Returning from EVE, any tips?

[maculator]

I've gotten this far:
Hyperedited my concept lander on the surface of eve and launched:
http://steamcommunity.com/sharedfiles/filedetails/?id=1312195708
INTO ORBIT:
http://steamcommunity.com/sharedfiles/filedetails/?id=1312195820
The odd thing however is that it took like half the DeltaV I thought it would
http://steamcommunity.com/sharedfiles/filedetails/?id=1312196001
So I can downscale by baby and make it a bit easier to haul to eave in my actual career game.

[maculator]

Normally I would've started the photo series with the thing landed, but steam wont upload that screenshot so Ill try again later..

[maculator]

There it is in the VAB:
http://steamcommunity.com/sharedfiles/filedetails/?id=1312209045

Ill ditch the upper stage, tranform the "second" one into aspargus, put it in a fairing, pump the fuel out and drop it on eve. How hard can it be?

This should give me a payload of 8t to a secure 120+km eve-orbit.

[RoofCat]

Originally posted by maculator:

There it is in the VAB:
http://steamcommunity.com/sharedfiles/filedetails/?id=1312209045

Ill ditch the upper stage, tranform the "second" one into aspargus, put it in a fairing, pump the fuel out and drop it on eve. How hard can it be?

This should give me a payload of 8t to a secure 120+km eve-orbit.

I would add size adapter there in the middle. That upper end of central jumbo tank has quite some drag launching in Eve atmosphere. Plus 0.1t shouldn't kill your business. Other than that it looks fine. The actual setup is less important as long as you use the right engines.

If you want to dig deeper, first stage needs a bit less fuel compared to next ones due to low kN below 5km on Eve. It just helps to lift off at all and reach those 5+km and then it is gone once you reach full ASL power. You don't need too much acceleration on Eve, as the start has some limits - first around 100m/s, then closer to 170m/s, etc. That 5 atm thick soup doesn't like speeding at all.
But in the end it is just slightly finetuning asparagus you already use.
Then you can improve performance a bit by using 2.5m-1.25m size adapters plus sharp nose cones above Jumbo tanks. Regular 2.5m nose cones aren't best. Pricier that way, but less mass and great aerodynamics.
Also why don't you do it manned with MK1 pod right away? Should work just fine. Seat is for female kittens

But in the end - if it works on Eve, I'm perfectly fine with all that. Eve is hard enough for everybody.

[maculator]

Well this is my barebone. I threw it together and thanks to hyper edit I was able to test it now I'll fine tune it. Less fuel would do, but it would also mean I should use smaller tanks, and that would mean more tanks.... Thanks to HE I could avoid the craken while testing, I won't be able to avoid it in my career game! As few parts as possible is what I aim for here.

But to that sizeadapter thing:
That really matters? I thought it is blocked by the next stage so I don't need to pay attention.
Well I'll put a fairing on that tank anyways but I'd like to know how such stuff affects me.

[RoofCat]

This was my lander. Quite similar initial setup, just a bit less. And I used mining on Eve to be able to fly both ways with it just adding some Kickbacks for Kerbin launch. Kerbin launch price is slightly above 300k iirc. ISRU is left on Eve of course.
http://steamcommunity.com/sharedfiles/filedetails/?id=863867824
This one reaches Eve orbit with last fuel in Skipper stage. Upper stage is for return or whatever. Considering 3700m/s on Terrier you can replace half of that tank with crew cabin, send 3 astronauts instead at once and still return to Kerbin safely. Also just 2 inflatable shields on top or even one with proper balance should be enough. Whatever, it was made this way with 3. Faster slowdown.
Why Skipper in the middle? Mostly for the size and sturdiness reasons. Vectors are fine for all stages, but it would wobble above the large ISRU in my case.


regarding noses:
- send two Jumbo tanks with Skipper or whatever straight up on Kerbin and compare?
There is heat shadow in KSP, but not really drag shadow. You have to connect inline and use adapters to avoid "ladder" drag.

[maculator]

^I'll concider this while tweaking my EVE_Escape.

Thats the nicely packed version:
http://steamcommunity.com/sharedfiles/filedetails/?id=1312294730
Stil room for improvements since I got 4000+m/s left in eves orbit. Gotta strip it a bit more.
http://steamcommunity.com/sharedfiles/filedetails/?id=1312294610
But it flys perfectly and absolutly stable and really easy to handle.

[maculator]

Oh and landing it is a job for future me....

[RoofCat]

Originally posted by maculator:

^I'll concider this while tweaking my EVE_Escape.

Thats the nicely packed version:
http://steamcommunity.com/sharedfiles/filedetails/?id=1312294730

What's the mass of that fairing?

[maculator]

I'll look it up when I start KSP later. But it really helps, I'm wasting less fuel and the thing is as stable as it can be. But now I'm starting to think about landing it and maybe I'll have some issues^^

[RoofCat]

I'm just curious. I have mediocre experience with fairings. And you should be careful with active torque within them and a few more things. Sometimes people complain about exploding bugs.

your example with central 1.25m profile and 6 around it:
Fairing radius 1.25+0.5*1.25=1.875m
Front area 1.875² x 3.14159=11.044m² (actually more because you are not allowed to touch parts with fairing)

while 7 separate 1.25m profiles would have 0.625² x 3.14159 x 7 = 8.59m² front area or ~27% less drag. Fairings cover not just parts, but also a lot of useless space in between.

Now mass for the same. Let's say you replace it by 7 sharp nose cones. Because you can't leave them flat of course. That would make it too easy for fairing to win.
7 x 0.075 = 0.525t
Considering the length, chances are high your fairing weights more than that.

Of course, it is a bit more complicated than that due to upper/lower stage, payload proportions in space travel. When you get rid of what.
In best cases I have seen fairings are really close to good non fairing solutions, probably a little bit better occasionally. In the rest it is rather worse. Another reason for that is fairing does increase drag area faster than it increases mass, thus reducing density. Considering most fairings are on top, you need more wings on bottom to keep it stable eventually. Having fairing is often like having an air baloon on top of your rocket in KSP.

Works nice in real world where every part is adjusted to the size and packed tight, but not so great in default part KSP.

[Roasty my Toasty]

Originally posted by RoofCat:

I'm just curious. I have mediocre experience with fairings. And you should be careful with active torque within them and a few more things. Sometimes people complain about exploding bugs.

your example with central 1.25m profile and 6 around it:
Fairing radius 1.25+0.5*1.25=1.875m
Front area 1.875² x 3.14159=11.044m² (actually more because you are not allowed to touch parts with fairing)

while 7 separate 1.25m profiles would have 0.625² x 3.14159 x 7 = 8.59m² front area or ~27% less drag. Fairings cover not just parts, but also a lot of useless space in between.

Now mass for the same. Let's say you replace it by 7 sharp nose cones. Because you can't leave them flat of course. That would make it too easy for fairing to win.
7 x 0.075 = 0.525t
Considering the length, chances are high your fairing weights more than that.

Of course, it is a bit more complicated than that due to upper/lower stage, payload proportions in space travel. When you get rid of what.
In best cases I have seen fairings are really close to good non fairing solutions, probably a little bit better occasionally. In the rest it is rather worse. Another reason for that is fairing does increase drag area faster than it increases mass, thus reducing density. Considering most fairings are on top, you need more wings on bottom to keep it stable eventually. Having fairing is often like having an air baloon on top of your rocket in KSP.

Works nice in real world where every part is adjusted to the size and packed tight, but not so great in default part KSP.

So 9/10 times, fairings are actually just harmful to your craft?

[RoofCat]

Originally posted by Roasty my Toasty:

So 9/10 times, fairings are actually just harmful to your craft?

I would say more often than not - in KSP. But it really depends on person designing them. If you check fairing mass and don't cover triangle with a huge circle, they may work fine occasionally.

If they are heavy and huge with a lot of empty space inside and you also have to add a lot of extra fins not needed otherwise to the bottom to avoid flipping, then you are rather better off without fairing. Also depends how horrible do you design your landers. Terrible fairing on terrible lander may still be better than terrible lander sent naked :D