eve

[Cannon]

I'm building a ship that is capable of landing on eve and returning crew safely to the kerbin (no randezvous, cheats or mods).

I need your help guys, how would you make it?

Which engines and fuel tanks would you put on lander (consider that lander will have to get back to kerbin!)

Share your thoughts, let's build this thing

[EdFred]

Here's three different Eve ships I've made (they have the MJ module on them) if you d/l the craft file at the end.

EveGigantus - 2 Man lander can to Eve Sea Level

EveCake - Single Man lander can to Eve Sea Level

EveChallenge - my first Eve sea level and back craft.

(I'm currently rebooting the mail/web server, so they may be temporarily unavailable)

Edited October 13, 2014 by EdFred

[Taki117]

IF you are trying to get back to Kerbin from Eve you're going to need a ship that is twice as large as it needs to be. I suggest getting better at at lease rendezvous, if not docking.

[Laie]

Basic requirements:

when launching from sea level and maintaining an Eve TWR of 2 (that is, staying close to terminal velocity) you'll be running at atmospheric ISP for more than two minutes. After another minute, the atmosphere will have become thin enough that TWR2 can no longer keep up with terminal velocity. At that point, you still need about 4000m/s at an Eve-TWR of 1 or better.

You can possibly test your vessel on Kerbin, if the design allows you to put on launch clamps and keep them locked while you run through the first few stages. Use Mechjeb to limit the acceleration to 34m/s². Release the clamps after about 140 seconds, start a gravity turn right from the ground, and keep going at 34m/s² for 70 seconds. Now check you delta-V map. If you have 4000m/s left, your vessel will do.

On Kerbin, one can get away with a relatively low TWR on the last leg of the ascent: TWR 0.3 is possible, 0.7 is painless. Eve is a much deeper gravity well, you want TWR>=1 all the way to the top. Less is doable, but can be quite difficult -- and frankly, the Rockomax 48-7s is your friend. Just slap on a few more of them.

Terminal velocity on Eve is like 60m/s at sea level, 80m/s at 5km. On my ascent from <100m, getting to 4000m required about one minute and more than half of my fuel. Landing on and taking off from higher ground makes a huge difference.

EDIT TO ADD: you lander does not need to return to Kerbin under it's own power. Only land the fuel and engines you need for the ascent, anything else should stay in Eve orbit. See this for an example.

Edited October 13, 2014 by Laie

[Sirrobert]

So you want to lift the fuel you need to get from Eve to Kerbin FROM Eve itself...

Good luck

[juanml82]

You'll be a lot of time in Eve's thick atmosphere so I'd recommend aspargused aerospikes and 48-7s for the upper stage. Another idea is to use girders to mount the aerospikes radially instead of at the bottom of the fuel tanks: Eve's gravity will cause the landing legs to lower a lot when you touch down and that can destroy bottom mounted engines.

[Cannon]

Thanks everyone, I'd love to create a ship that can do it without leaving anything in orbit and docking, but if it turns out to be impossible (which i guess it probably will) then i guess I'll do it other way

[Red Iron Crown]

Thanks everyone, I'd love to create a ship that can do it without leaving anything in orbit and docking, but if it turns out to be impossible (which i guess it probably will) then i guess I'll do it other way

It's not impossible, just more difficult. Very roughly, every ton of mass in orbit means about 150 tons of rocket at sea level. Make your return stage as small and light as possible; a lander can with a small parachute, 200 unit tank, 48-7S and some OX-STAT panels will get you home for not too much mass.

Are you using a delta-V calculator like MechJeb or Kerbal Engineer? It's possible to make an Eve ascent vehicle without one but it is either very, very difficult (doing it via trial and error) or very, very tedious (calculating by hand).

[StrandedonEarth]

Eve is hard enough without lifting the fuel to return to Kerbin from the surface. You need to lift as little as possible to maximise your chance of making orbit, never mind getting home. I did one manned Eve return mission, and I "cheated" by riding a lawn chair, er, external command seat to orbit and spacewalking to the interplanetary habitat. I had all my landing gear, science experiments, and chutes mounted on trusses that I ejected before liftoff.

Here it is on the pad for a kerbinside test. Note that you need a lot more struts on Eve than on kerbin or the "snap" when they open in Eve's soup will rip them off, even just the drogues)

.

[Zylark]

Eve is an ambitious target that needs a lot of work to get done. Not visited Eve since .23.5, but I don't think much have changed. I required three big launches to get all the gear into orbit.

Launch 1: Sending up the Eve Lander under its' own power

Launch 2: Sending up the Eve Transfer stage

Launch 3: Sending up the Eve Return vehicle with a small lander to visit Gilly

Then docked the Lander and Transfer vehicles together. Fueled up the return vehicle and sent that off to Eve. Then followed a lot of fueling missions to get the Lander and Transfer vehicles filled up. Had in that save a couple of refueling stations and a Kethane operation going on the Mun, so it required no extra launches.

A few pictures:

Arrived at Eve, ready for landing.

Down safe, not a drop of fuel spent on the lander itself, as the Transfer Vehicle had a small stage I used to do the insertion burn.

What remained once back up in orbit again...

---

Doing such a project in career mode now that it cost a barrel-load of funds on stages you can't recover is a bit more than I'm willing to do quite yet. Maybe later once I got funds to spare. For now I'll settle for a simple tiny unmanned lander. Much simpler, and at only a fraction of the cost.

[Laie]

Doing such a project in career mode now that it cost a barrel-load of funds on stages you can't recover is a bit more than I'm willing to do quite yet. Maybe later once I got funds to spare. For now I'll settle for a simple tiny unmanned lander. Much simpler, and at only a fraction of the cost.

My huge, four-person mission cost on the order of 1.5 million. I left the mission on the ground until the return launch window came up. In the mean time, each flag I planted was worth 280k.

Other than that, *landing* stuff on Eve is cheap. I suggest to bring a rover or (if you have the mods to make it happen) a plane or dirigible. Eve actually is a beautiful place and well worth exploring.

[DrMonte]

My signature says it all.

[Cannon]

My signature says it all.

nice one xd

[GoSlash27]

Cannon,

Eve's challenges are, in order:

1) Atmospheric DV

2) T/W in the 2:1 region

and

3) stability as a lander

Shooting for high cumulative DV is a matter of small payload, appropriate engines, and lots of efficient staging.

Getting the t/w necessarily impacts how much engine/fuel you will use.

Stability as a lander requires a shorter and wider vehicle than you would normally use on Kerbin.

My designs all start with the payload to orbit and work their way backward through the launch profile and this one is no different. Bare-bones mk 1 lander can with FL-t200 tank and Rockomax 24-7S.

Around that is an asparagus arrangement of the same; FL-T200 and 24-7S.

Layer-caked below these is an asparagus arrangement of X200-8 tanks with Aerospike engines.

^ Illustration of the basic concept during field trials on Kerbin.

My Eve strategy involves not only rendezvous in Eve orbit, but also on the surface. I personally wouldn't bother making it any more difficult than it has to be, and the "one big rocket" concept is not something I'd be keen to pursue.

I understand that you're not interested in rendezvous, so your design will necessary lift a whole lot more payload than this. Nevertheless, the same design principles hold. The further up the stack, the more critical it is to keep mass to a minimum. Lots of staging and make sure you're using the right engines for the job to maximize mass efficiency and Isp while still generating adequate thrust. And finally, make sure it won't tip over or break on landing.

Good luck!

Best,

-Slashy

Edited October 14, 2014 by GoSlash27

[Oafman]

A successful launch from Eve is the hardest thing you can do in stock KSP. Combining sufficient thrust with sufficient deltav - through Eve's soupy atmosphere - is very tough.

But it's achievable, with enough thought and planning, and enough help from people here, so I certainly would not want to discourage you.

Also, there are things about Eve that work in your favour. It's easy to get to, because it's not far from Kerbin's orbit, and because it's a big target. And its thick atmosphere - such a problem when you try to launch through it - is very helpful for slowing down on arrival, and for getting your ship down to the surface without using much fuel.

A couple of tips:

1) Aim for high ground. If you start a few km above sea level, you'll find the ascent is much much easier, because there's so much less atmosphere to fight your way through. Use the map on Eve's wiki page to find a mountainous area to land on.

2) as others have said, use a mod to help you build. Kerbal Engineer and Mechjeb both give you TWR and deltaV stats - specifically for Eve - in the VAB. So you can build a launcher without having to do trial and error testing.

Good luck, and keep us informed

[Cannon]

A successful launch from Eve is the hardest thing you can do in stock KSP. Combining sufficient thrust with sufficient deltav - through Eve's soupy atmosphere - is very tough.

But it's achievable, with enough thought and planning, and enough help from people here, so I certainly would not want to discourage you.

Also, there are things about Eve that work in your favour. It's easy to get to, because it's not far from Kerbin's orbit, and because it's a big target. And its thick atmosphere - such a problem when you try to launch through it - is very helpful for slowing down on arrival, and for getting your ship down to the surface without using much fuel.

A couple of tips:

1) Aim for high ground. If you start a few km above sea level, you'll find the ascent is much much easier, because there's so much less atmosphere to fight your way through. Use the map on Eve's wiki page to find a mountainous area to land on.

2) as others have said, use a mod to help you build. Kerbal Engineer and Mechjeb both give you TWR and deltaV stats - specifically for Eve - in the VAB. So you can build a launcher without having to do trial and error testing.

Good luck, and keep us informed

Thanks dude, gonna let you guys know what's happening.

I'm kinda busy right now, but I'll continue my development as soon as possible