What's your average cost per ton to orbit?

[Brainlord Mesomorph]

My new launch system (100% recoverable SSTO rockets) costs me about $1000 (funds) per ton to LKO. (after recovery)

Is that really good? My previous system of multistage rockets cost more than twice that.

How much do you pay?

[GoSlash27]

Last I checked, I was down to $35 per tonne with my VTOL lifter and $43 per tonne with SSTO spaceplanes.

I don't know why yours are costing so much. I assume that all the cost is in fuel?

Best,

-Slashy

[Brainlord Mesomorph]

Stock game pretty much rules out large payload spaceplanes.

But I had a $68,000 "50 ton Lifter" now I have $130,000 SSTO that I get 70,000 <> 113,000 back on (depends on how well I throw it at the KSC) that carries 30 tons.

And its scaleable, 2 cost 60,000 and lift 70+ tons, and I just launched 160 tons with 4 of them.

(I'm not really talking about "1" ton)

Edited January 24, 2015 by Brainlord Mesomorph

[GoSlash27]

Stock game pretty much rules out large payload spaceplanes.

But I had a $68,000 "50 ton Lifter" now I have $130,000 SSTO that I get 70,000 <> 113,000 back on (depends on how well I throw it at the KSC) that carries 30 tons.

And its scaleable, 2 cost 60,000 and lift 70+ tons, and I just launched 160 tons with 4 of them.

(I'm not really talking about "1" ton)

I think that partially answers the question; it depends on how accurately you land. But it doesn't explain why you're expending $1000 a tonne when you should be under $50.

I'm not talking about 1 tonne either. The two examples I cited have payload ratings of 23 tonnes (vtol lifter) and 6 tonnes (spaceplane) respectively.

That is; they launch from KSC, intercept, rendezvous, and dock with a target in LKO, place their rated payload on station, and return to KSC intact for no cost other than the fuel and monopropellant expended.

http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/Lifter-Ception/Flight

I'm guessing you're not using turbojets for the job? Or are you not subtracting the cost of the payload itself in the calculation?

Best,

-Slashy

Edited January 24, 2015 by GoSlash27

[UmbralRaptor]

I'm not sure what the big deal is, when expendable LFEs are so cheap*

This can get 6.6 tonnes into LKO, runing you 1114√/tonne.

My less trollish answer is ~2 to 4 kilofunds per tonne because I'm rarely in a position to optimize for price, and am bad about reusability.

*Mk3 parts are... odd.

[Brainlord Mesomorph]

I'm guessing you're not using turbojets for the job? Or are you not subtracting the cost of the payload itself in the calculation?

I'm talking about payloads of 50, 75, 150 tons. (not 6, I can do that in a little spaceplane too)

But I mean big rockets. Raptor sez 1<>4 kilofunds. That sounds like the game I'm playing.

EDIT: I tried turbo rockets, there's a reason NASA doesn't do that.

- - - Updated - - -

This can get 6.6 tonnes into LKO, runing you 1114√/tonne.

that sounds like what I'm getting, but for payloads of 150+ tons

Edited January 24, 2015 by Brainlord Mesomorph

[Laie]

Because of your last thread, i started refining a two-stage rocket tanker. During tests, it delivered 231 tons of fuel for ~160k. The fuel delivered costs 20k on the launchpad, so if you swap that for another payload, you're looking at 140k/230 -> 600 funds per tonne.

[GoSlash27]

I'm talking about payloads of 50, 75, 150 tons. (not 6, I can do that in a little spaceplane too)

But I mean big rockets. Raptor sez 1<>4 kilofunds. That sounds like the game I'm playing.

EDIT: I tried turbo rockets, there's a reason NASA doesn't do that.

- - - Updated - - -

that sounds like what I'm getting, but for payloads of 150+ tons

Brainlord,

This isn't the question you originally asked. You asked whether $1000 per tonne to LKO is "really good" and how much I pay. The answers are "not really" and "$35 per tonne".

For SSTO pure rockets and payloads above 50 tonnes, I have no idea what a "really good" figure would be because 1) I don't do pure rocket SSTOs and 2) I don't have a need to lift such huge payloads in one shot.

Clearly the reason your SSTOs are so expensive to run is because you use pure rockets and you've chosen payload mass over launcher efficiency. Nuthin' wrong with playing your game your way, but it's kinda pointless to ask about cost efficiency when you've already decided that cost efficiency isn't your priority.

Best,

-Slashy

[Brainlord Mesomorph]

Brainlord,

This isn't the question you originally asked. You asked whether $1000 per tonne to LKO is "really good" and how much I pay. The answers are "not really" and "$35 per tonne".

For SSTO pure rockets and payloads above 50 tonnes, I have no idea what a "really good" figure would be because 1) I don't do pure rocket SSTOs and 2) I don't have a need to lift such huge payloads in one shot.

Clearly the reason your SSTOs are so expensive to run is because you use pure rockets and you've chosen payload mass over launcher efficiency. Nuthin' wrong with playing your game your way, but it's kinda pointless to ask about cost efficiency when you've already decided that cost efficiency isn't your priority.

Best,

-Slashy

Sorry Slash, I didn't mean to give you attitude, but you can imagine my disappointment. I was all excited that i cut my launch prices in half, and you tell me you spend 0.35% of that!

Also I am frustrated at the "failure" of my own spaceplane project. After my first successful orbital fighter jet, I spent weeks trying to "scale it up" into a payload carrier, but the biggest payload I could feasibly carry was about 20 tons. As I went larger it just kept burning more and more fuel, taking longer and longer. I am told its a flaw in the stock game. So I suspect that anyone making real use of spaceplanes is using mods. I never bothered to count but I expect I was putting those 20 tons in orbit for next to nothing, just fuel and jet fuel at that. But you can't build a massive interplanetary space program lofting one big gray tank at a time. (well, maybe you can, but I don't want to)

- - - Updated - - -

Because of your last thread, i started refining a two-stage rocket tanker. During tests, it delivered 231 tons of fuel for ~160k. The fuel delivered costs 20k on the launchpad, so if you swap that for another payload, you're looking at 140k/230 -> 600 funds per tonne.

I'd like to see a pic of that.

Were you one of the guys talking about a "recoverable first stage"? I couldn't follow that. How does that work? How do you keep it from falling out of the 2.5 km simulation bubble?

Edited January 24, 2015 by Brainlord Mesomorph

[Laie]

Were you one of the guys talking about a "recoverable first stage"? I couldn't follow that. How does that work? How do you keep it from falling out of the 2.5 km simulation bubble?

kahlzun tipped me off to the idea, see his Eve Rocks Mission for the concept:

once you're higher than ~20km, the stage may drop out of the physics bubble and won't be deleted immediately. It will be on rails until it's trajectory takes it back below the 20km line. If your second stage can complete it's ascent until then, you may switch views back to the first stage before it gets deleted, and oversee it's landing.

[Brainlord Mesomorph]

kahlzun tipped me off to the idea, see his Eve Rocks Mission for the concept:

once you're higher than ~20km, the stage may drop out of the physics bubble and won't be deleted immediately. It will be on rails until it's trajectory takes it back below the 20km line. If your second stage can complete it's ascent until then, you may switch views back to the first stage before it gets deleted, and oversee it's landing.

OOOHHH.

(the things you expect, then learn, then have to re-learn in this game...)

When I first started in career mode, I put parachutes on all of my SRB’s, and couldn’t figure out why they weren’t waiting for me in the ocean after launch. (I could watch them land but if I took my eyes off them for a moment they would disappear!) Then I found out about the 2.5 km bubble. And more recently I couldn’t figure out why some stuff that was suborbital or even “in-flight †was being saved. Jeez.

Redesigning this as a two stage launch system, I should be able to lift twice the payload. $500 a ton: Here we come!

[Hodo]

This is my very light lifter I use it for science experiments in orbit. And it is CHEAP, I think it is around 300-500 per mission.

Meanwhile this was my medium to heavy lifter for the last version and it was about 1000-2000 per mission.

But I haven't launched anything heavy in a LONG while. Mostly I have been concentrating on my military arm of development.

[Brainlord Mesomorph]

This is my very light lifter I use it for science experiments in orbit. And it is CHEAP, I think it is around 300-500 per mission.

Meanwhile this was my medium to heavy lifter for the last version and it was about 1000-2000 per mission.

But I haven't launched anything heavy in a LONG while. Mostly I have been concentrating on my military arm of development.

Those are neat!

But you sort of make my point here about spaceplanes. One, your game is clearly modded out the wazoo (NTTAWWT) , and 2 your "heavy lifter" has what? 15 tons in that payload bay?

No offence but that's not really heavy lifting by interplanetary standards (IMHO)

Thanks for the pics! Cool planes.

[Pecan]

Jets for launch are THE way to do things if you want cost-efficiency. That doesn't have to mean spaceplane but, obviously, you'll want to fly high/fast as long as possible to get the most from them. Not worrying (much) about aerodynamic flight and landing makes a VTVL 'tail-sitter' jet vehicle a lot simpler than a spaceplane although they are still a bit harder than a pure rocket.

[GoSlash27]

Sorry Slash, I didn't mean to give you attitude, but you can imagine my disappointment. I was all excited that i cut my launch prices in half, and you tell me you spend 0.35% of that!

Also I am frustrated at the "failure" of my own spaceplane project. After my first successful orbital fighter jet, I spent weeks trying to "scale it up" into a payload carrier, but the biggest payload I could feasibly carry was about 20 tons. As I went larger it just kept burning more and more fuel, taking longer and longer. I am told its a flaw in the stock game. So I suspect that anyone making real use of spaceplanes is using mods. I never bothered to count but I expect I was putting those 20 tons in orbit for next to nothing, just fuel and jet fuel at that. But you can't build a massive interplanetary space program lofting one big gray tank at a time. (well, maybe you can, but I don't want to)

Brainlord,

It's all good. Our numbers don't line up simply because I use engines you don't and I enjoy building my program "one big gray tank at a time".

Difference in playing style that allows me to design my launchers in a much more efficient regime.

Looking at it mathematically, It'd take a pair of KR2Ls to SSTO a 50t payload cheaply and with low part count. This would require roughly 250t of fuel and oxidizer (roughly $23,000), so that's $460 per tonne.

This would serve as a theoretical floor, and would serve as a better yardstick to judge your cost efficiency than what I'm doing with jets and smaller payloads.

Best,

-Slashy

*edit* I wonder if in your case it might not make more sense to use SRBs on the first stage and not bother to recover them. SRBs are cheap!

*edit 2* Monkeying around in the VAB suggests that disposable SRBs could get the cost down to $414 per tonne.

Edited January 24, 2015 by GoSlash27

[Brainlord Mesomorph]

LOL!

It IS the KR2Ls I'm using and turning one into an SSTO "booster" works, and strapping 2 said boosters on a 70 ton(!) payload works.

And I DO add SRBs! (it can't get off the pad w/o them)

I've been trying Laie's thing of trying to recover a suborbital first stage:

It sez you can't switch vehicles in the atmosphere. (although I do at the KSC all the time) Your first stage has to be aaaallllmost orbital if you're going to have time to switch to the 2nd stage, do some kind of burn to to get to a safe (if suborbital) trajectory, wait until your officially out of the ATM, and switch to the first stage and reenter, recover and switch back to the 2nd stage for the rounding burn. (whew!)

In doing all that you lose "revert to launch" and so far, I've only seen about a 50% improvement in payload capacity. (I'm pushing what the KR2Ls can lift off the pad) It's almost not worth it!

Laie, I want to see pics of that thing!

EDIT: Shash about those prices, I think you're forgetting all the hardware needed to turn that SSTO into a functional probe SAS, RC unit, etc, PLUS all the recovery hardware; chutes & gear, it adds up.

Edited January 24, 2015 by Brainlord Mesomorph

[GoSlash27]

LOL!

It IS the KR2Ls I'm using and turning one into an SSTO "booster" works, and strapping 2 said boosters on a 70 ton(!) payload works.

And I DO add SRBs! (it can't get off the pad w/o them)

I've been trying Laie's thing of trying to recover a suborbital first stage:

It sez you can't switch vehicles in the atmosphere. (although I do at the KSC all the time) Your first stage has to be aaaallllmost orbital if you're going to have time to switch to the 2nd stage, do some kind of burn to to get to a safe (if suborbital) trajectory, wait until your officially out of the ATM, and switch to the first stage and reenter, recover and switch back to the 2nd stage for the rounding burn. (whew!)

In doing all that you lose "revert to launch" and so far, I've only seen about a 50% improvement in payload capacity. (I'm pushing what the KR2Ls can lift off the pad) It's almost not worth it!

Laie, I want to see pics of that thing!

EDIT: Shash about those prices, I think you're forgetting all the hardware needed to turn that SSTO into a functional probe SAS, RC unit, etc, PLUS all the recovery hardware; chutes & gear, it adds up.

Brainlord,

I haven't forgotten it, I've ignored it. All of that gear is recoverable, so it doesn't figure into the operating cost.

Best,

-Slashy

[Delrey]

Well I just launched my first attempt at a recoverable second, orbital injection speed.

Part of the interstage fairing exploded causing one radial chute to go. The ship (debris) ran out of power and I had trouble zooming inside the ship to activate the reserve battery. Mistakes were made on this go.

Once I get this sorted out I'm going to work on the first stage.

[Laie]

Redesigning this as a two stage launch system, I should be able to lift twice the payload. $500 a ton: Here we come!

500 funds without jets? I don't say it's impossible to do, but you'll have to work hard for that figure. The fun part about two-stage is that the first stage needs to be just strong enough; it has to provide enough momentum that it will stay at safe altitudes while your second stage is doing it's thing. But if the first stage is any stronger than that, it will fall further away from KSC, depressing the recovery value. If you want to take this to it's extreme, timing will become super-critical, the ascent trajectory has to be perfect, and the whole launch will be a frantic affair. Great way to get an ulcer. Might be challenge-worthy, though.

That said, here's a proper gallery documenting the tanker I've been speaking of. 160k for 234t, making 683 funds/t 592funds/t. Recovering on the runway would reduce this by 17 funds/t, but that's a lot more difficult with this vessel.

See for yourself:

-> craft file <- (requires Mechjeb)

Also, Slashy is giving good advice there: in most cases, throwing away some SRBs will reduce the launch cost. My vessel doesn't use any because it works so well without, but I guess it's more expensive because of that.

Edit: the fuel delivered is itself worth about 20k; so the cost for lifting 234t to orbit is "only" 140k, or 590$/t. Each ton of fuel in orbit cost me 680$, though: 90$ for the fuel itself, plus 590$ for delivery (figures rounded to the nearest tenner).

Edited January 24, 2015 by Laie

[Brainlord Mesomorph]

Brainlord,

I haven't forgotten it, I've ignored it. All of that gear is recoverable, so it doesn't figure into the operating cost.

Best,

-Slashy

well, in a perfect world, yes. But Kerbin is not a perfect world.

But if you actually want to talk about estimating operating costs, I've been taught you should always is estimate your costs high and your profits low. And I was. (Given random payload drops your average recovery rate would be 75%)if you want to talk about maximums:

One KR2L SSTO Booster costs 130,000 funds, has a maximum recovery value of $113,000 and a payload capacity of 33 tons. So that technically $27000 per flight (minimum) and $810 per ton of payload. (I had rounded to $30000 per flight, and 30 tons and called it $1000 a ton)

And if I do the suborbital recovery thing I can increase the payload capacity by 50% which comes down to about $500 a ton.

But of course suborbital recovery cannot be at the KSC and cannot get maximum recovery value. And the convenience of parking those boosters in orbit until I’m ready to carefully deorbit them directly to the KSC… seems to be worth it.

- - - Updated - - -

Well I just launched my first attempt at a recoverable second, orbital injection speed.

Part of the interstage fairing exploded causing one radial chute to go. The ship (debris) ran out of power and I had trouble zooming inside the ship to activate the reserve battery. Mistakes were made on this go.

Once I get this sorted out I'm going to work on the first stage.

yeah, it's looking to me to be more complex than its worth.

Edited January 24, 2015 by Brainlord Mesomorph

[GoSlash27]

I just ran an exercise to see what such a vehicle might look like.

The core was a pair of S3-1440s and a KR-2L. Stage 1 was 6 KD-25Ks (disposable).

I put a 41.5 tonne payload into orbit, did the whole intercept/rendezvous/ docking thing and recovered the launcher. Total fuel, oxidizer, and monopropellant for the mission worked out to $580 per tonne.

I'll upload the craft file if you want it. I personally have no use for it since I can lift the same mass in 2 launches using turbojets for $70 per tonne.

*edit*

But if you actually want to talk about estimating operating costs, I've been taught you should always is estimate your costs high and your profits low.

Aye, but I didn't provide an estimated operating cost. I provided a theoretically perfect floor.

Operating cost is bound to be higher than that. It just gives you a basis to judge your cost efficiency.

$800 per tonne is pretty decent considering the numbers the rest of us are seeing (approx. $600-700/tonne)

Best,

-Slashy

Edited January 24, 2015 by GoSlash27

[Laie]

I've been trying Laie's thing of trying to recover a suborbital first stage:

It sez you can't switch vehicles in the atmosphere. (although I do at the KSC all the time) Your first stage has to be aaaallllmost orbital if you're going to have time to switch to the 2nd stage, do some kind of burn to to get to a safe (if suborbital) trajectory, wait until your officially out of the ATM, and switch to the first stage and reenter, recover and switch back to the 2nd stage for the rounding burn. (whew!)

Yeah. The initial ascent has to be rather steep, approaching the "launch straight up then circularize" strategy. It is not very fuel efficient on the face of it, but shedding all the mass of the first stage makes it more worthwhile than even the most fuel-efficient ascent with any SSTO.

In case of the vessel I posted, when the first stage burns out you should have a 60km+ apoapsis. Then, two things should happen quickly:

a) set the vessel to pitch=0

stage the KR-2L as soon as the first stage is sufficiently far away

By the time your vessel has turned to zero pitch, the projected apoapsis will probably already be in the 68-69km range. If it isn't, pitch up (slightly!) until AP reaches 69km. Then back to zero and keep it there. AP will still increase slowly; by the time you get there, you will be out of the atmosphere. When time to apoapsis is no longer decreasing, toggle the center engine (Action Group 1). Wait until time to apoapsis is at about 3 seconds, then switch it on again. Place a finger on the 'X' button. If you hit it at just the right moment, you'll be in a circular orbit of about 72km.

The beauty of this vessel is that it has just the right amount of thrust that you can keep it at zero pitch and it will reach a near-circular orbit almost on it's own. Others need more convoluted maneuvers, like actually pointing them 20 degrees down at some point and similar shenanigans. I spent a day figuring out launch profiles; it was a bit like learning to fly a spaceplane, but nowhere as difficult (learning spaceplanes took me not one day, but many!).

General advice for doing the 1st-stage recovery:

• first stage's TWR can't possibly be too high. After climbing out of the lower atmo, you want to accelerate like a bullet in the barrel.
  
• you don't have to circularize. An apoapsis some eight minutes in the future will be more than enough to watch your first stage land, and circularize afterwards.
  
• it is easier to aim for a 90km orbit to begin with, this pretty much ensures that you'll be out of the atmosphere by the time you want to switch vessels.
  
• keep the throttle at 100% (almost) all the way. You don't have time to coast anywhere. Control your apoapsis altitude by pitch, not throttle.
  

In doing all that you lose "revert to launch" and so far, I've only seen about a 50% improvement in payload capacity. (I'm pushing what the KR2Ls can lift off the pad) It's almost not worth it!

Yes... almost. The price difference isn't so high that I'd say one *has* to do it this way. But boy, is it one helluva ride!

Seriously, when doing a tanker (that is, something that has to be properly deorbited anyway), I'd probably stick with an SSTO (actually I use jets, but those are out of bounds for the purpose of this thread). For me, the first-stage thing is interesting when launching interplanetary vessels. Most of those can well circularize under their own power and only need a first stage to take them to altitude. For my most recent Jool-5, the difference in size between 1st stage and SSTO was tremenduous; and I didn't need to schedule a de-orbit burn.

Also note that the first stage can be dumb: No probe core, batteries, reaction wheels, nothing but a handful of parachutes that you activate as you stage it away. And if you chose the right parts to land on, it can be very few chutes indeed. That's why I've become so fond of the LFBs: high TWR, and resilient. They can splash down at 16m/s -- and by the time they're fully immersed, they've slowed down enough that anything on top of them will be safe as well. Aquabreaking works, if you use the right parts.

Edited January 24, 2015 by Laie

[Hodo]

Those are neat!

But you sort of make my point here about spaceplanes. One, your game is clearly modded out the wazoo (NTTAWWT) , and 2 your "heavy lifter" has what? 15 tons in that payload bay?

No offence but that's not really heavy lifting by interplanetary standards (IMHO)

Thanks for the pics! Cool planes.

That was a light load for it and the cargo was only 18 tons. It was the base part for the space station. It could haul up to 40-60 tons. It is in my medium class of lifters, my heavy lifter which I dont use much anymore is the SP-406 and SP-409.

Javascript is disabled. View full album

It was more than capable of hauling over a 120tons to an orbit of 125-100km.

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It could haul 120tons to a 200km orbit.

And all of my mods are not to make the game easier but harder and more realistic. I even built a SSTO in RO.

[Brainlord Mesomorph]

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.

Edited January 25, 2015 by Brainlord Mesomorph

[Brainlord Mesomorph]

I just ran an exercise to see what such a vehicle might look like.

The core was a pair of S3-1440s and a KR-2L. Stage 1 was 6 KD-25Ks (disposable).

I put a 41.5 tonne payload into orbit, did the whole intercept/rendezvous/ docking thing and recovered the launcher. Total fuel, oxidizer, and monopropellant for the mission worked out to $580 per tonne.

I'll upload the craft file if you want it. I personally have no use for it since I can lift the same mass in 2 launches using turbojets for $70 per tonne.

*edit*

Aye, but I didn't provide an estimated operating cost. I provided a theoretically perfect floor.

Operating cost is bound to be higher than that. It just gives you a basis to judge your cost efficiency.

$800 per tonne is pretty decent considering the numbers the rest of us are seeing (approx. $600-700/tonne)

Best,

-Slashy

Slashy,do you use a modded atmosphere? because I am not coming up with the samenumbers

Basically the same ship, using 4 s3-7200s same fuel, same mass, (oddly not the same price*) I thought the white ones were prettier, hauling 42 tons (one 33 ton tank and a 9 ton) here's what I get:

Entire vehicle cost: $157,430

Payload incl probecore etc (doesn’t count) $21,370

Booster (recoverable value) $102,381

Cost of 6 SRBs (plus addl hardware): $20,460

Cost of fuel $13,219

Divide by 42 tons = $ 801 per ton.

Am I missing something?

*off topic side note, , the 1440 is $6000 cheaper than 2 7200s. Every other capacity based part in the game is priced linearly (the half-sized one is exactly half the cost and half the weight of the full size one) the 1440 is $2280 but based on a linear projection it should be $2880. i think its a a typo. doesn’t effect the cost of fuel though.

EDIT: ran the numbers on my best spaceplane, after the turbojets cut out, 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?

Edited January 25, 2015 by Brainlord Mesomorph