What's your average cost per ton to orbit?

[GoSlash27]

Brainlord,

No, I'm running all stock.

Entire vehicle cost

$125,802

Launch vehicle minus 41.5t payload

$109,442

Launch vehicle minus boosters

$97,790

Less fuel/ oxidizer/ monoprop

$84,499 (recoverable)

Supplies/ parts expended

$24,943

Operating cost= 24,943/41.5 = $601/ tonne. In my case I didn't use 100% of the supplies and was able to recover them.

Best,

-Slashy

*edit* I think I found the problem: You said your boosters cost $20,000 for 6 (plus hardware)?

KD25k boosters are $1,800 per, or $10,800 for 6. How much do yours cost and what additional hardware did you use?

Edited January 25, 2015 by GoSlash27

[Laie]

EDIT: ran the numbers on my best spaceplane, its RAPIERS burn a bunch of LF+O above 30km, so hauling 18.5 tons with $3,500 in fuel comes out to $190 per ton. Are you using an *only*turbojet solution?

Rapiers are gas-guzzlers. Also, my best spaceplanes (here's a really oversized model) have so many jets and the appropriate amount of intakes, even at 50km altitude they can still run a few of their jets alongside the rocket engines. That makes a real difference.

For any plane over four or six jets, I'd recommend using Turbojets and dedicated rocket motors. Those inevitably have to be either LV-N or 48-7S.

[GoSlash27]

Rapiers are gas-guzzlers. Also, my best spaceplanes (here's a really oversized model) have so many jets and the appropriate amount of intakes, even at 50km altitude they can still run a few of their jets alongside the rocket engines. That makes a real difference.

For any plane over four or six jets, I'd recommend using Turbojets and dedicated rocket motors. Those inevitably have to be either LV-N or 48-7S.

^ seconded. Rapiers can't get you nearly the efficiency of dedicated turbojets and rockets. For a single turbojet (6 tonnes payload) I use 2 48-7S rockets. For a twin (14 tonnes payload), I use a single LV-909.

Best,

-Slashy

[Brainlord Mesomorph]

Brainlord,

*edit* I think I found the problem: You said your boosters cost $20,000 for 6 (plus hardware)?

KD25k boosters are $1,800 per, or $10,800 for 6. How much do yours cost and what additional hardware did you use?

I'll have to go look, I think my standard "Large SRB" is the KD25k, plus a nosecone, one fin, a sepratron and a radial decoupler. I guess I could lose the nosecone.

[GoSlash27]

I'll have to go look, I think my standard "Large SRB" is the KD25k, plus a nosecone, one fin, a sepratron and a radial decoupler. I guess I could lose the nosecone.

You can lose the fin also. I went with a reaction wheel in the lifter since it's recoverable. If you just want fins, you can always place them on the lifter

Looks to me like you're right in the ballpark AFA cost efficiency. A few minor differences due to aesthetics are the only reason you're not at $600 per tonne, and even with that $800 is still pretty darn good.

Best,

-Slashy

[Pecan]

I posted a 40t payload spaceplane a while ago. Version change meant its balance was a bit off but anyone who knew spaceplanes can easily adjust it.

40t ain't "heavy" so a spaceplane can do it easily enough. There isn't much point in launching more than that it one go though.

Edited January 26, 2015 by Pecan

[GoSlash27]

I posted a 40t payload spaceplane a while ago. Version change meant its balance was a bit off but anyone who knew spaceplanes can easily adjust it.

4-t ain't "heavy" so a spaceplane can do it easily enough. There isn't much point in launching more than that it one go thought.

Agreed. I've found that there's very little you can't do within a 15t per launch limit (and supplies can be much less than that).

The one exception I've found is an Eve launch vehicle because it's staged and physics demands that it be big. Other than that... you can build pretty much anything you want in orbit without needing huge boosters.

Best,

-Slashy

[Brainlord Mesomorph]

Agreed. I've found that there's very little you can't do within a 15t per launch limit (and supplies can be much less than that).

The one exception I've found is an Eve launch vehicle because it's staged and physics demands that it be big. Other than that... you can build pretty much anything you want in orbit without needing huge boosters.

Best,

-Slashy

A space station (in launchable kit form): 70+ tons

another space station (I was going to do in two launches): 120 tons

A tylo lander: 72 tons

Interplanetary fuel tanker: 150 tons

I could go on...

^ seconded. Rapiers can't get you nearly the efficiency of dedicated turbojets and rockets. For a single turbojet (6 tonnes payload) I use 2 48-7S rockets. For a twin (14 tonnes payload), I use a single LV-909.

Best,

-Slashy

Never occured to me to kill SOME of the jets. And I recently learned that the Nuke has a pretty good Isp as low as 10 km. (i'll keep all that in mind when I revisit the spaceplane project)

You can lose the fin also. I went with a reaction wheel in the lifter since it's recoverable. If you just want fins, you can always place them on the lifter

I needed fins on something before I saved that sub-assembly. and it really, really, bothers me that nosecones and fairings are just cosmetic. I get that its a simplified physics engine, but really needs to be some kind of penalty for not using nosecones.

(guess I'll be installing FAR)

Looks to me like you're right in the ballpark AFA cost efficiency. A few minor differences due to aesthetics are the only reason you're not at $600 per tonne, and even with that $800 is still pretty darn good.

Best,

-Slashy

LOL you want me to stop.

Like I'm some kind of obsessive who will just keep beating my head against the wall trying to get these last $200/ton. And you're right! It used to cost me over $100,000 to loft 50 tons, now I can do it for $40,000 (and I'm pissed it isn't 30,000)

I should stop.

Thanks guys.

[InterCity]

I'm at about $600 per ton on a 100% non-reusable rocket, but that's for my Duna base heavy lifters that take about 10 tons each, one way.

I'm working on a SSTO system, however, that should noticeably cut down this price. I'm expecting $350, but I may be wrong

[Van Disaster]

FAR, B9 bits. FAR is not very forgiving these days. A week's progress on rebuilding an 0.25 design just put 185t up to 90km at a cost/T of 110 assuming I burned all the consumables, which I didn't. Previous versions in previous game versions lifted 280t, which is enough to do an awful lot in orbit.

Substitute Mk3 parts for B9 HL, you'd have to use the B9 wings & engines though.

[GoSlash27]

A space station (in launchable kit form): 70+ tons

another space station (I was going to do in two launches): 120 tons

A tylo lander: 72 tons

Interplanetary fuel tanker: 150 tons

I could go on...

Space stations, tankers, and mass movers can always be made modular, launched empty, and assembled/ fueled in orbit. That's the point.

I needed fins on something before I saved that sub-assembly. and it really, really, bothers me that nosecones and fairings are just cosmetic. I get that its a simplified physics engine, but really needs to be some kind of penalty for not using nosecones.

(guess I'll be installing FAR)

May as well hold off on that. The next update will make fairings useful.

LOL you want me to stop.

Like I'm some kind of obsessive who will just keep beating my head against the wall trying to get these last $200/ton. And you're right! It used to cost me over $100,000 to loft 50 tons, now I can do it for $40,000 (and I'm pissed it isn't 30,000)

I should stop.

Thanks guys.

Nah, by all means, carry on. You just asked whether $1000 per tonne was good, and have since gotten it down (or at least figured out how) to an efficient figure for rockets. So it looks like the original question has been answered.

You're welcome, and we're always here if you have more questions!

Best,

-Slashy

Edited January 26, 2015 by GoSlash27

[Hodo]

Hodo:

Dang I gott get me some of those mods.

I didn't think mods make the game easier, just saying that the stock game is just biased against big spaceplanes.

Those craft primarily use three mods b9, procedural wings and procedural fuel tanks. These are to cut down on parts count.

[KerikBalm]

I manage 100 tons to orbit in stock easily enough with jetpowered space planes.

I find its harder with NEAR, and much harder with far, but I even managed a 150 ton to orbit lifter in FAR.

This monstrosity was my first successfull lifter SSTO, her carrying a 30 ton payload Duna mission.

It had some stability issues on reentry, but I was able to land it (barely)

This monstrosity was one of my first "100 ton to orbit" planes

I modded the intakes to produce both intake air and intake atmosphere for use with "electric fans", which weren't used on this craft (the atmosphere intakes were closed the whole time)

Then when .23 came out, I made this one, but as the LFB ISP was nerfed, it doesn't do as well anymore:

Then I switched to NEAR, and added SP+ in 0.24

Then the mk3 spaceplane parts came out, and I used FAR (there was a 0.25 FAR design I made that lifted 150 tons, I didn't take any screen shots of it though.... it was big..) and tried a more conservative, realistic looking design:

As I can put all of them back on the runway, and I use jets (with their ridiculous effective ISPs of up to 40,000), I imagine the cost per ton is quite low.

[Jouni]

The biggest issue with spaceplanes isn't payload mass but payload dimensions. My typical large payloads are interplanetary tugs/transfer stages. With a large central fuel tank and a number of nuclear engines attached to radial fuel tanks, they're usually over 5 m or 6.25 m wide. While smaller transfer stages can be redesigned to fit into a Mk3 cargo bay, larger tugs would need a spaceplane designed around the payload.

[Brainlord Mesomorph]

The biggest issue with spaceplanes isn't payload mass but payload dimensions. My typical large payloads are interplanetary tugs/transfer stages. With a large central fuel tank and a number of nuclear engines attached to radial fuel tanks, they're usually over 5 m or 6.25 m wide. While smaller transfer stages can be redesigned to fit into a Mk3 cargo bay, larger tugs would need a spaceplane designed around the payload.

Funny you should mention, this is the “Gullwing 17D Module Carrier †(even though its wings are no longer gull wing shaped):

The big gray tank with the Clampotron Sr. is the payload module for this flight.

Able to carry large and irregularly shaped payload modules. As you can see, it carries a payload module docked at the center of gravity, so whether it’s carrying a five ton, or 20 ton payload, or none at all, she still flies quite well.

I recently found out the RAPIERs aren’t a good choice for the OMS, and the airframe is a little wobbly, she’s due for another redesign.

[KerikBalm]

The biggest issue with spaceplanes isn't payload mass but payload dimensions. My typical large payloads are interplanetary tugs/transfer stages. With a large central fuel tank and a number of nuclear engines attached to radial fuel tanks, they're usually over 5 m or 6.25 m wide. While smaller transfer stages can be redesigned to fit into a Mk3 cargo bay, larger tugs would need a spaceplane designed around the payload.

If you look at my designs, the ones that split and have 2 orange tanks "booms", and the payload is mounted in the center, they can fit payloads 3 orange tanks wide, and I think it was 2 orane tanks wide. I even made a special "oversize" version of the 0.24 version thaht has more ground clearange to allow for even bigger payloads (that one I made because the Laythe base/Habitat+ surface fuel depot was a bit too big for my standard lifter, and I really didn't want to try a peicewise orbital assembly, on top of the ones I already was planning on doing to connect it to the orbital fuel depot and tug.)

A design like that should work for you, no?

[Brainlord Mesomorph]

Slashy: the SRBs cost more than they're worth.

Laie: "Straight up and make a right" can never be the most economical way to orbit.

Working with the same SSTO booster ( two S3-1440s and a KR-2L), I was trying to determine how much help I was getting from the SRB’s. So I decided to see how much payload I could loft without any SRB’s at all.

Knowing that NASA begins their gravity turn pretty much the moment they clear the gantry, I figured that a very shallow orbital entry would be the most fuel efficient. (You see what I did there ,Laie ?) The answer is 23 tons. ($588 per ton!) granted, 23 tons is nothing to write home about. Even my space planes can compete with that.

But this booster was never designed to be used alone. You can use 2 to lift 46 tons, four for 92 tons , all the way up to a cluster of nine (eight around one) and haul 200 tons to orbit, ALL for the same $588 per ton!

(EDIT: heck, you could put 8 more around that, for 391 tons)

At these prices, it becomes no longer economical to try to dock 2 50-ton vehicles in orbit. This drastically effects the design of all my interplanetary vehicles. I have work to do.

(Drops microphone, walks off stage, launches rocket.)

EDIT 2: I just flew a cluster of five of these to orbit and back, and would you believe its ALSO by far the stablest and easiest-to-steer 100 ton lifter I ever built! NO WOBBLIES!

Edited January 27, 2015 by Brainlord Mesomorph

[Laie]

Laie: "Straight up and make a right" can never be the most economical way to orbit.

That's not what I said, and certainly not what I did (have you even looked?)

I figured that a very shallow orbital entry would be the most fuel efficient.

And I figured that a very shallow ascent requires only a very low TWR. By the time I'm at 40km, there may still be 1km/s or more to orbit, but all the engines I needed to get off the ground run at 30% throttle or something; and ever less the further I get. In other words: a good deal of the stuff has become dead weight. Your ascent profile may be the most efficient, but the approach of carrying everything to orbit and back is not.

What I claim is that discarding stuff early and recovering it at a considerable discount can be competitive with rocket SSTOs. Mine cost 592funds/ton; your 588 aren't exactly a huge improvement. So far, I'm under the impression that I'm right.

Edited January 27, 2015 by Laie

[Brainlord Mesomorph]

That's not what I said, and certainly not what I did (have you even looked?)

And I figured that a very shallow ascent requires only a very low TWR. By the time I'm at 40km, there may still be 1km/s or more to orbit, but all the engines I needed to get off the ground run at 30% throttle or something; and ever less the further I get. In other words: a good deal of the stuff has become dead weight. Your ascent profile may be the most efficient, but the approach of carrying everything to orbit and back is not.

What I claim is that discarding stuff early and recovering it at a considerable discount can be competitive with rocket SSTOs. Mine cost 592 funds/ton; your 588 aren't exactly a huge improvement. So far, I'm under the impression that I'm right.

I've seen, and I've been trying it (without success). My boosters don't have that TWR, and don't even survive splash down. you have to put them on the ground.

(and I didn't say you said that, I was sorta kidding) EDIT:Oh, I did use quote marks, sorry.

Absolutely competitive! we're neck and neck. I'm just thrilled, I was giving up at 800. NOW I'm done designing boosters.

Carrying it all to orbit and back only works because of the game engine. What would be best is if the SRBs were recoverable LIKE IT SEZ THEY ARE IN THE GAME!

[Laie]

I've seen, and I've been trying it (without success). My boosters don't have that TWR, and don't even survive splash down.

And I thought the design I posted was easy to use. The splashdown issue is the main reason why I'm using the LFBs. Otherwise (if you have real chutes or less deadly water, for instance) throw-away SRBs plus plain old mainsails might be even better.

But yes: I'm running at a horrible ISP along a wasteful ascent profile, recover 2/3rds of my vessel at a 10% discount, and still come out even with your SSTO. In my eyes, this only goes to show just how inefficient SSTOs really are.

[GoSlash27]

Slashy: the SRBs cost more than they're worth.

Laie: "Straight up and make a right" can never be the most economical way to orbit.

Working with the same SSTO booster ( two S3-1440s and a KR-2L), I was trying to determine how much help I was getting from the SRB’s. So I decided to see how much payload I could loft without any SRB’s at all.

Knowing that NASA begins their gravity turn pretty much the moment they clear the gantry, I figured that a very shallow orbital entry would be the most fuel efficient. (You see what I did there ,Laie ?) The answer is 23 tons. ($588 per ton!) granted, 23 tons is nothing to write home about. Even my space planes can compete with that.

But this booster was never designed to be used alone. You can use 2 to lift 46 tons, four for 92 tons , all the way up to a cluster of nine (eight around one) and haul 200 tons to orbit, ALL for the same $588 per ton!

(EDIT: heck, you could put 8 more around that, for 391 tons)

At these prices, it becomes no longer economical to try to dock 2 50-ton vehicles in orbit. This drastically effects the design of all my interplanetary vehicles. I have work to do.

(Drops microphone, walks off stage, launches rocket.)

EDIT 2: I just flew a cluster of five of these to orbit and back, and would you believe its ALSO by far the stablest and easiest-to-steer 100 ton lifter I ever built! NO WOBBLIES!

Sounds like you've got the efficiency problem licked (you're now on par with the rest of us... sorta), but I'm confused about the bolded part.

If I can lift the same payload at $35 a tonne and assemble it in orbit, why is is not economically worth my time to do it? Especially since my lifter is much smaller and easier to recover?

As an aside, I did use boosters and still came out cheaper than you did and at nearly twice the payload. Glad you got it sorted out and all, but running victory laps is poor form when nobody's competing with you.

Scratchin' my head,

-Slashy

Edited January 28, 2015 by GoSlash27

[Brainlord Mesomorph]

I didn’t say it wasn’t cost effective to dock 20 ton payloads in orbit. That’s still true. My best space plane can lift a 20 ton payload. But I don’t have a lot of 20 ton payloads, or even payloads that can be divided into 20 ton units. And it seems even your space planes can’t handle much more than that.

Let’s look at how I used to do this: To build a 200 ton vehicle, I divide it into 50 and 75 ton in units, launched on what I thought were cheapish disposable rockets (four rocket launches at $2000 per ton) and assembled in orbit. All that orbital maneuvering and docking requires fuel. I eventually came up with the rule of thumb that every 70 to unit needed one big gray tank just for orbital construction. (another 18 tons). If I didn’t send extra fuel to use during construction, I’d have to send a fuel tanker up to the finished ship to top off all the fuel tanks before departure (another rocket launch).

Now, for a flat $588 a ton, (from 50 to 400 tons) I can build the whole thing in the VAB and loft it to orbit fully fueled. I can build bigger things that are more complex and more solid, that are better centered around their CoG.

For me, it makes orbital construction of 50 ton units a waste of time. And changes how I design things.

And I wasn’t running victory laps, I’m just happy to have reached a conclusion to this design process and I really want to get out of the VAB and finally fly all this stuff to Jool!

But how do you build a 200 ton vehicle? Ten space plane flights? 10 docking ports? (two tons of docking ports, 1% of the ship’s mass). Docking ports are wobbly. I had too many docking ports with 50 ton modules.

As an aside, it’s poor form to scold me for attitude while in the same sentence you gloat with a tongue-wagging emoji. (no one was competing with me, but you did win ). As I said, I never did get the same numbers you did.

But seriously, thanks to the help guys, I couldn’t have done it without you.

- - - Updated - - -

And I thought the design I posted was easy to use. The splashdown issue is the main reason why I'm using the LFBs. Otherwise (if you have real chutes or less deadly water, for instance) throw-away SRBs plus plain old mainsails might be even better. But yes: I'm running at a horrible ISP along a wasteful ascent profile, recover 2/3rds of my vessel at a 10% discount, and still come out even with your SSTO. In my eyes, this only goes to show just how inefficient SSTOs really are.

Oh, I wasn’t trying to use your design, I was trying to use your method.(you have a horrible ISP along a wasteful ascent profile )

I thought I could modify my design into a two stager. And do your trick. But adding the second engine ruined the TWR.

And yes, we’re both pretty much topping out what you can do with recoverable rockets in this game engine. Whether it’s SSTO or recoverable suborbital stages.

Edited January 28, 2015 by Brainlord Mesomorph

[TimePeriod]

Way too much, for each payload I build a new type of delivery rocket

[GoSlash27]

Brainlord,

The SRBs aren't actually a "waste". They improve your mass ratio, which keeps cost down and simplifies recovery. lifting 40 tonnes without the boosters requires twice the stage mass, all of which must be recovered.

As for the rest of it, it's a difference in philosophy rather than technical ability. I *could* build a bigger spaceplane or vertical lifter... I simply have no use for one.

As a rule, I build things only as big as they need to be, which isn't very big.

On docking ports... I haven't had a problem with wobble.

A 200 tonne payload? Probably a failure of imagination on my part. I can't even imagine why I would ever need to lift something like that... although I'm keen to see you try to recover the 150 tonne empty lifter for it intact

Best,

-Slashy

[Brainlord Mesomorph]

Brainlord,

The SRBs aren't actually a "waste". They improve your mass ratio, which keeps cost down and simplifies recovery. lifting 40 tonnes without the boosters requires twice the stage mass, all of which must be recovered.

As for the rest of it, it's a difference in philosophy rather than technical ability. I *could* build a bigger spaceplane or vertical lifter... I simply have no use for one.

As a rule, I build things only as big as they need to be, which isn't very big.

On docking ports... I haven't had a problem with wobble.

A 200 tonne payload? Probably a failure of imagination on my part. I can't even imagine why I would ever need to lift something like that... although I'm keen to see you try to recover the 150 tonne empty lifter for it intact

Best,

-Slashy

As I keep saying, I’m not getting your numbers. According to my spreadsheet, throwing away the SRBs costs money.

As for recovery: that’s the beauty part! It’s a completely modular system. The boosters come apart and land individually. I can separate them in orbit and bring them in one at a time, or, I just had success with bringing in a cluster of five of them, and separating them after drouge chute deployment, about a kilometer up. They all came down within the same 2 ½ kilometer bubble. On their wheels.

I’m telling you it works. I’m so done designing rockets!

EDIT:

Oh, as for imagination:

I’m sending a massive fleet to Jool! 100 days of operations in the Joolian system. Multiple landings on every Moon, rover missions, science missions (trying to max out all the science I can get in one mission) We’re going to build three space stations. Circumnavigate Laythe with a flying rover. And as a crowning achievement trying to retrieve a low atmosphere sample from Jool itself. The Jool Atmosphere Recovery Scientific Expedition (A.R.S.E) And we’re going to knock out a Jool-5 challenge while we’re there).

I’ll need large boosters.

Edited January 28, 2015 by Brainlord Mesomorph