How to launch really heavy stuff?

[Leslie110501]

Are there any general tips or methods on how to launch REALLY HEAVY STUFF into orbit. I'm talking about 1 Million kg.(It's going to go to EVE and then to Gilly and land there. Then back home, but it has tons of science equipment from mods and it has a science lab and 2 command pods so thats why its so heavy.)

[Tyko]

wow, a 1000 Tons...what about lifting it in parts and then assembling in orbit?

Along the same lines but a little simpler - lift it with empty fuel tanks and launch fuel separately - fuel it in orbit. what's the Dry Weight of the craft?

Edited July 27, 2016 by tjt

[Leslie110501]

First of: I am right now trying to use 4 of these huge B9 Aerospace engines. These produce 66.530 kN but still it only accelerates at 10,71/ms² O_O Dry mass is 275.400 kg. Btw, with the B9 thrusters and fuel it weighs fricking 6246,82 tons... THATS OVER 6 MILLION KILOGRAMS!!!!!

[DaMachinator]

If you're amenable to installing mods, install SpaceY Heavy Lifters and SpaceY Expanded and make a 7.5m megalifter with side boosters (because usually the core stage will not be able to orbit on it's own - you'll need aspargus or onion staged boosters, or some of the really big SRB's)

Mod also comes with massive radial decouplers with integrated sepratrons, and a bigger version of the sepratron.

Edited July 28, 2016 by DaMachinator

[ZooNamedGames]

List the science mods- I might be able to trim your Eve vessel down in weight and get you what you need. As to teaching you about how to save weight and build those big crafts (whilst staying realistic, effective and not relying on the asparagus/onion staging techniques), I can do that. We just need to discuss how I will do so (me coaching you in the comments of a livestream you host, me send you pictures and diagrams and explainations, or me simply typing the reasons up in a big lecture). I can try to help you in many ways, just let me know if you want me to.

Hope I can be of help.

[steuben]

I'm working on a 1kt lifter... and still working on it. I know that I can lift about 600 tons to orbit and then up to 1000km x 1000km rendezvous. I've been working with stock parts, mostly the 3.75m class. Working on a lifter to get my station modules up there.

The general approach as mentioned previously:
- break it apart into sections. About 90% of the max rated capacity of the best launcher you have.
- lift the sections dry. You can lift the fuel later.

My approach, though YMMV is:
- forget about aero, go brute force. the rockets are all 3.75m parts
- forget about the "perfect" launch path. basically launch straight up and turn right, at about 60km.
- use lots of the reaction wheels, and a few batteries.
- use a semi-puller design, or build the boosters around the ship. this will look something like a capital M, with payload hanging off the middle.

I should be able to find some shots of my Bell class lifters. "When the bell tolls, your launch is doomed."

My suggestions:
- pics of the finished boat in the VAB will help us point your specific case in the right directions. and help suggest different directions for others looking at similar things.
- 300 ton dry weight is not too bad. Feels light for what you're planning, but then I design and launch heavy.
- with approx. 6 kt of fuel you may want to look at fuel generation plant it, for the return trip. Even with a 1kt launcher that's 6 launches to fuel it for the trip. What's the total DV you've got?

[Mystique]

Assembling something that huge in orbit may be difficult, time-consuming and wobbly (I tried assembling 1-2 kton motherships with modded nuclear reactor and biofuel farms, wasn't stable enough until I made it all in VAB and lauched as single ship without those docking ports), I made such huge Eve manned returnable mission and went with assembling whole ship as it is and launching it straight to LKO without staging anything in process (1st stage for Eve takeoff had more than enough TWR for launch to LKO, I just had to route fuel from upper stages to 1st stage's tanks to make sure I have enough juice). Then I just sent fuel barge (just batch of fuel tanks, to which I forgot to add RCS, so docking was really intense) to resupply that monstrocity and it went to Eve pretty nicely.

Edited August 1, 2016 by Mystique

[Leslie110501]

So guys, basicly I just put 4 of those B9 booster on it and it works but in the beginning it has such a terrible TWR :c I will try SpaceY. And I have DMagic Orbital Science, Station Science, KSP-I Extended. I think thats it regarding science mods. I may have more but im not sure right now.

[Mystique]

You may also consider procedural parts mod. It allows make somewhat custom-sized/shaped (and textured, for style!) SRBs with adjustable thrust, while not clogging part list with tons of parts. Also it's much more convenient to use procudural fuel tanks for constructing complex rocket (you may change its size and thus capacity and immediately see how it affects twr&delta-v, if you have any mod that calculates these parameters, really saves time on the long run).

[Heimder]

You are using gravity assist? If not try to project with this in mind, because can save a lot of delta-v when travel to more distant planets, like Eve, and less delta-v = less mass.

 

Break the transfer part in two or more smaller parts, launch each part individually and them assemble all in orbit (just put docking ports on every individual part and dock all together in space). KIS + KAS can assist you to assemble you crafts in space.

 

Also, you can build a mining, process ore and refueling outpost in Minnus, so you can launch you transfer stage just with sufficient fuel to reach Minnus and refuel completely in there.

 

You can also make a smaller transfer stage and put mining and process ore in this stage, than instead of a direct travel to Eve, visit some planets along the way to refuel you craft, lots of SSTO’s use this technic to reach almost all planets in Kerbol (or even all).

[Leslie110501]

Well my ship is fakin big and only the part that is delivered to eve weighs A LOT. Currently im not playing ksp actively anymore but it won't take long until I will do again. Thanks for all the suggestions. I will definatly use them for my future ships but my eve vessel now works with 3 mil credits worth of B9 thrust. I will just go with it  and use you FANTASTIC Ideas later in other vessels. Btw i don't really know the mechanics and the how to behind gravity assists  Would be nice if someone COULD ...MAYBE...,POTENTIALLY...explain it

[Heimder]

Scott Manley have done a video tutorial about gravity assist a long time ago (https://youtu.be/lIORB7svhaA)  , you simple need to make an encounter with a closer planet, note that the maneuver node will drastically change, showing two rotes, one is the route you is current in, and the other is the new route after you enter the SOI of that planet.

If you plan careful you encounter, you can manipulate the second route do get in encounter with another planet, this is the gravity assist, basically the gravity of that planet will change your rote,  instead of project you craft to get delta-v to reach Eve’s SOI, you project it to reach another SOI planet closer to Kerbin, put a little more Delta-v for corrections and use it’s gravity to change you route to EVE.

You can train you skills with Mun and Minnus, it is possible to use either mun’s gravity or Minnus gravity to change you rote to the other Kerbin moon, also it is a good way to get science early game because using this trick you can visit both moons SOI with just one trip (but just can land in the last one)

Edited August 4, 2016 by Heimder

[Leslie110501]

Ok i will look into this.