SSTO Help

[XeroCoolUSN]

99,

I was hoping to see if anyone could lend a hand and give me some pointers/critiques to help my SSTO. I generally like the way it looks, though I have been unable to get into a stable LKO. Thus, not fulfilling the role I designed it for. I seem to have approx. 150-180 units of fuel left and run out of Oxidizer before I can complete circularization burn. Any tips would be appreciated.

It appears that Forge is down right now so I will upload the craft file at a later time but until then here are some pics.

--Xero

[JebThePilot]

I would reccomend removing all extraneous sensors (I see three extra seismometers) and replace the Rapiers with Rockomax 48-7S 0.625m parts on FL-A5 adapters for activation exo atmosphere only. Also, if you need those Rapiers for lift, just replace the large control surfaces with more small ones.

Edited June 4, 2014 by JebThePilot

[Hodo]

I have several questions before I can help out.

Are you using FAR?

Are you using DRE?

Do you have TAC Fuel Balancer?

Depending on your answers will dictate what my suggestions will be.

[Pauly]

Without being able to test it I am guessing you are engaging the rapiers to early and not doing a long enough speed run, but who knows need more pics of you trying to get to orbit or craft file to test it out.

[XeroCoolUSN]

Mods using are Kerbal Interstellar, Kerbal Engineer, KAS, Kethane.

[Hodo]

Ok simple.

You should as others have said drop the rapiers in favor of the Rockomax 48-7S, they are just better for this application.

Unless you drop the turbojet instead, then I would put a single LV909 back there and two ramjet engines in place of the rapiers. This would give you more in atmosphere speed and power but still giving you decent ISP and thrust in space.

The other thing is your accent profile is probably to aggressive, you should go for as much speed as you can on jet engines before switching over to rockets. On average I would get to mach 4.5 before I even considered switching to rockets and burning to orbit.

[O-Doc]

Try removing some fuel, that loadout is a bit too greedy(ditch those front 200s). You should be setup on two turbos and a 909 for this type of weight category. You will also need at least 4 ram intakes or 2 ram and 4 radial intakes to get that small amount of wing into space.

[Clockwork_werewolf]

Firstly Replace the Jet with a Turbo jet, it's much better at high altitude.

Secondly MORE ram intakes. I can't even see any and you have at least 4 surfaces without them even if you want it to look right. You can even add circular intakes on the rear of 2 of the tanks (these still work).

With a space-plane SSTO you want to be using air breathing mode to get you as high and as fast as you can before switching modes. You want to be flying sideways at about 10-15 degrees rather than 45. With enough intakes it is possible to have an AP outside of 70k and 23k of lateral velocity without using any rocket fuel. This does require air hogging though (12 air intakes per engine).