven't installed NEAR correctly, do not have a copy of ModuleManager installed, or are using something that interferes with NEAR.

[Guest]

I have a question regarding the fairings.

http://i.imgur.com/CzUKcqh.jpg

http://i.imgur.com/MzqF56o.jpg

The question is, why is my ship isn't shielded (by all logical means, it should be - there is no openings between fairing and LES) and how do I make it shielded? "Delete LES and use usual fairings" is not an option

I've tried to add a second ring between LES and ship to make fairings clip there, but that didn't work either - the payload is still labeled as unshielded.

Or I should go somewhere else with tht question (like PF thread)?

This fairing type is bad at actually shielding anything. Try attaching another fairing base upside down under the LES, and using normal fairings.

[Streetwind]

Hey guys,

I want to report issue with NEAR. Initially I had problem with parachutes (excessive heat damage) and then they just get ripped off. I have NEAR, Deadly Reentry and bunch of other mods installed, everything up to date. I skimmed through the thread and it looks like you need to be below 400m/s to deploy chutes (I am using RealChutes), fine.

However there is a problem, I cant slow down to that velocity...

Using Mk.1 pod going straight down from 100km I hit the ground at about 500-600 m/s.

I suspected it might be something to do with drag so I installed FAR and it worked perfectly, it slowed me down significantly, enough to deploy chutes safely at subsonic speed (at around 7km). So I believe it is safe to assume that there is an issue with drag in NEAR.

I'm coming here to report this exact issue.

NEAR v1.3.0

Deadly Reentry v6.2.1

Trajectories v0.4.1.0

That's all the mods I have that involve the aerodynamics model in any form, I think. This is on KSP .25 32bit.

Sample bug description:

Bog-standard single person pod with three items weighing 0.15 each attached to it: two radial chutes, one DMagic Orbital Sciences magnetometer. Also two physicsless 2HOT thermometers. Finally, there's a Kerbal Engineer Redux chip (zero weight and drag) clipped into the model under the heatshield. I'm going to test again if this is messing with the aerodynamics, but the first two times I landed this pod everything worked fine, so it doesn't seem to be a guaranteed cause.

The next two times I attempted to land this capsule, it suddenly decided to not want to slow down properly anymore.

The first instance was on an aborted launch. My experimental strut-less SRB assembly wobbled itself to pieces and I had to decouple the capsule 20km up. From that height, it fell, and I expected it would eventually hit terminal velocity between 100 and 200m/s when nearing the ocean, which would allow me to open the chutes safely (as I had done in the past). But instead, it accelerated. And accelerated. And accelerated. By the time it hit the water, it was supersonic and of course the chutes had torn off because it was moving so fast. The next launch after that succeeded, I reached orbit and did some sciencing. I then deorbited from a 73x71 km orbit in a nice and gentle, shallow slope. The pod came down in a fiery show of reentry effects, the heatshield held, and then it was Mach effects all the way down until it impacted the grasslands at less than 50 meters elevation going nearly 450 m/s still. Needless to say that the chutes did not survive me trying to open them this time either.

It could be that this is an issue that randomly starts happening after scene changes. Something that causes the drag calculation to trip over itself? I'm really not sure how to pin it down myself, or if it is even NEAR's fault and not some other mod, but I'll try testing more. If there's anything you want me to provide - more details, logs, etc. - feel free to ask.

[ferram4]

And an output_log.txt? Something is clearly breaking, but I have no idea what without a log.

[Sobanaut]

And an output_log.txt? Something is clearly breaking, but I have no idea what without a log.

Would love to help, but log of what do you want to see? I can crash a mk.1 pod straight into the ground from 100km, and upload a log, is it going to help?

[Streetwind]

Okay, two more test flights conducted today. Output log: https://dl.dropboxusercontent.com/u/44754370/output_log.zip

Right after loading KSP, I grabbed my saved rocket design, flew it into orbit, and performed a reentry. Once again, aerodynamics failed to provide enough drag to get the pod out of the supersonic regime before faceplanting into the ground.

I then reverted to vehicle assembly, pulled the clipped KER chip out of the pod, and put it inside a decoupler elsewhere in the vessel. That means there is no longer a KER part present anywhere on the pod when it reenters. I launched the craft like that, orbited, and performed a reentry. Suddenly, drag! This time everything worked, and I was slowed down just as expected.

Potentially, NEAR reacts allergic to this zero mass, zero drag KER part. I think it flew okay at least once or twice, so it may not be guaranteed to fail, but it's pointing more and more strongly in that direction. I've had other inexplicable landing failures in the past while playing this savegame too, during which I might have had the KER chip attached to the side of the pod (not clipped under the heatshield). So maybe the mere presence is enough, regardless of it's position? I'm not sure.

I'm wondering if things would change if I give the KER part proper mass and drag and just declare it physicsless (I'm not sure why it isn't configured like that to begin with, as the intention is obvious). How does NEAR usually react to a physicsless part? Is it completely ignored, or will the shape influence aerodynamic properties while only mass is ignored?

EDIT: I tested this by reloading a quicksave from a previously failed attempt to land after making the part genuinely physicsless. The landing still failed.

Edited October 26, 2014 by Streetwind

[ferram4]

I see nothing breaking in the log. I also know from experience that KER parts do not cause the behavior described. In particular, 0 mass, 0 stock drag parts aren't treated any differently by NEAR, so there shouldn't be any problems. The only issue is that the KER part clipped into the bottom of the pod might confuse it into thinking that the heat shield is covered, and so that there is no drag there. In practice, this should lead to the KER part being destroyed during reentry.

[Streetwind]

It heats up a whole lot (1500+ degrees) but due to having maxtemp = 3600 set in the config, it does not get destroyed. This might be different for a more steep or higher speed reentry than the shallow, low-orbit reentries I tried so far... but I have a feeling that every other part in the reentering vessel will have long since melted down before this thing dies

Now I wonder of Pondafarr's spaceplane and Sobanaut's pod had similar issues with the game thinking the heatshield was covered so much that it didn't produce drag. It's odd though that Sobanaut stated that he was able to fix things by switching to FAR. I'm also wondering how a spaceplane could avoid having objects interposed between the air and the heatshield, since it kind of requires carrying landing gear under the belly.

In any case, I'll be keeping a very close eye on this kind of behavior from now on. If I notice any odd landing failures now that I stopped carrying the KER chip on the pod, I'll report it.

[AHDB]

I experienced the same bug as Pondafarr and Xenro66 after playing successfully with NEAR for some time. Aerodynamics dropped out of the game completely, and no control surfaces would function. Turned out, the near.dll had gone missing from its plugin folder, and replacing it with a fresh copy solved all problems.

No idea why it vanished in the first place, but I'm happy to have it back.

[stardestroyer]

I'm getting a trouble: with Kerbin Shuttle Orbiter System (EWBCL) I do a quite normal reentry (exeption for battery depletation) until I descent under 8000m at less than 400m\s; in proximity of the runaway I reactivate SAS and i get an incredible acceleration over 1000m\s and I can't land... Everytime I try I get this effect. Is it NEAR related?

I also use: Deadly Reentry v6.2.1, Trajectories v0.4.1.0, Firesplitter latest hotfix and B9.

[ferram4]

That is because KSO is not set up to be NEAR / FAR-compatible. This is a problem on their end, nothing I can do about it.

[Mekan1k]

Anyone know why the Radial engine body (from stock + Stock Part Revamp) and the smaller version (from Tavarius's Pizza and Aerospace) is listed as having fuel when this mod and the Modular FuelTanks mod is active?

Can anyone duplicate this result, or is it just me?