Lightest Eve Lander Challenge v1.1.x & v1.2.x

[Redshift OTF]

Anyone want to take on the tough challenge of making an Eve lander for 1.1.x? We had a thread around 2 years ago that came up with some excellent designs for Eve landers and I thought it was time to revive this for the current version of the game.

Challenge description - Build the lightest Eve Lander possible!

Category 1) Take off from anywhere on Eve and reach a stable orbit.

Category 2) Take off from an altitude of under 100 meters and reach a stable orbit.

Challenge rules:

You need Kerbal on board who can exit and enter the vehicle prior to take off. What would be the point of landing on Eve if you couldn't have a walk around on the surface.

No external command seats! That rules out using a seat in a service bay. You'll need to use a lander can or command pod or something similar. I may add an extra category if there is a demand for the use of a chair in a service bay method later.

Stock parts and physics only. Exceptions are Autopilot and navigation aids like Mechjeb, Kerbal Engineer etc and any building mods like Editor Extension, Hanger Extension, Infinite offset limits etc. These are allowed.

You do not have to transport your lander to Eve. you may use Hyperedit to reach an Eve orbit and the Vessel Mover mod to move your vessel once it has landed, (useful if you want to take off from a specific altitude!)

Post screenshots of proof as well as the lander prior to take off. Craft files would be most welcome and videos are optional.

Why this challenge? Well, in some ways an Eve Lander is easier to build in this version since v0.9 as you probably only need around 9000 DeltaV to reach orbit from sea level compared to the 12000 DeltaV. However, the journey to Eve is harder compared to earlier versions. Aerobraking is difficult due to the heating effects of the atmosphere and Eve is inclined so it take more DeltaV to get there. This makes building the lightest craft possible an important factor in enabling inter-planetary transfer stages to be of reasonable sizes, especially if you plan on using engine thrust to achieve orbit. Obviously you do not need to build one of these for this challenge but a light lander will help anyone who wants to use a submitted lander to build a craft that is fully capable of a mission to Eve and back from Kerbin.

Here is what I have come up with myself:

With de-orbiting, re-entry and landing parts attached.

With above parts removed, (that are jettisoned at lift off).

This weighs 74.220 tons, 86 parts and completes Category 2. It can reach a 100 km orbit from under 100m with 444 DeltaV left over so I think there is a lot of margin left over for better designs! It's a simple asparagus design however the first 2 stages are just fuel tanks with the 3 Aerospikes and 2 vectors all firing from launch. Mixing the engines like this gave me the best balance between TWR and DeltaV. The biggest challenge was ensuring the craft could survive entry into Eve's atmosphere without flipping out as the inflatable heatshield has so much drag it tends to flip the craft out. I realise now that I could have just used the Vessel Mover mod to spawn a saved vessel directly on the surface and not worried about re-entry but this makes this design one step closer to a fully functional Eve capable craft anyway.

Download > https://drive.google.com/open?id=0B9mK0rPybNaxSHNVZ2JPZm5UdWc

Good luck!

Edited December 12, 2016 by Redshift OTF

[OrbitalBuzzsaw]

@EvermoreAlpaca did something really small in his Grand Tour.

[astrobond]

Hi @Redshift OTF and all

 

Here is a test of my 1.0.5 lander slightly modified for a 1.1.2 mission to Eve.

46.3T landed, 7794m/s, 105parts.

Ascent path from 88m asl: vertical until 20km, then 80deg until 25km then 45deg until 40km then switching between prograde and normal sas to keep nose above 10deg.

About 400m/s left in orbit

Fly safe with Valentina !

Edit: I also used the inflatable heatshield for reentry tests, the key is to add airbrakes on top of the lander to avoid ship flipping (i don't remember who had this excellent idea sorry...) works like a charm

 

Edited May 21, 2016 by astrobond

[Redshift OTF]

Woah, nice entry astrobond! I didn't bother with nosecones on mine as I didn't see any difference in performance but it looks like it is working for you. How did you manage to de-orbit that without it burning up? It's not needed for the challenge, I'm just curious. I'm also surprised you got enough TWR out of the last Aerospike with the weight it is carrying.

[astrobond]

5 minutes ago, Redshift OTF said:

Woah, nice entry astrobond! I didn't bother with nosecones on mine as I didn't see any difference in performance but it looks like it is working for you. How did you manage to de-orbit that without it burning up? It's not needed for the challenge, I'm just curious. I'm also surprised you got enough TWR out of the last Aerospike with the weight it is carrying.

Thanks a lot @Redshift OTF

Twr out of the last aerospike is only 1.14, but as heating is coming soon above 25km on Eve in 1.1.2, this is enough !

For reentry, i use the "return to Kerbin ship" to slow the PE to 70km, decouple the lander, re-push the PE of the "return to Kerbin ship" to a safe 95km then switch to the lander to land on Eve

(That's why i have a small docking port on the command pod, to redock in orbit)

Not really easy to land exactly where you want, but that's how i do

 

 

[astrobond]

I think that's @Foxster who gives me the idea of the airbrakes with inflating heat shield !

He made a lighter lander than me btw xD

 

[Mister-Spock]

I build a 70ton design in 1.0.5 (and im using KerbalJointReinforcement)

Sorry but i have not much time!

 

Deorbiting and Returnmodul (decoupeled):

http://images.akamai.steamusercontent.com/ugc/263837612155116266/E4C4561EA17539F36C82DDCCA2DFFF85E4E6E386/

 

Descent stage:

http://images.akamai.steamusercontent.com/ugc/263837612155094985/06458FB6B75BC17C3794158DEBCAB173A286E01F/

 

Landet at sealevel + mechjeb and delta V stats:

http://images.akamai.steamusercontent.com/ugc/263837612155095207/E9D49D74CFBD699E28CC6EEB31B52CF45A3B217C/

 

Ascent of last 2 stages:

http://images.akamai.steamusercontent.com/ugc/263837612155095509/89F2D03453FCA7C09E16986AC02190EC4C5D32A6/

 

Orbit 100km with 700 m/s left. Enough for a rendevous and/or additional sciencemodul:

http://images.akamai.steamusercontent.com/ugc/263837612155095685/AFC0F65CFF6AA0C0D9A6D9458ABC3D5A7CB0FA23/

 

PS: Glimbal of my engine is 50%, but this doesnt matter much

Thrust is locked to 30m/s² - 35 m/s³. Should depend on starting high.

And yeah for some reasons i miss one ladder. Must be lost while building my ship.

Edited May 27, 2016 by Mister-Spock

[Foxster]

Sorry to be bit dim here...when do we measure the mass? Just before lift-off from Eve with all the landing stuff dropped or..?

Anyway, assuming its the mass on-orbit (i.e. all of the lander before burning any fuel or dropping anything)...

Here's my go at 43.763t:

Could be lighter by cutting some corners but I know this will work every time with some dV to spare from any height. 

 

Edited May 27, 2016 by Foxster

[Mister-Spock]

Guys, why do u use airintakes instead of nosecones?

[tseitsei89]

15 hours ago, Foxster said:

Sorry to be bit dim here...when do we measure the mass? Just before lift-off from Eve with all the landing stuff dropped or..?

Anyway, assuming its the mass on-orbit (i.e. all of the lander before burning any fuel or dropping anything)...

Here's my go at 43.763t:

Could be lighter by cutting some corners but I know this will work every time with some dV to spare from any height. 

 

I would say measure mass on orbit. Since the lander has to get to eve somehow too. Also nice craft  I'm working on my own entry but I doubt I can beat that...

[Foxster]

2 hours ago, Mister-Spock said:

Guys, why do u use airintakes instead of nosecones?

Lower mass and drag. I know it doesn't make a lot of sense but it's just how the parts are designed. 

If you really want to hack things then rotating them 180° (blunt side up) reduces their drag quite a bit - but that's getting a tad cheaty. 

[EvermoreAlpaca]

As someone mentioned previously, I used a 9.685 ton eve lander in this mission.  I've used an almost identical lander in a couple previous missions.  A version I used in a previous mission is the exact same weight and actually flies a little better due to different wings being used.  Not tested since 1.05.  It does use an external command suit so take this as a interesting note rather than a submission.

 

Edited May 30, 2016 by EvermoreAlpaca

[Foxster]

Interesting stuff. Shows just what a difference taking off from a high altitude and not using a capsule can make to an Eve lifter.

I wish the Eve to-orbit part of the video had not been at night so more could be made out of the craft used. 

[EvermoreAlpaca]

5 hours ago, Foxster said:

Interesting stuff. Shows just what a difference taking off from a high altitude and not using a capsule can make to an Eve lifter.

I wish the Eve to-orbit part of the video had not been at night so more could be made out of the craft used. 

Daytime ascent with the exact same eve lander with better wing design due to it not needing to fit inside a cargo bay for this mission:

[Psycopyro]

What's the difference with that one?

 

[*MajorTom*]

I can't understand all rules for this challenge: Is it must only land from Eve orbit and take-off Eve to stable orbit of Eve? Not go to Kerbin? only landing gear on lander? not wheels? not wings? not mining ore?

So to easy land to Eve just forget about parashutes -its mass too big. Simply make spaceplane-like heat-shielded wings lander, and use rocket-take-off from Eve.

-------

My craft not for this challenge of course (because you post "stock"rule, but my craft for "hard-life with life support" it also using TAC-LS containers and it is add some additional mass to lander...or spaceplane...or spaceplane-rocket-lander.. brrr just name my craft how you want..:) )

Because i can't understand all rules look at this mass parameters:

 

-52,722 kg on large eccentricity orbit, drop mass of (ablator burn) to 50,7tonn to low orbit, drop 9tonn refueling probe, then 40,3 tonn landing craft, mining ore, take-off from Eve, fly to Kerbin and land to Kerbin (craft from 1.0.5, but it is also works in 1.1.2) . Look before I drop fuel-tanker on orbit.

so i dont know what paramer of this craft i can use to "mass"

I fought - I can make 20-30 tonn of this on stock just to land and to orbit Eve (with this cheating-like new 1.1.2 heat shield ) . So I build it and post it here if i found time to do it.

ps sorry for my poor english

Mass in KER (left KER window) . You may enterest in only Eve orbital manuvers from 20:17 . And it can start from sea level of Eve (trust me i checked it, flight in this video manual non-MJ )

 

[Foxster]

I've done a couple of flavours of these challenges and usually what it involves is:

1. Get your lander to a stable Eve orbit (Pe and Ap above atmosphere) anyway you like - usually hyperedit. 
2. Record its mass now - that's what you will submit for your entry. 
3. De-orbit your craft, land it, get it back to a stable orbit. 

If you want to use mining stuff then I'd guess it is OK but the mass of it might make it not worthwhile. If you want to fly it down then I'd say that is fine but it will likely be an awkward shape.  

[Interplanet Janet]

Will a probe work?

[McQuacker]

Here's mine. 68.350 tons at lift-off (including landing struts), reaches a 100km orbit with about 150 m/s left over. I used this one in a single-launch Eve sample return mission documented here: http://imgur.com/a/DLmc6

[Martian Emigrant]

Hey all.

This ship entry is done on V1.2. All stock, no mods.

Eve was on my list of personal challenges.

 

http://imgur.com/a/1g4YY  Imgur has the pictures ordered earliest at the bottom, latest at the top.

 

The 3 Kerbal-ship is Teleported to Eve via the cheat menu. The menu chose the orbit for me.

The de-orbit re-entry configuration is 119 parts, 202.2t. or 39.9 parts and 67.4t per Kerbal.

The ship comes with a ladder....but a better set of Kerbin trials would have demonstrated that they were inadequately built. Call it WIP.

On the teleporter pad:

At Eve ready for work:

After the de-orbit burn, jettisoning the engine and inflation of the heat-shields.

During the re-entry phase the SAS isn't required. The ship is self-aligning.

After the initial deployment of the chutes the upper-shield if dismissed.

When fully deployed and the ship as slowed down the lower-shield is also dismissed.

The landing legs are deployed. They aren't exactly required but they do help stabilize the craft on slopes. Plus they do take an "Explosive" interest in protecting the engine bells.

Landed on Eve. A few legs have sacrificed themselves that the ship may live. The landing site wasn't chosen. I was just aiming at "East of the sea".

I am including a picture of Jeb on Eve. But as mentioned the time-line was altered with an F5 to get him back in the cockpit.

The undressing of the ship started immediately.

Parachutes:

Ladders:

And legs:

The Initial climb is straight up.

Thanks for the boost.

Made space with fuel to spare.

Thanks for reading.

It was a challenge alright. Eve hates visitors.

 

ME

 

PS

I intend to redo this with a reworked ladder. Also Starting from sea level is I believe possible. The hard part is to find somewhere low and not be in a lake. I tried making a floating ship but they always topple the wrong way.....

Edited December 6, 2016 by Martian Emigrant

[Foxster]

Well done, Martian Emigrant!

Welcome to a small and exclusive club of Eve devotees. 

[Martian Emigrant]

Follow up.

I rectified the ladders. easy enough.

Went from a tri-booster to a quad. An landed in water. The SAS could keep it upright long enough for me to ditch the excess weight and zoom out.

The atmosphere is like sirup. All the boosters are spent before 5km. That's the altitude I took off successfully from last time.

The centre stage got to about 25km.

So.....I still think it can be done but require so much delta-v.....

 

ME

[Redshift OTF]

I didn't realise this challenge was still active so well done on continuing with it! Also I must admit at the time @Foxster had made some great Eve landers in another thread that I honestly didn't think could be beaten however since my experiments with the Most DeltaV for an SSTO challenge I have come up with some unique ways to reduce drag so I think improvements can be made. I will see what I can come up with.

[Foxster]

Ah, Eve is showing some love atmos-wise recently. There's scope for slimming down, especially if you change from the trad lift profile. 

[Redshift OTF]

Since you are here @Foxster I will share what I came up with. You advised me that quad couplers were really draggy in another thread and I should try and use something else. Using the Show Aero in Action Menus option, (or whatever it is called), does indeed show quad couplers are very draggy however, when I attached fuel tanks radially to a part that normally has low drag it becomes just as draggy as a quad coupler. It seems the game adds on extra drag to any part that has other parts added to it radially. One exception to this is the Big S Wing Strakes. If you add these to a craft and add parts radially unto the Strakes the game doesn't add extra drag to the craft and you can save up to 50% drag on some builds.

Anyway, just thought I would share. Reducing drag on an Eve lander could be as useful as making a low drag SSTO for getting to Low Kerbin Orbit.