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multi stage rockets for leaving planets

Discussion in 'General' started by mdram, Jul 11, 2017.

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This last post in this thread was made more than 31 days old.
  1. mdram Apprentice Engineer

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    104
    is this even possible?
    maybe using connector blocks to attach atmos thrusters

    diconnect them when you reach altitude and turn on the hydrogen?

    anyone try it?
     
    • Agree Agree x 1
  2. Sirhan Blixt Apprentice Engineer

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    Merge blocks are a thing.
     
  3. mdram Apprentice Engineer

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    aaahh, thanks, missed them on the wiki
     
  4. Taemien Apprentice Engineer

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    468
    Possible, yes.

    Feasible.. that's a question I'd like to ask. Has anyone utilized a cheap multistage system to get into orbit that was more efficient than simply using one piece?
     
  5. ShadedMJ Apprentice Engineer

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    217
    I agree with Taemien.

    Last time I checked, full and empty hydrogen tanks weigh the same. Fuel (ice) is fairly easy to find.

    That said, it feels a little fitting to get a ship to space and jettison the atmospheric thrusters as "Bye planet, don't need you any more."
     
    • Agree Agree x 1
  6. SilentShadow Apprentice Engineer

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    286
    Jettisoning iron is no problem. But that's a lot of nickel in those thrusters...
     
  7. FlakMagnet Senior Engineer

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    1,551
    I have built various multi-stage efforts using merge blocks or rotors, where you can detach the thruster .... but it's more for the look than the practicality.

    As you don't have proper thruster control with the booster rockets, you are just setting them as 'over-ride' and just binning the weight of the tanks when you are done Using rotors you can have a large grid body and attach small grid tanks and hydrogen thrusters....then detach the rotor heads when the fuel is used up.

    In practice, though, filling the boosters is a pain, and including O2 generators and loading with ice is easier but increases the loss of materials when you dump the booster.

    In strict survival terms, it's easier not to bother as there is no way to simply recover the things. Perhaps with parachutes in game, you could come back and recover the things intact to re-attach and refuel.
     
  8. odizzido Junior Engineer

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    670
    There is no point in making multi-stage rockets in SE because hydrogen is the easiest and cheapest part of the ship by far. It's almost free.

    Though thinking about it couldn't you use auto pilot to land the atmo thrusters?
     
  9. SilentShadow Apprentice Engineer

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    286
    Before they buffed small grid hydro tanks it was actually somewhat practical. At the previous 80 seconds per tank I ended up with excess weight I was glad to toss.
     
  10. mdram Apprentice Engineer

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    104
    i may just keep the atmo engines, in case i dont make the required height

    dont wanna crash and burn

    i can always disassemble the parts later
     
  11. Ronin1973 Master Engineer

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    4,801
    Hydrogen is cheap to make. Hydrogen thrusters and hydrogen tanks are pretty light.

    If mass is a concern, ships can be made as skeletons... just the working parts and almost no armor. Your speed is capped at 100m/s in vanilla, the gravity zone of a planet is capped around 40km from the surface. Once you're high enough the gravity constant decreases, meaning less force is needed to accelerate. You need only to burn fuel for around 400 seconds.

    When working with hydrogen, people will either use bursts letting the speed fall to a minimum level and then triggering the thrusters until the maximum speed is released. Or you can switch off individual thrusters until you're running barely above the threshold for hover once the ship is traveling at 100m/s, just to maintain that speed. This conserves hydrogen. There's no advantage to burning your hydrogen at maximum force constantly as the speed limit just nullifies it once you're at 100m/s.
     
  12. FlakMagnet Senior Engineer

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    1,551
    I have a simple design for a ship that uses one large atmo and one large hydrogen thruster to get into space. It carries enough cargo to make an assembler, med bay and refinery once I make it into space.

    It is capable of making the return trip .... landing tail first ... but I seldom bother.
     
  13. mdram Apprentice Engineer

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    104
    1 atmos?

    doesnt that cause tipping?

    or are the physics not that advanced. i have been going on assumptions
     
  14. Vrmithrax Senior Engineer

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    1,017
    Thrust is simplified in the game engine. Center of thrust vs center of mass does not have any real bearing on attitude of the ship, to make it easier to just build something that flies straight right from the starting block. You can build a totally asymmetrical ship with no maneuvering issues.
     
  15. mdram Apprentice Engineer

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    104
    guess im too used to KSP :)
     
    • Like Like x 1
  16. Elfi Wolfe Apprentice Engineer

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    498
    I use it for getting a orbital recon bird to orbit.
    Once parachutes get into vanilla game, need to add one to stop that released first stage from slaming into ground near launch site.
     
  17. Bumber Senior Engineer

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    1,018
    Atmospheric thrusters only get you to around 8000m (on Earth planet) before they cut out completely. The efficiency begins dropping at around 2000m, so over-weighted craft won't make it far past there. Considering how quickly you reach that versus escape time, it's not really worth it.

    Plus, you might want them for re-entry. If you're going to use them, might as well keep them.
     
    Last edited: Jul 13, 2017
  18. macgeifer Apprentice Engineer

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    138
    i build several multi-staged hydrogen rockets with merge blocks and/or connectors. my experience so far:

    pro:
    best thrust/mass ratio of all thrusters
    looks badass
    engineering task^^
    no uranium needed
    high payload

    cons:
    only useful with parachutes, when you dont recover the parts its better to build a multithruster-ship in survival
    each rocket stage needs atleast a battery, some timer or a programmable block, a parachute and a beacon for recovery
    thrust override must be calculated considering the rocket mass (or remaining stages), accelerating too fast is a waste of hydrogen when flying at speedcap (this can be done easily in excel); a perfect rocket stays below speedcap until all fuel is burned
    speedmod highly recommended; 300m/s works fine for me
    sideways mounted boosters sometimes need an additional thruster for decoupling, otherwise they can damage the next stage; when you decouple a stage with a connector make sure to shut off the block and not only unlock it. yellow aligned connectors have a force of attraction which can destroy the stage during decoupling. you can avoid this using merge blocks, but than you need to refuel every single stage
     
    Last edited: Jul 13, 2017
  19. mdram Apprentice Engineer

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    104
    in the same line as the main question

    1. is the moon i see the actual one i will be aiming for (i relize it does not move)
    2. how difficult are asteroids to find?

    plan is to switch to ion once i get out in space
    using hydrogen as a backup once i find a good source of ice there
     
  20. FoolishOwl Junior Engineer

    Messages:
    510
    Yes, it's the same model, rendered at a different scale. This means, by the way, that you can detect beacons and radio antennae in their actual positions, when you're in broadcast range.

    Depending on what scenario you're using, there may be several other planets and moons you can see and travel to.
    They're easy to find. It depends upon the density of the asteroid field set for the game, but generally, off planet, you're always going to be able to see a few asteroids within a few kilometers of your current position.
     
    Last edited: Jul 13, 2017
  21. Elfi Wolfe Apprentice Engineer

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    498
    I use a script to keep the launch speed at about 90m/s or at 5 sec of Gravity, which ever is lower.
     
  22. ViroMan Senior Engineer

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    Why not add a projector/weld/grind system to your ship for atmo vs space flight? Why would you ditch those useful components??

    Even if you are just starting out you can have it grind down your atmo thrusters. IF you already have the platinum you could have it build up your fav ion thrusters.
     
  23. PyreStarite Junior Engineer

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    559
    Why dispose of a perfectly good rocket when you can instead make a trans-atmospheric ferry?
     
  24. Bumber Senior Engineer

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    1,018
    Only practical with high inventory multiplier. The components weigh the same as the block in 1x setting.
    Atmo and Ion don't share their heavy components, unfortunately.
    (Atmo are 81% motor by mass, Ion are 89% thruster component.)

    Personally, I would give the stages a remote control and have them fly themselves back to the launch pad.
     
    Last edited: Jul 14, 2017
  25. mdram Apprentice Engineer

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    104
    wait, so in 10x inventory, ore is .27per not 2.7?
     
  26. Bumber Senior Engineer

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    1,018
    I think so. I wonder if it affects damage calculations for loose rocks, or if it's just applied to inventory.
     
  27. ViroMan Senior Engineer

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    1,123
    wait wait wait... I too wonder if it affects damage calculations...
    If you shoot with an ore cannon at 1x inv. it would do 10x more damage then at 10x inv. ?
     
  28. dispair Apprentice Engineer

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    252
    I can see doing a staged rocket for the cool factor. As far as practical go-to no.
    I have a massive sphere (MechWarrior) dropship. 4 large hydrogen and 8 tanks. It is amazing. And I use a minimum amount of fuel just with thrust override on the toolbar.
     
  29. May Rears Apprentice Engineer

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    411
    As far as imagination and the fun of building is concerned then multistage ships are good however if efficiency is what matters then there is no need. Use thrust override on your main thruster to keep thrust just high enough to stop you being pulled back to the planet, as your altitude increases the thrust required drops. You can make a hydro powered ship very efficient this way.
     
  30. oleando Apprentice Engineer

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    145
    Yes, unfortunatly there's no point in doing that, for so many reasons: 1 tank can make you leave and reentry planets a lot of times when manually controlled; conveyors can let 1 thruster be fueled by multiple tanks; small large ship rockets mass are so
    irrelevant that large hydrogen thusters can lift them effortlessy.
     
Thread Status:
This last post in this thread was made more than 31 days old.