Gaming The Kerbal Space Program - Version 1.2.x

[Chub777]

Here's the odd thing, pressing the space bar twice will make it launch. (See this video.)

Kerbal Space Program - Testing Rocket Configuration 2

I use this technique to launch my heavy rockets. Also, could someone please post a orbit-capable stack?

 

[blixel]

Reverse your stack, place the SRB on top, and the liquid stage on the bottom, then before launching, push the throttle all the way up (Shift), and then launch. The liquid one, at full power has a larger thrust-to-weight ratio.

Yeah, that works. Seems backwards though doesn't it? Shouldn't the SRB's burn first?

Also, if I add a 3rd liquid stage rocket, it behaves the same way. Pressing the space bar once - the rocket stack stays on the pad. Press the space bar twice, it apparently decouples from the second stage and then launches anyway. (Without exploding on the pad?)

I made another video that shows this. (I guess I was bored, because I took the time to annotate the whole flight starting with the first stage separation.)

[ame="http://www.youtube.com/watch?v=hXDD7-WnUV8"]Kerbal Space Program - Just Messing Around[/ame]

 

[Fabri91]

Yesterday I reached 1990km of altitude, just lifting off straight-up. "Reentry" is going to be interesting with such an angle.

 

[HarvesteR]

Yeah, that works. Seems backwards though doesn't it? Shouldn't the SRB's burn first?

Also, if I add a 3rd liquid stage rocket, it behaves the same way. Pressing the space bar once - the rocket stack stays on the pad. Press the space bar twice, it apparently decouples from the second stage and then launches anyway. (Without exploding on the pad?)

I made another video that shows this. (I guess I was bored, because I took the time to annotate the whole flight starting with the first stage separation.)

Kerbal Space Program - Just Messing Around

IT depends really, with the shuttle (and most commercial rockets anyway) the SRBs fire together with the main liquid engines, to boost it along... IDK of a present-day rocket with a first stage composed solely of solid booster engines.

You can do parallel staging by strapping SRBs to those radial decouplers. They will be added to a stage of their own. THen, just drag the main (center) engine down to the SRB stage. THey will fire off all at the same time, but since the SRBs will burn for a shorter time, you can then hit space to jettison them and keep on with the main.

BTW, nice video! the annotations had me laughing all the way!

 

[Fabri91]

It seems a miracle but the Kermans survived!
Should be possible to load my ship by downloading the file and renaming it lastShip.craft in the "Ships" directory.

EDIT: stable orbit confirmed! Ap=287764m Pe=41668m
Luckily the atmosphere is gone at 40km here! Now coasting to apogee, the remaining fuel SHOULD be enough to deorbit. It would be nice to have a fuel indication also for liquid stages.

EDIT2: added image with the stats at the end of the two-orbit flight!

 

[Chub777]

Also, would it be possible to have a Service Module in the game? You could use it for de-orbiting and orbital maneuvers instead of bringing another stack.

 

[RisingFury]

I have another suggestion... when the game is paused, please make the smoke pause too. If you're riding SRBs and press pause, the smoke keeps filling up your screen and it does murder to my framerate...

Also, I know my machine isn't up to specs, but at low frame rate, the mouse starts moving slowly too and it gets awkward. Could you address that, please?


Other then that... this game is awesome! It already got me hooked and I can't wait for future releases

---------- Post added at 12:38 ---------- Previous post was at 12:36 ----------

EDIT2: added image with the stats at the end of the two-orbit flight!

Most G-force endured: 20 000+?! Wtf! :lol:

 

[Fabri91]

That's likely the g-force peak on impact or one of the stage ignitions, where I only waited a minimal amount of time for the spent stage to clear...this way not much momentum is lost, but the spent stages explode.

 

[Fizyk]

I have a suggestion to add a possibility to manually add stages. Automatic adding fails a bit with the radial decouplers.

But yeah, it's great fun anyway I'm still trying to do better measurements of the mass and radius of the planet. This time I entered an orbit, measured the velocity and altitude at periapsis and apoapsis and tried figuring it out from that. I got:
[math]M = 5.285 \times 10^{22} \; kg[/math][math]R = 599.2 \; km[/math]
I suspect the radius is actually just 600 km and the mass is defined so that the acceleration on the surface is 9.81 m/s^2 (This doesn't match my data as well as what I calculated, though, so probably it isn't exactly 9.81 m/s^2.)

 

[Jarvitä]

This doesn't match my data as well as what I calculated, though, so probably it isn't exactly 9.81 m/s^2.

Maybe it's 9.80665 m/s/s?

 

[HarvesteR]

Hi,

@Fabri91: Yes, the liquid engine should have a fuel indication. In fact, it isn't the engine itself that should indicate fuel, it's the fuel tank above it. All it needs to do that is a couple of lines of code, but in the rush to get everything working for the first release, it got overlooked. It'll be up on the next release, along with the other icons that should pop out information too.

@RisingFury: Yes, pausing the smoke effects is another one of the points that got overlooked on this release. It should be fixed for the next one.

@Fizik: About the stages, do you mean manually creating new stage indicators on the staging stack, or simply being able to change the stage a part belongs to? If the latter, that is possible already, by dragging the part's icon up and down the stack. THis way you can have parallel stages firing along with your main ones, by dragging the main engine down to the first stage.

That isn't saying there won't be means to add and remove stages from the stack however. As many other things, that system is only half-finished, so it'll have more capabilities added to it as the game progresses.


Oh, and about the radius and mass of the planet, I can answer that, but it might ruin the fun
Let's just say you're pretty close :thumbup:

Cheers

 

[iamwearingpants]

What is orbital velocity for the Kerbal Planet?

Oh yeah, and when is the next release?

 

[Fizyk]

@Fizik: About the stages, do you mean manually creating new stage indicators on the staging stack, or simply being able to change the stage a part belongs to? If the latter, that is possible already, by dragging the part's icon up and down the stack. THis way you can have parallel stages firing along with your main ones, by dragging the main engine down to the first stage.

I mean creating new stage indicators. Sometimes I would like to separate engines which are automatically put in one stage and the only way there is currently to do that is to activate the engines simultaneously with some decouplers. A way to just add a new stage would be a lot more convenient

BTW, I tried to "cheat" once and trick the game into creating more stages than it should - by placing a decoupler on a decoupler (which created 2 stages), then dragging some engines into those stages, then removing the unneeded decoupler. The game almost crashed after that

Oh, and about the radius and mass of the planet, I can answer that, but it might ruin the fun
Let's just say you're pretty close :thumbup:

Yeah, that's why I didn't just ask - I'll be trying to get more precise results I wonder how accurately I'll be able to reconstruct those values

 

[RisingFury]

Oh yeah, and when is the next release?

Tuesday!

---------- Post added at 15:38 ---------- Previous post was at 15:33 ----------

A small bug I also found... you can move the command module through the roof in the VAB when constructing your rocket.

And a suggestion: Make the liquid rocket stages be throttled up to 100% by default. I sometimes forget to throttle them up...

 

[Fabri91]

A suggestion related to the liquids: turn the effects and the sound off with throttle set to 0% (Or maybe assign a key to ignition, with the number of possible firings limited? but that would be pushing it a bit).

 

[spacekid1998]

I think I figured out why some people are having success launching their rockets if they hit the space bar 2 or 3 times like in this video

So after hitting spacebar the first time, the solid rocket at the bottom fires but it does not produce enough thrust to lift the weight of the command module, parachute, fuel tank, liquid engine, and solid rocket. After hitting the space bar again, this makes the game recognize the vehicle as a command module, parachute, liquid fuel tank, and liquid engine. The weight of the solid rocket has become "detached" from what the game recognizes as the vehicle but due to physics the solid rocket engine is right below the vehicle. Now the thrust that the solid rocket produces is sufficient to lift the lesser weight.

 

[RisingFury]

The atmosphere gets thinner with altitude (I didn't get any accurate data, but my guess exponential decay) and ends abruptly at 34 +- 1 km altitude. It's still *very* thick right under the 34 km mark.

I measured that by going orbital to about 60 km altitude, then burning the last stage towards the ground. I increased speed to about 2600 m/s, but the periapsis was well within the atmosphere - probably below the ground. I then deployed the chute and watched the speed and altitude... the speed decreased dramatically when I hit the 34 km mark and dropped to about 500 m/s within a few seconds...

I'd suggest that the atmosphere drops in pressure more quickly. Right now the initial stages can only get to about 100 m/s due to the heavy drag and it takes 3 stages to get outside the atmosphere and and the remaining two are sufficient to get you escape velocity...

So after hitting spacebar the first time, the solid rocket at the bottom fires but it does not produce enough thrust to lift the weight of the command module, parachute, fuel tank, liquid engine, and solid rocket. After hitting the space bar again, this makes the game recognize the vehicle as a command module, parachute, liquid fuel tank, and liquid engine. The weight of the solid rocket has become "detached" from what the game recognizes as the vehicle but due to physics the solid rocket engine is right below the vehicle. Now the thrust that the solid rocket produces is sufficient to lift the lesser weight

I noticed that too, but I though that by the time I hit space a few times, the next stage fires as well and then both push the rocket up...

---------- Post added at 16:45 ---------- Previous post was at 16:36 ----------

A better estimate for the cuttoff altitude: 34.5 km +- 0.5 km ...

I also just achieved my best 4th stage cutoff velocity by flying straight up until the atmosphere ended, then burned parallel to horizon... It seems the air drag is much greater then the "centrifugal force" holding you up...

 

[HarvesteR]

I think I figured out why some people are having success launching their rockets if they hit the space bar 2 or 3 times like in this video

So after hitting spacebar the first time, the solid rocket at the bottom fires but it does not produce enough thrust to lift the weight of the command module, parachute, fuel tank, liquid engine, and solid rocket. After hitting the space bar again, this makes the game recognize the vehicle as a command module, parachute, liquid fuel tank, and liquid engine. The weight of the solid rocket has become "detached" from what the game recognizes as the vehicle but due to physics the solid rocket engine is right below the vehicle. Now the thrust that the solid rocket produces is sufficient to lift the lesser weight.

Hmm, this is kinda weird, it shouldn't happen like that, because the physics engine acts much more globally on the ship than that... each part is being simulated as if it were a ship on it's own... there are no mass interchanges happening...

My guess is that for some unfathomable reason, the liquid engines are getting slightly stuck to the platform, so you need to jolt it out. And decoupling creates just the needed forces to do that... I'm thinking there might be something wrong with the liquid engine's collider... I'll look into it.


About the atmosphere and drag, yes, the drag calculations and atmospheric decay are still a little off... The atmosphere does seem to be too thick right now, and it it's cutting off at about 35k altitude... The formula for atmospheric decay is correct, though (it's an exponential decay with a scale height of 7)... the problem is how that is being integrated with the physics to create a drag force. As I said, there's still a lot to do

About the liquid engine effects, yes, I do plan on disabling them on ECO, it's just another of the thousand little details that need to be taken care of.

Cheers

 

[Nistenf]

Looks amazing, good job, downloading!

 

[insane_alien]

just had an interesting one, i bumped up the srb power to see how high i could get before the program crashed, errored or just froze.

so i had a triple connector right at the start and about 5 stages of SRB's

i got to about 5km and to my surprise the 'legs' (each column of srbs) seperated, then collided and exploded)

probably not an issue as i'm using it for a purpose it was never meant to be used for