Lightest Eve Lander

[GeorgeG]

Generally the challenge writer is the arbiter of what is acceptable and what isn't, disqualifying those that break the spirit of the challenge. Since we don't have much feedback on that, nor a scoreboard, what can we do? Personally, I've enjoyed seeing the creative and innovative flyweight designs posted in this challenge, but you're right that some of them don't follow the letter of the submission requirements.

Well, I had just tweaked and flown mine, and was about to post it, when I got called out for my last one being under 8700. It was not the OP who said so, but that comment instantly killed my interest in continuing. Because I really have no interest in building a rocket that has way more D-V than it needs, due to an arbitrarily bad decision that the OP made.

And then yet some say it does not matter .... but it has to, one way or another.

Because it's a challenge thread, and not a "demonstrate how lightly you can build an Eve Lander" general thread where documenting things is of no importance.

And the OP has not been maintaining this challenge. I see he's made several posts elsewhere, so he's around, just not doing it here. I hope the moderators take note of people who do not maintain their challenges.... when it comes to the same people posting any future challenges.

Edited May 7, 2014 by GeorgeG

[Red Iron Crown]

And the OP has not been maintaining this challenge.

That's the root of the problem there, I think. Which is too bad, because it is an interesting challenge that has drawn a good variety of entries.

[Redshift OTF]

Is it too late to make an entry?

Yeah, it doesn't win the contest for the lightest design, (although it is close), but I think it is the most compact design I have seen. I used almost this same thing as the core for my full Eve lander so I think it is a good design.

Edited May 7, 2014 by Redshift OTF

[RocketBlam]

I'm around, I've been waiting for some of the entries so I could check them out.

The space plane entry particularly is causing me some consternation. It uses control surfaces, and some unusual usage of SAS modules, which concerns me as far as the rules go. I didn't specify that control surfaces were prohibited, but they can be exploited.

Of more concern is the novel placement of the SAS modules.

The craft files that I cannot load to check out are from:

GeorgeG (all three)

Metaphor

Nedal

sdj64

bhauth: Your craft appears to exploit the infiniglide bug - 30 control surfaces in one axis alone. I'm not going to forbid all control surfaces, but this one seems to exploit a bug. I've edited the original posting to clarify.

Tavert: Great design, but when I view it (with the detachable chutes removed) your D/V is a tad too low. You can fix this if you like, even if you add a little more fuel you're still really light.

Please resubmit these using only MechJeb or Kerbal Engineer add-ons, from version .23.5.

Sorry for my tardiness in this update!

Edited May 8, 2014 by RocketBlam

[RocketBlam]

I can't load many of these files. When I put some in my /VAB or /SPH folder, the game won't load any saves. If I remove them, it will load saves normally. Anyone seen this or had this problem? They may be from .23, that may be the problem.

Edited May 8, 2014 by RocketBlam

[RocketBlam]

A couple of clarifications:

1. I originally intended for the 8700 D/V to be the atmospheric value. However, since I didn't specify it, and there have been several submissions meeting only 8700 D/V in vacuum, I have edited the challenge to clarify that it can be 8700 D/V vacuum.

2. I chose to include a D/V requirement to make confirmation possible. It may be possible to fly some craft from some point on Eve into orbit with less D/V, but I frankly don't have time to test all of them in flight, and I may not be able to get it to orbit, while someone else (a better pilot, that is) might. It just makes it too difficult to confirm. So that is why the 8700 D/V requirement is there.

[tavert]

Tavert: Great design, but when I view it (with the detachable chutes removed) your D/V is a tad too low. You can fix this if you like, even if you add a little more fuel you're still really light.

I'm not really playing lately so I'm not sure whether or not this is still the case, but last I checked you can't trust the dV numbers from MJ or KER in the VAB, you have to go into the flight scene from them to properly take into account massless parts. In the VAB MJ will (or used to?) think that the aircraft landing gear are 0.5 tons a piece, but in flight they have no mass. Using them instead of landing legs is considered a little bit exploitative by some people for this reason, but it would be a very minor change to just use conventional legs on decouplers and the ascent vehicle would perform the same.

[Red Iron Crown]

^^ The latest version of KER handles massless parts appropriately, not sure about MJ's calculator.

[bhauth]

Eh, my spaceplane might be able to infiniglide, but I didn't. The deluxe winglets have more lift per mass than swept wings, and you can stack them closer, and you do need some control surfaces, but most importantly, without using them it would look less "Kerbal".

I'm curious if anyone else managed to get metaphor's ion glider craft to orbit.

[metaphor]

Eh, my spaceplane might be able to infiniglide, but I didn't. The deluxe winglets have more lift per mass than swept wings, and you can stack them closer, and you do need some control surfaces, but most importantly, without using them it would look less "Kerbal".

I'm curious if anyone else managed to get metaphor's ion glider craft to orbit.

It took me many tries to do that. Things like physical time warp and the angle of attack seem to make a big difference. It's more of a proof of concept that it's possible. I'm horrible at building spaceplanes so that is definitely not the best design possible. I was hoping other people with more plane experience would try to make something like it but more efficient.

[Galane]

These are all very interesting designs. Good to see all stock parts Eve landers that work.

For my Eve lander I've exploited the power of lighter than air flight (four large Hooligan Labs lift bags) to get up to 25KM before lighting the engines. Works from any starting ground altitude. Making it extra difficult I set out to make a lander that could bring a 2 man lander can back to orbit. I also have rovers to mine, refine and refuel the lander because it starts its landing with less than 50% fuel load. Not for weight savings, it can land starting with a full load, but to save fuel in the transfer stage because it'll have to go out to Gilly to top off for the trip back to Kerbin.

Just need to get my quad core AMD Phenom II system put together to be able to handle the parts monster ship for the "real" trip out to Eve. 2.5 Ghz dual core AMD 7550 is surprisingly laggy with KSP once the parts count gets up there.

[MrOnak]

*knock* *knock* Sorry for interrupting...

You guys are clearly the right people to ask. The Wiki lists 11,500 m/s delta V required to get into orbit from Eve. This challenge requires a minimum of 8700 m/s for a craft to be valid but if I read some posts here correctly, less seems possible?

Reason I'm asking is cause I have a stranded Kerbal on Eve which I'd very much like to bring home, trying to figure out the Eve ascend stage at the moment. Without cutting it razor thin (no "lightest Eve Lander" required, just getting the boy home), what dV would you aim for to get a single Kerbal back into orbit? There'll be a return vehicle in orbit ready to get him back to Kerbin.

Thanks a lot

[Nedal]

*knock* *knock* Sorry for interrupting...

You guys are clearly the right people to ask. The Wiki lists 11,500 m/s delta V required to get into orbit from Eve. This challenge requires a minimum of 8700 m/s for a craft to be valid but if I read some posts here correctly, less seems possible?

Reason I'm asking is cause I have a stranded Kerbal on Eve which I'd very much like to bring home, trying to figure out the Eve ascend stage at the moment. Without cutting it razor thin (no "lightest Eve Lander" required, just getting the boy home), what dV would you aim for to get a single Kerbal back into orbit? There'll be a return vehicle in orbit ready to get him back to Kerbin.

Thanks a lot

The higher the elevation you take off from the easier it is. My first successful eve ascent was rescuing two kerbals and the transport pilot I sent with a plane to transport the stranded ones to the launch vehicle, so 4 kerbals total. Was a pretty big challenge, and there was much lag launched from like 1400m elevation. But to answer your question. Shoot for 12000m/s or more dv, and try to hit a higher than sea level landing spot.

[MrOnak]

Yikes Thanks for the quick answer.

[Nedal]

Yikes Thanks for the quick answer.

Np. Also note that the dv isn't really the hard part. It's getting that much dv with the required twr.

[Nao]

@MrOnak the 11500m/s (or 12000m/s) is from the Eve sea level. If your guy is on higher area, the mission could require less deltaV. Speaking very roughly, you could assume 45m/s of Dv per 100m of takeoff altitude. So if the kerbal is sitting on a 3000m elevation, it will take ~1350m/s less than launching from sea level (a little above 10000m/s)

But as Nedal mentions, TWR is the key! These deltaV numbers assumes ascent at a speed close to terminal velocity (which is painfully slow in low Eve atmosphere). The required Eve TWR of ~1.8-2.0 is almost 34m/s^2 of acceleration, without it the delta V requirement will be bigger.

[MrOnak]

Yeah I noticed that. Had a few tries building something in the VAB but all designs turned out to be quite monstrous OR not having a suitable TWR. Anyway I don't want to hijack the challenge thread, thanks for confirming the dV I'll figure out a craft eventually.

[KandoKris]

Wow you all astound me with your brilliance. So many creative ways to get off eve. It is certainly encouraging to see such variety.

I'm trying to build a 3 man return pod for changing over base crew & this thread has been hands down the best resource on the net I've found. (better then Manley’s vid even)

So Thankyou all you great KSP engineers

[BMBender]

The Eve Viral lander

34.47 Launch wegith 7,438 atmo dV 8,678 Vac dV. no where near the lightest. But aesthetically, I make this look good.

Javascript is disabled. View full album

http://www./view/9ca74mtirixyprs/ET.craft

It sucks though couldn't get the look I wanted under 30ish tons the <20t one just didn't have the dV while still look

http://cloud-3.steampowered.com/ugc/486698014785891327/634BA2F1526BC374A22C504EF47038746872E4EE/

Edited May 24, 2014 by BMBender

[Blind Dead McJones]

I haven't gone to Eve yet, but I had an idea involving the electric propellers in Kerbal Aircraft Expansion. Basically, a plane with those, lots of solar panels, and a conventional rocket. Use the propellers to get as high as possible and then fire the rocket to achieve orbit.

[rtxoff]

I haven't gone to Eve yet, but I had an idea involving the electric propellers in Kerbal Aircraft Expansion. Basically, a plane with those, lots of solar panels, and a conventional rocket. Use the propellers to get as high as possible and then fire the rocket to achieve orbit.

This challenge here requires not to use mod's, you can do it however for fun

[GoSlash27]

Eve seems to be the big challenge to crack, but I think I've made a breakthrough today.

It's not just designing a booster to get off Eve, but also one that can be lifted from Kerbin and be deposited on the surface of Eve. I *think* I can do all that with 52t total if I sort out a couple engineering wrinkles. 8,960 delta V atmospheric with at least 1.1G (eve) throughout the launch.

It'll take a lot of testing before I'm comfortable risking a little green butt in it, so it'll be a while before I submit my entry.

Wish me luck...

-Slashy

[KNSA Scientist]

Have you guys ever thought of removing the monopropellant from the crew capsule? It would reduce the weight by a little I imagine...

[GoSlash27]

I went through an entire dress rehearsal with my Eve 14 lander. Everything works and it seems to make the delta V, but getting this thing from Kerbin to Eve is gonna be a headache.

52 tons. Not light compared to most of the stuff here, but it's equipped for every phase of the mission. retro burn, parachute descent, stable landing platform, refueling capability while on the surface, and boarding access.

This pic is kinda neat. One of my rovers busted a wheel, so I sent another to assist it in getting to the lander for refueling.

Edited June 8, 2014 by GoSlash27

[raygundan]

I'm not going to win, or anything... but I've finally succeeded in bringing a pod back from Eve! It's a little overbuilt because I'm a lousy pilot, so all my designs take that into account-- but at 26.1 tons at landing, and 23.8 tons just before takeoff ('chutes, outer wheels, and landing legs dropped) it's at least respectable.

If it's not too late to put my name on the scoreboard, here is the Heron II, complete with exceedingly overexcited and verbose trip report.

Heron II Craft File

I know lifters aren't required, but I wasn't building for this contest directly... so the whole mess is there. All stock except MechJeb. Here's a picture parked just before ascent. I've tested takeoff from as low as 6300m, and from 6500m, it makes orbit with about 91m/s of delta-v left. 9157 total delta-V before takeoff.

After detaching unneeded parts for launch, with delta-V numbers:

And after reaching orbit:

Many thanks to a post Tavert made at some point in the dim and distant past, explaining why TWR is at least AS important as delta-V, if not more so, when doing Eve ascents. My last design was seriously underpowered by comparison, and it was this insight that made it all possible.

Edited June 27, 2014 by raygundan
Added craft file link directly to post so it's easier to find.