Interplanetary spaceplanes and money: Will it be worth it?

[Themohawkninja]

Upon getting my first SSTO into orbit that has an LV-N on it, it occurred to me that I would still need to launch a re-fueling mission to get the ship interplanetary (or at least to the Mun/Minmus). Such a refueling mission would seem to take away from the (will be) increased cost efficiency of an SSTO.

If I can just launch a craft via rocket that has the same interplanetary capabilities as my SSTO once the SSTO has been refueled (via a slightly less massive rocket mission), is it going to be all that much worth it to make interplanetary SSTO if they will need refueling before doing a mission?

Now, obviously this is going to be almost 100% dependent on the specifics of the craft and the rocket, but I would like to know what people think about this. Once money becomes an issue in the game, skilled players will try to make everything a single-stage-to-whereever, but (IMO) most of those are going to be something along the lines of either RAPIERS with one or more LV-Ns, or turbojets with one or more LV-Ns, which means that the players will have to spend all that extra money to refuel the craft, which may have been better spent on a single rocket mission to launch a nuclear powered, not-so-plane-like interplanetary craft.

So, on average, will space planes that need refueling once in orbit to do the mission still be more cost efficient then a (possibly) larger single rocket launch, or not? Or is this far too case-by-case to really make any solid predictions?

[tetryds]

Some SSTO's can orbit with like 3000dv, and another smaller ones can orbit with less percentage of fuel yet require less fuel to fill.

Orbiting 500l for the SSTO might not be that expensive.

But I can only say for sure that they will be deffinitelly worth if you already have a refueling station setup in orbit.

But specific refueling missions just for one SSTO will deppend a lot.

[Themohawkninja]

But I can only say for sure that they will be deffinitelly worth if you already have a refueling station setup in orbit.

You'd still have to re-supply that station though.

[crazyewok]

Why do think NASA went back to capsules.

Space planes may look cool but they come with some huge difficultys and limitations.

[Themohawkninja]

Why do think NASA went back to capsules.

Space planes may look cool but they come with some huge difficultys and limitations.

Seeing as NASA never made an SSTO in the first place, I don't see your point. I mean, I get that you are referring to the Space Shuttle, but that has nothing to do with interplanetary flights.

[Guest]

I'd really have to see how future implementations handle reusability, especially with science collection and possible contract completion mechanics, to really say whether a spaceplane would be "worth it", especially if it needs to sit around at KSP like it does now. I don't, however, think money is going to be the big issue people seem to be making it out to be.

[crazyewok]

Seeing as NASA never made an SSTO in the first place, I don't see your point. I mean, I get that you are referring to the Space Shuttle, but that has nothing to do with interplanetary flights.

Well thats the thing. SSTO are likley not ever going to be meant for interplanetry flights only for earth or in this case kerbin to LEO

[xrayfishx]

You'd still have to re-supply that station though.

Yes, but there's a cost difference between launching 50 small tanks to refuel 50 SSTOs and launching a station and then 2, maybe 3 tanks for those 50 SSTOs.

[Themohawkninja]

Yes, but there's a cost difference between launching 50 small tanks to refuel 50 SSTOs and launching a station and then 2, maybe 3 tanks for those 50 SSTOs.

I'm confused.

If I have an SSTO that needs 100 fuel to get topped off again after getting into LKO, it will still take 100 fuel to top the craft off whether I'm doing it from the ground, or from the station (which will need to be resupplied from the ground anyways). If anything, you're just cutting out the middle man by not bothering with the station.

[nholzric]

...I don't, however, think money is going to be the big issue people seem to be making it out to be.

I agree, there are a ton of fun incentives an economy could make without sweating these types of details. I expect the economy will provide pressure to keep launch sizes down, like don't launch a little Mun probe with a massive 6+ Mainsail launch system, without *forcing* you to use SSTO's for interplanetary travel. Of course, KSP has an awesome community so you know there'll be people pinching every penny and that'll be fun for them too.

[tetryds]

I'm confused.

If I have an SSTO that needs 100 fuel to get topped off again after getting into LKO, it will still take 100 fuel to top the craft off whether I'm doing it from the ground, or from the station (which will need to be resupplied from the ground anyways). If anything, you're just cutting out the middle man by not bothering with the station.

When you launch more fuel at once, its more "efficient" (we talking about LKO payload/lifter costs here) and requires less missions and less time.

[Blondai]

Obviously it all depends on what you want to do, a space plane is Ideal for a laythe mission, and it will save a lot of delta v, rather than carrying a large multi-stage lander. And of course in the final game everything costs money. A space plane will be reusable, if you can land it, you can refuel it. So efficiency certainly increases at low kerbin orbit, or even orbiting bodies. There are some videos on the internet where people have made large deliveries to duna and joolian moons with ssto's without refuel. It isn't impossible. So if you got the skills. It can certainly increase efficiency.