Launch pad refueling systems

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Hello world SirLaurenceNZ here and I recently had an idea for an interesting concept (if you know of anyone who has previously brought up this idea up previously I'd love to know and knowledge them.)

The idea placing your rockets from the VAB on the launchpad with empty fuel tanks, then using a vehicle with the appropriate mining equipment to refuel your rocket prior to launch. This can be done using a set of radial decoplers with fuel cross feed on and a docking port (which can be ejected before launch.)

Alternative ideas that might be worth investigating in terms of refueling is having a helicopter type plane with jet engines and rcs for lateral translation. this would help you to refuel things from above if refueling if the angle on the launchpad is not an option.

Below is an example which I had tested on the grass next to the runway and also on the launchpad (the launch pad is significantly more difficult.) Note, the three of those fuel tanks would refuel in approximately 7-8 days (ksp time) adding essentially a construction time for fueling your rocket.

http://imgur.com/a/LjDQV (anyone know how to directly attach an image?)

 

I'd just like to thank Marcus House for highlighting fuel costs in career mode in the most recent episode of his great LP (180k funds in fuel,) cheers.

Marcus's channel here --> https://www.youtube.com/channel/UCBNHHEoiSF8pcLgqLKVugOw/videos

(suggested improvements is using the claw instead of the docking port, cheers Marcus)

Edited August 14, 2016 by [email protected]
Attempting to get image working

[samstarman5]

Only if you have a kerbal next to the fuel port looking like a bored fuel jockey that you'd see at some pump station along Route 66.

[Foxster]

It is do-able but it gets tedious. 

You have to have the fuel tender slightly away from the launch pad otherwise you can't deploy a new craft. Then you roll it up to the pad to refuel. But you have to do this for every launch and if you are just testing craft then that gets oneus. Still a fun thing to build and try though. 

[SinBad]

Its easier if you are refueling space planes on the grass. I've got a save with a runway marked out with flags next to the real one. Spaceplanes line up on the aprons, payloads get spawned in on the runway, picked up with an infernal robotics mobile gantry crane and loaded into the payload bays, then the kas refueling hose is connected to fuel the spaceplane (and payload if required) off the back of the apron is a trunkline connected to an isru setup with a tank farm of 7.5m spaceY tanks. Unplug the hose, get a tow to the starting line and go to space. That save was great, after the infrastructure and space planes were paid for I only had to foot the bill for payloads. It really makes you appreciate the loss of a spacecraft when you don't throw away 90% of them every mission.

[Rocket In My Pocket]

Unless you've got the reward sliders turned way down, money just isn't a big issue in Career mode.

I can't see this being practical or worth the time except for role-playing purposes.

Also, yes. This "idea" has been mentioned several times before.

[Superfluous J]

The EVA Transfer mod would make this much easier, if you're willing to go that route.

I would be, if what @Rocket In My Pocket said wasn't so true.

[suicidejunkie]

If you want to go with the fueller route, consider using the megawheels to make a crawler and park it on the crawlway.  Have 6+ orange popsicle tanks, or whatever amount is required to fully fuel your rockets in one go.

Then trundle up and use a claw on the nose to grab a launch clamp rather than the rocket itself (for safety).  Pump and go.

 

If you can't get your crawler safely up the ramp, you can use 2-3 jeeps and daisy chain fuel hoses up the ramp, but that gets old very fast.

 

If you want 97.2% (LF=80cents/unit, Ore=4cents/unit; Ore->LF =2.2cents/unit) of the economic efficiency with only 1% of the faffing about with trucks and hoses before launch, then consider this:

Take the launch clamps on your rockets, and build out from them.  Add an ISRU unit (or five) to the base of the launch clamps, and then a large array of heavy ore tanks.

Deploy with the ore tanks full and fuel tanks empty, then convert and fuel the rocket on the pad with the ISRUs under timewarp, powered by the launch clamps.

You may want to cluster-spam launch clamps for sufficient power input.  Take a launch clamp and attach two more clamps to it using mirror symmetry.  Then copy that first clamp and attach the copies with symmetry to the first set of mirrored clamps.  Repeat one or two more times, and you will have a thick forest of launch clamps producing gobs of electricity.

(Or just jack up the clamp power generation with MM)

[Brainlord Mesomorph]

I thought of this and someone pointed out its easier to refine the fuel and just recover the vehicle, the same money-wise and no launch pad refueling.

(and I think someone mentioned that just mining the ore is actually more profitable)

 

Edited August 15, 2016 by Brainlord Mesomorph

[suicidejunkie]

Mining fuel has a slightly higher margin (~3%), but much worse ROI.

To mine, you need to buy a lot of drills in order to feed the ISRU, keep a high ranking engineer on site, and provide a lot more electricity.

To refine, you simply buy ore for dirt cheap, and convert it at 100% rate with a probe core.

[Corona688]

Is it really cheaper to buy ore than fuel though?

[MaxwellsDemon]

I don't see why people jump all over ideas like this.  If you want to play that way, play that way, and phoo on everyone else.    

I've prestaged some full jet fuel tanks on the apron for refuelling... once I get to that stage.   (I keep finding VAB things to do for the present...)  I really like the idea of 'spawning' the payloads and re-using the vehicle @SinBad , and I'm going to try that.

[suicidejunkie]

Quite.

As I noted above, LF wholesale costs 80 cents per unit.  LF converted from purchased ore costs a smidge over 2 cents per unit.

In terms of absolute value, the rocket will still cost much more than the fuel, but you can recover the rocket (and moreso with spaceplanes)

 

For example, my mk2 SSTMinmus spaceplane can take 5 tourists to Minmus surface and return for about $3500 in LF, and maybe $5 in TACLS catering.  If I convert that LF from ore, it will cost about $100 for the ore.

The plane itself costs between 80k and 250k depending on if you get the base model with fuel cells or the deluxe model with RTGs, but it lands on the runway for 100%, so that doesn't matter.

I've also considered building a mk3 bus with a claw; it would be able to rumble out to the runway, swap out the tourists and trainees, refuel the plane and then roll away so the plane can take off immediately.  In practice, I've got a hanger full of about 8 spaceplanes, so the KCT recovery time is a non-issue and I just rotate through my fleet.

[SinBad]

4 minutes ago, MaxwellsDemon said:

I really like the idea of 'spawning' the payloads and re-using the vehicle @SinBad , and I'm going to try that.

Its fun If you can manage a tail loading spaceplane it will make your life easier. Launch you payload on a clamp, drive a loading truck under it, and drop it on. Secure it however you can contrive, then roll it up, clamp it in and off you go. Um, dont forget to remove the truck.

Alternatively, if you have top loaders, look into infernal robotics and kas. The idea is a tall n shaped vehicle that can drive over the plane and drop the load into the bay. This gets tough with heavier loads.

A switch on those is to have a bottom loading cargo bay. The plane lifts itself up (landing gear on IR pistons) or parks on a platform with a payload sized hole in it. Then either the plane lowers, or the payload rises. This one is made trickier with the way wheels are, as quadricycle undercaŕiages are needed, but they dont steer straight at the moment.

Ive been playing around trying to get a vertical launch ssto loading figured out. Its tricky, because you generally need to handle the payload vertically, and either lift it higher, or have a rocket with a gaping hole in the side. If you want to try that out, have a look at modular rocket systems mod. Some good inline bays that work with far properly.

[Tex_NL]

Free fuel can be down A LOT easier.

Design and build your rocket as you would any other. One important note; do not forget to add launch clamps.
Add an ore tank, fuel tank, converter and drill to the outside of the launch clamps.
Deploy your drill straight into the launchpad. The yield may be low but the pad also contains ore.
Since the launch clamps supply infinite electricity you can process as much ore as you like night and day.
After launch the clamps and ore processor can be recovered for an 100% refund.

Edited August 15, 2016 by Tex_NL

[Sneaky Bstard Sword]

On 8/15/2016 at 1:56 PM, Tex_NL said:

Free fuel can be down A LOT easier.

Design and build your rocket as you would any other. One important note; do not forget to add launch clamps.
Add an ore tank, fuel tank, converter and drill to the outside of the launch clamps.
Deploy your drill straight into the launchpad. The yield may be low but the pad also contains ore.
Since the launch clamps supply infinite electricity you can process as much ore as you like night and day.
After launch the clamps and ore processor can be recovered for an 100% refund.

Isn't that pretty much what OP was suggesting?

[Sharpy]

Personally, I don't bother.

If I need cash for fuel, I deploy a 'vessel' consisting of about 40 ISRU units, each with 2 gigantors, some 10 full ore tanks, 2 empty monoprop tanks, and leave them running all day. In the evening I collect some 200,000√.

Of course, to the runway. The launchpad tends to explode under that mass.

[Rath]

What will happen soon (This is an actual story involving my moms old guidance counsellor, who happens to run  EEA chapter 1158 in west bend, WI): 

The fuel boy forgot to put back on the fuel cap on his Cessna 172, so when he was flying back, he noticed a weird brownish streak on his wing and a slight roll problem he had instinctively corrected with trim hours before, and once he glanced at the fuel gauge  half of his tanks were empty and he had to land in Alabama, of all places.  in a storm.

[magnemoe]

On 15.8.2016 at 7:20 PM, MaxwellsDemon said:

I don't see why people jump all over ideas like this.  If you want to play that way, play that way, and phoo on everyone else.    

I've prestaged some full jet fuel tanks on the apron for refuelling... once I get to that stage.   (I keep finding VAB things to do for the present...)  I really like the idea of 'spawning' the payloads and re-using the vehicle @SinBad , and I'm going to try that.

Yes, for one that this is an good training for bases serviced by SSTO rockets or planes, this might also include moving base modules from lander.