Are SSTOs' overpowered?

[rdem]

With adding many intakes to your spacecraft you can make it able to reach almost orbital speed at about 35 km high while using very low amount fuel compared to rockets. If this can happen in reality why they are stil using rockets to put small payloads or astronauts into orbit.

[temporalExile]

Have you ever tried to design an SSTO? Building a decent looking hybrid engine type SSTO is not an easy thing to do. I've built like two or three of them, but none of them could carry much into orbit.

[rdem]

I'm not saying it's easy but with many intakes and turbojet engines you can even reach a speed about 2200 meters Per second at very high altitude and you don't need much d/v to reach a stable orbit. Is that possible?

[Tank Buddy]

Because KSP, especially the jet engines, are far from reality. Pretty much anything you do in KSP is upwards of 10 times more difficult IRL. I recommend taking a look at this comparison and this SSTO design currently in the works.

[GusTurbo]

It's not that difficult to create single-stage to orbit craft in KSP, but it is much more difficult to create one with a large payload. It's also more time-consuming to achieve orbit with an SSTO vs. a more traditional rocket. That said, intake spam is silly and the turbojets are overpowered.

[GoSlash27]

I'm not saying it's easy but with many intakes and turbojet engines you can even reach a speed about 2200 meters Per second at very high altitude and you don't need much d/v to reach a stable orbit. Is that possible?

It's even worse than that. You don't actually need a lot of engines or intakes to do it. Yes, turbo jets are ridiculous in KSP.

Best,

-Slashy

[kStrout]

2 big problems for doing this in real life: 1. Kerbin is quite small compared to the earth, and has MUCH lower orbital velocity. The orbital speed of the ISS for example, is ~7.5 km/s so real life SSTOs require a lot more fuel. 2. KSP has crap aerodynamics, I bet 95% of spaceplanes made in KSP would survive at mach 5 in real life.

[Laie]

Gameplay-wise, they're ridiculously overpowered even if you do it with rockets. Fuel is cheap compared to parts, and with 100% recovery you can afford to waste a lot of fuel and still come out a lot cheaper than even the best throw-away design.

And jets? Don't get me started. Lifting >100t payloads to LKO at <20 funds/ton. In real life, riding an elevator to the 12th floor would be more expensive.

But, just for the record: it's not only because jets are incredibly overpowered (although they are); Kerbin is a small world where getting to space is very easy.

[Van Disaster]

Fuel is a very small percent of real life rocket costs too. It's Kerbin's size which does it - you can SSTO just about any launcher, although really huge rocket stacks are probably more efficient with one lower stage at least.

And yes the stock "jets" are daft.

[Linear]

The ISP of the Jets outweighs everything else, it's stupidly high.

[Pecan]

SSTOs don't need intakes, or jets.

Probe-core, fuel tank, 48-7S = SSTO.

Probe-core, big fuel tanks, 2x drogue parachutes, KR-2L = 25t-payload reusable SSTO.

Yes, they're overpowered. No, you can't do it in real life - or wouldn't want to because other ways are cheaper/easier.

Yes, there is a big rebalance intended for 1.0. No, we have no idea if that will nerf SSTOs of any, or every, type.

[klgraham1013]

My Space Program uses a lot of SSTO flights. That being said, yes, they are overpowered.

I think they should still be in the game, but maybe with more specialized / expensive engines. The whole jet engine / air intake situation in KSP needs to be reexamined.

[strongest_2hu]

The "tiny rocket SSTO" problem is more related to the way that in KSP most smaller engines have a similar, if not better ISP than their larger counterparts, and small fuel tanks have the same full:empty weight ratio as large ones. Assuming somebody tried to balance them and didn't just assign values randomly it makes some sense from a gameplay perspective: if the mainsail, for example, had better ISP than everything else, in addition to its superior thrust, I wouldn't ever need to use anything else (instead the 48-7S has better ISP and TWR so only partcount keeps me from never using anything else); having fuel tanks with varied mass ratios would drive people to use the better tanks whenever possible, in which case, why bother including the others. However, it does ruin the rocket equation for those silly cases where you don't take any payload.

It's worth noting that you only need somewhere over a 10:1 fuel:everything else ratio to get into earth orbit (with an ISP typical of a large bipropellant rocket), so if real life rocket engines were balanced (or not) from a gameplay perspective and fuel storage scaled as well as it does in-game you could do some pretty unrealistic things here as well.

[SorryDave]

Maybe air breathers should not exceed 600m/s without melting the compressors.

If the game was very realistic SSTO would not even be possible, like on earth.

Rockets are also way overpowered in this game.

It's almost like squad was more concerned about building and flying things in space than just struggling to get there.

It seems that these old arguments may be only for pre-release versions of the game, but who knows?

Maybe the release will also be easy for experienced players and focused on fun.

[Robotengineer]

It's less an issue of 'are SSTOs OP?' than it is 'Is the stock system too small for the part stats?'. The DV requirements to orbit in stock KSP are ridiculous, therefor SSTO's become an uber cheap way to deliver stuff and get the funds back for the vessel. The rapier needs a massive vacuum ISP nerfing, and the jet engines are about as bad. It's a balance issue, which will hopefully be addressed in 1.0.

[Laie]

Fuel is a very small percent of real life rocket costs too.

Show me a real life design where topping off the tanks covers all costs.

It's not the cheap fuel per se that does the trick; in KSP, it takes three times as much fuel to do a SSTO than a throw-away lifter. Also three times as many tanks and engines to lift the whole of it to space. But that doesn't matter because you can recover it a book value. There's no tradeoff, nothing.

[MartGonzo]

Everything is overpowered in KSP.

I don't know if it's possible but it would be good if the Solar system could scale with difficulty rather than just costs, which doesn't make the game more difficult, just more 'grindy'

Changing the ISP with difficulty would work too, but I'd prefer the larger planets like with the 6.4x mod or RSS.

This can get to orbit with fuel to spare

Edited February 25, 2015 by MartGonzo

[quasarrgames]

Look, the reality is that, In ksp, jets are very overpowered. In fact, compared to the real world, EVERYTHING is overpowered, as Mart pointed out.

However, it just makes the game more FUN! I mean, if sstos were "realistic", A: they wouldn't be as fun and creative to build and fly, and B: very few would ever be made, as nobody would want to spend hundreds of hours designing and building them just to have them not do anything!

The same goes for rockets too! If getting into orbit was almost impossible, very few people would have the patience with this game to actually do it!

Also, one of the fun things about KSP is that there';s so much room for creativity! You can build and fly anything ! however, if parameters for getting to orbit were more strict, then that creativity would be partially lost.

Anyways, i like the way the game is now.

P.S. THIS IS JUST MY OPINION!

P.P.S. I'd recommend Advanced Jet Engines to anyone who wants to play around with realistic jets.

http://forum.kerbalspaceprogram.com/threads/70008-0-90-Advanced-Jet-Engine-v2-0-3-Jan-29?highlight=realistic+jet+engines

[Van Disaster]

SSTO launchers don't require jets ( or wings ), I think there's two sets of definitions clashing here... it's not just an issue with jets. You can easily SSTO just about *anything* thanks to the physical makeup of the planets. Full-size RSS is not actually fun though, I've found personally.

I'm not sure completely thrashing jets is the answer here - what they do need to be is *way* larger, especially the Rapier - that thing shouldn't function at all without a cooler. Jets with performance anything close to the stock ones should probably take up most of the fuselage of a Mk1 plane instead of being an afterthought stuck on the back. Not quite sure what to do about jetspam for first stage vertical launchers, if there's anything you can do... and none of that makes SSTO ( and indeed fully recoverable ) rockets any harder either. But, so what.

[Vashts]

were still expecting scramjets right? that will take ssto space planes to a new level.

[GreeningGalaxy]

were still expecting scramjets right? that will take ssto space planes to a new level.

Even hydrogen-fueled scramjets (the most powerful airbreathing combustive engine design known) have a top speed of around Mach 17, or about 5000 m/s at 80,000 meters (assuming you can get it to run at full thrust that high) which is just over half the 8000 m/s you need to make Earth orbit. Scramjets are attractive, yes, but you're still going to need most of your vehicle to be rocket propellant.

[Van Disaster]

Skylon-type engines are airbreathing rockets rather than scramjets ( although at that point what is a jet & what is a rocket starts to get a little blurred ) - and they're looking at most of the payload being liquid hydrogen, iirc. That's with jet levels of specific impulse in airbreathing mode. However if you try a spaceplane in RSS full size you'll also end up with it being mostly fuel, and then you go back and look at rockets again

[AbacusWizard]

I don't mind overpowered launches... because for me, the game really begins once I'm in orbit. I'm all about the colossal long-term interplanetary voyages of exploration.

That being said, getting the colossal interplanetary starships (and their supply freighters) into orbit in the first place is an interesting part of the challenge.

[Madrias]

Are SSTO's overpowered? I don't see it as such.

Sure, you can chuck a cheap, disposable satellite into orbit with a handful of parts. Congratulations, you have, what, one satellite that can't go anywhere but Kerbin?

As for my area of building, SSTO aircraft, they seem overpowered at first (and some designs take it to the ridiculous and extreme), but they counter themselves with the design time, RTO duration (runway-to-orbit), and minimal payload capacity. Most of my SSTO's are great... For transferring crew to stations, returning crew to Kerbin, or filling up the slots on a colonization ship. Sure, I can chuck a satellite in the cargo bay and do something with it, but it's not really worth doing. I'm going to spend the next hour flying the bloody thing to orbit, put a satellite in orbit, and come home. In that same time, I can launch a 2STO or 3STO rocket, toss an extension onto my space station, put a satellite around Duna, and transfer some crew home from Science Station Alpha.

What I've found overpowered is Jet-Assisted Rocket Takeoff Systems. Slinging your rocket upward on 3 to 6 screaming jet engines, only cutting them off before flameout, then igniting your primary rocket stage to make orbit is a bit more... crazy.

Then again, is it really 'overpowered' if you're having fun?

Might have to give 6.4x Kerbin a try. I could use a good fun challenge.

[Van Disaster]

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...