[Stock] Presenting: The Most Fuel Efficient Super Lifter! Version 2!

[gyro2death]

Version 2 of the Super lifters I\'ve designed. This one is a straight improvement in every category; greater fuel efficiency, easier control, higher orbital altitude, fewer Stages, greater potential payload. To top it all off it still leaves no debris other than whatever you want to drop off!

This still lifts 70 tons of anything (up to 28 full fuel tanks) into orbit but now has the following efficiency ratings:

- 70 Tons to LKO (Low Kerbal Orbit [130-200KM])

- 389 fuel per ton put into orbit

- Fuel ratio of 1:1.94

- Possible to fly safely!

Without Load:

With Load:

To put this in earthy perspectives the Delta IV currently the most powerful rocket in service can put a mere 24 tons into LEO (Low Earth Orbit)

Source: http://www.space.com/16362-air-force-rocket-launches-spy-satellite-nrol-15.html

Feel free to critique or try and beat my design.

Notes: It is quite easy to add another 2.5 tons to the load (1 more fuel tank) increasing the efficiency to (1:1.88 Fuel Ratio) and (376 fuel per ton) however this is rather difficult to get into a stable orbit and requires a near perfect gravity turn. As such I\'ve opted to make a more reliable rocket with a small hit in efficiency.

Flight Video:

Older Versions:

Version 1

My first rocket I posted on these threads was a modded one with NovaPunch, and while great and awesome, having a good set of parts makes building things easy. As such I wanted to give myself a challenge.

With docking coming in the next patch people are flooding this forum with heavy lifters for space stations and fuel depot for space. My task was to create the most fuel efficient lifter possible, the result....

Introducing a powerful and efficient fuel rocket is designed to get a massive load of 70 Kerbal tons (28 full fuel tanks) with an efficiency of 403.5 fuel per Kerbal ton lifted. Another way to think about it is 2.017 units of fuel per 1 that is put up. This means it only costs around 2 tanks to send 1 up into orbit. Best part about this lifter is it is put on top, even with placing a brick of fuel tanks on top it still flies (somewhat) like a champion. This is extremely efficient believe it or not, even use the NovaPunch pack I was only able to get it down to 2.1:1 fuel ratio (lower is better), but I have new plans now that I\'ve built this.

To give some quick stats of it:

-Lifts 70 Kerbal tons into low orbit

-Efficiency of 403.5 per Kerbal Ton or 2.017:1 fuel ratio

-Leave no debris in orbit

-5 stage rocket using 56.5 fuel tanks and 25 engines

-Near impossible to fly!

-Comes with insane launch platform to hold it up free of charge! (Contributes to most the lag)

Craft file - http://www./?dh9ej2uv6c8e4dj

Quick note about my specs:

i-5 2500 3.3 GHz

8 GB DDR3 RAM

Radeon HD 6870

I get 15fps while flying this...good luck!

[MrPwner]

With docking coming in the next patch

Docking isn\'t coming in the next patch, EVA\'s and IVA\'s will.

Nice rocket btw

[Dobrodav]

I am little bit aware to use mods, if i am absolutely not forced to use them (like mechJeb for controlled detachable parts, or fixed camera - to fly space-planes). Its not proved that i can not survive in game, without Nova punch mod, and i am sure as hell, that that 200 parts mod, will kill my notebook, so ... (there is goes lot of censored words). I can survive without this.

[gyro2death]

Docking isn\'t coming in the next patch, EVA\'s and IVA\'s will.

Nice rocket btw

Thanks but what? I thought because of the eva\'s and such they were gonna add docking for space stations BOO...Oh well I guess my floating ring a fuel tanks can act as a jumping platform then...

[adammada]

I wanted to beat your record, and this is mine super efficient lifter (yes, TurboJet engines rules)

1. 28 FUELS Payload - just like yours.

2. Uses 33 FUELS + 7 0.5 FUELS = 36.5 in TOTAL

3. It can get to 75 km orbit easily, with 3 fuel tanks still full.

3. Rocket is very stable and pretty easy in handling.

4. Not debrisless...

[Phoenix Aerospace]

Just curious: Is there actually any advantage of using turbojets over using solid/liquid strap-on boosters?

[adammada]

Big. Turbojet uses much less fuel and gets the same thrust (200) like liquid engine. I think about 1/6 of liquid engine fuel consumption. Of course its best below 10 km, but in mine design six 0.5 fuel tanks are feeding 18 turbojets and they are lifting whole rocket to 10 km.

Disadvantage - rocket cannot 'stand' on turbojets.

Edit:

Liquid: Mass 2 , Burn rate 8, Thrust: 200, Vectoring: NO

Turbojet: Mass 1.2 Burn rate 0.4, Thrust 200, Vectoring: YES

So 20 times less fuel consumption, almost half weight + vectoring.

[Corona688]

Just curious: Is there actually any advantage of using turbojets over using solid/liquid strap-on boosters?

Turbojets burn for a long, long, long time, because they use air from the atmosphere -- you get to carry more fuel with you.

[Androsynth]

I just designed a stock super heavy lifter that expends 65 fuel tanks in order to deliver 83 fuel tanks into orbit. Either I\'m really good at this, or I\'m exploiting a bug without realizing it..

Honestly, I\'m inclined to think it\'s a bug related to fuel lines, but I\'m going to have to do some testing. I\'d might as well point out that I\'m letting Mechjeb do my launches for me, and the routine for that seems pretty efficient. I\'ve managed to beat it a couple of times, but not many. If you want to enhance your efficiency more, your angle of ascent could definitely use some work. You\'re getting up to 50/60km without much horizontal momentum at all. Overall I like your design though; minimalist with respect to payload and not overly complicated on staging, and nice choice of engines. I love that you\'re dropping the payload off with the front of the ship, and using the return vehicle to de-orbit your debris.

EDIT: I can confirm that I\'m definitely taking advantage of a bug in the system to gain extra efficiency, possibly a rounding error. My rocket has 37 aerospike engines at launch, which should burn fuel at a rate of 281.2 per second. The first stage of 8 fuel tanks carries 500 * 8 = 4000 fuel, and so it should be empty in 4000 / 281.2 = 14.22 seconds. Instead, the first 8 tanks are taking 23 seconds to empty completely. Performing the same math on a single engine and a single tank yields a 65 second burn time, and physical observations confirm that it does indeed run out after exactly 65 seconds. Something about the long chain of fuel lines must be reducing the consumption rate, without hurting my thrust.

[gyro2death]

I wanted to beat your record, and this is mine super efficient lifter (yes, TurboJet engines rules)

1. 28 FUELS Payload - just like yours.

2. Uses 33 FUELS + 7 0.5 FUELS = 36.5 in TOTAL

3. It can get to 75 km orbit easily, with 3 fuel tanks still full.

3. Rocket is very stable and pretty easy in handling.

4. Not debrisless...

Yeah they\'re going to fix using rocket fuel in turbo jets btw , and debrisless is kinda important too. But props on it, great idea using the tri-coupler and feeding fuel through it rather than using tanks, saves both weight and lets you be more flexible with the release point without wasting fuel (I use this design in several of my space planes)

I just designed a stock super heavy lifter that expends 65 fuel tanks in order to deliver 83 fuel tanks into orbit. Either I\'m really good at this, or I\'m exploiting a bug without realizing it..

Honestly, I\'m inclined to think it\'s a bug related to fuel lines, but I\'m going to have to do some testing. I\'d might as well point out that I\'m letting Mechjeb do my launches for me, and the routine for that seems pretty efficient. I\'ve managed to beat it a couple of times, but not many. If you want to enhance your efficiency more, your angle of ascent could definitely use some work. You\'re getting up to 50/60km without much horizontal momentum at all. Overall I like your design though; minimalist with respect to payload and not overly complicated on staging, and nice choice of engines. I love that you\'re dropping the payload off with the front of the ship, and using the return vehicle to de-orbit your debris.

EDIT: I can confirm that I\'m definitely taking advantage of a bug in the system to gain extra efficiency, possibly a rounding error. My rocket has 37 aerospike engines at launch, which should burn fuel at a rate of 281.2 per second. The first stage of 8 fuel tanks carries 500 * 8 = 4000 fuel, and so it should be empty in 4000 / 281.2 = 14.22 seconds. Instead, the first 8 tanks are taking 23 seconds to empty completely. Performing the same math on a single engine and a single tank yields a 65 second burn time, and physical observations confirm that it does indeed run out after exactly 65 seconds. Something about the long chain of fuel lines must be reducing the consumption rate, without hurting my thrust.

Would love to see your craft file, are you using part explosions to separate stages? There\'s a post about a bug where if you over-heat a piece with a LFE (Liquid Fuel Engine) that they seem to burn at around 1/6th the normal rate, a guy was able to get a rocket up to 200km rather than a mere 40km before engine cut off without this glitch

Also a note about the efficiency of the launch angle. I still am trying to figure this out completely but mechjeb actually uses a poor angle of assent for crafts with lots of drag, while testing this due to several dozens of flights I started putting mechjeb on to launch it (just have to disable him in the upper part once the rocket starts to spin as it would lose control). But I couldn\'t get to orbit with its angle of assent. I looked it up and there\'s a whole set of formula\'s on it but the optimal way of doing a gravity turn is based on a load of factors. I bet there could be some improvement on mine for sure, but jeb\'s angle adds too much drag from the atmosphere with these kind of larger designs. I should play with jeb some more though, you can edit a lot about the launch angle inside it, but its quite time consuming hehe.

[Analogy]

Wow, I didn\'t realize that a jet engine produced just as much thrust as a rocket engine in this game. Real-life jet engines can only achieve about one fifth of the sea-level thrust of a comparable rocket engine.

[gyro2death]

Wow, I didn\'t realize that a jet engine produced just as much thrust as a rocket engine in this game. Real-life jet engines can only achieve about one fifth of the sea-level thrust of a comparable rocket engine.

Yeah jet engines have some balance issues currently, I imagine when they overhaul the in atmosphere flight again they\'ll address this. But yeah they\'re a reason no one at NASA straps jet engines to the side of the shuttle to launch it

[Phoenix Aerospace]

...Unless it\'s an air-launched TSTO...

[gyro2death]

...Unless it\'s an air-launched TSTO...

Yeah honestly until the balance out jet engines TSTO is definitively the most efficient way to get to orbit using jet engines. At 20 times the efficiency and the same thrust under 10km using it instead of a booster makes orbit very easy (I have a design up atm that\'s just barely over 1.1:1 fuel ratio to get to orbit with 28 fuel tanks). But I\'m gonna not use them till they\'re changed as its a bit too broken since as someone stated, jet engines really can\'t put out equivalent thrust to a LFE in reality.

[gyro2death]

OK, just updated my lifter to version 2.0 and as such it is pretty much a flat out better in every way lifter. Enjoy.

[adammada]

I think that it may be using fuel flow bug. Its hard to avoid it in more compex designs.

[Apotheosist]

I\'m not satisfied that any of the designs I\'ve seen here are very efficient at all. I see a lot of extra mass and staging sequences I dont think are very efficient. The title 'The most fuel efficient super lifter' seems misleading to me. I may of course be wrong. I will try build an efficient heavy lifter rocket of my own.

[gyro2death]

I\'m not satisfied that any of the designs I\'ve seen here are very efficient at all. I see a lot of extra mass and staging sequences I dont think are very efficient. The title 'The most fuel efficient super lifter' seems misleading to me. I may of course be wrong. I will try build an efficient heavy lifter rocket of my own.

Well to start off you\'re being quite rude, second feel free to build an efficient heavy lifter.

This rocket is only labeled as 'The most fuel efficient' since there was no other fuel conscious designs that I\'ve seen and until someone else builds one more efficient the title isn\'t misleading at all. I\'m welcome to constructive criticism but you could try to be a bit more polite when posting in someone\'s thread.

[Apotheosist]

@gyro2death, I\'m very sorry if I seemed rude, and looking back at my post now, I understand what you mean. I did not intend to be rude, I am all for constructive criticism, which I was aiming for, but I veered off too much to the criticism side. I appreciate the effort being made to build efficient rockets, and would like to contribute to the effort. This way we can all learn from one another. Once again, apologies for my inapropriate post.

[gyro2death]

@gyro2death, I\'m very sorry if I seemed rude, and looking back at my post now, I understand what you mean. I did not intend to be rude, I am all for constructive criticism, which I was aiming for, but I veered off too much to the criticism side. I appreciate the effort being made to build efficient rockets, and would like to contribute to the effort. This way we can all learn from one another. Once again, apologies for my inapropriate post.

Well I\'m glad it wasn\'t intended to be rude. As for the efficiency of the designs combing through some of your threads (specifically the bare min mun trip) i\'ve learned quite a bit about things I was curious about such as optimal TWR, which the rocket actually does very well on (TRW 1.94 climbing to a peak of 2.5 as fuel drains at around 35km).

Also I tried redesigning my rocket to have greater TWR (aiming for scaling near to 3 which someone calculated as optimal at the upper edges of the atmosphere) by keeping all the engines and just staging off tanks, but this seems to have too much thrust and wastes much more on delta-v on drag (TWR was 2.05 sea level, 2.5 at 12km and 2.8 at 34km). Also I\'m very curious to see how you would design a rocket for this, I\'ve gotten into quite a pattern of using 6-symmetry be interesting to see another design.