(EVE) Vangelist II Science Mission - Manned EVE return: A Beginner's Debriefing

[wild_quinine]

So I set myself a mission in KSP. Not one of these crazy challenges you see, I'm no expert. Heck, before this all began I was little more a beginner. I'm still a beginner, except that I feel like getting to EVE and back with a ship I built myself is kind of a badge of honour...

But ultimately I'm here to share an experience not pretend I know what I'm talking about.

So. First things first, I might not have gone nuts, but I made life hard for myself. I decided right from the off that I wasn't going to build a lander that was basically a chair with 10k delta V stuck on the back of it, like this guy did:

I was going to:

a) Send down a Kerbal in an enclosed command module and

get him home in a single launch - no rescue missions and

c) conduct every science experiment on the surface of EVE and

d) fly the whole mission in stock 0.23.5

but I did allow myself some compromises:

i) I didn't feel the need to build the craft in stock. Getting a report on deltaV from MechJeb or Engineer didn't feel like cheating to me.

ii) I could fly the mission with MechJeb (if I thought that would help) to see if it was possible with a given craft, but I'd still have to fly it solo before I could call it a successful mission

iii) I could fly other peoples crafts, and 'borrow' good ideas where necessary, but my own ship had to be built by hand, by me, from scratch.

As it happens, this third one wasn't such a problem. Building a lander with a science module and a goo chamber didn't seem to figure highly on other people's priorities, so I had to go my own way to some degree, but in the end, I borrowed ideas pretty heavily from the EVE Comet mission:

http://forum.kerbalspaceprogram.com/threads/78852-Want-to-go-to-Eve-and-back-Try-this

Ideas I particularly took away with me from the EVE comet:

1) using aircraft wheels as landing gear, because of higher impact tolerance/better stability.

2) using parachute stacks, to make ditching them easier

3) using 48-7S to increase efficiency on the final tank of the lander

(By the way, if you're just looking for a craft to use, the EVE Comet is a better craft than mine. But here is the Vangelist II .craft file, for the curious: http://s000.tinyupload.com/index.php?file_id=45390559062659057832)

So. A science mission. What I discovered, of course, is that by the time most people can get to EVE and back science isn't that much of a problem for them. But I devised this challenge off the back of my first successful return (with a rescue!) fom Duna, so I was still thinking the science would be nice... I was wrong.

In fact, I had to run a few caravan missions to different biomes on the Mun and farm science just to earn the parts I'd need to pull this mission off.

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Anyway, once the gauntlet had been thrown down, I wanted to stick to my original goals, so it was a science mission regardless.

I went through *so* many iterations of different crafts. I think this is the learning curve everyone goes through - the landers just got too big. And then they got rickety. And then you needed more parts to hold them together, and more parts to add delta V, and the returns just start

dropping off really fast. And all that bloat has a significant and increasing knock-on effect on the next stage, and the next stage, so so on. And even when you think you might finally have got a solid lander, you realise that you just can't build something that will put the bugger into orbit.

And so sooner or later, you go back to the drawing board and try to do it better.

I toyed with doing multiple launches and docking landers to transfer stages in LKO, but that is a whole new kettle of fish. I learned a lot about what's involved with that, but the main thing I learned was that I didn't want to do it. Docking 2000 tonnes of bloated ship is a lot less satisfying than designing a better ship, and the damn thing's going to fall apart in transit if you don't know what you're doing.

So I redesigned again and again, and in the end I got my lander down to around 220 tonnes. And this was a decentish lander, and I flew the mission. And this is where I learned about the importance of sensible 'Thrust to Weight' ratios. So that was another Kerbal who was not going to see the rec rooms at the KSC again.

So I went back and I started again on the lander.

One time I thought I had it, but I was scuppered by a fuel lines bug that distributed the fuel unevenly and led to a lean (and eventually a crash). If it had worked, it would have been even better than my final design. But it didn't, so I needed to go back to the old drawing board.

(Tip: don't go from multiple tanks, to one tank, back out to multiple tanks again. Things can get confused).

So anyway, eventually I had something at 234 tonnes, with 10.4K delta V (9.8K Eve Atmospheric), and TWR of between 1.5 and 2+ at all the lower stages and I just *knew* that I had something that would work, although the altitudes were going to need to be a ways above sea level. But that was good enough for me.

Here are the stats on the lander: http://i.imgur.com/mmu20iV.jpg

Here's the top part of the lander: http://i.imgur.com/MRNvZTA.jpg

Note that all of the science modules will be detached after their data has been gathered, leaving an intact docking port beneath. Note also the inverted ladder, which allows our brave pilot to climb up to the level of the science modules and gather their data, before ejecting the modules.

Here's the composition of the ship: http://i.imgur.com/iMjbWwv.jpg

Now, it's not a perfect ship. An earlier version launched more easily. I needed to make some tweaks, to correct for a poorly placed decoupler, and now it's a bit more lairy. You'll fight it a bit in the first stage, and you'll use a tiny bit of dV from the transfer stage to complete the orbit if you waste too much dV on the way up. But there's a decent-ish margin in the transfer stage.

So how did it work?

Well, it went pretty OK on my MechJeb dry run. Running the mission without MechJeb, the hardest thing was ensuring a landing at a decent altitude.

Turns out my lander is good from about 4000m. If I were going in for this again, and didn't want to challenge myself to build a sea-level lander, I'd defintely try to go for something more in the region of 1.5k to 2k capable, because although there are places on EVE right up to 7000m, spots above 3K are relatively rare. And the problem with landing on peaks is that, being what they are, they're rarely flat, and don't even get me started on the trouble of landing 234 tonnes on a hill.

What you want to do to land high on EVE is find a nicely dark bit of the planet, and arrange your orbital inclination so that you're travelling over it for the longest time.

Take a look at this shot: http://i.imgur.com/SD9MJ4G.jpg

See how the orbital path follows the longest line through a darker coloured mountain range. That's where I think the skill in landing on higher ground. (The luck part is finding somewhere that's flat, because there's little or no chance to correct once you're inside the atmosphere).

So it all came together, and I brought it home in the end, so now I can honestly say that I've joined the ranks of the EVE returners.

Here's an album of shots from the mission

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Here's a satisfying clip of my ship on EVE's surface, blowing the parachute stacks and then the science equipment to save weight on the return journey.

http://youtu.be/MWhJ4eZYnRw

Here's a blooper shot of an earlier launch that... well, someone pressed the wrong button.

And here's Mr. Kerman realising he is the first kerbal on EVE with enough dV to go home.

Edited May 30, 2014 by Specialist290
Fixing some embedding code...

[Specialist290]

Welcome to the forums, and impressive work! A successful manned return from Eve is one of the most difficult missions a player can accomplish. That's quite a way to make a splash on the forums!

For the record, you can embed Imgur albums into forum posts by taking the album identifier found in the URL (using one of your own, for example):

http://imgur.com/a/aeIjd#0

And putting it in tags like so, minus the asterisks:

[*imgur]aeIjd[*/imgur]

Which should give you:

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EDIT: And I've gone ahead and fixed them in your post for you. Thought you might appreciate the knowledge for the future, though.

Edited May 30, 2014 by Specialist290

[wild_quinine]

A successful manned return from Eve is one of the most difficult missions a player can accomplish.

I sure hope so! Half the motivation behind posting was because I spent so much time figuring this out that I had to tell someone. I hope it's of interest for other players attempting the same, although a good portion of it may be examples of what not to do. I enjoyed reading reports by others while I was attempting the mission, and thought it would be worth doing the same when I got there, too.

(PS. Thanks for fixing the errors in my post.)