[0.14 stock] Asymmetric Kerbin Orbiter

[antbin]

Well, it ain\'t too pretty, but it makes orbit.

Inspired by Kosmo-not\'s Deimos II space shuttle, I had a go at making a space-plane-like craft with asymmetric drop tanks/engines. It uses all three types of liquid engines, and even has ASAS on one side pod and SAS on the other. The lack of a tail is due to the current aerodynamics producing almost uncontrollable roll-coupling on ships with a single tail fin.

The wobble on stage transitions can be a little hairy, but it makes orbit with a half-tank left.

Instructions:

[list type=decimal]

[li]SAS on - this ship pitches down hard on launch and barely clears the tower![/li]

[li]Full throttle all the way[/li]

[li]The pitch handling is neutral between around 1250-2500 ft. Pulse SAS off (\'F\') and make your roll maneuver here, with your desired heading down. For now the ship starts to pitch up until the main fuel tank is empty. Hold her steady.[/li]

[li]When the main fuel tank is about empty, get ready to separate the stages, and hold on tight![/li]

[li]After main tank separation, the ship pulls pitch-down again. Pulse the SAS off to make your orbital turn.[/li]

[li]As the side boosters are almost spent, the ship starts to pull pitch-up. Hold on tight![/li]

[li]Congrats, you\'re in orbit. Too bad those wings are useless with the current aerodynamic model.[/li]

Full orbital album here

[Kosmo-not]

I guess I\'m the first member of the public to get this into orbit (first try, too). How did testing of it go during construction? Are there any challenges that you overcame that you feel particularly proud of?

[antbin]

Hey Kosmo-not! I\'ve got to thank you for all your tutorial videos. They\'ve given me both hope and a bit of knowledge. I still can\'t get Koelamos II back to Kerbin, though.

Testing went OK... I should have taken screenshots of all the gruesome explosions. After deciding on the capsule/decoupler and 1 RCS, I followed three principles:

[list type=decimal]

[li]Lift SAS only as necessary (so none on the main orbiter). This meant having to split the SAS/ASAS units between two side pods. Luckily they have the same weight (and aerodynamics ignores surface area). [/li]

[li]Don\'t hit the tower.[/li]

[li]Exercise the full range of SAS/ASAS as each stage\'s liquid fuel tank weight drops from full to empty. I did this first by adjusting the mounting angle of the side pods to have only as much torque as 1 SAS unit could handle, then by shuffling fuel tanks between the orbiter and main drop tank to balance out the thrust difference between the large and medium liquid engines.[/li]

Then there were some mistakes with not enough bracing, etc. But I couldn\'t have done it without Deimos II\'s inspiration!

[Kosmo-not]

I hope you build more asymmetrical craft in the future.