Economic Fuel to Oribit

[Bothersome]

I need fuel in orbit. You really can't do anything great until you get fuel in orbit. It allows you to go places, see things, and do things.

But, as always, money is tight. So we need to figure out a way to get fuel into space so we can refuel our space crafts.

So, I challenge you to come up with the most COST effective way to put fuel into space.

Now, I know some of you will want to just take a 5 gallon can up and call it a day. Even if you find some super cost effective way of doing it, 5 gallons is just not enough. So we will have to have a formula to calculate the winner. Say, (fuel + oxidizer) / (COST / (fuel + oxidizer)). This should encourage a good size payload so we don't constantly have to dock small ships with small payloads to unload a small amount, even if it is cost effective.

The rules:

1. MODS are allowed provided only the STOCK tanks and methods of propulsion are used. (No magic engines) You can use any stock method you see fit though.

2. No cheats with editing or any of that.

3. Must get fuel to orbit. 70 x 70 km is fine with me.

4. Screen shots are required. You should have 1 screenshot showing your cost, 1 showing your orbit with fuel quantity, and 1 showing your return money if you have any.

5. You may remove launch towers or other things that will be returned to you upon next launch from the initial cost screen.

6. You may update your attempt as you see fit. For instance, you might not have yet landed back on Kerbin your storage tanks for refund. You may come back and edit your posts for an update once you do claim your refunds.

May the greatest tight wad win !!

Score Position:

1. Dundral @ 148,179 (using FAR)

2. Vector @ 126,792

3. Laie @ 56,251 (using Procedural Wings)

4. Norcalplanner @ 16,713

5. Wanderfound @ 10,438.8 (using FAR)

6. Pecan @ 1,502.07

7. Bothersome @ 1,487.38

8. s1l3nt_c0y0t3 @ 466.314

- - - Updated - - -

OK here is my own attempt at the record...

357506 - (8 x 200 for launch towers) = 355906

10354 + 12654 = 23008

23008 / (355906 / 23008) = 1487.38 <<< this is my score.

Later, I will update my scores after I get a refund from the tank once returned safely to Kerbin (if I can save it).

Edited September 26, 2014 by Bothersome
Score update

[Wanderfound]

This is just something I had lying around rather than an optimised budget lifter, but it can casually toss a Rockomax 64 into orbit for about √4,000.

http://forum.kerbalspaceprogram.com/threads/88628-Kerbodyne-D7-Heavy-X5-a-heavy-lift-SSTO-spaceplane

[Foxster]

I think it would be good to tighten up on the payload to make comparison much easier. How about the cheapest ship that puts a full orange tank with a clamp-o-tron docking port on each end (so its useable) into a 75k orbit? Cost reduced by any funds returned on recovery of lifter.

[Bothersome]

Because not all of us want an orange tank in space for a fuel depo. What you suggest seems to be legal in the sense of the challenge though, so go for it. Just don't use non-stock parts for tanks, engines, and wings. If you stay stock, then those of us interested might be able to copy or download your craft.

You can use space planes to get the fuel up there if you want. We're looking for cheapest cost to get large quantities of fuel and oxidizer up there.

Wanderfound posted a link to a plane that supposed to be able to get an orange tank (full) into orbit for the minimum cost of about 4000. I downloaded his plane and gave it a shot but it didn't look as though it was possible to get it to space with my flying skills. I'm not using ANY mods for this challenge, and that might be what the problem is. His plane was tuned for FAR and that's not installed here. So his plane may not be performing as advertized.

But, if someone could get that orange tank to orbit for just the cost of fuel, then it probably would set a very high score.

[Wanderfound]

Because not all of us want an orange tank in space for a fuel depo. What you suggest seems to be legal in the sense of the challenge though, so go for it. Just don't use non-stock parts for tanks, engines, and wings. If you stay stock, then those of us interested might be able to copy or download your craft.

You can use space planes to get the fuel up there if you want. We're looking for cheapest cost to get large quantities of fuel and oxidizer up there.

Wanderfound posted a link to a plane that supposed to be able to get an orange tank (full) into orbit for the minimum cost of about 4000. I downloaded his plane and gave it a shot but it didn't look as though it was possible to get it to space with my flying skills. I'm not using ANY mods for this challenge, and that might be what the problem is. His plane was tuned for FAR and that's not installed here. So his plane may not be performing as advertized.

But, if someone could get that orange tank to orbit for just the cost of fuel, then it probably would set a very high score.

Almost all of the serious spaceplane crew use FAR; you're not likely to get many willing to fly under stock aero.

It's certainly doable, though. Stock lets you get away with unaerodynamic monstrosities that FAR would tear to pieces, as well as doubling the power of RAPIERs and turbojets. The major difficulty in building the D7 was in stopping it from breaking apart under aerodynamic stress; that's why it has a few zillion struts on it. That's not an issue in stock.

You're right that it's not the easiest of planes to fly, though. It's a big and brutal beastie.

[Vector]

Your formula is essentially quadratic in payload and linear in cost, so bigger will win even if it's less efficient cost-wise. The penalty for inefficiency is relatively minor as long as you can get the biggest payload possible into orbit, so it's more of a size challenge than an efficiency challenge.

A while ago I made this rocket, trying simply to get as big as possible. Thread has link to craft file.

It has fuel + oxidizer of 485411, and loading in the current version shows a cost of 8029533. According to your calculation this has a score of 29344.

[Stratzenblitz75]

As stated above, I think you should have contestants build lifters for one payload like a jumbo-64 fuel tank (or multiple payloads and divide them into categories based on their mass). Not only would this make comparing entries easier, it would also get rid of insanely low or high mass entries and therefore, put the focus on efficiency rather than size.

[Laie]

pre-submission: http://ksp.schnobs.de/k-prize/screenshot53.png

takes 2.25 large kerbodyne tanks to orbit, requires ~50t of fuel and oxidizer to do so. Uses procedural wings and rockomax-sized intakes (basicaly a quadcoupler worth of intakes rolled into one part). If it would be disqualified for one reason or another, please tell me now.

Your formula is essentially quadratic in payload and linear in cost, so bigger will win even if it's less efficient cost-wise. The penalty for inefficiency is relatively minor as long as you can get the biggest payload possible into orbit, so it's more of a size challenge than an efficiency challenge.

This may be intended. Personally, I'm willing to sacrifice a few funds if it means that I have to fly only one mission rather than three. (however, quadratic goes a bit far IMO).

Edited August 12, 2014 by Laie

[Bothersome]

I guess I can put it into a non-stock category. I'm more interested in full stock crafts (ignoring piloting assists) because of newer people playing in stock carrier mode, but it seems everybody wants to try it in their own game, so go for it.

We seem to have plenty of critics on the formula for scoring, yet I see no postings of a better formula to use. And yes, I did want to reward more work done with a better score. And I don't mean more work done by multiple launches and docking in space to unload.

[Pecan]

This should be bigger to be competitive but it happily SSTOs an orange tube. I might strap a few of them together just for more points later.

Javascript is disabled. View full album

Payload: Orange tube = 2,880 + 3,520 = 6,400

VL-40 A: 133,618 - 109,839 = 23,779

Fuel Module: 25,840 - 22,350 = 3,490

Total: 159,458 - 132,189 = 27,269

Cost / Payload = 4.26

Payload / (Cost / Payload) = 1,502 <== score

[Stratzenblitz75]

We seem to have plenty of critics on the formula for scoring, yet I see no postings of a better formula to use. And yes, I did want to reward more work done with a better score. And I don't mean more work done by multiple launches and docking in space to unload.

... But we HAVE given you an alternate formula for scoring:

How about the cheapest ship that puts a full orange tank with a clamp-o-tron docking port on each end (so its useable) into a 75k orbit? Cost reduced by any funds returned on recovery of lifter.

Also, if your intent is to reward more "work", then you should really rename your challenge from "Economic fuel to orbit" to "Most fuel to orbit" because as it stands, you scoring system promotes building the largest rockets possible rather than the most efficient or cost effective ones (See Vector's post).

Edited August 13, 2014 by Stratzenblitz75
brain smart good

[Vector]

If one orange tank is too small, decide on some fixed size, maybe four orange tanks or ten S3-14400 or whatever you think is the right size, and score based on lowest cost to get it to orbit. Then you will have an efficiency challenge and not a size... no wait, efficiency... no wait... actually size challenge.

[Laie]

""Most economic" without any qualifiers is somewhat pointless, but "most fuel" isn't better in any way. Maybe size classes?

[Bothersome]

That looks like a good ship Pecan, congrats, you have top score, so far.

I don't think I'll change the scoring system. It seems to be working as expected. More fuel is what we need in space, and simplicity to get it there should be rewarded. Looks like it's working as expected.

[gchristopher]

Your formula is essentially quadratic in payload and linear in cost, so bigger will win even if it's less efficient cost-wise. The penalty for inefficiency is relatively minor as long as you can get the biggest payload possible into orbit, so it's more of a size challenge than an efficiency challenge.

Yep, it needs a better scoring formula.

Maybe if you still want to reward bigger payloads without it being as dominant a factor, something like:

P = Payload, fuel + oxidizer, in tons

C = Net Cost after recovery of any launchers

Score: P/C * Log10(P)

Then a 100 ton payload is worth only twice as much as a 10 ton payload?

If the intent wasn't to make a size challenge, Score = P/C with a minimum size, or size categories, is fine.

[Bothersome]

The way I see it, is two is better than one. And those that build a good ship that can win the scoring challenge will most likely be able to use that ship in their normal KSP operations. If the score was based too much on efficiency, then people would build ships just to win the competition. Instead I want people to build ships that will have useful value that also happens to win the challenge. Look at Pecan's ship, looks useful to me in normal KSP operations, challenge or not.

I have not seen any examples where some crazy design would win the challenge, but wouldn't be a useful ship under normal circumstances. Convince me otherwise. A score based where 80% is based on efficiency is not what I'm after. I want the payload size to be about half of the score value. I want efficiency to get large payloads to space. The challenge may not be aptly named, but it's named enough. It is what it is. Do it or don't.

[gchristopher]

Your formula is essentially quadratic in payload and linear in cost

Actually, I think I was wrong to agree with this. I'm sorry!

Cost is intrinsically related linearly to payload, since the game doesn't really have any economies of scale beyond very small values.

The formula really should produce only 2x a score for a payload that's twice as large. You use twice the lifting parts and spend twice the fuel.

I'm sorry! The formula should only be linear in payload size, as Bothersome correctly points out.

[Kasuha]

The evaluation formula is flawed. If one ship gets certain amount of fuel at certain cost into orbit and another ship gets two times the fuel into orbit for four times the cost, they get the same score. That's not 'economical'. That's 'size beats anything'. Economical is if getting two times the fuel into orbit at once costs me less than two times the cost of single transport. Even the P/C formula favors large ships as these can be built more effective than small ones. P2/C is just wrong.

[Sun]

Am I the only one who at first glance, thought the title said "EVA Fuel to Orbit"?

[s1l3nt_c0y0t3]

I use a modular system of parts, orbital buses, and boosters to build ships and stations. Everything is 100% reusable. So this is my Modular Fuel Unit (MFU) that I use as a fuel tank and as a resupply ship.

K238,955.6 Total

K194,781.6 Booster

K 30,350.0 Orbital Bus

K 5,980.0 Nose Cone

---------------------------

K 7,844.0 Final Cost

1440 L+1760 O=3200 Fuel

3200/(7,844/3200)

3200/2.45125=1,305.5

Album

Javascript is disabled. View full album

Edited August 13, 2014 by s1l3nt_c0y0t3
I embeded a photo album wrong.

[Bothersome]

s1l3nt_c0y0t3, I looked in your album photos but didn't see a screen showing the cost or a screen shot showing your refunds. The reason why these are required is because the refunds are proportional to where you land. So piloting skills are involved a bit here. You can't just present a proposed or theoretical entry. You must actually do this and show screenshots for the numbers. Sorry, but carrier mode is going to be required.

I'll look again, but I don't think I missed it.

[Bothersome]

That's not 'economical'. That's 'size beats anything'. Economical is if getting two times the fuel into orbit at once costs me less than two times the cost of single transport. Even the P/C formula favors large ships as these can be built more effective than small ones. P2/C is just wrong.

Humm, lets see...

For sake of argument, lets say we can get a ship to put 1000 cargo in orbit for cost of only 10000 funds.

1000 / (10000 / 1000) = 100

Now lets say we build the ship a little bigger (say tie two of those together).

2000 / (20000 / 2000) = 200

Like I said, 2 orange tanks in space is better than 1 orange tank in space. So the score should reflect said work. The formula is correct.

Edited August 13, 2014 by Bothersome
Missed a divide sign

[s1l3nt_c0y0t3]

As I said, I did this is Sandbox mode, which, in 0.24, doesn't have a recovery screen. I'll redo it in career mode later to get better numbers.

[Keldaria]

Humm, lets see...

For sake of argument, lets say we can get a ship to put 1000 cargo in orbit for cost of only 10000 funds.

1000 / (10000 / 1000) = 100

Now lets say we build the ship a little bigger (say tie two of those together).

2000 / (20000 / 2000) = 200

Like I said, 2 orange tanks in space is better than 1 orange tank in space. So the score should reflect said work. The formula is correct.

Not to rock the boat any further but based on those assumptions you are saying buying 2 Orange tanks of fuel for $10,000.00 each is twice as good of a deal as buying 1 orange tank for $10,000.00. The problem lies in the fact that your not exactly getting any better deal here, you're just buying in bulk. If this was a Bulk launch challenge rather than an efficiency challenge I think you'd be ok.

Take a look at the 2 existing scores. Yours you costed 13 times more to send into orbit and only brought up 3.6 times the fuel.

Your entry was

23008 / (355906 / 23008) = 1487.38

And Pecan's was

6400 / (27269 / 6400) = 1502

Pecan could (in theory) tie 4 of his devices together and achieve a score like this.

25600 / (109076 / 25600) = 6008.28

But since he didn't, his score appears to be on par with yours. So in essence the formula favors quantity over efficiency. My suggestions (if you were aiming for an efficiency challenge) would be to simplify the formula and set minimum fuel loads to be transported to avoid having any entries which launch 5 gallons at a time.

[Batz_10K]

This one is a scaled-up reverse-engineered copy of an air-hogger that somebody posted earlier. It is SSTO and can get a full 14400 tank into LKO (barely). Cost is about 600K (all recoverable depending on your mad piloting skills)

...Given enough thrust, pigs fly just fine. Now with cool smoke rings at 20000m

You do need to leave some for de-orbit and landing. So not quite a 14400 is useable.

Full disclosure - this is from an earlier test. but you get the general idea.