[1.2] Real Solar System v12.0 Dec 8

[iVG]

Nathan, I've never grasped what KATO actually is... nevermind a new version of it

Any clarification?

[li7in6]

Nathan, one thing I can see a big use for is some sort of procedural tank that allows the smooth adaptation between various diameter stages (changing the diameter of both faces independently).

For instance RSS sometimes requires very large diameter lower stages to get the dV to get larger payloads to orbit, however there is no good way to aerodynamically adapt from say: a 3.75 meter upper stage to a 6-8 meter lower stage.

I seem to recall stretchytanks allowing this but I can't remember. If this is already a 'thing' and I'm just missing it somehow let me know.

[NathanKell]

It's my alternate history spacerace. The link to the reboot (100% non-Kerbal) is in my sig. KATO was Earth alternate history with a laughably thin veil of Kerbal names; now I'm not even pretending. It's kinda how I got started on all these realism projects. The old KATO is still in Mission Reports, just buried a few pages back; Reaching for the Stars should have a new episode soon.

KhaosCorp: I'm about to release that rescale I was talking about. Combined with StretchyTanks, you can make stages as large as you like. (Well, you can now with stretchytanks, you just have to use lots of small engines for your 10m cores). Note that StretchyTanks has a "super stretchy" whose radius as well as height you can scale.

Regarding planes: You want the blue of the CoL _just_ on the back edge of the yellow CoM sphere, and you want (via RCS Build Aid) your red dry-CoM sphere inside your yellow CoM sphere.

EDIT: li7in6: I believe e-dog is working on that now! For now you have to use the pfairings interstage and place a ST inside.

EDIT2: Note that if you aren't using pfairings, it's a must. Note that most stages are cylinders, and instead the interstage adapts beween sizes. And the procedural interstage is just that, procedural, with rescalable base and top width.

[iVG]

And why would we need these KATO engine cfg's outside your mission reports. I mean, does it contribute to realism and in what way?

[li7in6]

EDIT: li7in6: I believe e-dog is working on that now! For now you have to use the pfairings interstage and place a ST inside.

Ah yes, that's where I've seen that functionality. I've been using pfairings but never used it in that way. Tried it out and while effective it is a bit clunky to implement, what's e-dog's mod called/going to be called?

Also, I've been experiencing some inconsistency in launches and I don't know where it's coming from. For example I'll build a LV with a surface TWR of about 1.35 that weighs about 1200t. First launch everything is fine it slowly lumbers into the air at full throttle then half way up I'll do something dumb like hit spacebar too early and it will disintegrate. Reset on the launchpad from Esc menu (same craft), launch at full throttle, and now it rockets into the air and mechjeb shows a TWR of ~2.2 then the TWR will drop back down to 1.5 or so and start climbing again as I burn off fuel. I haven't been able to note total weight yet when this happens as it's pretty inconsistent.

Edit: Just recreated it and mass is consistent it's thrust that's starting out about 10,000kN (~25,000kN) higher than it should be and quickly falls down to where it should be (~15,000kN) about 10 seconds after liftoff.

LV is using 11 KW Maverick-V's. When it loads out of the VAB it seems to have the correct thrust, but on resets it does this.

Pics to clarify, just before and just after launch out of the VAB:

And here's right after a launch from an Esc Menu reset:

Edited November 18, 2013 by li7in6

[iVG]

Don't know about the screens but thats one fat booty baby on the launch pad out there.

BTW did you use struts or failed docking ports (darn, can't stick this name to my brain) for the engine cluster?

[NathanKell]

li7in6, are you sure you've totally uninstalled KIDS?

Oh, no, it's Mechjeb. You need the latest development build of mechjeb, that works properly with MFS thrust correction. Your version gets confused about engine thrust and lies about TWR. Once you get the latest dev build, install that. Then, ingame, click "All Stats" and a new column, SLT, will appear. That shoes thrust at sea level. TWR and Max TWR are for vacuum. Also, Atmo Time is then obviously redundant, since it's properly identical to Vac Time.

iVG: The point of the engines mod is that, for regular MFS RF (and RFRM) we've felt obligated to use the existing thrust and mass. Well, in my engines mod, I went whole hog, and basically restatted everything. You get realistic mass, TWR, thrust, Isp, and fuel usage for every engine, and proper TL support (most engine start at low TLs). To the best of the limited realism of the models and their limited selections, engines are classed according to what they look like. (Exception: most upper stage engines have too-small nozzles. The LV-909 is a case in point, it should have a bigger nozzle than the LV-T30!)

Also, in the soon-to-be-released latest version, I undid the Great Rescaling. Engine sizes are now 0.5m, and then every meter on. This is to go with the latest stretchytanks, which has even meter sizes and displays width and height. You'll be able to create realistic rockets without a dozen lower-stage engines (the largest engine in the rescale is the NovaPunch 1.5 M-50 5x, which is a Saturn V bottom lookalike with 5 F-1 lookalikes. And yes, it's now scaled to 10m diameter and 38MN thrust).

[li7in6]

Don't know about the screens but thats one fat booty baby on the launch pad out there.

BTW did you use struts or failed docking ports (darn, can't stick this name to my brain) for the engine cluster?

Used small cubic struts to attach the motors to the bottom of my fatty fuel tank.

She gives me JUST enough to nudge my ~50 ton moon payload into orbit. Not enough to actually send it to the moon though. Need to tweak it more to get it mission capable in one launch... Or refuel in orbit.

Edit: Nathan. That fixed it, thanks!

Edited November 18, 2013 by li7in6

[iVG]

Yup, got the new jeb 2 days ago,forgot to mention it though No more guesstimates about Sea level TWR.

[iVG]

li7in6, are you sure you've totally uninstalled KIDS?

Oh, no, it's Mechjeb. You need the latest development build of mechjeb, that works properly with MFS thrust correction. Your version gets confused about engine thrust and lies about TWR. Once you get the latest dev build, install that. Then, ingame, click "All Stats" and a new column, SLT, will appear. That shoes thrust at sea level. TWR and Max TWR are for vacuum. Also, Atmo Time is then obviously redundant, since it's properly identical to Vac Time.

iVG: The point of the engines mod is that, for regular MFS RF (and RFRM) we've felt obligated to use the existing thrust and mass. Well, in my engines mod, I went whole hog, and basically restatted everything. You get realistic mass, TWR, thrust, Isp, and fuel usage for every engine, and proper TL support (most engine start at low TLs). To the best of the limited realism of the models and their limited selections, engines are classed according to what they look like. (Exception: most upper stage engines have too-small nozzles. The LV-909 is a case in point, it should have a bigger nozzle than the LV-T30!)

Also, in the soon-to-be-released latest version, I undid the Great Rescaling. Engine sizes are now 0.5m, and then every meter on. This is to go with the latest stretchytanks, which has even meter sizes and displays width and height. You'll be able to create realistic rockets without a dozen lower-stage engines (the largest engine in the rescale is the NovaPunch 1.5 M-50 5x, which is a Saturn V bottom lookalike with 5 F-1 lookalikes. And yes, it's now scaled to 10m diameter and 38MN thrust).

Cool! I'll be waiting for yet another pinch of realism

[Mounti]

If you want to aerocapture into a Mars orbit, you need about 1km/s of braking delta-v. You can get that with a periapsis of about 30-40 km (depending on your craft's aerodynamics).

It is very hard to land on Mars with a big payload in real life. That translates pretty well to this mod. A heat shield alone will only take you down to about 1000 m/s in the very thin atmosphere.

There is also a problem with the way terrain altitudes work in KSP. In real life, all the rovers and lander we've sent to Mars have landed below "sea level" (the average altitude of Mars), where the pressure is higher. But in KSP the 0m altitude is that of the lowest point on the body. The atmospheric pressure of Mars is 0.007 bars at the average altitude, but the KSP Duna/Mars has its pressure set to 0.007 bars at 0m, which is its lowest altitude. One way to fix this is to make the atmospheric pressure at 0m equal to the atmospheric pressure at Mars's lowest point, which is about 0.012 bars.

Since the stock parachutes have their minimum inflating atmospheric pressure at 0.007 bars for the drogue and 0.01 bars for the regular parachute, the parachutes will never work on Duna/Mars as it is now. You can change the values that the parachutes open in the Squad folder to make them able to be opened on Duna/Mars. Or if you set Duna/Mars's base atmospheric pressure to 0.012 bars you will be able to use the stock parachutes.

Hey Metaphor! Thanks for the help!

I did it and landed my little rover curiosity-style. However, I had to raise the atmospheric pressure to 0.02 bars and had to raise the chute opening altitude to 9000m I think. Nevertheless I am happy now! This was so far the hardest thing I did in KSP. The key in the end was to find a position of the descent stage, in which it wouldn't raise vertical velocity. I even found a position in which it ascendet a bit and was able to burn off enough velocity to open the parachute without snapping everything in half.

Next time I will try it with those 0.012bars of atmospheric pressure. I know I cheated somehow by raising the pressure but here I am...

[p3asant]

All you need to do to build rockets properly in FAR is to remember three things:

1. TWR ~1.4; higher than 1.8 leads to overspeeding and losing control.
   
2. Put fins at the bottom / flare the rocket at the bottom; this is less critical with MFS (since engines are lighter, so the rocket is more stable).

How does high sea level velocity lead to unstable rockets? Why does the engine mass matter and how do the fins negate the effect of big engine/bottom mass?

I've been using srbs with couple second burn times to quickly kick the velocity to 100m/s or so with quite high normal twr's (>1.6).

No wonder my rockets often go the way of the kerbal.

Rocket overspeeding tickets .

[KhaosCorp]

Hey Metaphor! Thanks for the help!

I did it and landed my little rover curiosity-style. However, I had to raise the atmospheric pressure to 0.02 bars and had to raise the chute opening altitude to 9000m I think. Nevertheless I am happy now! This was so far the hardest thing I did in KSP. The key in the end was to find a position of the descent stage, in which it wouldn't raise vertical velocity. I even found a position in which it ascendet a bit and was able to burn off enough velocity to open the parachute without snapping everything in half.

Next time I will try it with those 0.012bars of atmospheric pressure. I know I cheated somehow by raising the pressure but here I am...

I like to use airbrakes for aerobraking (B9 and Firespitter both have good airbrakes). Even in Duna's super thin atmo they work really well for this application.and start working pretty much the moment your in atmo. They are small and very little mass, so you can put alot on a craft..I have gotten the equiv of almost 2km/s braking Dv doing this before (though that was without FAR, so guessing it would be a bit less effective with FAR). Not to mention you can flare em, open and close them as needed unlike a chute.

[AndreyATGB]

Fins don't negate anything, they make your rocket the shape of an arrow which is supposed to fly straight. My heavy launcher with 4 F-1's has quite large fins, given a slight nudge at launch it perfectly executes a gravity turn by itself. Also don't worry about terminal velocity, you probably won't reach it easily with FAR.

[iVG]

Hey Metaphor! Thanks for the help!

I did it and landed my little rover curiosity-style. However, I had to raise the atmospheric pressure to 0.02 bars and had to raise the chute opening altitude to 9000m I think. Nevertheless I am happy now! This was so far the hardest thing I did in KSP. The key in the end was to find a position of the descent stage, in which it wouldn't raise vertical velocity. I even found a position in which it ascendet a bit and was able to burn off enough velocity to open the parachute without snapping everything in half.

Next time I will try it with those 0.012bars of atmospheric pressure. I know I cheated somehow by raising the pressure but here I am...

Hi there. Why not try the new realistic parachutes mod. I think it will help landing on Mars (Duna, whatever). The chutes there open much higher (40=45k) in altitude and to that not instantly but rather realistic - a couple of seconds deployment time.

[Starwaster]

Hey Metaphor! Thanks for the help!

I did it and landed my little rover curiosity-style. However, I had to raise the atmospheric pressure to 0.02 bars and had to raise the chute opening altitude to 9000m I think. Nevertheless I am happy now! This was so far the hardest thing I did in KSP. The key in the end was to find a position of the descent stage, in which it wouldn't raise vertical velocity. I even found a position in which it ascendet a bit and was able to burn off enough velocity to open the parachute without snapping everything in half.

Next time I will try it with those 0.012bars of atmospheric pressure. I know I cheated somehow by raising the pressure but here I am...

I don't consider that cheating, what you did. As is, it wasn't behaving as it would IRL. The real world doesnt always conform to the simplistic models imposed by a computer game and the previous atmo values were probably a little too low.

That's assuming I even believed in the concept of cheating in a sandbox game.

Remember Starwaster's rules:

It's your sandbox, don't let anyone tell you how to play.

Don't tell anyone how to play in their sandbox.

[iVG]

Starwaster, what's in you signature? Same real fuels we all use or... ?

[Captain_Party]

Building on from what Starwaster said, I just lowered the atmospheric height from 104 to 100, a) It's easier to orbit, and its just better rounded up. I recommend it

[Starwaster]

Starwaster, what's in you signature? Same real fuels we all use or... ?

Ack, what's in my signature is not updated for MFSC so masses are all wrong, don't use that....

I need to finish updating it for MFSC but I've been lazy and too busy screwing around with RSS. (dammit Nathan, look what you've done)

(I edited the signature to signify that it's not for MFSC... if anyone tried to use it with MFSC I apologize)

[diablos]

Building on from what Starwaster said, I just lowered the atmospheric height from 104 to 100, a) It's easier to orbit, and its just better rounded up. I recommend it

If anything, at 104km the atmosphere is too low, but unfortunately the lowest atmo pressure you can have in KSP is 10^-6 SL, so there's really very little FAR and RSS can do to simulate realistic orbital drag. Would be kinda cool if I were able to dispose of spent booster stages by leaving them in a ~150km parking orbit, though.

[iVG]

And what exactly are you modding there?

[Miller]

I am watching MAVEN launch live right now and I just can't help but think that they should broadcast their simulation from KSP with RSS,MF,FAR and etc.

[StainX]

I am watching MAVEN launch live right now and I just can't help but think that they should broadcast their simulation from KSP with RSS,MF,FAR and etc.

Damn i missed the launch

[iVG]

Was a nominal flight. Waiting for spacecraft sep.

[StainX]

Seperation also was pretty nominal

Anyway with mods like this KSP is going to get a real simulation for such crafts!

Yeah.. why not just build MAVEN right now?