So, I slapped an SSTO together, and it worked first flight.

[RAINCRAFTER]

You see the title. Introducing: Artemis I.

I whipped her up just earlier today; I was on a whim trying to test out new, creative ideas in KSP. Then, I started thinking about the SSTO I had made just a few days before (The Billy-Bobdock I, just entered it into the K-Prize) and how it was so overkill, so that lead me to challenging myself with this question:

How small can I make a typical spaceplane SSTO?

This was my answer to the challenge, and it SERIOUSLY WORKED ON THE FIRST TRY. Sure, I had to quick load a few times, but the craft succeeded the first time out of the SPH, and that was amazing to me.

The Stats: ~1700 Liquid Fuel. 165 Oxidiser. 1 R.A.P.I.E.R. Hybrid Engine. Let's get into the details of the first flight, shall we?

Takeoff was a little daunting due to the back of the plane being low to the ground, but not pitching up and just letting the plane glide off the runway solved that problem. The rest of the assent seemed pretty average as of the actual experience, but something I only found out about once I was in space really changed my look on that part of the flight. After only ~5 minutes in the atmosphere, I put myself on a sub-orbital trajectory that I would extend into an orbit with my propellant as per the usual, but that's when I noticed I had less than 100 oxidizer left in my tanks (due to burning high-atmo), and that got me kind of startled. I thought,

Could this really be the end, this far into take-off?

Thankfully, presumably due to good technique during assent, good maneuver planning, and a whole load of luck in what LF/O hybrid tanks I put on the craft, I got into a 70x70 orbit with less than 35 oxidizer to spare. After this, I let the craft move around Kerbin once, and I then deorbited it in such a way that it would land near the KSC, normal normal normal. Reentry was pretty hard, mostly because even though my plane was stable, this would force all the heat to flow into the cockpit and destroy the craft, so after a few failed attempts pointing straight up and down to spread the heat, I actually tried to make the plane unstable, and I succeeded, kicking the jets back on after getting to ~15 kms BC I had quite a bit of LF left over to regain stability. After this, I simply changed the direction of my plane (I had overshot the KSC) and landed on the runway. Hope you enjoyed that short story, reply with constructive criticism, Billy-Bobdock v. Artemis as a name, or suggestions for new designs if you wish, Rain Out.

[NotAgain]

I'm slightly concerned by the lack of vertical control surfaces, but apart from that, I like it.

[problemecium]

Less than 35 Oxidizer actually seems about right for returning that sort of minimal orbital shuttle. Especially with KSP 1.2 aerodynamics, it's easy to get back down to the ground from 70km even with as little as 10 units (I do it all the time) ...although a precise landing at KSC might take a few tries before you get the timing right.

[Lokachop]

that is awesome

[The Space Dino]

My poor SSTOs barely get out of the atmosphere. Good job!