Spaceplane vs capsule/ballistic pod

[lobe]

4 hours ago, Streetwind said:

Ah, so it's suborbital. Pretty good idea actually.

But how does it take off? The Terrier's thrust is absolutely anemic at sea level. Do you stick on on top of a BACC?

This is actually the payload for a 10-ton to LKO launcher. The wings are styled the way they are to fit into the 1.25 m fairing. As you say though, it is very good for the suborbital tourist contracts, you don't have to worry about speeds coming in to land. Flare above the land and deploy chutes, because it already slowed the plane to below 250 m/s.

[Matuchkin]

I play via Realism Overhaul, so I can't really say anything here. But I just need to tell you guys to use it. You'll understand how amazing any capsule/command pod is, compared to any plane, etc. For one thing, command pods (with heatshields) can survive for very long amounts of time. I recently dropped a soyuz pod from a 5000 km elliptical orbit. It was reentering for something like twenty minutes, and the temperature gauge only popped up at the very end. By that time, a reentering plane would have completely broken up. I also prefer an easy parachute landing, compared to landing on a runway strip (which some people can't even do anyway, mind you).

[Plusck]

6 hours ago, Temstar said:

What, that's not true. Here for example is my true SSTO tanker that I use to refuel LKO:

[pic1]

If I burnt that fuel instead that would be a lot of delta-V.

Here's a cargo carrying variant, releasing two full ore tanks:
[pic2]

I'm more of a rocket person but for these sort of mundane surface to orbit jobs I use my SSTOs to save cost. But then again I play on hard mode so maybe I'm just a masochists.

ok, ok, I fully admit that I was slightly overstating my case ...

According to my trusty calculator, my less-than-entirely-trusty Excel sheet, and after some squinting at those screenshots, it looks like you can get a bit more than 3300 fuel to orbit for a total wet mass of 72 tons, giving 2150 m/s dv.

That is, admittedly, far more than I've ever managed (which has been more in the 500 m/s dv range, tops).

 

I should maybe add I wasn't intending to be pedantic by saying "true SSTO". Maybe should have said "actual SSTO" instead. The intent was to be clear I was talking about exactly the sort of craft you pictured here - and which requires a lot of work to get that sort of performance - and not just anything with wings. And I don't have expectations about magically building an SSTOJoolDunaEveDrillISRU either...

[Wemb]

On 02/02/2016 at 9:16 AM, lobe said:

Some users here do say that the capsule, especially early game, is the superior option. However in my case, once I achieve level 3 tech level, spacplanes are the primary option. So, I bring this question: Do you continue to use capsules until you develop a horizontal-launch SSTO, or do you keep with the capsule/ballistic doctorine until the end of days?

For a given value of 'superior' - it really depends on what you're trying to achieve...  Long term cash savings within the game - go SSTO, especially if you 'simulate' the testing via liberal use of  'revert to ...'.  If you regard use of 'revert to...' as 'cheating', I doubt the R&D required to build a usable SSTO will be worth it, unless you can design and fly a working one out of the box.

Otherwise, if you'll enjoy the challenge of building something as complicated and fine-balanced as an SSTO, it might be superior. Same if you really enjoy planes and the challenge of flying against aerodynamics as much as gravity.

Alternatively, if you don't want to spend the time having to (mostly) micro-manage the ascent and, even more so, the descent of your vessel, then capsule's are superior. 

I've occasionally flown SSTOs, and while they're a lot of fun to fly occasionally, and provide a real sense of achievement compared to lobbing a Spam can up on a firework; you could hardly call them efficient from the player's point of view when with a sound design and, perhaps a bit of KOS or MJ, you can almost entirely automate a launch and descent with a traditional rocket/capsule.

Finally, by the time you can really build SSTO's I suspect most players most significant and important launches will be for interplanetary missions, in which case, I'm not sure how much use an SSTO would be.  If we return to the Moon, or ever to go Mars, it won't be in a Space Shuttle, or anything like it.

Wemb

 

[Wemb]

3 minutes ago, Wemb said:

Finally, by the time you can really build SSTO's I suspect most players most significant and important launches will be for interplanetary missions, in which case, I'm not sure how much use an SSTO would be.  If we return to the Moon, or ever to go Mars, it won't be in a Space Shuttle, or anything like it.

 

 

Right, I should qualify this.  For -me-, by the time I get the tech-tree opened enough to build usefull SSTOs, I'm already doing interplanatery missions.  For me, the SSTO is about as much use as the Buran was to the Russian space programme - it'd be a tech demonstrator and a prestige project (with possibly useful technological spin-offs, Energia?) - rather than a meaningfully useful spacecraft.

Now, that's the way I'm playing KSP.  Some players may wish to play a more Kerbin-centric game - for all I know, you could make a really interesting and challenging game in Hard mode using thinks like Remote Tech which would really, really suit re-useable LKO launch vehicles - but it's probably not the game most people are playing.

Wemb

[Evanitis]

9 hours ago, Temstar said:

There's nothing stopping you building a craft that launches vertically like a rocket, then recover horizontally like a spaceplane.

Yay! Seeing that picture saved me like ~6 launches on my ongoing Elcano challenge. I was launching unwieldy messes, just because I could.

Thanks!

[RizzoTheRat]

17 minutes ago, Wemb said:

If we return to the Moon, or ever to go Mars, it won't be in a Space Shuttle, or anything like it.

No but that Mars ship is going to be big and will probably be assembled in space, in much the say way the ISS was from sections flown up on the shuttle.

 

Having done my first proper SSTO mission in over a year last night there was a sense of achievement, but in the real world time it took me just to fly it to LKO, drop the payload, and land it again, I could have scratch built, launched and recovered 2 or 3 rockets, and that's not taking in to account the time spent building and testing the SSTO the night before.  I think it kind of depends if your goal is the challenge of doing the launch and recovery, or if you're more interested in the mission once you've hit orbit, which is probably similar to the reasons why some people launch rockets with MechJeb while others spend more time designing them to be much easier to fly.

[Evanitis]

27 minutes ago, Wemb said:

...with a sound design and, perhaps a bit of KOS or MJ, you can almost entirely automate a launch and descent with a traditional rocket/capsule.

I was under the impression that kOS could fly any SSTO to orbit and back, given enough time to teach it how to. Trying to write such script is definitely on the list of my long term KSP projects that I'll probably never do, due to lack of sufficient freetime and patience.

Edited February 3, 2016 by Evanitis

[Brainlord Mesomorph]

9 hours ago, lobe said:

This is actually the payload for a 10-ton to LKO launcher. The wings are styled the way they are to fit into the 1.25 m fairing. As you say though, it is very good for the suborbital tourist contracts, you don't have to worry about speeds coming in to land. Flare above the land and deploy chutes, because it already slowed the plane to below 250 m/s.

Wouldn't call that a spaceplane. sorry,

Looks a lot like the capsule from my "Zed-04 Passenger Missile." ( i love that name) which was designed for orbital tourism. The Zed-02 was sub-orbital.

Edited February 3, 2016 by Brainlord Mesomorph

[Wemb]

4 hours ago, Evanitis said:

I was under the impression that kOS could fly any SSTO to orbit and back, given enough time to teach it how to. Trying to write such script is definitely on the list of my long term KSP projects that I'll probably never do, due to lack of sufficient freetime and patience.

Sure, it could - the challenge is designing a plane that stable and with enough tolerances in it's aerodynamics and flight characteristics that would allow a computer programme to fly one. I'm not sure if KOS is Turing-complete or what other limits it's language may have  - but regardless - that would be as much an exercise in computer programming flight simulators as spaceship design - that might be appealing to some folks. I'd prefer the light the blue touchpaper and stand well back approach. 

Wemb

[Evanitis]

I never did programming, besides some really basic flash-stuff if that counts. But I skimmed trough the kOS documentation, and it looks -really- simple, even for a mortal like me. And it looks interesting for me to translate my SSTO-plane orbiting procedure to simple commands. Like "if speed > 100, raise AoA to 30°", "if height > 10.000, set AoA to 10°" "if acceleration = 0 STAGE". The language isn't much more complicated than that. I'm pretty sure I could write one for a specific plane in 1-2 hours. Maybe in a few days, I could come up with something that could orbit most of my crafts.

I'm pretty sure I could just google for a script that does that, but that looks like an interesting, irregular challenge for me to do it myslef. One day.

[lobe]

3 hours ago, Brainlord Mesomorph said:

Wouldn't call that a spaceplane. sorry,

Looks a lot like the capsule from my "Zed-04 Passenger Missile." ( i love that name) which was designed for orbital tourism. The Zed-02 was sub-orbital.

Isn't that a spaceplane? I mean if the X-37 or Dynasoar can be called a spaceplane, I think any vehicle made to re-enter and land with the assistance of aerodyanamic lift surfaces is a spaceplane. A capsule, such as the Apollo CM, cannot generate conventional lift, only a small amount of body lift. It can't glide in to land safely.

[Vegetal]

Maybe you aren't interested in taking the spaceplane interplanetary, but that same spaceplane could carry an interplanetary vessel to orbit. That is something some of my SSTO planes can do, so the entire mission is reusable.

Maybe spaceplanes aren't really your thing too. I don't like the idea of throwing away expensive hardware, even if it's not really a problem in the game. We do that in real life because space is HARD, but we do it in game because we are lazy to be honest, even me, a plane (helicopter actually) guy, have felt the laziness and launched a rocket instead. But I like the exercise to throw away the least as possible.

[Brainlord Mesomorph]

1 hour ago, lobe said:

Isn't that a spaceplane? I mean if the X-37 or Dynasoar can be called a spaceplane, I think any vehicle made to re-enter and land with the assistance of aerodyanamic lift surfaces is a spaceplane. A capsule, such as the Apollo CM, cannot generate conventional lift, only a small amount of body lift. It can't glide in to land safely.

 

Technically you are correct. And that is the best kind of correct!

But in my defense, a lot of ppl on this forum (including myself) use the word "spaceplane" as shorthand for (specifically) a horizontal-take-off, SSTO spaceplane. You know, winning the K-Prize.

So by the technical definition, I've been using spaceplanes since tech level three also.

In the OP your question was Why don't more ppl use them? My answer is drag on the rocket, and the wish to use the more advanced command pods in space.

Edited February 3, 2016 by Brainlord Mesomorph

[Evanitis]

1 hour ago, lobe said:

Isn't that a spaceplane?

Rule No.1. of spaceplanes - never argue about semantics, as unless you are -really- precise, the words will mean something entirely different to everyone. In my book anything that has wings and goes to space is a spaceplane. Dun' let the purists say otherwise.

[FlyingPete]

I prefer using capsules. I've built a couple of spaceplanes as crew shuttles, but to be honest they're not worth the hassle. I find it tedious launching them to orbit, once there they can't really go anywhere. So you need reusable spacecraft in orbit for running routine missions to Mun and Minmus, which need refuelling. By the time you're running tanker flights to service the orbital bus, it's just simpler to use a capsule.