Space Shuttles: Are they Good in KSP?

[SelectHalfling0]

I have just started toying around with the new STS-Alike parts. I was wondering how good they are compared to normal rockets. The real STS was far less efficient, and a normal rocket could carry just as much cargo for a cheaper price. Does this apply to KSP or can they be made to be better than rockets?

[Pecan]

Kerbol technology is only 'like' Earth technology, it isn't the same at all.

Designs like the American "Space Shuttle" are very difficult to balance in KSP (and real life) so are harder to build and fly. All that mass of wings, etc. makes them less efficient on the way up too.

The big advantage is that you can land them more accurately - for more funds recovery.

Jets in KSP are much, much more efficient than real-life and can make much better launch-vehicles in atmosphere than rocket engines.

But they can be difficult to land accurately for recovery, so 'pure' horizontal take-off and landing spaceplanes (which have never been done in real life) are most people's preferred reusable vehicles in KSP.

[harlikwin]

Pretty much what the previous poster said. If I build reusable vehicles they typically will land with parachutes and engines and vertically. I have built vertical takeoff SSTO's without much issue as well. Planes are just much harder to build and fly in stock KSP compared to rockets, IMO.

[SelectHalfling0]

You're explanation does help, but has anyone calculated the amount it costs to launch say, 2 tons with the rockets/fuel/boosters of a space-shuttle-like vehicle vs a rocket?

(in other words, only the boosters and rockets and fuel tanks off of a space shuttle, not the wings/cockpit/cargo bays)

[SkyHook]

The shuttles that I have built in game have been...sort of lackluster. I will do a quick economics breakdown for you.

Eurobird (1.25m payload shuttle):

Launch Cost: 54k + Payload

Recovery cost at KSC: `27k

Total Loss/Gain: ` -27k+ payload.

Ursa Shuttle (2.5m payload shuttle):

Launch Cost: 141k + payload.

Recovery cost at KSC: `70k

Total Loss/Gain: -70k + payload.

As you can see, I lose about 50% of the whole launch system because of KSP limitations with recovering spent stages (as they fall out of physics distance and unload). My shuttles are quite lean as far as cost goes, but comparing my 1.5m boosters and 2.5m boosters (which cost 11k and 55k respectively), the shuttles start to lose benefit. The shuttles may cost more, but they allow me to bring kerbals along, as well as boost into multiple orbits. This adds flexibility ans the ability to have multiple missions per launch, reducing the cost of the shuttle systems. There are ways to make a shuttle work, but if you are simply launching light payloads into space, they are NOT the way to go. Hope this helps!

[FishInferno]

The big advantage is that you can land them more accurately - for more funds recovery.

I disagree. If you used a normal rocket, you would never have to build the shuttle in the first place, so why waste the money?

In KSP, space shuttles are just a fun design challenge. I plan on building one this winter with the new Mk3 parts, as a personal challenge.

In real life, the space shuttle DID have one big advantage. Since it carried both crew and cargo, astronauts were on hand to EVA and help do the "dirty work" of whatever the payload was. This proved especially useful in the construction of the ISS and the Hubble service missions.

[SelectHalfling0]

Those images/cargo values help. Its about 20,000 funds cheaper to send something that large to LKO onboard a rocket than a shuttle. Thanks for the help!

I still will try to build a cheap shuttle though

[MKI]

The biggest problem finacially with the real Space Shuttle is the upkeep. There was a HUGE underestimation (or straight up denial) of how much manpower and resources it would take to refit the space shuttles between launches.

In KSP there is no upkeep. We also have much easier time getting things to space and better equipment.

Bottom line is the most EFFICIENT way to use the MK3 parts to get things in orbit (cargo and all) are any large SSTO designs.

Now if we are talking about semi-re-usability things get a little more gray. I do believe you can make a semi-reusable shuttle efficient in a career mode aspect, as the recovery of the engines and the Plane itself should offset decent chuck of costs for the cargo. But this is only for moderate cargo or larger. If the cargo is to small your wasting the extra fuel to carry the Orbiter up when you could use an expendable launch system to do the same.

If anything the game does offer boosts to recovery, which could possibly help. I so far haven't gotten far enough to use any of the new space plane parts in my career. But plan to when i get to the create station missions. As I believe using the MK3 parts would help greatly there, and make things much more interesting than just using rockets all the time haha.

[zekes]

They're definitely less efficient as the get bigger... my 2400 tonne one can only carry 33 tones of cargo But i imagine smaller craft get better rates. But still, more costly than a normal launch, and takes longer.

[Pecan]

...(in other words, only the boosters and rockets and fuel tanks off of a space shuttle, not the wings/cockpit/cargo bays)

If you remove the wings, cockpit and cargo bay of a 'shuttle', what is left except the rocket?

@FishInferno - I have no idea what you're disagreeing with. Shuttle design is inefficient, difficult and pointless - but at least you have the wings for landing accurately. I can happily land SSTO rockets and VTVL jets at KSC for 98% funds recovery and I've said elsewhere I don't think the possibility of another 2% pays for the complexity and comparative inefficiency of runway landings.

[Frozen_Heart]

With the ones I've built I find that they are slightly cheaper to use than disposable rockets. Much more expensive to launch but you get back a chunk on landing.

[FishInferno]

@FishInferno - I have no idea what you're disagreeing with. Shuttle design is inefficient, difficult and pointless - but at least you have the wings for landing accurately. I can happily land SSTO rockets and VTVL jets at KSC for 98% funds recovery and I've said elsewhere I don't think the possibility of another 2% pays for the complexity and comparative inefficiency of runway landings.

You said that an upside to a shuttle is that you can recover it for money, but I was saying that even if the shuttle is reusable, why waste the money on making it in the first place?

[Pecan]

You said that an upside to a shuttle is that you can recover it for money, but I was saying that even if the shuttle is reusable, why waste the money on making it in the first place?

Oh right - yeah, I agree; it's an inefficient thing to do in the first place, so any 'benefit' is only comparative. Using a SSTO rocket, VTVL jet or spaceplane is a much better way to go.

[Empiro]

Yeah definitely put me in the camp that Shuttles aren't really worth it in KSP (or in real life, for that matter).

The large, expensive LFO tank that a shuttle ditches costs about the same as the smaller LFO tank + engine that a disposable rocket ditches. Add to it the design challenge, plus the time it takes to land the shuttle, it means that it's much faster, simpler, and only slightly more expensive to use a disposable rocket. If cost is the main concern, then designing an SSTO space plane is much cheaper, and yet still simpler than a shuttle. The shuttle just has no niche in KSP.

However, it is still a fun and rewarding challenge, and I've designed a shuttle similar to the real-life shuttle in KSP.

[Temeter]

The important stuff has been said. A shuttle basically means that you bring a 100 ton heavy spaceshuttle into orbit, when you actually just want the 20 ton satellite.

Can be a neat challenge, tho. Shuttles are hard to built. Spaceplanes on the other hand? Those are time-intensive, but incredibly efficient (and tons of fun), especially with FAR.

I guess a better 'spaceshuttle-like' concept in KSP would be this: Make a single stage SSTO rocket (potentially plus detachable booster). Then reenter the atmosphere with the empty rocket, and use carefully placed parachutes to slow it down, until the rocket splashes down horizontally with relatively low speed. Recovers less money than a real spaceplane, but it's probably the best compromiss between speed and cost-efficiency in the game.

There is ofc an issue with extremly high starting weights, too. It's a lot of weight without fully upgraded starports.

Edited December 19, 2014 by Temeter

[Captain Sierra]

Okay, you can go two routes with shuttles.

Option 1:

This bird will orbit a 11.7 ton payload, and is 100% recoverable minus the cost of fuel.

Option 2:

This has yet to make orbit. Payload orbit capability unknown.

SHe's a lot more difficult to build and fly, and generally an inferior option to one of my normal Delta V lifters which can orbit 30 tons.

[Temeter]

SHe's a lot more difficult to build and fly, and generally an inferior option to one of my normal Delta V lifters which can orbit 30 tons.

I think the point of a space shuttle is putting the expensive equipment (like high performance LF-engines) into the recoverable shuttle.^^

[Empiro]

One thing in KSP is that LFO tanks are quite expensive. For example, a single orange tank is $10k empty. While a Mainsail that can lift 2 orange tanks with ease costs just $5.65k. I don't know if this is realistic at all, but it does mean that going through lots of trouble to recover an engine is pointless if you wind up ditching a larger LFO tank to do so.

[foamyesque]

There's a bunch of things that argue against a Shuttle design in KSP:

1. KSP rocket engines have much more limited gimbals than the SSMEs. This makes balancing the thrusts and masses far more difficult, even if you pre-tilt the engines as the real Shuttle did.

2. As far as I am aware, none of the KSP solid rockets have gimballed nozzles; the Shuttle's did. Again, this makes balancing thrusts and masses a much bigger hassle.

3. KSP's... odd... treatment of aerodynamics and jets and Kerbin's low orbital velocity means you can get to a very high percentage of orbital velocity on airbreathing engines alone; upwards of 2km/s, if I recall right, of the needed 2.3km/s. Contrast Earth, where LEO velocity is 7.8km/s and the official speed record for an airbreathing plane is around 1km/s.

4. KSP's low orbital velocity, extremely forgiving aerodynamics, and complete lack of re-entry heat makes a pure rocket capable of both reaching orbit in a single stage and then being safely landed without difficulty.

What these combine to is that: 1. the factors that led the Shuttle to be designed the way it was don't exist in KSP and 2. the factors that let the Shuttle work the way it does also don't exist in KSP.

If you build one it's purely for the design challenge. If, however, you go play with Realistic Solar Systems, building reusable SSTOs becomes a lot harder.

[rodion]

i take my shuttle lessons from real life - that is, it's not very safe to fly and kind of pain in the ass to operate in general.

[War Eagle 1]

My advice….just have fun

I have been finishing making a Mk3 Space Shuttle that can carry space station stuff to a 200km orbit. (I may try to release it on my thread some time soon

Is it efficient…NO. if it fun…DUH!

[Pixel of Life]

Build two-stage designs that use SRBs for the first stage. That way you can just put parachutes on the second stage and land it after your payload is in orbit. SRBs are cheap (Or are they? They should be, right?) and you'll be spending most of your Funds on the second stage so it makes sense to land and recover it.