Are SSTO space planes really worth it?

[The Wet Dog]

In career mode that is.

[FourGreenFields]

Without Stage Recovery (mod) or something similar, I'm allmost certain they are. AfaIk costs more fuel (and fuel does cost some funds), but that should be nothing compared to the money you lose from decoupling engines.

Combine that with the cewlness factor, and bragging rights, and it sounds like a pretty good idea.

[Gob]

Not really. The limited payload and the lack of contracts requiring regular small shipments to orbit mean they aren't much use.

Very satisfying as an exercise in craft design and optimisation though.

[The Wet Dog]

Originally posted by FourGreenFields:

Without Stage Recovery (mod) or something similar, I'm allmost certain they are. AfaIk costs more fuel (and fuel does cost some funds), but that should be nothing compared to the money you lose from decoupling engines.

Combine that with the cewlness factor, and bragging rights, and it sounds like a pretty good idea.

oh yeah I didn't think of that.

[Azunai]

in my opinion they really aren't. by the time you can build useful SSTOs money is generally not an issue any more. you can farm huge amounts with fairly trivial contracts. much more than you can save with reusable launchers.

you'd have to change the settings dramatically to make the cost saving worthwhile. basically you have to make disposable stuff so expensive (or rewards so low) that you can only make a profit by reusing as much as possible. normal game difficulties (including "very hard" setting) are nowhere near that level.

[Chibbity]

Useful? Yeah, for LKO transfers, short ranged stuff; absolutely.

Still, mostly for bragging rights and cool factor when compared to standard rockets. Money just isn't that big of an issue on standard settings.

They are also a lot of fun, and you will learn a lot about the game by designing them, I don't think you should ignore them completely or use them exclusively. Use them for short range missions that get repeated a lot or for crew transfers. Use standard rockets for pretty much everything else.

[Jupiter3927]

I only ever use SSTO's for Laythe landings.

My strategy is to accept as many contracts as I can near a planet or system and send one huge rocket there to do all of them.
Funding isn't an issue for me, even with reduced rewards.

You could create a huge booster stage then de-orbit it and recover it to get your engines back.
Just make sure you have a probe core and some fuel left over to actually land it.

[CBR JGWRR]

As someone who enjoys SSTOs a lot, and is in the process of an "SSTO as much as possible" playthrough (which is further complicated because I do "single stage to Minimus", as I use Minimus for all the things people normally use LKO for) they have their uses.

The things that SSTOs do well is deploying small satellites, bringing Kerbals to orbit, and avoiding the "destroy the other stages while in an atmosphere once you get too far away" thing.

The flaws though? Firstly, lifting and assembling orbital infrastructure is better done with rockets.

Secondly, once in orbit, a lot of bits of the spaceplane are dead weight; wings that aren't fuel tanks, air-breathing engines for example.

So far, I have uploaded two of my SSTMs to the Workshop - the smaller one, a 2 Kerbal "sports-spaceplane", has 2640 units of liquid fuel, 4 rapiers and 2 LV-Ns. From that, it can get from KSC to the Minimus refuelling infrastructure, and has a mass of 37 tonnes/part count of 66.

An equivalent vessel designed for purely space operations could be comfortably less than 23 tonnes/30 parts, and so, has almost twice the delta-v for the same amount of fuel. (it looks terrible though) And on costs, even with a total-loss launch vehicle (which need not be the case) can be cheaper to build.

Fuel can be obtained for free once you have the infrastructure in place, so that's irrelevant either way really.

I enjoy SSTOs, but they are limited tools.

[Vectura]

For reference, my 36 ton spaceplane costs me around 13k funds in fuel for a full-payload launch to LKO and back.

[Mightylink]

They can save you fuel when balanced out correctly, and of course the part recovery right on the runway is the most money you can get back. They are well worth it unless your playing in sandbox mode then you only do it for fun.

[XLjedi]

Rockets are disposable boosters that commission orbital command vessels to space. ...beyond that, they have no purpose for me.

Question is, do you like playing a career that involves a lot of intercepts and docking? If you don't like that style of play, or find it tedious... Then rockets may be more your thing, but they are definitely more expensive to operate.

I can see a certain coolness/triumph in designing a single all-in one rocket for some specific mission. It's not a very cost effective approach.

For me, spaceplanes are faster and cheaper than rockets. I have not seen a compelling argument yet to sway my opinion. I'm always open for someone to show me where I'm wrong. I'd use a rocket if it made sense.

People tend to speak in terms of space plane as if you need to fly them through space. Let them carry up the 40-60t load to your nuclear light carrier to make the efficient transfer through space. How did that carrier get in space? Rocket boosters; once. ...but now it's there and I can refuel/reload/reuse for as long as the Kraken allows.

[Yuki]

Originally posted by XLjedi:

Let them carry up the 40-60t load to your nuclear light carrier to make the efficient transfer through space. How did that carrier get in space? Rocket boosters; once. ...but now it's there and I can refuel/reload/reuse for as long as the Kraken allows.

This exactly.

They are a tool with a specific purpose. Every mission is more or less suited for some tools ;)
For me they are especially good at bringing my Kerbals into space. Beyond LKO its efficient nuclear driven space only transports.
Or small cargo. They can certainly release a satelite. Large cargo however... Sure you can make a giant SSTO as well (personally my largest SSTO had ~ 975T starting weight...), but...rockets are just more easy/faster in that case.

Also depending on how you design your rockets and maybe given some mods (e.g. Stage Recovery), rockets aint too expensive anymore (though SSTO will still usually beat em). And landing your lower stage rockets is certainly another neat challange.

[Jupiter3927]

I'm a big fan of solid rocket boosters.
They're cheap and get things to space.
I'm also a big fan of building my ships as lightweight as possible.
The light payloads and excessive thrust is a really good combination for getting a few satellites to LKO.

[GunnyErmy]

Define "worth it". To me, they are fun, hence worth it.

[Wobbly Av8r]

In consideration that SSTO's have their niche in KSP my interest is piqued and I'm wondering how everyone works through the "balance" issues, both with hauling a Jumbo-64 to refuel as well as returning the SSTO to KSC for full credit.

I got some input from Yuki on the Orbital Refuelling thread (thanks Yuki!) but my experience with making an SSTO went something like this:

• Make a design that "looks cool" and would probably fly if made by NASA.
• Return to SPH after running off end of runway at 180 m/s with full back elevator and unable to lift off.
• After 5 iterations of running off runway (crashing) and adding yet ANOTHER set of canards just to get your brick to "look skyward"...
• "Hallelujah! But wait... now I can't control pitch to save my Kerbal's life. After sequence of "pitch-ups" and "pitch-downs" that make the 737-Max look like a kiddie ride at Disneyland... and return to drawing board

Okay, hopefully we all get the gist of it...

How do you "think" about designing (with minimal PTSD from testing said design) SSTO's considering the changing center of mass / center of lift issues with huge weight changes (for refueling missions) not to mention the center of mass / RCS location and effectiveness issues for maneuvering a changing weight and mass issue.

Or is my problem that I'm overthinking it? I see a lot of cool designs but not having flown them, I'm wondering what other's experience is with them?

[Vectura]

The SSTO which I've been using for the jumbo-64 sized payload has an equal number of fuel tanks in front and behind the payload bay, so COM doesn't change with fuel load or payload deployment all that much. Needs dropped SRBs to get off the runway, so not strictly SSTO, but you do recover them too (assuming they don't just smash straight into the ocean).