Rockets or Space Planes?

[eddiew]

3 minutes ago, KerikBalm said:

Yea, but you play with KR&D so you're always starved for science because you can always upgrade a part to the next level even if its >1000 science for 5% more base Isp.

That is true, but I also turn science to 40%... although that's in part because I add DMagic Orbital and Surface Experiment Packages, and more planets, so I have more potential ways to get science   Although I'm starting to feel that this just results in a lot of right-click-run-tests and an excessive part count... Oh well, something to review for my next career  

[GoSlash27]

5 minutes ago, KerikBalm said:

Spaceplanes can handle bulky cargo too, its just that the "development time" for such a spaceplane is much much higher than spaceplanes that use the mk2 or mk3 bays... hence why we see so few "bulky lift" SSTO spaceplanes

^True.
 I've seen your bulk lift space planes in action before. I believe you're the resident expert in that field

Me personally... I don't invest the time and effort into designing a space plane unless I'm going to get a lot of use out of it. I don't envision having enough missions for such a design to justify building it. I just stick to tankers and personnel transports.
 

Best,
-Slashy

[Brainlord Mesomorph]

13 minutes ago, KerikBalm said:

People have figured out heavy lifter SSTO spaceplanes for a while now. I think I was one of the pioneers of oversized ssto spaceplanes, but I've seen other deisgns that can lift impressive payload sizes as well.

I'm not talking about a design. I'm talking about a method that will enable all of us to lift much larger payloads that we are now (even in fairings).  I'm expecting you guys to design much better planes for this than I can.

I have an 8 page tutorial done, I just need to get the pictures online.

[Majorjim!]

9 hours ago, GoSlash27 said:

Space planes take a lot more skill to develop and fly,

I do not agree. I think for most folks rockets seem easier as you play with them from the start. Rockets and getting into orbit with bulky cargo/safely/efficiently is at first very hard. I didn't touch spaceplanes/SSTOs for a while but when I did it was super easy. It's even easier in the new aero model. I personally think that once you know the flight plan of each ascent they are as easy as each other. KSP motors are OP as hell and make getting into orbit an absolute breeze.

 And I think making a detailed rocket and payload work well and function well is harder than making an SSTO any day of the week. The majority of SSTOs I see are just a few parts put together like lego with wings. I could make one in 5 minutes. In fact I did:

 

That was 5 minutes work. Got into a 220k orbit with 1782 units of fuel left. It glided empty like a bird and was a breeze to fly and land.

[KerikBalm]

Oh but I do use it. What I pictured there was using it for my reusable moho mission, and my 3 kerbal eve lander. What I didn't picture was using it to loft the mant section of my LKO station, my duna "station-ship", and a similar one for eve (that one changed so that the engine section is detachable and also functions as an orbital tug), it lofted my surface base packages to duna (which was relatively small), and laythe (quite large in diameter), my laythe station (similar to the eve one-> detachable engine section), 3 of my "deep space" vessels designed for plausible rotation to generate gravity (the first one was assembled via 2 launches, the next two were smaller single launch designs).

Also... my duna ISRU, my ike ISRU (though when I went to larger ISRU designs, I switched to ssto rockets.

Lets see what pics I have of payloads I used it for...

Spoiler

everything here except the two docked tugs that haev a single LV-N

http://i.imgur.com/4QmDTMP.png

a laythe sub:

http://i.imgur.com/v5ENaz9.png

http://i.imgur.com/fwSr4TR.png

http://i.imgur.com/uY2JEIu.png

My laythe mission (except the laythe SSTO, which self launched)

That was the same booster from the moho mission, so just a launch for the main section and the "centrifuge" habitat (which doesn't actually spin)

http://i.imgur.com/ZZq1nXU.png

http://i.imgur.com/tmySg36.png

My asteroid pushers (that's an E-class):

This thing, the eve lander, but slightly modified (already pictured in my previous post)

My "eve station"

My LKO station:

my deep space vessels (ignore the docker craft... thats also seen docked to the duna station... but it was lofted by the same spaceplane)

The moho mission package (already shown in previous post)

 

So yes... I got a lot of use out of it. I designed it to be able to take pretty much any reasonable payload, and as such, used it for pretty much every payload above a certain size.

Now I've moved on to mk3 bay spaceplanes, and mk3 bay rover modules for the fun of a spaceplane that can operate on laythe (or my modded world Rald), and pic up and drop off payloads.

That massive LKO one needs the payload to be strutted to it, often should use a fairing, and thus can't be "reused" in a seamless way, but must be recovered and then a new one launched with the payload installed.

Unlike surface bases like this:

Spoiler

Which I can deploy from and load into mk3 bay designs like these:

Spoiler

Of course, "rockets" don't do that so well.. although that Mun-Dropship is a rocket, its not built like a normal one

[Red Iron Crown]

8 minutes ago, Majorjim! said:

I do not agree. I think for most folks rockets seem easier as you play with them from the start. Rockets and getting into orbit with bulky cargo/safely/efficiently is at first very hard. I didn't touch spaceplanes/SSTOs for a while but when I did it was super easy. It's even easier in the new aero model. I personally think that once you know the flight plan of each ascent they are as easy as each other. KSP motors are OP as hell and make getting into orbit an absolute breeze.

 And I think making a detailed rocket and payload work well and function well is harder than making an SSTO any day of the week. The majority of SSTOs I see are just a few parts put together like lego with wings. I could make one in 5 minutes. In fact I did:

<snipped pics>

That was 5 minutes work. Got into a 220k orbit with 1782 units of fuel left. It glided empty like a bird and was a breeze to fly and land.

I'd think you're in a bit of a minority here, most players I've discussed it with find rockets easier than spaceplanes (I certainly do). For any given payload I can put together a rocket in a matter of minutes, a spaceplane not so much. And testing them takes longer and requires more piloting skill.

[KerikBalm]

12 minutes ago, Majorjim! said:

 And I think making a detailed rocket and payload work well and function well is harder than making an SSTO any day of the week. The majority of SSTOs I see are just a few parts put together like lego with wings. I could make one in 5 minutes. In fact I did:

 

That was 5 minutes work. Got into a 220k orbit with 1782 units of fuel left. It glided empty like a bird and was a breeze to fly and land.

Well, I know it was only 5 minutes... but its got no payload bay, didn't use airbreathers, so probably just took a standard rocket ascent... looks like a winged rocket really.

1782 units of fuel isn't even 9 tons. I'm guessing its takeoff mass was well over 200 tons. Thats a terrible payload fraction, less than 5%. When you make one that gets over 40% payload fraction in 5 minutes, and uses airbreathers, and can deploy a payload, come back.

While its true that something like a shuttle orbiter is a "spaceplane" most people here talk about functioning like a plane on ascent and descent, not just descent.

And clearly you're not concerned about being technically correct over what is commonly meant by a term, because:

Quote

rocket and payload work well and function well is harder than making an SSTO

A rocket can be a SSTO, the topic was about spaceplanes, not SSTOs. There are SSTO rockets and SSTO spaceplanes.

A winged rocket doin a gravity turn on ascent isn't functioning as a spaceplane during ascent.

[Sharpy]

53 minutes ago, KerikBalm said:

To be fair, if you look at the payload fraction challenges, SSTO spaceplanes are scoring over 50% and are just barely beat by designs which involve staging airbreathers.

Oh, that largely depends on the payload.

Can you suggest a spaceplane to bring mine to orbit?

20 large ISRUs, a single unit of 4 columns of 5 ISRUs each, reinforced with I-beams; bare minimum of guidance, and landing support. Bound to Minmus. The largest fairing *barely* managed to cover it by width.

Or if I wanted to be really nasty, at least 50,000 units worth of LF tankage space (empty, can be launched full, used up underway), plus corresponding amount of oxidizer. Minmus, precision landing required.

My point: SSTOs are a one-trick-pony. They are for payloads of specific sizes, they underperform with smaller payloads and they are entirely helpless for really large payloads.

My "2STO" which I had posted in a spoiler in my post was meant to be a remedy against that - especially "atypical dimensions". The open construction of the airplane allowed for really huge payloads (by size, not by mass... sorry, 1.1.3 wheels put a ceiling on that.) The engines had enough power to accelerate quite large payloads to 1000m/s and lift to the engine performance ceiling. The rest would be done by a rocket booster custom-tailored for the payload, recoverable or not. Then I started a project where my 2STO could only watch and cry. 4 Mammoth-based boosters in asparagus staging, and the payload would struggle to reach the orbit. Even with recovery of the stages it cost an arm and a leg though. Not that a legit way to do it any cheaper exists at all.

 

 

Edited September 7, 2016 by Sharpy

[Majorjim!]

Just now, KerikBalm said:

Well, I know it was only 5 minutes... but its got no payload bay, didn't use airbreathers, so probably just took a standard rocket ascent... looks like a winged rocket really.

1782 units of fuel isn't even 9 tons. I'm guessing its takeoff mass was well over 200 tons. Thats a terrible payload fraction, less than 5%. When you make one that gets over 40% payload fraction in 5 minutes, and uses airbreathers, and can deploy a payload, come back.

While its true that something like a shuttle orbiter is a "spaceplane" most people here talk about functioning like a plane on ascent and descent, not just descent.

And clearly you're not concerned about being technically correct over what is commonly meant by a term, because:

A rocket can be a SSTO, the topic was about spaceplanes, not SSTOs. There are SSTO rockets and SSTO spaceplanes.

A winged rocket doin a gravity turn on ascent isn't functioning as a spaceplane during ascent.

LOL, easy fella. I assumed that the OP meant SSTO when he said spaceplane. Many make that mistake, I do know the difference, thanks.

 Yes what I made there is not efficient and has no payload, it did however take an SSTO high TWR ascent profile, and it glided beautifully into a safe landing so it is very much an SSTO. It is of course very clear that it is not efficient and has no cargo. My point was that it was very easy to build and fly. I stand by that.

Just now, Red Iron Crown said:

I'd think you're in a bit of a minority here, most players I've discussed it with find rockets easier than spaceplanes (I certainly do). For any given payload I can put together a rocket in a matter of minutes, a spaceplane not so much. And testing them takes longer and requires more piloting skill.

I agree that rockets are better for large payloads man, that is very obvious. My point that making an SSTO to get into orbit is as easy or easier (for me) to build. I also agree that to make an efficient SSTO takes time but it's not hard. Just time consuming.

@KerikBalm where was this pic taken?

Edited September 7, 2016 by Majorjim!

[KerikBalm]

Ummmm, payload fraction is payload fraction, not size. Your quote is out of context:

I was replying to this (I don't know why you quote my response and talk about your point when I quoted and responded to someone else): "They deliver far less payload for the same launch size."

So one should look at your rocket that will launch that, and then see if a smaller SSTO can be made. It wasn't about absolute payload sizes, but relative sizes of payload to launch vehicle.

Also, your 2 stage to orbit uses mods. I quite like the idea of two stage to orbit designs, but stock KSP doesn't support that. If you use stage recover mods, go for it, but I think we should have stock in mind unless the question specifies otherwise.

"20 large ISRUs, a single unit of 4 columns of 5 ISRUs each, reinforced with I-beams; bare minimum of guidance, and landing support. Bound to Minmus. The largest fairing *barely* managed to cover it by width. "

I think I could manage a SSTO for that. I rate my large SSTO already pictured for 160 tons, but I know it can do more (I tested a 160 ton payload, and it had a fairing which I didn't include in the payload mass), and I had spare fuel). It can also handle payloads greater than 7.5m wide.

so 20 ISRUs= 4.25 * 20 = 85 tons. 4 columns -> we'll do 1 center, and then 3 fold symmetry around it... within the width requirements.

landing support for minmus... lets say uses a single KR-2L as a lander engine, and has a full:empty mass fraction of 1.1... thats a dV of 317 m/s- that works.

(85 tons of ISRU + 9 tons engine) *1.1 = 103.4 tons... we've got another 160-103.4 = 56,6 tons for some vernor thrusters (again, 317 m/s is more than enough for landing on minmus, so it may be more mass efficient here ot use vernors over reaction wheels) or reaction wheels, and your i beams.

 

Although I do wonder... why the heck do you need 20 large ISRUs?

Pic of the payload, I'll be my spaceplane could lift it

 

 

[Majorjim!]

Just now, KerikBalm said:

Ummmm, payload fraction is payload fraction, not size. Your quote is out of context:

I was replying to this (I don't know why you quote my response and talk about your point when I quoted and responded to someone else):

You didn't quote anyone dude. Who are you replying to?

[eddiew]

@Majorjim! - the picture is from @KerikBalm's Rald. Great spaceplane playground  I believe it's the volcano/mountain I flew past yesterday...

Spoiler

(top right, looks like KerikBalm is approaching from the desert side, heading west)

...which I think is also this one...

 

Edited September 7, 2016 by eddiew

[Majorjim!]

Just now, eddiew said:

the picture is from @KerikBalm's Rald.

It's beautiful!

[KerikBalm]

11 minutes ago, Majorjim! said:

LOL, easy fella. I assumed that the OP meant SSTO when he said spaceplane. Many make that mistake, I do know the difference, thanks.

 Yes what I made there is not efficient and has no payload, it did however take an SSTO high TWR ascent profile, and it glided beautifully into a safe landing so it is very much an SSTO. It is of course very clear that it is not efficient and has no cargo. My point was that it was very easy to build and fly. I stand by that.

I agree that rockets are better for large payloads man, that is very obvious. My point that making an SSTO to get into orbit is as easy or easier (for me) to build. I also agree that to make an efficient SSTO takes time but it's not hard. Just time consuming.

@KerikBalm where was this pic taken?

Well, you may know the difference, but you're still using ssto and spaceplane interchangeably.

"it did however take an SSTO high TWR ascent profile" I don't know what this means? I think it means a rather steep climb that flattens out at the end... a gravity turn... that you might find a SSTO rocket does.. which obviously has a high TWR if it launches vertically.

"so it is very much an SSTO" I never said it wasn't, What I'm saying is that I doubt it acts like a space "plane" on ascent, at least within the way the term is commonly used here, to describe something airbreathing that needs wings because its starting/launch TWR is < 1. Sounds to me like its just a rocket doing a gravity turn on the way up, and then acts like a spaceplane on the way down.

That pic was taken on a modded world I'm developing based on Mars, but scaled down to fit in with the stock KSP system, given a thicker O2 containing atmosphere, and oceans. Its still in a state of change... What you see is essentially Olympus Mons (its about 9km high, but the real olympus mons is ~22km high, however, because the width of it is roughly 1/10th scale, this means there is a relative vertical exaggeration of about 4x)

but here's a pic of it thats fairly representative:

Spoiler

 

Quote

You didn't quote anyone dude. Who are you replying to?

Sorry, that post was in reply to Sharpy, I started typing it out before you posted.

[Majorjim!]

Just now, KerikBalm said:

That pic was taken on a modded world I'm developing based on Mars, but scaled down to fit in with the stock KSP system, given a thicker O2 containing atmosphere, and oceans. Its still in a state of change... What you see is essentially Olympus Mons (its about 9km high, but the real olympus mons is ~22km high, however, because the width of it is roughly 1/10th scale, this means there is a relative vertical exaggeration of about 4x)

It looks stunning! I wish Squad made worlds like that.. Great work man!

Just now, KerikBalm said:

"it did however take an SSTO high TWR ascent profile" I don't know what this means?

It's an ascent that is between a rockets and a low TWR SSTO. It does make use of the lift of the wings and is launched flat from the runway on its landing gear.

Edited September 7, 2016 by Majorjim!

[Van Disaster]

4 hours ago, Sharpy said:

And how long until landed back at KSC?

And an MK2 cargo bay sized payload... it's been years Kerbin time since I launched something like that.

Takes me 20 mins-ish, usually, half of that unattended. I've lifted 280t in the past with a payload fraction of 55%, I don't do that recently because I don't want to. Awkward one-off stuff I'm quite happy shoving into orbit on a rocket, but I think the last career had 6-7 of those and those were station parts. In the past I'd have lifted those in a spaceplane too.

So I'm biased and frankly I enjoy flying spaceplanes, recovery is not a chore. I can make the aircraft parts very minimal indeed if I have to, which means I have self-recovering satellites a lot of the time.

[mk1980]

i use both rockets and planes. planes are more of a vanity item in my opinion. its fun to design and test them and they can also be useful for some tasks in career mode, but they aren't really required - everything you can do with planes, you can also do with rockets.

in some cases planes offer better performance, so it also makes practical sense to use them (getting crew to orbit or back, or getting large quantities of fuel to orbit almost for free)

if you never made a spaceplane, you should try it. when i first started, i used only rockets. easier to design and use. after a while i got curious and started messing around with spaceplanes and found that i enjoy the design process. it's a bigger challenge, so it also feels more rewarding when it works.

[KerikBalm]

24 minutes ago, Majorjim! said:

It looks stunning! I wish Squad made worlds like that.. Great work man!

I'm getting off topic with this post but...

To be fair, my contribution to this is fairly minor.

The heightmap is ultimately thanks to NASA (with the RSS mod as an intermediate). Most of the work was just playing with the heightmap to decide how high I wanted sea level, and then how much higher the "green stuff" should extend... then playing with the colormap to color the ocean blue, and the terrain above the ocean green, etc.

Then little tweaks like how mugh vertical exaggeration I should have, size, surface gravity, atmospheric thickness, etc.

I defined biomes and custom science defs for it, but that does nothing for the screenshots

Later I made a Scatterer config for it (props for the scatterer mod for making KSP prettier)     

I think the blue skies do a lot for its looks, but I'm also trying other atmosphere colors... such as a reddish atmosphere, although now I've got it somewhere inbetween... more greyish with a faint pinkish-purple hue

Spoiler

I also can't decide where to put it.

The version I first shared with Eddie (and then others via a forum thread) has it as a closely orbiting moon of kerbin, tidally locked to kerbin and vice versa (ie it orbits at geostationary orbit, Kerbins day length is the same) like a binary planet system (I had is as 1/10th the mass of kerbin). However my initial version I placed it at sun-kerbin pseudo L4 (ie, same orbit as kerbin, but 60 degrees ahead).

My latest incarnation scales it up from 320km radius to 450, and a surface gravity of 0.33 Gs to 0.42 Gs... making it significantly more massive than Duna. I moved it to where duna was, and made duna a moon if it (I call it Rald). I'm having trouble deciding if I make Ike a distant moon of the duna-rald pair, or move Ike to sun-kerbin pseudo-L4. I didn't want to make Rald at the other locations bigger because then "realistically" the orbits wouldn't be stable over long periods of time (>10% kerbin mass at L4 probably means a mass kerbal extinction in a few thousand/million years... and as such shouldn't exist if we assume Kerbin is at least a billion years old)

 

Spoiler

*from duna:

One of my main reasons for scaling it up (getting back to spaceplanes with this... whew...) was that SSTO spaceplanes were too easy with the smaller Rald. Orbital velocity was previously only ~5% higher than orbital velocity in low Duna orbit... less than 1,000 m/s... Turboramjets and rapiers (which are the best due to their better performance in thin air) easily exceed that - particularly as you can have a low AoA because you won't need to be generating any lift. Airbreathers were OPd when you'd get a 300km apopapsis and a PE above the ground on airbreathing. The scaled up Rald had airbreathers not so OP for SSTO purposes.

40 minutes ago, Van Disaster said:

Takes me 20 mins-ish, usually, half of that unattended. I've lifted 280t in the past with a payload fraction of 55%,

I would like to see that, I don't think I've ever seen a 55% payload fraction, even in payload fraction challenges... are you calculating it correctly?

Its Payload mass/(Craft wet mass+ Payload mass), not Payload mass/craft wet mass

[Van Disaster]

25 minutes ago, KerikBalm said:

 

I would like to see that, I don't think I've ever seen a 55% payload fraction, even in payload fraction challenges... are you calculating it correctly?

Its Payload mass/(Craft wet mass+ Payload mass), not Payload mass/craft wet mass

Yes. I doubt you could do it under current FAR ( actually I don't know, I should try ), but in 0.25 you could do all sorts. Think this was it, don't seem to have a pic of the craft without the payload but there's launch + orbit mass to see the fuel burn at least. Might have more in an old install's screenshots if I can find it - the further ones from this sequence don't have the UI up.

Spoiler

 

[Guest]

2 hours ago, Majorjim! said:

I do not agree. I think for most folks rockets seem easier as you play with them from the start. Rockets and getting into orbit with bulky cargo/safely/efficiently is at first very hard. I didn't touch spaceplanes/SSTOs for a while but when I did it was super easy. It's even easier in the new aero model. I personally think that once you know the flight plan of each ascent they are as easy as each other. KSP motors are OP as hell and make getting into orbit an absolute breeze.

It's pretty much all about time spent in the game doing a thing. For instance, after building a small Buran-ish orbiter for RSS (never could get it to land but I definitely got it to orbit...) I find STS-style craft very easy to build for vanilla (I just have zero use for them). Similarly, I don't find "speisplains" all that difficult, just time-consuming all-around, mainly because I've been playing the game so long.

Edited September 7, 2016 by regex

[Diche Bach]

As one who: played the game 3 years ago, came back and I feel I've now more or less "gained/regained proficiency" with the tech tree (Community Tech Tree variant) up through about the 160 point tier, and have nearly ZERO experience with space planes (built a whacky thing: airplane with rockets strapped to the sides, didn't work but it was interesting to fail with) I find this thread very interesting.

I saw some posters in another thread lamenting that "spaceplanes are too easy/too lucrative/break realism, etc."

Well since humanity has yet to truly achieve a spaceplane, I guess having them at all _IS_ realism breaking, though it seems they are theoretically possible (in real life)? Would love to hear some of you gurus comment on that and in particular provide some synthetic view of what it is that needs to happen for it to become a reality and what implications it will have for the future of real-life human space exploration.

But based on comments here, it sounds like the "lamenters" I refer to above were probably overstating part of their lament. Sounds like spaceplanes in the game, while yes, inherently unrealistic in being a fairly doable system that has yet to actually exist in real life, are actually NOT so OP as some have argued. Sounds like they have a lot of tradeoffs both in terms of in-game resources, and meta-game resources (play time, difficulty, attention level, tedium, etc.).

So in real-life, is the idea:

1. Take off from a runway

2. Gain altitude and speed until you are as high as your airbreather engines can function (I'm assuming there are some special types of "airbreathers" that can function at even lower pressures?)

3. Switch to engines that use chemical oxidizers instead of atmospheric oxygen

4. Accelerate and gain more altitude until you are in orbit?

-=-=-ADDIT-=-=-

And one more question!

What is this Spaceplane/SSTO distinction I see some guys making?

Edited September 7, 2016 by Diche Bach
additional question

[Guest]

16 minutes ago, Diche Bach said:

Well since humanity has yet to truly achieve a spaceplane, I guess having them at all _IS_ realism breaking, though it seems they are theoretically possible (in real life)? Would love to hear some of you gurus comment on that and in particular provide some synthetic view of what it is that needs to happen for it to become a reality and what implications it will have for the future of real-life human space exploration.

I don't know if I count as a "guru", and this is a bit off-topic, but spaceplanes are theoretically possible, we just need to advance our material science sufficiently. I also feel like humanity will be able to build a space elevator before we make a functional, fully-reusable, quick turn-around-time "spaceplane".

And yes, KSP's air-breathing engines are incredibly OP, even after the recent rebalance. IRL we would never use heavy air-breathing turbine engines, we consider entire new things like the SABRE and then flounder around on the details because it is not an easy thing.

Edited September 7, 2016 by regex

[Red Iron Crown]

@Diche Bach The comparison with reality falls down due to the difference in orbital speeds. Kerbin's low orbit speed is about 2400m/s, Earth's is more like 7800m/s. KSP's airbreathers are awfully optimistic (but not outright ludicrous like they used to be), they can get 60-70% of orbital velocity in airbreathing mode. Assuming the same engines are used on Earth, they are only useful for about 20% of orbital velocity while airbreathing. That's why spaceplanes are so much more feasible in KSP, their most efficient operating mode is usable for the majority of the ascent rather than just a small fraction at the beginning.

[KerikBalm]

Yes. I realize spaceplanes as we have them in KSP are incredibly unrealistic, and I respect the POV of people like regex that want a more realistic space simulator.

The engines wouldn't be so OP'd if we were all playing in RSS, and had another 7km to goto get to orbit after switching to closed cycle... but we don't.

I still have fun with building them, the same way I have fun making stuff in the flash game "fantastic contraptions" - just for the fun of building/being creative within a defined set of rules and mechanics.

IRL... I'd be much more in favor of a gigantic launch gun... seems more practical to me than a space elevator.

[Diche Bach]

Interesting . . . so if Earth was a little smaller/less dense spaceplanes would be easier in real-life . . . but then, if you changed those upstream variables too much, Earth might never have developed an oxygen rich atmosphere much less rich ecologies or complex/intelligent/spacefaring life . . . so I guess we're stuck in the middle and the pain thunder?

 . . . sorry I'll show myself out.