Can orbit be achieved without rocket assistance in stock KSP?

[Roflcopterkklol]

So can it be done using only jet engines or another means?

I have been able to get pretty close using a Titan hunter, never been able to get completely into orbit though (not over 70km anyway, you can orbit at 40km with an air hogger)

Admitted Titan hunter is an air hogger and a half with something stupid like 30 shock cones making to run at 40+km in the atmosphere

Edited February 20, 2015 by Roflcopterkklol

[*Aqua*]

Can orbit be achieved without rocket assistance in stock KSP?

In theory you can "store" intake air, bring it to space to let the jets run for a fraction of a second. That could be enough to get the periapsis above the atmosphere.

There are some other ways but I consider them cheaty (infinigliders, Kraken drives, etc.).

[Superfluous J]

You could use the massively excessive force of a decoupler to get something small into orbit.

[Roflcopterkklol]

In theory you can "store" intake air, bring it to space to let the jets run for a fraction of a second. That could be enough to get the periapsis above the atmosphere.

There are some other ways but I consider them cheaty (infinigliders, Kraken drives, etc.).

Hmm i like that storing intake air idea

[Panzerbeard]

With turbojets, no; they'll only function well below 70km, and so you're never going to be able to raise your periapse any higher than that to be in what KSP considers to be a stable orbit, you're going to need something that can apply some sort of force once you leave the amosphere. Perhaps stack seperators could do it, if you only needed a tiny amount of dV to raise your Pe?

Otherwise I guess the only way to do it without Engines/RCS/SRBs/EVA-pushing would be exploiting some glitch in the physics.

[NoMrBond]

Turbojets to achieve orbital height AP then ion's to circularise wouldn't be hard

[Tex]

Though it works on the exact same principle, RCS does kinda fall right out of the sieve of rocket propulsion, if by rockets you mean engines that use oxidizer. If you achieved said orbit with your air-hogging space plane, then you should be able to put on a hefty amount of RCS thrusters to give you the final shove into (and out of, hopefully!) orbit.

[regex]

In theory you can "store" intake air, bring it to space to let the jets run for a fraction of a second. That could be enough to get the periapsis above the atmosphere.

There are some other ways but I consider them cheaty (infinigliders, Kraken drives, etc.).

The logic of what and why things are "cheaty" is beyond me. Overloading on air intakes and "storing" intake air are just as ludicrous as infinigliders and "kraken drives" IMO. Might as well just embrace it all if you're going to accept a jet engine getting a plane into orbit.

OP, I've heard of people using single-engine air-hoggers staying right on the edge of atmosphere and fluttering the engine on and off to get a periapsis that is nearly in orbit, but I don't recall if I've ever seen it done.

[Roflcopterkklol]

Though it works on the exact same principle, RCS does kinda fall right out of the sieve of rocket propulsion, if by rockets you mean engines that use oxidizer. If you achieved said orbit with your air-hogging space plane, then you should be able to put on a hefty amount of RCS thrusters to give you the final shove into (and out of, hopefully!) orbit.

Doesnt the space shuttle do something along those lines for its final orbital maneuver?

[Tex]

Yes, but it used hypergolic propellants rather than the nitrogen for the Shuttle reaction system. AKA, LiquidFuel, and so it wouldn't work for his exact thingamajigger, but I have seen KSP shuttles that use RCS OMS engines!

[Roflcopterkklol]

The logic of what and why things are "cheaty" is beyond me. Overloading on air intakes and "storing" intake air are just as ludicrous as infinigliders and "kraken drives" IMO. Might as well just embrace it all if you're going to accept a jet engine getting a plane into orbit.

OP, I've heard of people using single-engine air-hoggers staying right on the edge of atmosphere and fluttering the engine on and off to get a periapsis that is nearly in orbit, but I don't recall if I've ever seen it done.

Well i could see that working, the engines on my jet do not cut out completely until around 60km, maybe if you point the nose back down at 30 degree once you reach 45-50km and keep accelerating

[*Aqua*]

Overloading on air intakes and "storing" intake air are just as ludicrous as infinigliders and "kraken drives" IMO.

Retrieving and storing air can be done in real life. Kraken drives obviously won't work. That's where I see the line between "legit" and "cheaty".

[regex]

Retrieving and storing air can be done in real life.

Oh man, just like jet engines can get you to orbit?

[SkyRender]

Oh man, just like jet engines can get you to orbit?

I think he's referring to the fact that air intakes can be set up to gather and compress air in in real life instead of feeding that air into an air-breathing engine. Of course, you'd still never get a jet engine to spool up on stored compressed air like that, but you could in fact use air gathered in this fashion with a chemical rocket. It's not outside the realm of possibility to do that sort of thing in real life, just outside the realm of practicality to use that sort of thing on spacecraft at the moment.

[bigyihsuan]

You could use the massively excessive force of a decoupler to get something small into orbit.

Remember Plaid?

[RainDreamer]

You can try hauling some (read: a ton of) decouplers to space, and then detonate them at the right time to be a sort of small scale orion drive (what do you call a drive using explosive forces for propelling? Pulse drive?), propelling forward toward orbit instead of using a rocket.

[SaturnV]

You can't raise your periapsis any higher than your current altitude which means your can't raise your periapsis to space while you're in the atmosphere.

[khyron42]

Another option: get out and push with the EVA pack.

[Renegrade]

Well, my very first spaceplane that went into orbit needed only a small amount of circularization from either a 24-77 or 48-7S, so you could most definitely do it with ions or RCS.

Yes, but it used hypergolic propellants rather than the nitrogen for the Shuttle reaction system. AKA, LiquidFuel, and so it wouldn't work for his exact thingamajigger, but I have seen KSP shuttles that use RCS OMS engines!

Nitrogen? The only thing I've heard of that uses nitrogen is the MMU system for EVA - the Shuttle proper used MMH/NTO for it's RCS system (and I think for the OMS too)..

[Xavven]

I saw a video where someone used reaction wheels and a long lever arm to "catapult" the Kerbal at the apoapsis, thus achieving orbit. I thought that was pretty clever!

[strongest_2hu]

I saw a video where someone used reaction wheels and a long lever arm to "catapult" the Kerbal at the apoapsis, thus achieving orbit. I thought that was pretty clever!

You can use fuel pumping and a long arm to move yourself to a higher energy state without any fuel expenditure due to the way the CG moves when pumping fuel.

[Camaron]

So can it be done using only jet engines or another means?

YES, you can!!!

While I unfortunately don't have pics, and I don't recommend this since it takes forever, but I once got an airhogger pure-jet into full orbit by gradually increasing my apoapsis over tons of passes through upper atmo, and eventually getting pushed out into a full space orbit with a slight tug from the moon. Not exactly useful though. You're stuck once you've done that.

[Newt]

If you go fast enough in that atmosphere, you could either get the Mun to pull you into orbit, or escape Kerbin and achieve a Kerbol orbit.

[Corw]

YES, you can!!!

While I unfortunately don't have pics, and I don't recommend this since it takes forever, but I once got an airhogger pure-jet into full orbit by gradually increasing my apoapsis over tons of passes through upper atmo, and eventually getting pushed out into a full space orbit with a slight tug from the moon. Not exactly useful though. You're stuck once you've done that.

Wow, that is amazing. Not. N body physics is not a feature, you can't get "tugged by moon" unless you are not in moon's sphere of influence.

As for the OP, you can circularize with RCS easy. Been there, done that. Very low part count too

[RCgothic]

Who needs n-body physics to use the Mün's SoI for a trajectory change? I think that's very clever!