Post 1.0 - Lightest sea level* Eve ascent challenge

[KerikBalm]

Pretty simple, Land your craft on Eve, below 1000 meters (close enough to sea level) - then get back to a stable orbit.

Lightest mass wins

Rules:

* Your craft must start in Eve orbit - although it may be in a degrading orbit/considered suborbital by the game-> ie the craft must start in space, but may have a PE which is in the atmosphere.

* You must land below 1000 meters - suggest HE coordinates Lat 25, Lon 158.5

-- You may demonstrate a successfuly re-entry to full parachute deployment, and then use hyperedit to demonstrate a safe landing below required altitudes (so you can skip the frustration of trying to do precision landings to land at the right altitude)

** There is a 2nd catagory for landings from below 100m. these co-ordinates work: Lat: 0.0001707 Lon 229.9752826

*** 3rd category: Launch and land from Eve's oceans, ie, design something to do a water landing, and takeoff from the ocean.

* No ISRU is allowed, the point is to have a lander than can land *anywhere* on Eve with a solid and level enough surface, not restricted to ore concentration

* Rendevous is allowed (either on the surface, or in space but suborbital), but then you must add the craft masses.

* All parts must be stock.

* No external command seats may be used, Kerbals must be in a fully enclosed crew compartment.

* Kerbals must be able to reach the surface, and get back in the lander.

Leaderboard:

<1000m

Foxster - 33.83 tons

http://forum.kerbalspaceprogram.com/threads/131877-Post-1-0-Lightest-sea-level*-Eve-ascent-challenge?p=2152375&viewfull=1#post2152375

Nefrums -39.8 tons

http://forum.kerbalspaceprogram.com/threads/131877-Post-1-0-Lightest-sea-level*-Eve-ascent-challenge?p=2148989&viewfull=1#post2148989

KerikBalm - 44.5 tons

http://forum.kerbalspaceprogram.com/threads/131877-Post-1-0-Lightest-sea-level*-Eve-ascent-challenge?p=2152093&viewfull=1#post2152093

Astrobond - 45.9 tons

http://forum.kerbalspaceprogram.com/threads/131877-Post-1-0-Lightest-sea-level*-Eve-ascent-challenge?p=2151277&viewfull=1#post2151277

Moonk - 174 tons, 43.75/kerbal

http://forum.kerbalspaceprogram.com/threads/131877-Post-1-0-Lightest-sea-level*-Eve-ascent-challenge?p=2164240&viewfull=1#post2164240

*Mass per Kerbal ranking, 1000 m*

Foxster - 33.83

Nefrums - 39.84

Moonk -43.75

KerikBalm - 44.5

Astrobond - 45.9

<100m

Foxster - 39.3 tons

http://forum.kerbalspaceprogram.com/threads/131877-Post-1-0-Lightest-sea-level*-Eve-ascent-challenge?p=2161307&viewfull=1#post2161307

KerikBalm - 44.5 tons

http://forum.kerbalspaceprogram.com/threads/131877-Post-1-0-Lightest-sea-level*-Eve-ascent-challenge?p=2152093&viewfull=1#post2152093

Astrobond - 45.9 tons

http://forum.kerbalspaceprogram.com/threads/131877-Post-1-0-Lightest-sea-level*-Eve-ascent-challenge?p=2151277&viewfull=1#post2151277

Ocean Landing+Ascent

Foxster 39.3 tons

http://forum.kerbalspaceprogram.com/threads/131877-Post-1-0-Lightest-sea-level*-Eve-ascent-challenge?p=2161307&viewfull=1#post2161307

I'll start...

91.21 tons

Landing

Landed in all one piece, used a propulsive landing because an earlier version had parts fall off when it landed at 9 m/s:

Discarded deadweight (I could have used some of the fuel in drop tanks, but I forgot fuel lines)

Orbit, with 350 m/s to spare.... not sure if that would be enough if I had ascended from 0

(actually, that pic was from an ascent from the same basc craft ascending from 600 m, I didn't take a screen shot of this one, which actually landed in 1 piece and was a little lighter because the airbrakes were discarded, and some parachutes. The lander pictured above made it to orbit on my first attempt with 380 to spare)

Earlier design iterations, the one in the middle could ascend, but would need a propulsive landing to stop it from collapsing due to a 9m/s landing speed, which it maybe could spare if you timed it right.

I'm sure others can do better.

Edited October 24, 2015 by KerikBalm

[Nefrums]

Another light weight challenge! I'm in!

[astrobond]

Pffffff... Still Nefrums... OMG that will be hard but I can't resist to try that too lol

BTW, Congrats KerikBalm ! Nice ship and low weight

Edited August 18, 2015 by astrobond

[KerikBalm]

I didn't think 91.21 tons was low weight?!

I asked in the gameplay questions for suggestions on how to make it smaller, but there wasn't much help there, some consideration of a mammoth... but nobody provided actual working designs for comparison.

So... I figured I'd try here.

I've seen some other post 1.0 eve lander designs, but they all seemed to revolve around landing at a high altitude.

[astrobond]

We will try to make lower weight (I didn't test Eve ascent in 1.04), but I'm sure 91.21 tons in KSP 1.04 to an Eve takeoff from sea level is already a "low weight" ^^

Edit:

The lightest ship I found is The Foxster Ship with less than 74 tons, you are not so far away ^^

http://forum.kerbalspaceprogram.com/threads/76153-Lightest-Eve-Lander/page14

Fly safe with Val !

Edited August 18, 2015 by astrobond

[KerikBalm]

Hmm, he claims that a mk1 pod is better... and suggests an improvement... the center lv-t45 changed to an aerospike... he has it for the attachment point, which is something I managed to get around and get my craft to orbit without hyperedit....

[astrobond]

Hi all

Some news: 54t. ready to launch from Eve sea level (19m) to 100km orbit is ok for me at this time, still working on the project...

[Nefrums]

54t! That is low!

I made a 2 kerbal 150t lander for my first Eve landing a while back, in theory the wight could be halved for a 1 kerbal lander.

I do believe that a pod would be better than a lander can as aerodynamic properties is very very important in the thick atmosphere on Eve. Fairings might be a good idea to.

Mammoth was the best engine in 1.0.2, but after the aerospike buff in 1.0.3 it is the by far best engine.

[KerikBalm]

pics? craft file? I'd like to try it out.

Maybe I can even make a profit on the eve tourist contracts ... or rather enough that I may actually consider them

[astrobond]

Hi KerikBalm and Nefrums

That's only the Eve ascent part of the ship, i have not worked on the de-orbit and landing at this time ^^ (i hyperedit and slow land the ship to test)

But i'll send a pic and the craft in half an hour...

I have tried MK1 Can and Pod, best results with the Pod as Foxster said... not tested fairings, could be a good idea !

I'm working on a less than 48t. craft, seven spikes, almost good but no orbit... (could be ok with mechjeb, but i do it manually)

[astrobond]

Hi again

Even better ! less than 47t.

The craft: Eve 104-7.craft

The images:

Javascript is disabled. View full album

Fly safe with Val !

Edited August 19, 2015 by astrobond
New version :)

[astrobond]

Hi All

The ship used: Eve 104-9.craft

Just under 50t. in orbit, 47t. at Eve Launch.

My final submission with comments in the album:

Javascript is disabled. View full album

Fly safe with Val !

Edit: With this ship, it was a lot harder for me to reach orbit from 652m than with the Eve 104-7 ship from 19m....

I found that the clipping I made on the central Spike motor to attach the MK1 can added a LOT of drag in the ascent, I don't know why

Without clipping and without MK1 can, I have easily more than 200dV free from 19m to 95km orbit with the same ship ???!!!

I'll try to find a better way to add the MK1 under the spike...

I also tried to add ladders, but that also add a lot of drag...

Not totally happy with this ship... Back to the drawing board

Edited August 20, 2015 by astrobond
Added Comments

[astrobond]

Hi again

Just a link to a new version of the ship, almost the same but the Can attachment... Really a lot easier to orbit !

For those who wouldlike to test

I'm happy with this version

Eve 104-10.craft

Fly safe with Val !

Edited August 20, 2015 by astrobond

[Halo_003]

I'm curious what would be doable without asparagus staging, probably 95% of the Eve landers I see are asparagus staged. I know I made one in .90 that was like 500,000kg, 200+ parts and worked pretty well.

[astrobond]

I'm curious what would be doable without asparagus staging, probably 95% of the Eve landers I see are asparagus staged. I know I made one in .90 that was like 500,000kg, 200+ parts and worked pretty well.

Hi Halo_003

selfish_meme did something like that here:

http://forum.kerbalspaceprogram.com/threads/122925-Eve-landing-and-return-in-1-0/page3

But the problem is also to land such high ship without falling down on Eve !

Just make a new one to see if it's still well working in KSP 1.04

It now need only about 8000m/s to go from sea-level to orbit, that was 11000m/s in 0.90 ...

But you need good aerodynamic now, so a non asparagus could work very well too

[Nefrums]

Here is my entry: Got it below 40t

Javascript is disabled. View full album

[astrobond]

Arglllllllll !!! You beat me again... lol

Less than 40t... Really impressive !

This new Eve ascent path with wings is excellent

Congrat's again Nefrums !

[Nefrums]

Thanks!

I have to give cred to Val for the wings idea.

Edited August 20, 2015 by Nefrums

[Foxster]

There has been a technological leap here.

You are making orbit with only ~3000dV at the surface thanks to the wings? Are they providing real lift or is this some kind of Kraken drive?

I'm impressed either way.

[Nefrums]

The dv displayed by KER on eve surface is a bit misleading, vacuum dv is over 7k. For instance the dV for the last stage using the terrier engine is displayed as 0 by KER at eve surface but when that stage is engaged at ~43 km attitude KER is showing ~99% of the ~2.3 k vacuum dV for that stage.

The wings are indeed generating lift, and more than they do at Kerbin due to the thicker atmosphere. As the lift generated by the wings is far greater than the drag of the wings. The effect of Eves gravity is largely canceled by the lift at a comparatively small cost in extra drag.

The drag is also reduced because with wings the angel of attack (the angel between where the rocket is pointing and the direction the rocket is going) can be less, and the drag is a lot less for a rocket pointing prograde than one going sideways. This is apparent in this image where the rocket is pointing at 30 degrees and the prograde marker is close to the same direction, without wings the angle between the rocket and the prograde marker would have been 10-15 degrees.

I believe that this effect is largely due to that in the current KSP aerodynamics model the lift generated by non wing parts going at an angle to prograde is small compared to the extra drag, and it is large for wings (and probably mk2 parts to a lesser extent).

Another thing that is helping my rocket is that it is not a standard asparagus staging where engines are doped 2 and 2. After the first stage 4 of the 7 engines are dropped. This leads to less total dV but more sustained twr in the first stage, as all 7 engines are running longer.

Still the first stage has 870 dV at eve surface and takes the rocket 3500m up and to a speed of just over 200m/s. A tried with a standard asparagus staging and after 4 engines where dropped the rocket was only going ~150 m/s. despite having more than 870 dV for those two first stages.

twr is more important than dV for the first stages.

Edited August 21, 2015 by Nefrums

[astrobond]

Hi All

Just for fun, two new ships with little albums:

A non asparagus test for Halo_003, just get a look to KER dV on the 1st pic ! Less than 6500dV... (last pic of the album is another test with the same ship full throttle and 416dV left !!!??? high twr is really important...)

Javascript is disabled. View full album

And a new version of my Eve 104-10 ship with good cones, less fuel but better twr as Nefrum said... that is a good idea even without wings ^^ 46,7t. and still ok to make an orbit. (43t. at liftoff)

Javascript is disabled. View full album

Fly safe with Val

[KerikBalm]

Nice... I knew my 91 ton lander was overbuilt/suboptimal.

Also good to know that I was right for not choosing a mammoth engine... 104 tons, and it probably wouldn't make it if you launched from 600, or sea level (you launched from 1,300 meters, and only had 35 m/s left in a less than 100x100 orbit).

I just have one problem, and it wasn't specified in the rules, so you're fine... but...

It doesn't seem you can use that lander to get any science up to orbit for recovery.

I'd like to be able to send down a science package, take lots of science data, and have my kerbonaut take the science data and stick it in the command pod.

Your lander can solution on the bottom won't allow you to store the science data in the pod at the top.

Something tells me we won't see many lighter designs.

Aerospikes on the bottom, asparagus staged, it seems a mk1 pod is best, and the asparagus staging should be a ring of 6x FL-T800 tanks around a center one.

Edited August 21, 2015 by KerikBalm

[astrobond]

...I just have one problem, and it wasn't specified in the rules, so you're fine... but...

It doesn't seem you can use that lander to get any science up to orbit for recovery.

I'd like to be able to send down a science package, take lots of science data, and have my kerbonaut take the science data and stick it in the command pod.

Your lander can solution on the bottom won't allow you to store the science data in the pod at the top....

OMG you are right, not a good solution to recover science...

I'll have to find a solution to reach Mk1 pod with external ladders to avoid drag on the ascent ship

Back to the drawing board !!! lol

[Kelderek]

* You must land below 1000 meters

There is a fairly big difference between 200m and 1000m on Eve. Perhaps you should have 1000m as a main rule, but break up the leaderboard into segments like <250m, <600m, <1000m, or something like that.

You may also want to consider a rule to that the kerbal must grab a surface sample and get back on board; dealing with ladders and access pose an interesting challenge too, in addition to being a realistic reason to go to Eve in the first place (for science!).

[Nefrums]

What is the problem with ladders? Just add a couple of raidial decouplers with laders on and detach on lauch just like air brakes and chutes.