Need Advice For Refueling My Space Station

[Plaxo1]

Hi, I'm new to the forum, so I figured I'd ask you guys for some advice!

I currenly have my space station at a 100km orbit of kerbin. And though I'm able to refuel it, I can't seem to make the process both cheap or fast (fewer trips)..

Do you guys have any advice/designs that would make refueling my space station an easy task?

Picture of my space station:

[Choctofliatrio2.0]

If you're talented with SSTOs, you can use those to take fuel up there. If not... big rockets, I guess.

[RizzoTheRat]

For cheap you might want to look at reusability, if you can build an SSTO (either vertical launch or a space plane) and land it close to KSP it'll only cost you the price of the fuel used for the launch.

Alternatively you could set up a mining operation on the Mun or Minimus to make fuel there, and then bring it back to Kerbin to refuel your station.  you need around 900ish dV to launch from the Mun and get in to an aerocapture orbit of Kerbin, compared to 3300 or so launch from Kerbin.  Can't remember how much you need from Minimus but obviously its less to get to orbit, but a bit trickier to dock as you'll need to adjust to match the stations orbital  plane.

Edited January 25, 2016 by RizzoTheRat

[Just Jim]

I like to set up my refueling stations on Minmus, but it will cost you some of the fuel getting it into low Kerbin orbit.  

There is a third option, albeit a challenging one.  Bring an asteroid into Kerbin orbit and drill that for ore to convert to fuel.

This monster is part of my fan-fiction story, and has over 3000 tons... not units, tons... of available ore. I can't even begin to estimate how much fuel it will provide.  I've positioned it between the Mun and Kerbin to use as my main fuel processing (and tourist) station.

[Snarfster]

1 hour ago, RizzoTheRat said:

For cheap you might want to look at reusability, if you can build an SSTO (either vertical launch or a space plane) and land it close to KSP it'll only cost you the price of the fuel used for the launch.

Alternatively you could set up a mining operation on the Mun or Minimus to make fuel there, and then bring it back to Kerbin to refuel your station.  you need around 900ish dV to launch from the Mun and get in to an aerocapture orbit of Kerbin, compared to 3300 or so launch from Kerbin.  Can't remember how much you need from Minimus but obviously its less to get to orbit, but a bit trickier to dock as you'll need to adjust to match the stations orbital  plane.

What if you put the station on the same plane as minmus to start with? May be an option.

[Plaxo1]

53 minutes ago, Just Jim said:

I like to set up my refueling stations on Minmus, but it will cost you some of the fuel getting it into low Kerbin orbit.  

There is a third option, albeit a challenging one.  Bring an asteroid into Kerbin orbit and drill that for ore to convert to fuel.

This monster is part of my fan-fiction story, and has over 3000 tons... not units, tons... of available ore. I can't even begin to estimate how much fuel it will provide.  I've positioned it between the Mun and Kerbin to use as my main fuel processing (and tourist) station.

That looks absolutely amazing! What class is that asteroid?

[Tantalus]

I have a refueller rocket for the same purpose, with lifter and payload stage recoverable (except for the boosters, but if you use stage recovery even this doesnt matter). Payload is an orange tank to 150km, so should fit for you. If you are intersted, i can provide a craft file this evening (cet).

Regards

Tantalus

[Jhawk1099]

Why I was just going to ask a question similar to this. I am planing on building a mining base on Minmus with a fuel station either in minmus orbit or high Kerbin orbit. I would advise to do it the way i am because it would be further out (thus saving delta-v on transfer burns to other planets), it takes less fuel to get from minmus' surface  to minmus orbit, and everything can easily be reusable thus it would cost you nothing to re fuel your space station. It will be pretty hard for a beginner(like myself) but it's doable and hopefully cheaper long term. I will probably make a video of it if you would like to see that and see what messed me up and any tips i have so i can send you a link.

[regex]

It is ridiculously easy to put massive tonnage on orbit in the toy solar system.  So, IMO, the best fuel slug for a dedicated gas station like yours would be something like 1 & 1/2 3.75m tanks, which come to around 121 tons or something.  Add a small disposable tug to it and some RCS and you're good to go.  140 tons or so on orbit, NBD.

You can either make it a swap sort of thing and dispose of the tug when done or integrate the tug into the fuel slug and just deorbit the whole thing after transferring all the fuel.

Edited January 25, 2016 by regex

[Plaxo1]

1 hour ago, Jhawk1099 said:

Why I was just going to ask a question similar to this. I am planing on building a mining base on Minmus with a fuel station either in minmus orbit or high Kerbin orbit. I would advise to do it the way i am because it would be further out (thus saving delta-v on transfer burns to other planets), it takes less fuel to get from minmus' surface  to minmus orbit, and everything can easily be reusable thus it would cost you nothing to re fuel your space station. It will be pretty hard for a beginner(like myself) but it's doable and hopefully cheaper long term. I will probably make a video of it if you would like to see that and see what messed me up and any tips i have so i can send you a link.

If it's not to much work I would love to see what you've done. I'm a bit obsessed with only using my own spacecrafts, but I'd still like to steal some of your ideas and implement them on my own

[Plaxo1]

3 hours ago, RizzoTheRat said:

For cheap you might want to look at reusability, if you can build an SSTO (either vertical launch or a space plane) and land it close to KSP it'll only cost you the price of the fuel used for the launch.

Alternatively you could set up a mining operation on the Mun or Minimus to make fuel there, and then bring it back to Kerbin to refuel your station.  you need around 900ish dV to launch from the Mun and get in to an aerocapture orbit of Kerbin, compared to 3300 or so launch from Kerbin.  Can't remember how much you need from Minimus but obviously its less to get to orbit, but a bit trickier to dock as you'll need to adjust to match the stations orbital  plane.

I did actually make a SSTO spaceplane using R.A.P.I.E.R engines (not the most efficient engine, but easier..). But it still cost me about 50 000 in just fuel.. Which was more costly than just sending a staged rocket up.. I will admit I'm not an expert in SSTO spaceplanes though.

[LordKael]

7 minutes ago, Plaxo1 said:

I did actually make a SSTO spaceplane using R.A.P.I.E.R engines (not the most efficient engine, but easier..). But it still cost me about 50 000 in just fuel.. Which was more costly than just sending a staged rocket up.. I will admit I'm not an expert in SSTO spaceplanes though.

Watch a video tutorial on how to fly SSTO spaceplanes. There is NO reason for you to spend that much on fuel. Learning to fly them efficiently is half the battle, and not the most intuitive thing in the world. 

Edited January 25, 2016 by LordKael
addendum

[Just Jim]

2 hours ago, Plaxo1 said:

That looks absolutely amazing! What class is that asteroid?

That is a class-E.  About the biggest class-E I've ever seen.  That's why I started a fan-fiction story around it, it was just so huge!

The total weight is 3,801.2t and the total resources are 3,071.7t.  I'm hoping to use it for quite a while for my refueling needs.

[Fearless Son]

What @LordKael said.  Spaceplanes are theoretically very cost effective, but there is a large gap between theory and practice that is narrowed by the player's engineering and piloting skill.  If the fuel was costing you so much, my guess is that your SSTO was probably a) very heavy and b) had comparatively limited thrust.  I would speculate that it took you a while to get enough altitude that the RAPIERs became effective.  If that was the case, I would recommend adding more thrust on your way up.  I find an aggressive ascent might consume fuel faster, but it consumes less of it in the long run (just do not try to push the throttle too hard too soon lest you find the atmospheric compression becomes fatal.)  

[Plaxo1]

1 hour ago, Just Jim said:

That is a class-E.  About the biggest class-E I've ever seen.  That's why I started a fan-fiction story around it, it was just so huge!

The total weight is 3,801.2t and the total resources are 3,071.7t.  I'm hoping to use it for quite a while for my refueling needs.

great  the picture inspired me to try to catch my own asteroid... Going for a D-class to begin with, and here's my brand new asteroid catching rocket, docked to my space station! Not sure how much delta v I'll need, so this is going to be a test run to see approximately how much more/less I'll need.

[Just Jim]

3 minutes ago, Plaxo1 said:

great  the picture inspired me to try to catch my own asteroid... Going for a D-class to begin with, and here's my brand new asteroid catching rocket, docked to my space station! Not sure how much delta v I'll need, so this is going to be a test run to see approximately how much more/less I'll need.

 

Mine actually fell into Kerbin orbit on it's own!  I was tracking several of them, and this one's orbit path stopped at Kerbin.  I time advanced it to watch, and as it came in, it got a nearly circular orbit, then fell into Minmus's SOI just enough to throw it into a completely circular orbit around Kerbin!  All I needed to do was move it inward some to keep it from intersecting Minmus again in the future.  Wildest thing I ever saw.

[Evanitis]

6 minutes ago, Just Jim said:

Mine actually fell into Kerbin orbit on it's own!

How convenient... I picked mine from interplanetary space, almost at the height of Duna's orbit. Had to burn ~800 m/s with it. The fuel wasn't a problem as I took an ISRU for the task... but latching to an almost 2000 tonnes of rock resulted in a TWR of 0.01. I watched a few NASA documentaries while doing the interception burn towards home. Though I mined most of it's mass away on the way to Kerbin, so a Mun gravity assist was enough to instantly get a 100km PE. Easy-peasy.

[RA3236]

27 minutes ago, Plaxo1 said:

great  the picture inspired me to try to catch my own asteroid... Going for a D-class to begin with, and here's my brand new asteroid catching rocket, docked to my space station! Not sure how much delta v I'll need, so this is going to be a test run to see approximately how much more/less I'll need.

 

3 minutes ago, Evanitis said:

How convenient... I picked mine from interplanetary space, almost at the height of Duna's orbit. Had to burn ~800 m/s with it. The fuel wasn't a problem as I took an ISRU for the task... but latching to an almost 2000 tonnes of rock resulted in a TWR of 0.01. I watched a few NASA documentaries while doing the interception burn towards home. Though I mined most of it's mass away on the way to Kerbin, so a Mun gravity assist was enough to instantly get a 100km PE. Easy-peasy.

In my save game an E-class asteroid barely got me enough fuel to get another asteroid. In another I used five E-classes to fuel my five fuel tanks.

[GoSlash27]

Another vote for a big SSTO tanker. Fly it up, dock it, transfer the fuel, and fly your empty gas can home. Nothing else can match the cost effectiveness of it short of ISRU.

Best,

-Slashy

[nosirrbro]

16 minutes ago, GoSlash27 said:

Another vote for a big SSTO tanker. Fly it up, dock it, transfer the fuel, and fly your empty gas can home. Nothing else can match the cost effectiveness of it short of ISRU.

Best,

-Slashy

Same here. SSTOs are the best way to refuel, with conventional rockets the cost it takes to send up the fuel itself can be so much that it often merits simply adding a bit more fuel on the rocket and not refueling at all.

[Plaxo1]

5 hours ago, Jhawk1099 said:

Why I was just going to ask a question similar to this. I am planing on building a mining base on Minmus with a fuel station either in minmus orbit or high Kerbin orbit. I would advise to do it the way i am because it would be further out (thus saving delta-v on transfer burns to other planets), it takes less fuel to get from minmus' surface  to minmus orbit, and everything can easily be reusable thus it would cost you nothing to re fuel your space station. It will be pretty hard for a beginner(like myself) but it's doable and hopefully cheaper long term. I will probably make a video of it if you would like to see that and see what messed me up and any tips i have so i can send you a link.

Yes please! I would appreciate that alot , among my friends I'm by far the most advanced ksp player.. Now I'm realizing I've just barely started

[LordKael]

20 hours ago, Plaxo1 said:

Now I'm realizing I've just barely started

I hesitate to name any KSP player who isn't where you are now. There's always a more efficient way to do something old, or something new to do.

[Fearless Son]

21 hours ago, GoSlash27 said:

Another vote for a big SSTO tanker. Fly it up, dock it, transfer the fuel, and fly your empty gas can home. Nothing else can match the cost effectiveness of it short of ISRU.

 

21 hours ago, nosirrbro said:

Same here. SSTOs are the best way to refuel, with conventional rockets the cost it takes to send up the fuel itself can be so much that it often merits simply adding a bit more fuel on the rocket and not refueling at all.

Being pedantic, SSTOs are not necessarily spaceplanes.  A liquid fuel booster that can de-orbit and land near KSC ah-la a Space X Falcon also counts as an SSTO, and can still be fairly cost effective.  Not always as cost effective as a spaceplane in all circumstances, but the simplicity can be a benefit (easier to consistently pull off, quicker times to orbit, etc.)  

[GoSlash27]

4 hours ago, Fearless Son said:

 

Being pedantic, SSTOs are not necessarily spaceplanes.  A liquid fuel booster that can de-orbit and land near KSC ah-la a Space X Falcon also counts as an SSTO, and can still be fairly cost effective.  Not always as cost effective as a spaceplane in all circumstances, but the simplicity can be a benefit (easier to consistently pull off, quicker times to orbit, etc.)  

True. No point in not being precise

I'm talking about an air breathing SSTO spaceplane. It's the ultimate in cost efficiency.

Best,
-Slashy

[Nich]

Yes the best staged rockets in 1.0.4 were doing 28% payload fraction I believe and SSTO space planes were over 46% There is no comparison.  However space planes took 20 minutes to get to orbit and rockets could get there in 7.  So what is your time worth?  Also space planes are limited to about 100t of payload (runway length/part count) but a well designed rocket can deliver 100-200t fairly easy or up to 1000t if your computer is a beast.

 

Personally I dont like big Fueling stations.  I would rather have 15 -20 smaller stations (< 100t) all at 80km spaced around kerbin to make rendezvous easier