[1.3.1] Ferram Aerospace Research: v0.15.9.1 "Liepmann" 4/2/18

[Rokker]

Hey, I was wondering what somone would need to do to make a cargo bay be recognized as a cargo bay if they were doing something like, say, trying to use Touhou Torpedo's old Mk3 bomb bay.

[ferram4]

That should still be supported without any changes.

[Rokker]

That should still be supported without any changes.

Ok, thanks, just wanted to make sure.

[Dr. Death]

Yeah, most of them need a bit of a redesign. The Jet Airliner has been properly redesigned, the SR-71 is exactly correct to the best of my ability. The Thunderbird is deliberately unstable, since it's a maneuverable jet fighter.

Oh, sure. I'd love to add proper aeroelasticity and flutter, but haven't gotten to that yet. The best part is that adding that will lead to aileron reversal effects (go too fast with wings that are too thin and the ailerons cause the wing to bend so much that the plane actually rolls the other way). Lots of rage will occur once that is implemented.

-The blackbird should be able to reach for 20 kilometers, but that's more of the atomsphere limit.

You're just not handling the SR-71 right. It needs to pick up speed first so that you don't have to push the AoA too high and to get enough air. It's perfectly capable of going up to 25 km.

Ladders aren't normally my main priority. Besides, it lowers the part count.

This is actually completely correct. The SR-71 actually should be in danger of flying apart at mach 3, and I have caused it to disintegrate at those speeds.

Let me add the caveat that you neglected: all of those apply in a safe, well-designed plane that doesn't compromise stability for performance reasons. Most spaceplanes sacrifice stability for performance reasons; if you build a Cessna 172 it'll fly like a Cessna 172, including the pitch-down tendency even in a deep stall due to the weight of the engine at the front.

Well, if I made the air thicker, that would result in all the forces scaling up... including the ones keeping the plane in a stall. All that would do is allow you to take off at 20 m/s and run into the same issues at lower speeds.

@Castun: yeah, it turns out there's a bug in the Turbojet module manager fix. It needs to be changed to this:

@PART[turboFanEngine]
{
    @MODULE[ModuleEngines]
    {
        @maxThrust = 200
        @velocityCurve
        {
            @key,0 = 0 0.7 0 -0.00098

            @key,1 = 140 0.63 0 0

            @key,2 = 400 0.7 0.00049 0.00049
            @key,3 = 900 1 0 0

            key = 1800 0 -0.00098 0
        }
    }
}

[Pds314]

Lookie! It is amazing what broken Turbojets can do! (submitted this to machingbird before realizing something was extremely wrong.)

Just a pic of my new 2-man FAR craft in its completely unnatural habitat (it went there by accident). Apparently, in the new version of FAR or something, jets aren't limited to operating under 2.4 km/s in atmosphere =)

http://i.imgur.com/OruAPa1.png

I did a completely clean install and redownload of both FAR and KSP, so I know that no previous mods or anything are letting it do this.

Hmm... The .cfg seems to indicate that it oughtn't to work like that.

Grrr... Happened again, top surface speed captured on camera: 3049 m/s, (5000+ m/s surface-relative in the log, but that exaggerates quite a bit when your out at munar orbit, thanks to the fact that Kerbin rotates at 174.6 m/s, 18Mm away, the game thinks you are moving 5238 m/s BACKWARDS relative to Kerbin more than you are). This time it got into a stable orbit around Kerbin for several weeks and then hit the Mun.

Time for launch number 3...

Woops... Oh god! That's it! I'm heading west out of KSC.

Yeah, erm... can someone say: TWO AND A HALF YEAR PLANE FLIGHT between Kerbin and Eve?

Luckily, I managed to use 4 tanks of EVA fuel to correct my orbit and get a direct intercept with Kerbin. Unluckily, the damned thing is unlandable without fuel and I didn't make it to land before I ran out. *splashes into water at 90 m/s*

Time for number 4....

Yay! I'm the sole member of the mach-11 club... unofficially... since several of my speeds before the shown one are in orbital mode and were higher. Regardless, mach-10.9 club is still okay.

http://i.imgur.com/qVQPIak.png

http://i.imgur.com/d5ru1Kv.png

P.S. The highest speed overland doesn't work well for things that, under normal flight conditions, will escape Kerbin SOI even when going retrograde.

Anyway, it appears I have beat the FAR record by something like 1730 m/s.

[palker]

I am using Taverio pizza and aerospace and my jet engines are behaving as expected.

[tryder]

There was no output made for some reason only an error

http://pastebin.com/7rm1G8qL

Edited January 17, 2014 by DYJ
Pastebinned the log.

[AndreyATGB]

Damn use pastebin or something, don't just paste the log here.

[Tidus Klein]

Lookie! It is amazing what broken Turbojets can do! (submitted this to machingbird before realizing something was extremely wrong.)

Sorry bro I had a plane leave kerbin SOI with the borked turbos:)

At 4000 m/s surface speed

[ferram4]

@tryder: That's an out of memory error, which is something else entirely. Look, just delete all your mods and start over. Re-download all of them to make sure they're up-to-date and don't install them unless they're confirmed to work perfectly in KSP 0.23. If you have issues after that, come back.

[Thrombo]

Hey all,

Using FAR, what kind of payload fractions are you guys pulling, typically?

I'm quite used to asparagus staging in vanilla and getting fractions of 16% or better; I realize that in FAR asparagus staging is less desirable due to drag, but also that a well designed lifter uses ~1000 less delta-v to orbit. I have previously been designing the lifters using a 15-16% payload fraction, but using FAR this is really overkill with these lifters. Just curious what sorts of fractions others are using.

Thanks!

[Surefoot]

I didnt make any calculation yet (i'll do so today) but it's much higher than 15% by feel - i'll design a quick test rocket with a jumbo-64 payload.

[tryder]

I did re download ksp and installed all mods that is supposed to be in RPL pack from mednerd but i get same error/problem

Well this time i got the M18c version of RPL but it didnt work either...

Is there any way to increase my RAM? I know about the active memory allocation mod thing but there must be another way and i should probably ask Mednerd insted of bothering you since its not FAR that makes the head bugs only an aero dyn bug

Maybe i could send you the full folder but i dont know...

[Surefoot]

@Thrombo: a quick test gave me 21.6% in orbit: jumbo64 + RCS battery control module + small tank and engines, basically a refuel module, a bit over 54t in orbit with a 260t launcher (rounded down). Maybe one could do better i used a conventional staging and no detachable side engines for the launch... I think you cant do much better with conventional means since you are still fighting gravity anyway.

(edit) that's for reaching 80x80km orbit. Tried again with proper payload fairings and adjusted fuel volumes, still get to around 21% payload fraction.

Edited January 18, 2014 by Surefoot

[NathanKell]

tryder: this is clearly not an issue with FAR, please don't use this thread for it. I'm answering on the RPL thread.

[Sauron]

Another question: I'm having some trouble with reentry and landing. The ship below should be orienting itself nose-prograde in atmosphere, but regardless of how I tweak fuel (full, empty, front tank full rear tank empty etc.) I'm always reentering tail-first and struggling to glide safely. Even with all the airbrakes open. Landing aside, this plane works perfectly fine. So 2 questions:

What's the best way to approach landing something with a fairly low L/D?

Why can't I control it near the end of the reentry?

[Thrombo]

@Thrombo: a quick test gave me 21.6% in orbit: jumbo64 + RCS battery control module + small tank and engines, basically a refuel module, a bit over 54t in orbit with a 260t launcher (rounded down). Maybe one could do better i used a conventional staging and no detachable side engines for the launch... I think you cant do much better with conventional means since you are still fighting gravity anyway.

(edit) that's for reaching 80x80km orbit. Tried again with proper payload fairings and adjusted fuel volumes, still get to around 21% payload fraction.

Thanks for the info!

[taniwha]

Sauron: The wings are stalling, and thus the nose is taking over. You need to move your CoM forward. Take a look at your Cm line in the static analysis tab. I'm sure you'll find some nasty bumps in it around 20-25 degrees.

[Sauron]

@taniwha:

There's certainly a nasty stall around +/- 25 degrees, but I'm reentering at a much shallower AoA (on the order of -5 - -10 degrees)

[ferram4]

How does it flip out? Is it in yaw or in pitch? If it's in yaw (or something involving roll) you need more yaw stability, since that thing looks like it has very little yaw stability, especially at high Mach numbers. You might want to try angling the vertical stabilizers a bit so that they each start with ~5 degrees of angle of attack with respect to the flow to help.

If it's in pitch, I'd actually use larger control surfaces on the main wing for pitch and get rid of the canards. You've got too much weight near the back of the rocket with those RAPIERs back there, and the long body will add quite a bit of lift at the front without the canards.

[Sauron]

It's very much a pitch issue, but it's actually performing very well at high speeds (also, those airbrakes help with any stability issues on the high end of things).

I'm running into problems at the very end of the descent at around 150-100 m/s since I can't maintain enough lift without an outrageous AoA (which would produce a stall or a flip on account of being so far off-prograde)

[ferram4]

Then in that case the issue is that you're trying to stay in the air too long. What altitude are you trying to fly at when it flips? Honestly, for a very low L/D craft like that I'd expect it to land somewhere around 100 - 150 m/s. Come down closer to the space center and don't try to glide as much, since it's not designed for gliding.

[Sauron]

Okay, the more aggressive (and powered) landing approach is working a bit better, but even a very flat touchdown at ~150 m/s is not quite survivable. Any pointers on how to land at very high speeds? Especially, what's the optimum way to use of airbrakes etc. to slow the plane down)

...On that note, an Edwards AFB-like site in ksp would be awesome!

[ferram4]

The actual optimum way would be to use parachutes to slow it down, but you'd need to go to stupid_chris' RealChutes to get one that doesn't immediately disappear when you hit the ground.

Another thing to try would be to disable the brakes on the front wheel so that it can't wheelbarrow on you.

[GreeningGalaxy]

I just reinstalled this mod today after going vanilla since .19. I love it even more than before, but I'm noticing that it's really, really easy to SSTO now compared to back in .19 as far as I can tell. Stuff just seems to get really fast reallu quickly, to the extent that I managed to get the Grumman X-29A that comes with the mod up to quite a few km/s in the upper atmosphere, putting it on a nice suborbital trajectory peaking about halfway out to the Mun. If I'd stuck a few sepratrons on the fuselage before I launched, I probably would have been able to bring my periapse above the atmosphere and call it an orbit.

I'm just wondering, is this how it's supposed to be? I know Kerbin's small size compared to Earth makes it easier to SSTO, but this still seems a little much, and I'm wondering if things didn't get moved over properly when I installed the mod or something like that.

Thanks again for the great mod, by the way!

Edited January 19, 2014 by GreeningGalaxy
inaccurate values