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how to get further in space without making super massive ships?


jevry

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so i just finaly bought ksp. and i love it.

what exites me most is wondering where the planet is you are trying to land on and after looking on orbital map going, oh there it is!

and when u go out of map moe to look the other way....... BWAAAAAAAAAAAAAP oh dang that is a big planet!

anyways.

i have seen enough gameplay to know some basics though the sizes do freeze my actions and make me panic nearly ruining my first ladning that i chose to be on minmus cuz mun's 2scary4me

 

but i was wondering. will i always need 2 longest possible 3m parts and a 4 engine 3m part welded on my craft to even reach minmus?

or what are more effective design plans? i found the stock ones not help too much

 

thanks in advance

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Greetings @jevry and welcome to the forums.

Firstly - as with most things in this game after a little practice landings become routine.

When it comes to design I find it is really useful to have a Delta-v and thrust to weight readouts in the Vehicle assembly building (Kerbal Engineer Redux).  This helps with design in that you have an idea how much energy your rocket has on launch and it is useful as a yardstick to improve your flying.  With the community Delta-v map you can work out how much rocket you need to get places.

This thread contains a lot of useful information on building and you can always ask the community for help and advice:

 

 

 

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The blunt answer to your question is: No. Definitely not. 3.75m parts are not necessary. Neither are 2.5 meter parts. How to build and fly efficiently is something really complicated, with a lot of depth that involves a lot of not entirely intuitive physics, but here's an intro to delta-V, as a start. I don't know how much you know, so I'm going to assume nothing.

Delta-V is the way one measures capacity to go places in orbital mechanics. Basically, it measures your vessel's ability to change its own velocity by performing burns. If you have more delta-V, you can perform more/bigger burns and therefore can go farther. In practice it's more complicated than this because of things like gravity assists and the Oberth Effect, but for our purposes this explanation will do.

Delta-V is computed using the Tsiolkovsky Rocket Equation: Specific Impulse (Isp) * 9.81 * ln(wet mass/dry mass). Specific impulse is a measure of an engine's efficiency, and is measure in seconds. The specific impulses for every engine can be found in their right-click menus in the VAB. Why seconds, you ask? The 9.81 is there to deal with the particulars of what specific impulse is, and should just be treated as a constant, with no other meaning. The ln stands for the natural logarithm (log base e). The wet mass is the mass full of fuel, and the dry mass is the mass empty of fuel. Delta-V should be computed separately for each stage.

To go to Minmus, you need 3600 m/s to reach orbit, 900 for the transfer, 100 for plane change burn, say, 200 for the capture burn, 175 to 200 for landing, another 175 for re-orbit, and 200 for the return. That adds up to a total of 5350, but let's call it 5500 to be safe.

For good efficiency, design from the top down. Build the lander first, then a transfer stage, then a launch vehicle. Or some other configuration. Whatever makes sense.

Oh, also-use a small command pod. The Mk1 (the black Mercury-looking 1-crew one) is good. Using the Mk 1-2 instead will, assuming efficient design, more than quadruple the mass of your rocket, since the Mk 1-2 weighs more than 4 times what the Mk1 does (4.12 t as compared to .84 t).

And, of course, practice makes perfect. Really good efficiency takes time and experience.

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Often, a smaller ship can go farther than a large ship. Trim mass off the top and each of the lower stages gets longer range. 

Also, the stock ships are meant to give you ideas, but are not meant to be better than ships you can build for yourself. :)

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7 hours ago, jevry said:

but i was wondering. will i always need 2 longest possible 3m parts and a 4 engine 3m part welded on my craft to even reach minmus?

For Minmus you can do it pretty minimally, so long as you do your ascent and transfer burns efficiently. There was actually a discussion about minimal minmus landers earlier today so I cobbled this together as an example of a minimal Minmus craft. This will get to Minmus, land and return. But the lander is really minimal, no landing legs and uses RCS thrusters rather than a regular rocket engine as the gravity on Minmus is so low. But even if you beefed the lander up a bit the overall rocket won't need to be much larger than this.

ruvlFiH.jpg

 

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thx already guys. good to know the ksp community is indeed very friendly. the thread helped me better understand the SRB.

aside from srb's. delta-v i do know what that means thanks anyways though. i will look into getting some mods showing delta-v and other stats.

however, i don't think i fully understand the rest of the rocketry yet.  the stage that comes after the SRB stage. what should remain after getting out of kerbin atmosphere is probably not so clear to me . i got the minmuslander delivery stage with about 80% fuel into kerbin orbit. and how large the non srb part of the escape atmosphere stage should be i havent fully mastered either i think.

(also, how do i get over my omg that is a big planet/mün fobia? atmosphered and small icy/welcome colored planets/moons are less scary)

 

there, my craft to minmus. as you can see i have a giant ass bottom stage. the middle stage has the skipper engine i believe. the downgrade of the mainsail version. and the lander has a poodle engine that i cut its thrust limit to about 20 percent.

i got to minmus with 30-40ish% fuel remaining. sadly i forgot to lower the landing gear spring and damper as i was not aware of that update. therby my engine broke and 2 kerbals are now stuck on minmus. sandmox mode though so....

anyways. could anyone be so nice to point out the mistakes of the minmuslander i made here? that would probably help understanding( i think i didn't need the batteries, large solar arrays or robotic core but i was testing those together i think.)

unknown.png

Edited by jevry
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There is nothing "wrong" with your design per se, other than being 3x more rocket than you need.   Some people dig that, you don't always have to go places on the smallest, most efficient way available.

 

Some thoughts:

 

Too much monopropellant. You wont need nearly that much, and it is a very inefficient fuel.  2 of the rounded monoprop tanks on your lander should be plenty.  That big yellow 2.5m mono tank is definitely too much.

That first stage, its really far too large (for my tastes).   Try using the big orange tank and something like a skipper or mainsail as your main lifting engine.  You should be able to take the giant Mk3 parts and SRB's off (saving huge amounts of weight) and replace them with just 1 or 2  2.5m fuel tanks and a big engine.

 

You could lose both of those 4k inline batteries and run with just a few of the radially attached much smaller ones.  A few of the 100-unit tiny ones with the green light on them would be fine.  Your solar panels will recharge them.

 

The post above yours shows a rocket that is more similar to the sizes I fling at Minmus.  Indeed, sometimes smaller is better.   Also, the better you get at flying, the less margins you will need to build into the craft.  As that build stands, you could land it on Minmus with tons and tons of its fuel left onboard.  Each time you get better, you can think to yourself "what did't I need on this trip", and scale back your design accordingly. 

 

Good Luck, keep asking questions.

Edited by klesh
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just made a design based on the advice given and the idea to use that special fuel transfer stage techick on 4 SRB's

for people who don't know what i mean and i don't know how famous it is il explain what that technik means in my understanding is for example strapping 6 (liquidfuel) boosters around your main rocket. and adding fuel lines that move the fuel in such ways that first u have 7 thrusters, the fuel gets transfered away from 2 thrusters oposite from each other to the left(or right) booster. when these 2 emty u drop em. and the next 2 will then drain faster then the rest. and so on until u have the 1 middle left. this way you have the appropriate amount of thrust for each atmospheric stage.

i once saw this and was amazed and i remembered it from when i saw it.

 

anyways this is what i came up with. know the fering wont help too much but it looks better

not launched it yet. neither checked staging...

after i perfected my minmus length space trips with a 2M sized cockpit il definitly try science mode as i read that is usefull for new players since less parts n stuff. (yes i know has no rcs or control wheels yet)

unknown.pngunknown.pngwell not bad. better then i could have hoped although fuel tubes don't work with solid fuel boosters. guess i forgot the power of the orange fuel tank and engines (u can't completely see but it is a full orbit with both ends above 70k)

Edited by jevry
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5 hours ago, jevry said:

for people who don't know what i mean and i don't know how famous it is il explain what that technik means in my understanding is for example strapping 6 (liquidfuel) boosters around your main rocket. and adding fuel lines that move the fuel in such ways that first u have 7 thrusters, the fuel gets transfered away from 2 thrusters oposite from each other to the left(or right) booster. when these 2 emty u drop em. and the next 2 will then drain faster then the rest. and so on until u have the 1 middle left.

This is known as asparagus staging.

It looks like this is a one way mission to Minmus?  I don't see parachutes or a heat-shield on your vessel.

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5 hours ago, James Kerman said:

This is known as asparagus staging.

It looks like this is a one way mission to Minmus?  I don't see parachutes or a heat-shield on your vessel.

Yes James Kerman you are right. Listen for anyone needing advice; if you want to return Safely you must ALWAYS AND ALWAYS put a parachute and a heat shield and a decoupler beneath them!

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14 hours ago, James Kerman said:

This is known as asparagus staging.

It looks like this is a one way mission to Minmus?  I don't see parachutes or a heat-shield on your vessel.

well first of all yes i did think i wasnt making it back to kerbin anyways. but well... i hit the wrong button again and dropped my second orange tank that was still full. so it was a no-way mission. il need learning some rendevous basics first will i want to get back to kerbin the way id like to get a lander back. as in have the transportcraft also take the lander back to kerbin. just using the lander seems so weird in my mind. just me though i guess.

i also decided to start with science mode seeing i got into orbit with 1 orange tank and a mainsail plus 4 srb's. pretty good for me

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dunno if this thread is still active actually but i just made this great craft

unknown.png

i got this thing to the moon with 1/2 fuel left. note that this is the edited version. the bottom stage first had 3 LV-T 45 engines. also it had no RCS or SAS since i didn't have that tech yet.(science mode) planning replicating such design in my career mode world. also planning replacing the SRB decouplers, not enough tech

(btw rcs fuel is in the service bay)

so ofc i gotta ask, is this thing well designed? 

il quickly also that all engines but the bottom were th LV-T 30 as i felt that id only need the extra steering in atmosphere. after that i would move my craft into maneuver position ahead of the maneuver node

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On 16-12-2016 at 11:52 PM, TopHeavy11 said:

Two words: refueling stations.

yeah but that is kind of useless at lower stages of the game

would be more efficiënt to just make that oversized ship.

docking would be an ass and waste of fuel.

i got no docking ports yet.

in sandbox mode i do but then i might as well make that massive ship.

and shooting 2 ships into orbit is more expensive then 1 because u then need to pierce the atmosphere twice

even if u mean using drills i have no drills that is late game items and i would have to ran/ren/ron devou with either a planet or a meteor so that is also very useless to me until very-late game career modes.

in sandbox i do have drills but again, might as well make bigger ship.

so that really doesn't solve any of the problems.

altough it might work in certain situation it doesn't in any of the situations im in or will be in.

but to be more clear i ment how to more efficiently get ships into space/deepspace.

 

atm my furthest non-sanbox mode range is achieved with my lifter design i call the "casino".(pretty much exactly the H-1 seen above but with a bit less tech. the H-1 was in science mode the casino in career mode because it was a big gamble i only had enough money left for one ship launch after getting the upgrades needed for getting maneuvre planning)it can get from kerbin to the moon and back with half a standard sized fuel tank back to kerbin. or slingshot via the moon to get half a fuel tank into orbit with the sun. and guessing its masses i have been transporting i believe 5 tonnes in the payload is the optimal and max weight.

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3 hours ago, TopHeavy11 said:

Well...IRL if you built a ship in space, less energy would be used, it wouldn't have to deal with ascent, and you could save money.

Yeah, but I don't think the OP is at that stage of gameplay yet.

 

@jevry- one thing I see with your last rocket is that you're using decouplers with girders on the booster stage. You could replace that with the extended version of the decoupler to keep your boosters' clearance. Also, nosecones on those SRBs is a good idea.

 

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First of all congrats on buying KSP and welcome! New to the forums myself, but long time player.

Tips:

- Someone mentioned it, but every little bit of weight you can save on your top stage will reduce exponentially the needs for your ascent and transfer stages.

- Unless you plan on docking, don't use RCS and don't bring monopropellant. In fact, you should remove any monopropellant from a capsule not attached to something that is going to dock.

- Gigantors solar panels and these large batteries are overkill for a simple crewed mission without either a refinery or a mobile lab.

- Poodles, terriers and nuclear engines are much better to use once in space than skippers or mainsails.

 

On 12/16/2016 at 11:27 AM, jevry said:

dunno if this thread is still active actually but i just made this great craft

i got this thing to the moon with 1/2 fuel left. note that this is the edited version. the bottom stage first had 3 LV-T 45 engines. also it had no RCS or SAS since i didn't have that tech yet.(science mode) planning replicating such design in my career mode world. also planning replacing the SRB decouplers, not enough tech

(btw rcs fuel is in the service bay)

so ofc i gotta ask, is this thing well designed? 

il quickly also that all engines but the bottom were th LV-T 30 as i felt that id only need the extra steering in atmosphere. after that i would move my craft into maneuver position ahead of the maneuver node

Looks alright, don't need the RCS though if you are not going to dock. Also no need the extra SAS modules, Mk I capsule should be enough for your top stages and the radial engines should provide plenty of steering capabilities for your initial ascent.

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If you only want to land on Minmus and collect surface samples, build a craft that can get into Minmus orbit. That's all you need.

From a low Minmus orbit it's easy to EVA jetpack down and get back into orbit, and still have plenty of fuel left to repeat that 3 times over.

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Hm. Your design is quite good for someone so new to the game, to be honest. However, a couple of things jump out at me. First of all, you don't need RCS. At all. The reaction wheel will be more than sufficient. I would call even the big reaction wheel overkill, but that's just me. Also, you used the Rockomax adapter. Don't use that part under any circumstances. It's heavier than the alternative. Just mount your tanks radially around a center one and put an individual nosecone on each tank. Finally, you should have stuck with the LV-T30's. Thuds have too low a TWR for anything other than niche use.

Edited by IncongruousGoat
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On 18-12-2016 at 9:39 PM, Dman979 said:

Yeah, but I don't think the OP is at that stage of gameplay yet.

 

@jevry- one thing I see with your last rocket is that you're using decouplers with girders on the booster stage. You could replace that with the extended version of the decoupler to keep your boosters' clearance. Also, nosecones on those SRBs is a good idea.

 

yeah i know this but i do not have those ones yet in the world i build the rocket. not enough tech and stuff

 

22 hours ago, Stoney3K said:

If you only want to land on Minmus and collect surface samples, build a craft that can get into Minmus orbit. That's all you need.

From a low Minmus orbit it's easy to EVA jetpack down and get back into orbit, and still have plenty of fuel left to repeat that 3 times over.

wow genius. i mean i knew with the help of a upside down active rocket thruster you could get into orbit. but that must have been the mun when i saw it. not minmus.

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1 hour ago, jevry said:

yeah i know this but i do not have those ones yet in the world i build the rocket. not enough tech and stuff

Fair enough.

The point someone made about changing your lower engines is valid, and adding nosecones to the SRBs will help you.

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Something I use that can get out of the solar system entirely in just 1.25 meter parts for the first stage is my Cubesats. It uses the largest SRB in the game as the first stage, a "half" (I guess you would call it) 1.25 meter liquid fuel tank that uses the Terrier engine, and then within the payload bay I put an octoganal strut with 8 Sepratron motors around it, then put the Probodobodyne QBE on top with solar panels and an antenna. Launching it just before sunset can get you out of the solar system. It's quite uncontrollable (something you don't want with interplanetary missions) but it gets the job done. I'll try to post a picture of it sometime soon.

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On 14/12/2016 at 1:37 AM, jevry said:

just made a design based on the advice given and the idea to use that special fuel transfer stage techick on 4 SRB's

Asparagus staging doesn't work on SRB's. Solid fuel is non transferrable. Jeb learned it the hard way. :wink:

Edited by Atlas2342
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12 hours ago, Atlas2342 said:

Asparagus staging doesn't work on SRB's. Solid fuel is non transferrable. Jeb learned it the hard way. :wink:

yes i learned it the hard way too :D. forgot to mention that i believe. well my craft did well anyhow.

 

anyways i have an emergency and it hasnt been answered yet on another post i placed.

my emergency is as following: one of my crafts very much resembling the casino design just returened from minmus in a orbit with the short end at 500km and the long end at a few million km height(50m/s minimum to return to kerbin). however. i just found out i forgot to aded a decoupler on my last stage with the terrier engine. without it i cannot return to kerbin.i have an estimate of 300-400 science stored in it and cannot afford to lose it and revert flight has already been screwed and impossible by now.

the plan: get jeb outside the craft and use his rcs to slow down my command capsule and maintanance bay into the atmosphere of kerbin.

the problem: jeb will only look at one direction and even with his jetpack on will refuse to turn into the direction i want making steering imposible let alone pushing the craft

 

help!

(i have enough funding for an attempted rescue mission yes but i have not practised rendevousing yet and don't plan doing it on such a important mission

 

edit: why is evryone just liking this comment? it does not help me. is something funny here that i am not seeing?

Edited by jevry
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