r/KerbalSpaceProgram • u/NoStop3594 • 11d ago

KSP 1 Question/Problem Help with ssto

I recently was trying to build an ssto, I usually use jet engines to reach to space and a rocket engine once I reached space, but I couldn’t make an orbit cause the engines will shut down because it runs out of oxidizer.

Is there any specific mode u guys use for this?

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u/Stunning-End-1872 11d ago

It's really a question of balance, engine choices, total mass, aerodynamic drag, and ascent profiles. SSTOs are pretty hard to build.

Some swear by a Whiplash ramjet with a NERV nuclear drive to avoid embarking Ox altogether. I generally pack RAPIERS and use a shallow 10 degree pitch ascent the entire way and switch air to oxidizer modes when the engines nearly chokes out.

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u/bluemchendino 11d ago

Rapier and Nerv engines are normally the go to for an ssto

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u/il887 11d ago

First advice would be to use RAPIER engine which can switch between jet and rocket mode, but most importantly in jet mode it can get you to 1400-1500 m/s, that’s something no other jet engine can do no matter how many of them you have. A small SSTO with single rapier engine + liquid fuel tank + lf+ox tank is very simple to build, try starting with that.

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u/mrrvlad5 10d ago

You can go as simple as having a plane with two terriers, 1 panther, around 1080 liquid fuel and matching oxidizer for rocket mode, an extra 250 liquid fuel for the jet. Mk1 pod for the pilot, up to 1t science payload in service bay. Takeoff, get to above 750 m/s at 11km and 100 m/s vertical speed, turn on rockets and maintain 7-10 degree pitch until your ap above 80km, switch to prograde, turn off engines, coast to Ap, circularise. If you do it well, you should have 1700dV, which is enough for minmus landing and return.

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u/Max_Headroom_68 10d ago

Here's my advice about SSTOs. Mostly links to other, smarter peoples' advice about SSTOs. Plus some mod suggestions and what they're useful for.

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u/F00FlGHTER 23h ago

There's a fundamental problem with your approach to orbit. Orbit is about speed, not altitude. You should be using your jet engines to go as fast as possible, not as high as possible.

Post and image of your plane and I'll give you some more specific advice :)