Anyone Build TSTO's?

[Ravenchant]

I usually build 2.5 stage lifters (2 stages + boosters), though some reach 3 or 3.5 stages. The problem with pure two-stage vehicles are high G-forces near first stage burnout, unless you throttle down.

[merendel]

I don't know if there is a fancy acronym for it, but I'm working on a plane now that takes off, drops it's entire wing body and jet engines in orbit basically converting itself to a lander (1 piece, carefully crafted), goes to the mun, comes back, and docks with it's body for landing. The whole idea was to reduce mass of parts that wouldn't be used for the whole trip. Not sure if it will really have any benefit (or even it it will work at all) but hey, it's something to do.

It can be done theres just alot of engineering problems to overcome. The bigest issue is how to secure the orbital section to the aero section. On the way up you can strut like crazy but you need a mod that alows struting during the mission on the return leg or the two sections will be floping like crazy on the return. Chances are the COM of the payload will be vastly different after its used its fuel up. If you dont account for that the ship will be aerodynamicly unstable on the return as well. I've tried a few times but never got a design I particularly liked. Each one had to be custom built, any change to the payload often required a compleat redesign. In addition makeing the cradle that the wings and airbreathers were mounted on ridged enough to not fly like a flappy bird around the orbiter. Balancing rigidity of the flight frame, the COM, the center of thrust, and the center of lift was just an utter nightmare. Its somewhat better if you've got plane parts with a cargo hold big enough to carry your orbiter but stock parts its difficult for anythign larger than a probe.

[Pecan]

It can be done theres just alot of engineering problems to overcome. The bigest issue is how to secure the orbital section to the aero section. On the way up you can strut like crazy but you need a mod that alows struting during the mission on the return leg or the two sections will be floping like crazy on the return. Chances are the COM of the payload will be vastly different after its used its fuel up. If you dont account for that the ship will be aerodynamicly unstable on the return as well. I've tried a few times but never got a design I particularly liked. Each one had to be custom built, any change to the payload often required a compleat redesign. In addition makeing the cradle that the wings and airbreathers were mounted on ridged enough to not fly like a flappy bird around the orbiter. Balancing rigidity of the flight frame, the COM, the center of thrust, and the center of lift was just an utter nightmare. Its somewhat better if you've got plane parts with a cargo hold big enough to carry your orbiter but stock parts its difficult for anythign larger than a probe.

*Ahem* http://forum.kerbalspaceprogram.com/threads/93779-SSTO-Spaceplane-Airplane-Design-Contest-II-Akademy-Awards?p=1421588&viewfull=1#post1421588 40t, fuel, passenger, science, mixed. The only reason that design doesn't work in 0.25 is because the balance shifted with the introduction of the Mk2 parts, it's trivial to adjust it back.

SSTOs are best between the surface and orbit. For space-work use never-landing tractors. ANY mission then becomes; SSTO carries mission payload To Orbit (optionally lands). Tractor transfers payload to target (optionally returns), payload performs mission. When the mission is over the same or another tractor brings the payload back to Kerbin orbit (or the next mission target), the same or another SSTO lands it (if necessary).

My entire space-programme uses a SSTO, tractor, station infrastructure and only requires additional fuel and crews to be launched from (and science + old crews landed back at) Kerbin. Unless I crash there's no debris, no retired ships, no waste. (Harder in career/science mode, but easy once you unlock the first few tech-tiers).