Detachable Engines?

[AbuMaia]

Is it possible to design a rocket where the engine detaches from the end of the fuel tank to leave a tank with, say, a docking port at both ends? So far I haven't been able to work it out where the engine is both operational and detachable.

Edited September 6, 2013 by AbuMaia

[Vanamonde]

Tank, docking port, engine, then run a fuel line from the tank to the engine itself.

[AbuMaia]

Just one docking port? I've been trying with two to, ya know, undock the engine. But the docking port the engine is attached to comes undocked from the tank-side port when the engines ignite at launch. And why is a fuel line necessary? Isn't the docking port fuel crossfeed capable?

[LeFudge]

Use a SR docking port if you can, way more sturdy. Also you're putting it on upside down just flip it over. Backwards docking ports have ruined more than one of my ships lol.

[sojourner]

yep, I use this setup all the time. no problems.

tank,dockingport,dockingport,engine.

make sure you have the docking ports facing the right direction and as noted, SR docking ports are stronger.

[KatzOhki]

You can use just one docking port. All you have to do is right-click and hit "Decouple Node".

[AbuMaia]

Use a SR docking port if you can, way more sturdy. Also you're putting it on upside down just flip it over. Backwards docking ports have ruined more than one of my ships lol.

I am using SR ports, and I've been careful to make sure they are facing the right way. They stay together above the pad when physics kick in, but fall apart when the engines light.

You can use just one docking port. All you have to do is right-click and hit "Decouple Node".

Huh, I didn't know they could work that way. I'll give that a try. Thanks

[Crown]

Make sure that you throttle up slowly. Having full thrust and then hitting ignite could have bad consequences.

Some struts might help too.

edit:

Ok, I tested it. The Docking Port Sr. can only withstand about four fifth of the thrust of a Mainsail (=1200kN). And even with a Stack Separators and struts the engine acts the same.

Side-mounted engines could work. That's the only solution I can think of at the moment.

Edited September 6, 2013 by Crown
Tested in-game

[sojourner]

You can use just one docking port.

If you don't plan on reusing the engine.

[Vertibirdo]

I use detachable engines on SSTO crafts. Aerospike to fly in atmosphere, nuclear engine to fly in space. Mainsail engines won't hold on any port if fully thrusted unfortunately.

[tom1499]

I use detachable engines on SSTO crafts. Aerospike to fly in atmosphere, nuclear engine to fly in space. Mainsail engines won't hold on any port if fully thrusted unfortunately.

I think you ruined the point of the SSTO there.

[Crown]

I use detachable engines on SSTO crafts.[...]

SSTO, now with disposable engines. Wait.

[sojourner]

I see people on this forum using "SSTO" in place of "spaceplane" all too often without realizing there is a difference. A spaceplane can be an SSTO and an SSTO can be a spaceplane, but neither of those is always true.