Are SSTOs' overpowered?

[Corw]

I've put entire stations up in spaceplanes, but yes the time to orbit is usually at least 3x a rocket.

64x is my next port of call once I have a stable install...

I think your "three times longer than rocket" is way, way, waaaay underestimated.

[Van Disaster]

Well, actually yes - I forgot how fast rockets did get to a stable orbit, although my big rockets tended to chug along pretty slowly too - upper stage TWR is usually < 1 which is fine, but not actually necessary.

[rkman]

1.0 will show us whether or not Squad thinks space plane ssto's are currently over powered.

[GusTurbo]

I think there is an important distinction between getting to orbit in a single stage and getting something useful to orbit. In the game, aside from cost, an SSTO is worse in every way than a multi-stage rocket.

[Melfice]

No.

An SSTO isn't overpowered.

Now, before you jump me with facts and anecdotes about the turbojet and the intake spam... let me tell you why an SSTO isn't overpowered.

Because, unless you build some kind of monstrosity (and good luck with that come 1.0), your SSTO is going to lift jack squat compared to a multistage rocket. And it's going to lift that jack squat very, very slowly.

So, for heavy lifting, I'll stick to my multi-stage rockets. I'll leave my "overpowered" SSTO back on Kerbin to rust until I need to move a multitude of Kerbals into orbit. Assuming I can't just combine that with... nearly any kind of mission.

[Joonatan1998]

No.

Because, unless you build some kind of monstrosity (and good luck with that come 1.0),

Has SQUAD said anything about making SSTO's harder in 1.0?

The new aerodynamics will probably reduce the fuel required to get to orbit, making SSTO's easier. (and able to carry much larger payloads.)

[Frozen_Heart]

I think that they should change the fuel consumption of jets to be more realistic but apart from that I'm happy with them. The turbojet could do with renaming though. Its pretty much a Sabre engine without the rocket mode. A similar engine has been proposed for the LAPCAT A2

[wolfedg]

Has SQUAD said anything about making SSTO's harder in 1.0?

The new aerodynamics will probably reduce the fuel required to get to orbit, making SSTO's easier. (and able to carry much larger payloads.)

I may be all wet, but I would imagine the new drag model will take a big bite out of intake spam with the exception of perhaps clipped intakes which is borderline cheating anyway. Also I remember reading somewhere that you have to be real careful with maneuvering or you can rip wings and parts right off your ship.

[Renegrade]

Re: the argument that they aren't overpowered due to the drudgery of dragging them to orbit - that's not valid. It's still putting whatever payload you want into orbit for something like 50 spacebucks a ton.

Just because certain types of 'OP' are like watching paint dry doesn't make them any less 'OP'. It just makes 'em less playable... and their OPness more.. horrible.

If fuel consumption was more accurate and we had... refurbishment costs, then they'd be less 'OP'. Still horrible though.

I think that they should change the fuel consumption of jets to be more realistic but apart from that I'm happy with them. The turbojet could do with renaming though. Its pretty much a Sabre engine without the rocket mode. A similar engine has been proposed for the LAPCAT A2

Well, you could call 'em EPEEs or FOILs or something, to go with Reaction Engine's sword-fetish?

(or maybe Incom Corporation 4L4 Fusial Thrust engine...)

I may be all wet, but I would imagine the new drag model will take a big bite out of intake spam with the exception of perhaps clipped intakes which is borderline cheating anyway. Also I remember reading somewhere that you have to be real careful with maneuvering or you can rip wings and parts right off your ship.

Well, that depends on how they handle intakes, aerodynamically speaking. The inline one wouldn't add much drag to an existing plane.

They should really do away with the intakeAir system entirely, and just make it such that each jet-type engine has an intake requirement, and as long as there's sufficient intakes for all engines, they perform properly based on altitude/speed values (like AJE does, but simplified and abstracted a bit. Hey, where are we on SJE, anyhow?)

Edited February 25, 2015 by Renegrade

[GusTurbo]

Re: the argument that they aren't overpowered due to the drudgery of dragging them to orbit - that's not valid. It's still putting whatever payload you want into orbit for something like 50 spacebucks a ton.

Just because certain types of 'OP' are like watching paint dry doesn't make them any less 'OP'. It just makes 'em less playable... and their OPness more.. horrible.

Actually, being slow and kind of boring is a valid consideration, since this is a game. People spend their time playing a game, and for some, it's not worth spending their time doing something slowly when they can do it more quickly with expendable rockets.

[BagelRabbit]

I do think that SSTOs are overpowered.

A few weeks ago, I built this thing.

(I'm very proud of its looks )

This SSTO can lift payloads of up to about a ton into orbit. That doesn't sound like a lot, but the payload I put in it (the one in the second picture) made it to lunar orbit with fuel to spare. If I had designed it to be a lander, I could almost certainly land a Kerbal on the Mun with an external command seat. I would definitely call that a 'useful' payload capacity.

This guy does take a little longer than a rocket to get into orbit, but that's okay! You can time-warp up to 4x warp, and it will remain stable. I can get it into orbit in fewer than four minutes of IRL time (about eight minutes of game time). That's not too bad in the slightest.

And I consciously made some design choices that were really bad, such as putting all of the fuel below the cargo bay, so that the craft would be unbalanced, and then combatting that with loads of SAS torque (adding weight). I didn't spam intakes too badly. I even used the overly massive 2.5m capsule!

Oh, and if you land it safely near the KSC, you can get all of your funds back, except for the cost of the fuel. (SSTOs are especially overpowered in Career Mode.)

So, that's my $0.02USD.

[klgraham1013]

My main SSTO lifts 4 tons to a 150km orbit. I've made quite a few far reaching probes that are under 4 tons.

Edited February 25, 2015 by klgraham1013

[Brotoro]

I seem to remember the days when people were saying that making an SSTO spaceplane that could reach Kerbin orbit was one of the difficult challenges in KSP. Or maybe I was dreaming this.

[Laie]

Because, unless you build some kind of monstrosity (and good luck with that come 1.0),

You mean like this? Add nosecones/fairings and it shouldn't fare badly.

your SSTO is going to lift jack squat compared to a multistage rocket. And it's going to lift that jack squat very, very slowly.

Mostly due to part count, I presume. The most efficient launchers from the recent challenge (the above is one) have an initial TWR on the order of 1.8, so you can't possibly mean gametime to orbit. Everyone has his own idea of when a payload is "heavy" and what part count they can endure, but the pictured vessel has 90 parts and a 140t payload. I think that's still in the realm of what many people can consider practical.

The problem is that SSTOs have to be three times as heavy as a conventional lifter, and five times as expensive(1), yet there's absolutely no downside to going over the top like this.

(1) note how like 6t of deadweight were saved by using the single most expensive tanks in the game.

[Van Disaster]

Want me to dig my 0.25 spaceplane lifter out with it's 278t payload? even had more nerfed engines than most people use and a bug in the wings that took 30% of the wing area off. Can't do this, can't do that, blah. I use FAR because it's logically consistent, so everything else I use has to fit too, or it's just boring. If you really want to kill SSTO launchers, use bigger planets - nothing else is going to make multistage launchers necessary.

The Reaction Engines two-cycle atmospheric engine - it's a turbofan up to supersonic & then it's a ramjet with some tech derived from SABRE - is called Scimitar. I've got something basic running but I might just try doing it for AJE.

[rcp27]

Personally I don't think SSTOs are overpowered.

Let's consider the task of putting a small payload into LKO. A typical reason I want to put a small payload into LKO is as a first step towards a "place satellite in Kerbin/Mun/Minmus orbit" to earn funds. A typical contract will call for a probe core, power, an aerial and some sort of science instrumentation. I obviously need an engine and some fuel to get to the desired orbit from LKO, and some method of getting that payload up to LKO.

Here's how I approach such a contract: The satellite itself contains an OKTO (early career) or QBE (once unlocked) probe core, a couple of surface mount solar panels, a Z100 battery, a small reaction wheel for extra controlability, a FL-T100 fuel tank, the soon-to-be nerfed 48-7s, a communotron 16, whatever science instruments the contract requires, and a decoupler to attach it to whatever I use to launch it. From LKO, this has sufficient delta V to get to any of the obrits of Kerbin, Mun or Minmus I have so far been offered (being careful to launch retrograde or polar if appropriate).

So, using the "overpowered" SSTO concept, I have a spaceplane built around Mk2 parts. The design I have uses a pair of turbojets, a pair of small rocket motors, a bunch of fuel and a Mk2 cargo bay for the satellites. If I get an efficient ascent and accurate descent so that I use a small fuel load, I generally burn something like 1500 funds worth of fuel for the flight. I could probably get this down if I redesigned my spaceplane. To use this, I need a fully upgraded SPH to unlock action groups, and a level 2 R&D centre to unlock the Mk2 parts. I generally want at least a level 2 runway because the basic runway is a pain to use.

Alternatively, I can try to build the cheapest possible disposable rocket. I saw this design on a Scott Manley video, so I can't claim the credit. I use a BACC SRB for the first stage, TR-18A stack decoupler and an RT-10 SRB for the second stage. To work well I set the thrust on the SRBs to about 60% otherwise this rocket reaches a bit too high a speed in the atmosphere, and requires a bit of use of the satellite's own engine to circularise, but it still leaves enough fuel to reach the final orbit. Total cost for launcher, 2000 funds. All of these parts are available without upgrading the R&D centre, and can be launched from the level 1 VAB and launchpad.

I use satellite launches as the main way of earning funds to make my space program run. When I'm launching satellites, therefore, my main objective is to maximise profit per hour. Spaceplanes take ages to fly up to orbit and a fair amount of time to bring down safely. Rockets go up, well, like a rocket, and there is no bring-them-down to worry about because the launcher is disposable, and all the parts are discarded on a sub-orbital trajectory. I can complete perhaps three satellite contracts using my disposable launcher in the time it takes to get a single satellite up using a SSTO spaceplane.

Finally, when I want to put something heavier up, I use SRBs to get a decent payload up on an otherwise single stage liquid fuel second stage, and give the second stage a probe core and parachutes. I tend to aim to land them back in the sea east of the KSC because it's easier to not destroy the returning stage with a splashdown than a terrestrial landing, and I can usually recover about 85 or 90% of the value of what I bring back.

Sure, SSTOs are cheap, but they aren't so much cheaper than rockets that they are entirely unbalanced, in my view.

Edited February 25, 2015 by rcp27
fixed typo

[magnemoe]

No.

An SSTO isn't overpowered.

Now, before you jump me with facts and anecdotes about the turbojet and the intake spam... let me tell you why an SSTO isn't overpowered.

Because, unless you build some kind of monstrosity (and good luck with that come 1.0), your SSTO is going to lift jack squat compared to a multistage rocket. And it's going to lift that jack squat very, very slowly.

So, for heavy lifting, I'll stick to my multi-stage rockets. I'll leave my "overpowered" SSTO back on Kerbin to rust until I need to move a multitude of Kerbals into orbit. Assuming I can't just combine that with... nearly any kind of mission.

Presenting the SR-4.

TWR higher than 1 at sea level, 6 kerbals with escape system, TWR higher than 1 at sea level unless its fully loaded with 6 ton cargo, that setting is only relevant for life support for interplanetary ships where I also carry cargo under the wings, it used 50% longer time reaching orbit than an rocket, that it I have to start then the target is 1.5 times as far away as an rocket. 2 x with 6 ton cargo.

No real air hugging needed, Start to flatten out slowly at 10 km, around 5-8 degree climb from 20 km up to I go pure rocket at 1900-2000 m/s and 35km.

Decent is the main issue, around 3 times longer time than an rocket and the rocket can be handled entirely by mechjeb.

Don't use SSTO rockets as its cheaper with an core with TWR of 0.8 and 2-6 large SRB.

Caro in this mission is an life support resupply to Duna. SR-5 has better looking wings.

Edited February 25, 2015 by magnemoe

[Jouni]

I built a quick SSTO rocket for a heavy payload. It's a simple and practical design with no special tricks, apart from hiding some parts in the cargo bay.

1030.1 tonnes on the launchpad with 126.6 tonnes of payload. It's also recoverable, especially if you're better at precision landings with stock aerodynamics than me. It looks much more aerodynamic than most rockets I fly in FAR, so something similar should work in 1.0 as well.

The KS-25x4 and the KR-2L are just too good for the stock Kerbin (and even more so with FAR), especially because the engine cluster doubles as highly durable landing gear. The only reason I build staged rockets is that I like dropping huge boosters.

[Flixxbeatz]

SSTOs isn't overpowered, but the ability to create one, fly one to orbit and land back on kerbin (ESPECIALLY THE FREAKIN SSTO SPACEPLANE), and the ability to create one and fly it to orbit like it's none, IMO, is what separates the experienced and the experts.

(inb4 ksp pros and experts telling that ssto spaceplanes are helluva easy to build and fly)

[Roflcopterkklol]

Yes SSTO's are OP, case in point, white lightning can fly to the mun, then to minum then back to kerbin without refueling, if you refuel it in orbit you can add Duna to that list before returning and that is using nothing but stock parts.

Take off

10km

15km

21km

25km

30km

34km

40km

100km orbit

Map view of 100km orbit

Accelerating to a more distant position

2000km orbit seems nice, with a lot of fuel left over too.

Map view of 2000km orbit... a lot of fuel left in the reserve tanks.... this journey is not over!

To the Mun!

Hi mun!

This was a pretty scenic picture imo

in 140-150km orbit

in 110-15km orbit

Close fly bye

That was quick, bye mun!

Back to kerbin we go

in 4600km orbit - 500km orbit

Back at kerbin in a snug 500km orbit!

Map view, Lets land this bad boy

Going down (apo aps is at 5km)

easy does it on the way down, not quite so heavy anymore, dont want to stall it

this big missing section is where i totally did not stall it on the way down and have a few very tense moments that did not end until 5000 meters, not at all.

Touch down! with over 2k LF and nearly 3k OX after going to a circle 2000km orbit then into munar orbit followed by low pass followed by a return to 500km orbit before de orbit and landing, what a mouth full.

heck you can just about fly one of my SR-72's into orbit, Air hogging is what is OP, if you do not air hog SSTO's are hard.

(The plane goes to space toward the end of the video without rocket assistance)

Edited February 25, 2015 by Roflcopterkklol

[Laie]

the ability to create one and fly it to orbit like it's none, IMO, is what separates the experienced and the experts.

(inb4 ksp pros and experts telling that ssto spaceplanes are helluva easy to build and fly)

Building planes is a lot more trouble, but once you learned how to fly them... (took me a while, however).

BUT: never mind spaceplanes, look at Juonis SSTO above: That thing is no more difficult to build and fly than any other rocket. May be ten times as expensive to operate as a spaceplane, but is still dead cheap compared to a staging rocket.

[Corw]

When we are talking about SSTO we usually mean plane-based ones.

If you are talking about ingame cost to operate one, yes, SSTO are very efficient, off the scale. If you are talking about real time required to construct and operate one, it is simply not worth it. Let me compare it to ion engines. Yes, you get ....load of delta v out of ion engine, but you are going to grow a beard to actually go anywhere with them. You are not going to use them much.

Some people like the challenge. Hell, we have Whackjob. I could never get into things he is doing, I just don't have the inclination or patience for it, but that doesn't mean there aren't whack-jobs around to do it.

Yes, plane SSTOs have become easy to make. Maybe it is experience, it took me quite some time to break into them, but they seam to be very very easy to make after we got Rapiers.

However, I believe things are going to change drastically in near future. Nerfs to engines have been announced, the drag model is changing and re-entry heat is changing. It is unlikely SSTOs are not going to be affected. And huge monstrosities posted above will probably be affected the most.

p.s. most of them are too ugly to look at anyway

[Renegrade]

Actually, being slow and kind of boring is a valid consideration, since this is a game. People spend their time playing a game, and for some, it's not worth spending their time doing something slowly when they can do it more quickly with expendable rockets.

It's only a consideration if a particular type of gameplay is boring, not if it's balanced. And I certainly agree that it's like watching grass grow, but that doesn't make it "UP".

(this is leaving aside the #lolfake problems too, although that's ALSO unrelated to balance. Something can be boring or exciting, realistic, authentic, or #lolfake, while being unbalanced OR balanced. Also one's man's watching-grass-grow is another man's "yee-haw!". There are certainly enough 6.4x scale players, and full-scale players, and a 6.4x rocket launch makes a stock scale plane launch look instantaneous by comparison)

[RAINCRAFTER]

Now: MK1 SSTO Plane. Simple Enough. MK2? A little bit less challenging, actually. MK3? OMG IT'S HARDc

Near Future: IT'S ALL TOO HARDc

(This is my opinion, so please don't bash on me.)

[Jouni]

However, I believe things are going to change drastically in near future. Nerfs to engines have been announced, the drag model is changing and re-entry heat is changing. It is unlikely SSTOs are not going to be affected. And huge monstrosities posted above will probably be affected the most.

The biggest issue for large SSTO rockets will probably be slowing down to speeds where the parachutes can be safely deployed.

I launched my example rocket with FAR & DRE. The rocket had 1290 m/s of delta-v remaining in orbit, while the stock rocket had only around 50 m/s. Once I separated the payload, delta-v increased to 2114 m/s. Atmospheric reentry was not a problem, but I had to spend almost all remaining fuel to slow down, as the rocket was trying to hit ground at a supersonic speed.