Early Game Space Shuttle

[Aerograde]

Hey all,

I am still fairly new to Kerbal Space Program (about 90 hours) and I have recently established a space station. I have several designs for disposable launch platforms, all of which successfully get Kerbals to and from my space station. The thing is, I want to use at least a partially reusable launch system. My mind immediately jumped to NASA's late great Space Shuttle, which, as I'm certain you all know, was capable of carrying cargo to and from the ISS, as well as being able to put satellites in LEO. I have begun developing my own space shuttle, but it has numerous problems (flipping over, short range, etc.). Even with the help of Kerbal Engineer, I simply can't get it right. What I was wondering is whether or not anyone had a functioning design for a space shuttle that is capable at the very least of taking kerbalnauts (I'm guessing that's what their called) to and from LKO.

Thanks!

[Snark]

Moving to Gameplay Questions, since this is really a question about "how to build a reusable shuttle".  (Spacecraft Exchange is more for stuff like "Here's the neat ship I built!", that sort of thing.)

Welcome to the forums! 

Reusable shuttles are definitely doable-- in fact, it's possible to build a fully reusable craft, i.e. an SSTO that can take cargo to orbit and then return.  Lots of players have built craft like this, it's a popular gameplay option.

However, spaceplanes and shuttle-style orbiters are challenging, and it can be a steep learning curve to climb.  So don't get discouraged if you're finding it hard!  We've all been there.

There are so many different ways to design things in KSP, however (and so many different ways to "do it wrong") that it's tricky to offer advice without knowing more about exactly what issues you're running into-- different people have different problems.

The best way to get specific help is to post a screenshot of a design you're having trouble with, along with a description of what the problem is.  That way, people can offer specific suggestions for how to tweak your design.  Some of the most helpful screenshots are in the VAB or SPH, with the CoM and CoL markers turned on.  Posting a screenshot is really quick and simple-- here's how.

 

8 minutes ago, Aerograde said:

flipping over

A very common problem.  The reason why this happens is usually "because your CoM is in the back", and the fix is usually "move your CoM forward".  However, without a screenshot it's hard to say for sure exactly what your problem is.

 

9 minutes ago, Aerograde said:

short range

If you're running out of dV, then that'll certainly need a design tweak, but again, really hard to offer advice without seeing a screenshot.

[AeroGav]

25 minutes ago, Aerograde said:

Hey all,I am still fairly new to Kerbal Space Program (about 90 hours) and I have recently established a space station. I have several designs for disposable launch platforms, all of which successfully get Kerbals to and from my space station. The thing is, I want to use at least a partially reusable launch system. My mind immediately jumped to NASA's late great Space Shuttle, which, as I'm certain you all know, was capable of carrying cargo to and from the ISS, as well as being able to put satellites in LEO.

When you say low tech , how low? 

With panthers and terriers SSTO crew taxis are possible, though the design has to be well optimised.

With Panther & Nuke, you can actually go interplanetary https://kerbalx.com/AeroGav/Stretch-Ray

Before Panther,  partially re-usable might be the way to go, as you say.

The two most promising options 

• Wheesley horizontal takeoff  -  Hang a pair of wheesley engines under your wings at the craft's centre of mass , in line with the axis of thrust.  Use the jet engines to get you to 10km (almost certainly subsonic, but that's the trouble with low tech jets) at which point you fire the radial decouplers and kiss goodbye to the jets.  At this altitude,  high ISP upper stage engines like the Terrier and Poodle are already efficient and can push you the rest of the way.
• Thumper Vertical launch - Mount thumpers to your wingtips , these will get you to 10km when the liquid fuel upper stage takes over.   The second phase is flown much like a spaceplane rather than rocket, which can make the gravity turn tricky.

Here's an old video i did of a terrier juno ship, it gives you an idea of how the upper stage flies.    The wings make lift at a small angle of attack for low drag,  and enable us to get to orbit with a really low TWR.  Note that these days,  fuel drains evenly from every tank so you don't have to faff around locking tanks like  i did !

Note this ship is completely uneconomic to fly.   Junos don't cost much less than Wheesley's but because of their small size we have to use loads of them, you could build a disposable rocket cheaper.   

Quote

 

I have begun developing my own space shuttle, but it has numerous problems (flipping over, short range, etc.). Even with the help of Kerbal Engineer, I simply can't get it right. What I was wondering is whether or not anyone had a functioning design for a space shuttle that is capable at the very least of taking kerbalnauts (I'm guessing that's what their called) to and from LKO.

Thanks!

 

I build a lot of spaceplanes and find i don't use Kerbal engineer much.   Thrust Weight ratio is not very useful without lift: drag ratio and drag/gravity losses are so variable.    However, i strongly recommend  RCS Build Aid  so you can make sure your craft is stable with empty fuel tanks,  and that it doesn't suffer excessive torque from engines not quite in line with centre of mass.    Even more important,    CorrectCoL  fixes the blue centre of lift indicator in SPH so it shows the true centre of lift of your craft - the stock blue indicator does not take account of aero forces acting on non-wing parts.

For performance,  I just have the rule of thumb that you need 60kn of rocket power for every 12-15 tons of mass.   3 ft 400 tanks per terrier engine. 

Your performance issues are probably down to drag.  The mk2 body has very high drag.   Do you have any 2.5m parts?

ps.  very important, when two attach nodes meet in  a stack, they must be of the same diameter or you get a large drag penalty.  So when transitioning from parts of different diameters always use adapters!

[AeroGav]

OK Aerograde,  I made two "crew shuttles" with Hitchhiker passenger module and a Poodle engine.  I was going to control via lander can but a misunderstanding with Kerbal engineer had me strip it back to a Stayputnik (grossly overestimated delta V requirement of upper stage).

The horizontal takeoff version has two Wheesleys.  They only get us to about 3km at 240 m/s,  but after starting the Poodle we go supersonic.  At mach 2 and 15km or so i finally drop them.   Went to space with plenty delta V, but it's a barebones, no solar panels , docking or attitude control.

https://www.dropbox.com/s/grlfa52tecbuahk/unTeiteled.craft?dl=0

This is the vertical version, with 4 Thumpers to get it off the deck.

https://www.dropbox.com/s/13wv55dkhbmsbku/Standing Teitel.craft?dl=0

 

[Spricigo]

 Well, for launching satellites you can't go much cheaper than 1st stage SRBs do most of work, 2nd stage finalize the orbit and optional 3rd stage for orbital maneuvers. (or some variation). At this conditions (SRBs are dirty ship, 2nd stage is just a small tank/engine, 3rd don't return) recovering its hardly worth the time. So I suggest to just go cheap and cheerful for small payloads.

Another point to notice it's that you should not design recoverable vessels for the sake of recoverability. Instead decide what you want to do and design a vessel that do it better (cheaper, faster, smaller, cooler..you decide what 'better' is), that is the first and most important decision of a design. A design will be good or bad depending on how well it fulfil its purpose (e.g I have no use for https://kerbalx.com/Spricigo/Kaingang in my career game, its ugly, limited and not cost effective, a very successful design anyway, got me a badge, a few downloads and comments. {as a side note I need to update it sometime...but I need to do so many things}).

Now about you more pressing problem, craft capable of ferrying kerbals to orbit and back: what is the techs available? what did you build so far?

[Callmedave]

I made a early tech 'shuttle' I cant post a picture as im not at my home PC. but basically It was just a rocket with extra fins attached.

It uses 4 boosters to get it out the atmosphere, the rocket itself then gets to orbit (just) I used this for the tourist contracts.

the stage would deorbit and glide down and recovers. this gets to orbit for the cost of 4 boosters and some fuel. it will carry 4 tourists and 1 pilot so it was a good money maker.

I can post a picture of it later if you wish, its worked really well for such low tech.