SSTO experts, I come to you in a time of great need.

[Sanic]

Kings, I need your help.

I've been playing a 3.2x upscaled version of KSP career with a couple mods, nothing special. But I have a bit of a problem. I need to spend mountains of money getting stuff to orbit since stock parts are not quite optimized. I'm basically broke, okay?  I'm terrible at building spaceplanes, and when Kerbin is 3x larger that's obviously not going to happen. Stock parts only is rough.

If an expert builder can build an SSTO, any SSTO, that will work on this upscale, it would be greatly appreciated. I guess it could be a fun challenge if doing engineering work for random people on the internet doesn't sound enjoyable . 

If anybody wants to take a crack at this (please do i can't keep spending 130k funds to get 20 tons to orbit), here's some relevant info about the upscale.

• The atmosphere is 98kms instead of 70
• It takes about 6km/s DV to get to orbit instead of 3.5
• Orbital speed is about 4km/s
• It takes about 3000 m/s to get to Munar orbit and back 

Help a kerbal out if you have the time 

If you want to actually use the rescale to build instead of just having spare delta V here are the links if you're interested

https://github.com/Galileo88/Rescale/releases

https://github.com/Sigma88/Sigma-Dimensions

https://github.com/Kopernicus/Kopernicus/releases/

 

 

[Arugela]

Mine for resources on the ground and sell it. It's the not so new cheat! 8)

This may let you get money to burn. Keep optimizing an array to get more and more money. I think one of the resources makes more than others, but I forget which one. Not sure on time to money ratios.

Edited August 30, 2020 by Arugela

[JadeOfMaar]

Having someone build an SSTO craft for you is not the way. There are a couple of things you need to learn or address in order to escape your problem:

• You're at the edge of the practicality of the stock drag cube system. It's time to install FAR and adapt your craft design tendencies to it.
• You need the Contract Reward Modifier mod to re-balance your earnings and penalties so that in-game economy continues to make sense as you scale up.
• The "expert" SSTO builders you're hoping for probably only operate in stock scale. They cannot help you.
• If you really like jet engines you may want to consider adding scramjets to your spaceplane formula. When you leave stock scale, these become very practical and relevant.

[Lt_Duckweed]

4 hours ago, JadeOfMaar said:

• You're at the edge of the practicality of the stock drag cube system. It's time to install FAR and adapt your craft design tendencies to it.

I would argue that this is a case where you would prefer the stock system over FAR, as you enjoy substantially higher high supersonic and hypersonic lift to drag ratios in stock.  With a decent understanding of stock aero, it is easily possible to enjoy a 4+ lift to drag ratio from about mach 1.5 to well past mach 5, with a peak a bit past mach 2, without needing to resort to any weird aero exploits.  When using weird aero exploits it is possible to push this to close to 5, possibly a bit past 5.  As far as I am aware FAR planes do not enjoy anywhere near this l/d ratio at these high mach numbers.

4 hours ago, JadeOfMaar said:

• The "expert" SSTO builders you're hoping for probably only operate in stock scale. They cannot help you.

Conceptually, this isn't that hard to design for.  You need about 2km/s more dv and probably something like double the twr in the nuclear phase of flight, and while there may need to be some design changes depending on the heat settings, not a whole lot else changes.  Ballparking it here, but I would expect payload fraction would drop by a factor of 2.5 or so, so something like 20-25%.

[swjr-swis]

On 8/28/2020 at 11:37 PM, Sanic said:

I've been playing a 3.2x upscaled version of KSP career with a couple mods, nothing special. But I have a bit of a problem. I need to spend mountains of money getting stuff to orbit since stock parts are not quite optimized. I'm basically broke, okay?  I'm terrible at building spaceplanes, and when Kerbin is 3x larger that's obviously not going to happen. Stock parts only is rough.

If an expert builder can build an SSTO, any SSTO, that will work on this upscale, it would be greatly appreciated.

You don't mention at what point you are in your career, nor your chosen save game settings. What parts of the tech tree do you have unlocked? At what level are your facilities? Have you changed any game settings from the defaults of 'Normal', and if so, which? These are important to know, otherwise people might be building you something that you can't use in your game anyway.

[Lt_Duckweed]

So I was curious, so I swapped to 1.9.1 and installed the needed mods for a 3.2 rescale.  I then made a quick and dirty edit to my orange tank lifter.  Namely, I added an extra pair of Nervs to the front of my existing nerv stack, then rotated half the stack so they faced backwards.  Then I permitted pulling liquid fuel from the payload tank.

Starting mass is 78.587 tons, mass in orbit is 45.617 tons.  Payload mass is 21.950 tons (because I pulled fuel from the tank, I need to subtract the dry mass of the percentage of the tank I used to get the true payload)

This gives me 32.97 tons of liquid fuel (well a smidgen of ox is mixed into that number because I forgot to set the rapiers to manual switching) burned to get 21.950 tons to orbit.  This gives me about 240 funds per ton to orbit, only counting fuel costs.  Obviously the overall cost will depend on how accurate you can get with runway landings.
Payload fraction on this is 27.9%, so a bit better than I predicted, but this is a fairly optimal case, so I would expect a practical design using a fairing to land solidly in the middle of my predicted 20-25% range.

 

[jimmymcgoochie]

Have you considered using something like FMRS or Stage Recovery to get money back for dropped stages? It makes a big difference when you can get a hefty chunk of your launch rocket costs back especially on an upscale system- I’m doing a career in JNSQ which is 2.7x scale, so a 3.2x scale isn’t going to be too different from that. Combined with a good launch profile or a launch automation mod like KSTS, it becomes pretty easy to put stuff into orbit around Kerbin without breaking the bank; you can also change the parameters for FMRS or SR to vary how easy it is to recover stages and the refunds for doing so, in case it seems too easy.

You you’re set on using an SSTO, you could also try the (borderline cheating) method of using atmosphere-breathing nuclear engines for low altitude flight: Near Future Aeronautics has 2 and while they’re large and heavy, they also allow you to fly in the lower atmosphere for zero fuel expended because their only propellant is the air itself. (There is some historical precedent for this type of engine, look up Project Pluto.) If you’re determined to go down the SSTO route, they’re a good bet as they have plenty of thrust and high maximum speeds, although they tend to run out of thrust quite quickly at higher altitudes.

[Sanic]

@Lt_DuckweedThanks for the help bro! Very snazzy looking SSTO . Can I have the craft file?

On 8/31/2020 at 8:31 AM, jimmymcgoochie said:

Have you considered using something like FMRS or Stage Recovery to get money back for dropped stages? It makes a big difference when you can get a hefty chunk of your launch rocket costs back especially on an upscale system- I’m doing a career in JNSQ which is 2.7x scale, so a 3.2x scale isn’t going to be too different from that.

Very solid idea - I'll take a look at FMRS. I don't like stage recovery as much because it's very gamey to stick a bunch of parachutes on every stage to recoup a huge amount of money.

On 8/30/2020 at 4:20 PM, swjr-swis said:

You don't mention at what point you are in your career, nor your chosen save game settings. What parts of the tech tree do you have unlocked? At what level are your facilities? Have you changed any game settings from the defaults of 'Normal', and if so, which? These are important to know, otherwise people might be building you something that you can't use in your game anyway.

I have all the stock parts, and level 2 plane facilities. No settings changed. Didn't think it was that important to mention since usually only the most cyclopean designs exceed the level 2 limitations.

[jimmymcgoochie]

27 minutes ago, Sanic said:

Very solid idea - I'll take a look at FMRS. I don't like stage recovery as much because it's very gamey to stick a bunch of parachutes on every stage to recoup a huge amount of money.

I usually push the speed limits for recovery fairly low for that reason. Besides which, adding 5 tons of parachutes to the launcher won’t do you any favours for payload capacity (or your FPS count if you spam dozens of parachutes on a big launcher!). Configure the settings more aggressively to reduce the returns if it seems too easy.
I personally preferred the simplicity of SR over FMRS but it really depends on how challenging you want things to be for yourself- SR is very much fire and forget, whereas from what I remember FMRS is a bit more involved. There’s a mod called recovery controller that can make SR and FMRS work together, as they usually don’t work too well if you try to use both.

[Lt_Duckweed]

I don't have the craft file of the edit available right now, but I do have the file for the ssto it is based on: https://kerbalx.com/Lt_Duckweed/Nuclear-Grace

And here's an album about it: https://m.imgur.com/gallery/fTWS13F

Keep in mind that it is NOT easy to fly if you aren't already a pretty skilled plane pilot.  To upgrade it for 3.2x scale it needs about half the payload mass replaced with liquid fuel, and double the number of nervs.  It's already at the limit of what can make it off the runway, so if you add any mass to it it needs to take off from the flats around the ksc instead (which there is plenty of at 3.2x scale)

[moar ssto]

On 8/31/2020 at 11:31 PM, jimmymcgoochie said:

Have you considered using something like FMRS or Stage Recovery to get money back for dropped stages? It makes a big difference when you can get a hefty chunk of your launch rocket costs back especially on an upscale system- I’m doing a career in JNSQ which is 2.7x scale, so a 3.2x scale isn’t going to be too different from that. Combined with a good launch profile or a launch automation mod like KSTS, it becomes pretty easy to put stuff into orbit around Kerbin without breaking the bank; you can also change the parameters for FMRS or SR to vary how easy it is to recover stages and the refunds for doing so, in case it seems too easy.

You you’re set on using an SSTO, you could also try the (borderline cheating) method of using atmosphere-breathing nuclear engines for low altitude flight: Near Future Aeronautics has 2 and while they’re large and heavy, they also allow you to fly in the lower atmosphere for zero fuel expended because their only propellant is the air itself. (There is some historical precedent for this type of engine, look up Project Pluto.) If you’re determined to go down the SSTO route, they’re a good bet as they have plenty of thrust and high maximum speeds, although they tend to run out of thrust quite quickly at higher altitudes.

At most reasonable scales(x1-x10.6), you can't beat a rapier-nerv ssto with a mutistage rocket unless that multistage rocket is derived from an ssto(staged rapier-nerv plane), in terms of payload fraction. Going to larger scale, rapier-nerv ssto will start to fail,most likely completely failing at about x13, but some super sneaky propeller-dawn ssto will still hold strong and will overperform other means of getting into orbit, up to some really large scale, maybe well past x50. So i dounbt that will full full tech tree unlocked, stage recovery mods will be a more favourable option compared to sstos. I haven't compared the cost though, but I guess sstos(rapier-nerv for lower scale, and electric ssto for high scales) will still win due their drastically smaller fuel/payload, since a lot of their lauch mass is dry mass.

 

Edited September 21, 2020 by moar ssto

[Mikenike]

On 8/28/2020 at 4:37 PM, Sanic said:

Kings, I need your help.

I've been playing a 3.2x upscaled version of KSP career with a couple mods, nothing special. But I have a bit of a problem. I need to spend mountains of money getting stuff to orbit since stock parts are not quite optimized. I'm basically broke, okay?  I'm terrible at building spaceplanes, and when Kerbin is 3x larger that's obviously not going to happen. Stock parts only is rough.

If an expert builder can build an SSTO, any SSTO, that will work on this upscale, it would be greatly appreciated. I guess it could be a fun challenge if doing engineering work for random people on the internet doesn't sound enjoyable . 

If anybody wants to take a crack at this (please do i can't keep spending 130k funds to get 20 tons to orbit), here's some relevant info about the upscale.

• The atmosphere is 98kms instead of 70
• It takes about 6km/s DV to get to orbit instead of 3.5
• Orbital speed is about 4km/s
• It takes about 3000 m/s to get to Munar orbit and back 

Help a kerbal out if you have the time 

If you want to actually use the rescale to build instead of just having spare delta V here are the links if you're interested

https://github.com/Galileo88/Rescale/releases

https://github.com/Sigma88/Sigma-Dimensions

https://github.com/Kopernicus/Kopernicus/releases/

 

 

Why would one actually play on a 3.2x scale in the first place. But besides that. MOAR RAPIERs and the Panther jet engines or the scramjet engine. But I thinks you'll be screwed here. I'd make a reusable rocket. One that you deorbit after circularization of the payload. So that you don't have to pull an @Matt Lowne quicksave redo like he does for a few of his missions. But sometimes he'll do it the less efficient, but money saving method. Like I have stated. I  thinks you'll be so far up a creek that you're effectively screwed trying to send up payloads.

[Mephisto81]

I have an SSTO for JNSQ here. It is "only" 2.5x the stock system, but it might give you some insipirations:




https://kerbalx.com/Mephisto/JNSQ-02-Stiletto-SSTA-for-Je-ne-sais-quoi-Planet-pack

[Sanic]

@Mephisto81 My save is in serious trouble unfortunately - for some reason whenever I try to land on the Mun the ground level appears to be broken, and my craft always instantly destroys itself. Have you ever encountered this playing upscaled KSP?

[Mephisto81]

I had a different bug in 1.7.3., where the new ground objects from Breaking Ground where created based on tile size. As upscaled systems had much bigger tiles, lots of ground objects got created, making it unplayable for some time. I think it got fixed in the meantime.
If I were you, I would ask in the "Add-on discussion", there might be a forum for your mods.