Eve Launch simulation

[700NitroXpress]

Is there a way to simulate the conditions of Eve on Kerban for a sea level launch using throttle control at different altitudes?

Edited December 16, 2013 by 700NitroXpress

[Monkeh]

Throttle control isn't going to mimic higher gravity and more atmosphere. It will just make the fuel your carrying last longer. I suppose you could work it all out that if you throttle at 70% and assume the tanks are dry when they have 23% of their starting fuel left or something...

I shouldn't have started this reply, I'm off, cya and good luck.

[700NitroXpress]

Well, couldn't higher gravity be simulated with extra payload weight, and thicker atmosphere be simulated with parachutes deployed at launch to create drag up to a certain altitude?

[Monkeh]

If you're very good at maths and fancy sitting down and solving equations, I suppose yeah...

Easier to either use hyperedit and just shove the craft onto Eve or use the Engineer redux when building and set it to give you a readout for Eve.

I believe you need from 7,000 to 11,000 delta v to escape, depending on height above 'sea' level of the starting point.

[700NitroXpress]

I believe you need from 7,000 to 11,000 delta v to escape, depending on height above 'sea' level of the starting point.

Starting height is roughly 800 meters above sea level.

[Monkeh]

Then you'll need many and more delta v to escape, around 11,000 m/s iirc.

[numerobis]

Well, couldn't higher gravity be simulated with extra payload weight, and thicker atmosphere be simulated with parachutes deployed at launch to create drag up to a certain altitude?

At that point, why not just do the math on paper?

[700NitroXpress]

At that point, why not just do the math on paper?

I want a way to simulate it without math.

[Xetalim]

Use hyperedit to make kerbins gravity and atmosphere the same as eve.

[700NitroXpress]

Use hyperedit to make kerbins gravity and atmosphere the same as eve.

What's hyperedit and how do I do this?

[ddenis]

The best way to simulate it is simulating it within the game which simulate it by sending your craft to eve via HyperEdit. Because... really - this game is simulating "real" world, you can use it to simulate things in simulated "real" world.

[ddenis]

HyperEdit (http://www.kerbaltekaerospace.com) - it's plugin which allows you to move your craft into orbit in a second and then move it from orbit of Kerbin to orbit of Eve.

http://youtu.be/XDvedL-oo4I -Video tutorial

Edited December 10, 2013 by ddenis

[Excalibur]

I tried doing this with .cfg-modded parts when Eve first came on the scene. I changed the drag of each part to 5 times normal, and mass by 1.7 times to account for the different atmospheric density and gravity respectively. The idea was then to launch the test flight from KSC.

However I soon learned that physics doesn't work like that. Put as simply as possible, by increasing the mass by 1.7 times I also increased inertia by the same factor IIRC. This would not simulate Eve ascent properly, as the 'Eve Simulation Parts' would have greater mass than the actual rocket (and thus a much lower delta-v budget). Increasing drag by a factor of 5 was also fruitless, as Eve's atmosphere is larger than Kerbin's anyway.

So unfortunately I can't give you the answer you're after, but I can add something that doesn't work.

EDIT: As others say, HyperEdit is probably the easiest way for you to do this. Then just use trial and error. KER is also an invaluable tool.

[celem]

Hyperedit is pretty much the only simple way to do this.

I did use extraplanetary launchpads tweaked to not need resources for a bit to give me a 'VAB' on eve for some tests. But I had to send the damn launchpad there anyway...

Just hyperedit it.

[700NitroXpress]

Alright, thanks for the hyper edit info guys.

Also, If I put a craft into a circular orbit of Kerban going 2200 m/s and then go through all of the stages, it goes from 2200 m/s to 13200 m/s, so isn't that 11000 m/s delta V? Good enough for sea level of Eve?

[celem]

Not really. Since that craft would be gaining its 11kms dV from an orbit. So all engines running in vacuum, the isp values for atmosphere are lower and therefore more fuel to get the same dV. Plus from orbit gravity and drag are not fighting you, you even get oberth effect to boost you.

a vessel capable of 11kms dV in space wouldnt be nearly enough

[numerobis]

Atmo Isp will be lower, but 11 km/s is a good start; fair chance it's enough. You've actually got a bit more than 11 km/s vacuum if you can speed up by 11 km/s, because contra celem, gravity does fight you as soon as prograde points above the horizon.

Make sure your TWR is high enough. I don't know how you would test that without using the dreaded mathematics though.

[phunk]

Use hyperedit to make kerbins gravity and atmosphere the same as eve.

But it doesn't change kerbin's radius, so I don't think it's an accurate simulation.

[celem]

gravity does fight you as soon as prograde points above the horizon.

perhaps its the way this game models manouever nodes or something. But i always forget we dont insta-accelerate, he's quite right, you are climbing up the gravity well anyway the moment you pass periaps

[Stochasty]

Eve ascent takes between two and three times the delta-v that Kerbin ascent requires, and Eve has 1.7 times the gravity as well. So, in the spirit of making a test that is too hard (ie., over engineering), try the following: build a craft that is capable of taking off from Kerbin, reaching orbit, and then landing three times while never using more than 60% throttle.

This isn't by any means a perfect test, but it will give you an idea of the requirements without the need to edit your .cfg files.