The 'T' in SSTO stands for 'To'. There's nothing about 'from' for a reason.

[Sharpy]

A simple task: take the crew stranded at Umbrella Space Station.

They were on their way to Minmus by an experimental shuttle. The shuttle appeared to be a bad mistake, fuel from all side tanks had to be moved into the small central tank by hand all the time, it had no own power source and pitiful batteries, anyway, the crew was stranded in the station. Three Orange Suits and two Grey. The scientist was taken to Minmus, the rest had to wait for a return trip.

So, today I built my first SSTO plane. Creatively named SSTO-1; my line of failures of getting to the orbit with turbojet and LV-N ended when I included a good old Poodle, with enough thrust to keep me in orbit and enough ISp not to use up all the fuel. I equipped it with a passenger cabin for this flight, but it could take a cargo bay instead... or actually, two.

It required some fancy trajectory to get to orbit: rise to 10km, level the flight, gain speed until some 800m/s, then pull up, to escape the atmosphere at above 1000m/s. I'd switch the rocket engines on at about 20km.

It seems the idea worked, it was even a bit over-engineered; I had good 2000m/s of delta-V left when in orbit, and a plenty of oxidizer still left.

Well, I set the course for Umbrella Station, at its 1000km orbit. I set up an almost-perfect rendezvous, and executed first burn (2 minutes 39s!) with the lv-n to 0.1m/s precision. I warped to a minute before the rendezvous, and began braking.

Well, duh, I'd never get some 300m/s difference before getting waaay away from the station, luckily I still had a lot of oxidizer. Poodle activated again, and I ended braking when 1,4km from the target.

At leisurely 10m/s I approached the station, picked a free docking port and began docking. It went amazingly smoothly until the clamp failed to catch correctly. Attached loosely by the nose, I kept swinging to and fro in hopes the clamp would catch properly at last. Good half a hour of trying to align myself perfectly perpendicularly to the station.

At last, after a more rapid maneuver the joint broke off. I backed off a bit and docked again... and it caught at once. And right on time. My vernor engines had some 10 units of oxidizer left. (still plenty of liquid fuel, but dock something this big without RCS!)

BTW, seen these three headlights? They make docking a breeze. Each shines a different color, white in the middle should be where the port is.

And when everything docked to the station switches its lights on...

As for what you see: the big fuel depot on the left. A rescue tug next to SSTO-1 on the right. And three escape pods. The crew wasn't exactly stuck, it's just that the pods are single-use; one fits three kerbals, and provides bare necessities to reach Kerbin and land safely.

Well, crew exchange. My pilot would stay, to kerb the station. The rest would return. Crew transfer function refused to work as usual, so I had to EVA the kerbals one by one. Refuelling, not that it was needed. (actually, it caused a lot of trouble; I didn't load up any oxidizer, and oxidizer tanks sit in the back; the plane lost stability.)

The kerbals were ecstatic about going home. The flight back to the orbit was uneventful.

Quicksave before reentry. Good that I did.

The first three or so attempts ended in a disaster. The plane would flip, spin out of control and break apart.

Then I got to moving fuel from rear tanks to half-empty front ones. The plane didn't lose stability. It lost the crew cabin to overheating.

I began balancing frantically transferring fuel and keeping the plane flight path level, not to dive into deeper atmosphere. I succeeded getting out of flames at 30,000 only to be destroyed by them at 20,000.

Then I remembered that I took four drogue chutes, to make sure my landing path is short enough. Oh well, I moved two to a separate stage, deployed them, then began moving fuel, then stabilizing flight, then... somewhere around 25,000m I lost the rudder. The whole big fin just exploded. Why this? I'll never know.

I "cut" the two parachutes, and without rudder, but at stable speed, 20% throttle, I began crawling to KSC. Last jump over the mountains, and trying to fit into the runway...

Of course I missed the first approach. With engines roaring, I flew about the SPH building. Then another from the sea. Then from land. Then from the sea. I touched down, but moving too fast. The nose of the plane went far up for some reason, and I had to press full throttle not to flip over. Once again, mountains, once again the sea, each time either getting too late to land safely or getting some obstacles in my path.

At last I approached from the mountain side very slowly, descending really slowly too. And in the last meters, I stalled. Crash, explosions. Desperate, I was about to abandon the game, when I saw the whole front of the plane was still rolling!

Single Stage To Orbit. But losing a few stages on the way back.

[oriramikad]

A Poodle? On a spaceplane? *applause* Maybe I should try that. #stillnosstoinonepointoh

[Sharpy]

A very reasonable middle ground between high thrust and high ISp. Very good if you need to gain 1000m/s in some 3 minutes. LV-N simply don't have the thrust and anything stronger would quickly consume all the fuel, never reaching the orbital speed. Though I agree the size is silly.

[Geschosskopf]

This was a great battle against the odds. Salute!

And as Oriramikad said, I'd have never thought to put a Poodle on a spaceplane. Nor has anybody else, apparently. I'll have to keep this in mind

[GehringGame]

Single Stage To Orbit. But losing a few stages on the way back.

The most exciting flights are the ones that take a few parts of your craft with them I got a kick out of that last line, thanks for sharing!

[B-STRK]

My God she's large! I never thought about taking the big wings into space (disclaimer: have yet to make an SSTO since I first got KSP in 0.23.5!). I guess either RAPIER wasn't an option, or it didn't give you the performance you've wanted?

[Sharpy]

1. I don't have RAPIER yet.

2. It has worse ISp than Poodle in vacuum. (also worse in atmosphere than Turbojet, but with the numbers taken by the jet engines, who cares?)

Also, surprisingly, Poodle is considerably lighter than RAPIER (even lighter than a turbojet!) and provides twice as much thrust in vacuum. The only actual disadvantage is its size... and not being a jet engine. The need to carry a turbojet alongside negates most of the benefits (although if you forfeit the idea of SSTO and e.g. discard 4 out of 6 turbojets as they sputter out (you REALLY don't need that much power for reentry) , that might be a little different)

I guess RAPIER would be better - for the simple reason four RAPIERS would provide all the functionality of six turbojets and the Poodle, at 87% the ISp (but as I wrote, I was left with plenty of fuel on the orbit, so the 13% ISp sacrifice isn't much), and lower mass (8 tons vs 12.55 and all infrastructure to fit 6 smaller and 1 big engine). Well, it all boils down to some 1500 science points I still need to get there.

Anyway, my current plan is a "fully recoverable 2STO" - somewhat similar to SpaceShipOne - a "carrier stage" with a bunch of jets and a Poodle (or maybe something stronger - actually Rhino's ISp is only 10s less than Poodle!) that gets the craft into "almost orbit" (some 100m/s short of it), and the actual "plane/shuttle" that can travel the universe and land on a landing strip (with help of 2 turbojets). The idea is that finalizing the orbit with the "shuttle" should take short enough that I should still be able to bring the "carrier" safely to the ground before it enters the magical 22km vanishing altitude. And the "spacecraft" wouldn't carry all the oxidizer tanks around (only enough for Vernor engines), and all the dead weight of start mass.

[GehringGame]

"fully recoverable 2STO" - somewhat similar to SpaceShipOne - a "carrier stage"

I would be interested to see what you come up with. I've built a couple of space planes that launch from carrier planes before, but I've never managed to recover both stages. I usually just treat the carrier plane as a big disposable wing.

My last version (which I don't have a screenshot of) used a turbo-jet powered wing to cruise at Mach 3 at 20 km, then the small rocket plane decoupled and boosted into orbit. The problem is I didn't design the wing to fly on its own so it became unstable after decoupling and broke up from aerodynamic forces.

[Sharpy]

It came out monstrous. It needs a lot of work yet.

I got the plane to orbit. I recovered some parts of the first stage, would have more if I took more parachutes. But it was cutting it way too close. I didn't get the plane into a safe orbit before I had to switch to the stage. I switched a little too late, airbrakes failed to prevent one of the "arms" breaking off. Then the plane was at 55,000km when I switched back to it; again, an aerobraking altitude. Still, the concept is sound. I just need to make the stage more lightweight, base it off Poodle again (currently, it's Mainsail) and get the turn towards orbit perfected; the moment the plane stops gaining speed horizontally and starts a very fast climb. Currently, I lose good 300m/s doing it.