Here is one to drive you insane : Take 3 orange tanks to stable orbit.

[ASnogarD]

Short Version: Get 3 Orange tanks to LKO using STOCK parts (Mechjeb2 allowed), no 5000 part monstrosity, no hot seat uber pilots skills needed (a Kerbil must still be able to fly this thing after all).

Try get it as elegant as possible and with fuel to dock with a Station in LKO.

Long Story:

I watched Scott Manlys re-usable space program videos and in a few he struggle to get fuel to his station from Kerbin (he was limited to no staging and discarding parts remember) , I thought at the time why didnt he build a fuel delivery vehicle... a simple craft that carries 3 orange tanks up.

Boy was I naive...

I have been trying to make such a delivery craft since I got KSP, I havent even built a station or done a trip to the moon to plant my custom flag, I have been trying to get the bloody fuel craft built.

Each time I try drop the idea some other idea pops into my head and back to the VAB I go, and time and time again I hit the same snags, design after design ... all look elegant, and in theory once in space will work like a charm... just cant get the buggers into space.

I always end up in a vicious cycle of weight - power - fuel - weight - power - fuel ... its heavy I need more power, but the mainsails guzzle fuel like mad so I need more fuel but this makes the thing even heavier needing more power. SRB's do well initially but after they finish burning the craft loses speed and slowly falls back down.

Staging and stacking make the thing unstable and eventually ends up with something silly with way too many parts and more struts than ship left... yuck.

It also feels silly to spend 10000 tonnes of fuel to get up...100 ?

I do know that it is realistic that getting up that much fuel into orbit is a difficult job and will always end up wasting more fuel in getting the fuel to space than the amount you can deliver... but it is a challenge to see if a nice elegant solution can be found, or a insidious torment mechanism to drive you insane trying to get that elegant solution.

Ah, Scott , now I understand why you didnt fill up all 7 of the Stations tanks...

As for me I think I'll drop the idea and move on... to stations and docking, then the Mun... I hope I can shake the challenge off because I am stubborn.

NOTE: I can make a launcher that will be able to send up 1 tank, for some reason I got hung up on the idea of 3, and tri hull ships or tri engine designs. I also rage each time it fails so I dont have pics of my failed designs, sorry.

[GoDores]

Here's my design. It ended up being a little overbuilt and actually puts about 3.5 orange tanks worth of fuel, plus three large RCS tanks, in a 300km LKO. It seems to be just as fuel-efficient as my single orange tank launcher (~16% mass fraction to orbit). It's actually pretty easy to fly for its size; it will start into a spin in the upper atmosphere but that can be ignored or managed with RCS. It's 386 parts and 966.13 tons on the launchpad. Stock except for Engineer and Mechjeb, although I haven't tried flying it with Mechjeb yet.

Picture in the VAB:

Shot of the engines from below (I believe I have 63 engines, all of which burn from launch to orbit):

During the gravity turn after some staging (the first staging occurs below 500m):

Final amount in orbit. As you can see the last boost stage still has some fuel in it, and when combined with the small gray tanks under the main orange payload tanks, I have a total of about 3.5 orange tanks worth.

Tanker docked to my interplanetary stage and some new lander hardware I'm testing:

Edited June 18, 2013 by GoDores

[Bothersome]

OK here is mine.

Here is 18 Full Orange tanks ready to be a fueling station.

That's 4532 tons held together by 1719 parts (includes 16 towers).

That's 775 tons of Orbiting Fuel Station

[ASnogarD]

Hmmm , those are viable solutions just not very elegant or efficient... more like lets get as many engines and fuel tanks together to take 3 orange tanks of fuel up.

Not saying you guys havent done the challenge I set, just I feel those are 'monstrosities'... dont look like fun to fly and not something you can easily re-use each time you need to run a fuel run to the station.

I guess it isnt possible to send up fuel into LKO without using 500 engines and 1000 times more fuel than you are delivering... in terms of fuel tankers on the land, those ships would be using the huge cargo tank to travel and delivering the small fuel tank to the petrol station

I tried to keep a small profile and low profile so I attached 3 tanks to a central tower, and with girders attached 3 drive towers between the gaps of the orange fuel tanks (using symmetry, there is enough space to do this) ... so I had a pretty tidy ship but could never get the power to fuel to weight ratio down... not without adding a lower stage that did the mess of engines and booster stages.

[tavert]

101 parts, asparagus'ed skippers gets roughly 3.2 orange tanks to 100km orbit.

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[GoDores]

Physics pretty much dictates how much fuel you'll need to burn to put a given amount in orbit, based on the rocket equation. I plan for a 6:1 ratio from Kerbin's surface to LKO (burning 6 units of fuel on ascent for each unit of fuel you put in orbit), with engines of realistic ISP. I can do a little better than this but I don't think it's possible to do a lot better no matter how much you optimize your rocket. So unless you use very cheaty mod engines, you'll have to burn through 18 orange tanks worth of fuel to get your three full ones into orbit.

[tavert]

You could also use jets, at least 1 per 10 tons of total mass, but the part count gets quite large due to the number of intakes you need.

[1096bimu]

How will this drive me insane? seems pretty easy.

What do you mean no 5000 part monstrosity? What about 4999 parts?

How do you measure elegance?

[Lillegre]

I have a Saturn V / Ares lovechild that I use to put 80 tonnes into LKO on a routine basis., but it uses 4 modded parts that I have made (believable mods / stock equiv!)...

I use 600 tonnes to get 80 tonnes to orbit., I could easily make it from stock, but I would be lifting 2 orange / 2 grey 32x cans. Would that be permitted? Basically do you just want 8,640 Fuel + matching oxidiser to 100km?

[Cipher29]

This is my Orbital Refueling Station (ORS) and it is literally the first thing I made in 0.18 when I had to restart my save.

Here it is on the launch pad updated to 0.20.

[ASnogarD]

What I meant by elegant is more something that is believable ... a vehicle that would deliver those tanks on a routine basis, and I am sure we can agree that some of the marvels of Kerbal science are a tad large and unwieldy looking.

I could get the equivalent vehicle by launching up a ship with space for 3 tanks, and then launching the tanks up individually, then multiple launches to full up the 3 tanks... sort of defeats the purpose of a fuel delivery vehicle... it becomes a extra stage and be easier to send the fuel direct to the station.

I was trying to go for a neat shell around the 3 tanks with enough power to lift the lot into LKO, with perhaps a few SBR's to help with lift off but avoiding a scenario with heaped stacks of fuel columns... BUT as explained by other posters the ratio of fuel needed to get fuel up is too high for anything other than masses of engines with lots of fuel tanks to brute force the 3 tanks up.

In effect its more efficient to run several lesser launches than to try get that amount up in a single launch, so the 'simple' fuel delivery ship is not really possible... merely a noob KSP players (me) error.

If it makes you feel better I wasted a number of hours over a couple of days trying to get those tanks up, and each time ended up with a cluster**** of engines and fuel tanks ... the Mainsails got power but are inefficient , the KV's are more efficient but lack the power, SBR's can help with power but run out before you escape orbit, Nuclear engines are hyper efficient but probably couldnt even lift a probe out of orbit in atmosphere... so no matter how you play with the design of the rocket, the conclusion is always the same... a **** tonne of engines and fuel tanks to lift 3 tanks in one go.

Not elegant but a requirement.

... looking at some of the ships here, my 275 part ship is rather sparing of the parts... but the over 1000 part rockets did the job whereas my designs couldnt so they were superior designs.

EDIT: Cipher29's rocket is roughly what I was looking for ... a nice sleek design.... and GoDores design is also pretty sleek too , more compact actually, sorry I didnt look at it closer.

Edited June 18, 2013 by ASnogarD
Saw Cipher29's rocket.

[Fel]

I think you confused people when you said "no staging".

But a Saturn V has 3 stages for that 100Mg load.

Also, people use stage 1 or 1.5 (Skipper) engines far too long because KSP isn't balanced to real rockets. [infinite restarts, throttle control, Engine TWRs being rather low [which can be balanced by lowering isps (direct delta-v manipulation)] You also have some extremely elaborate pumping systems (Asparagus), extremely strong parts, or any number of "Made to Game" concessions.

[AustralianFries]

This isn't really too difficult...

[CGA1123]

This is my Orbital Refueling Station (ORS) and it is literally the first thing I made in 0.18 when I had to restart my save.

Here it is on the launch pad updated to 0.20.

That is beautiful!

[Bothersome]

Hmmm, here is another one of mine.

7 Orange Tanks (worth) to Stable orbit.

Yeah, I know it don't qualify because of launching it into orbit with two seperate launches. Still needed though.

[GROOV3ST3R]

I've taken the equivalent of 4 orange tanks up there, currently orbiting with my station. The problem is I had to consume the fuel inside of them.. I will now need to refill them before the station is of any use for interplanetary travel.

pic:

Edited June 30, 2013 by GROOV3ST3R