Herakles-R & Phaeton-R: recoverable first stages

[valens]

Somewhat inspired by SpaceX and countless KSP forum members, I tried my hands at recoverable first stages. Based on my expandable lifter lines, I present Herakles-R and its smaller sibling Phaeton-R. 

Both first stages are designed to land with parachutes and can deliver sizable payloads (over 10 t on "naked" Phaeton, 20 t on "naked" Herakles) to LKO or, for heavier payloads, bring an upper stage on a suborbital trajectory for circularization ("à la SpaceX"). The stages are compatible with MechJeb's autopilot and develop by themselves over 4800 dV.

For re-entry, just extend the AIRBRAKES, point retrograde and burn to deorbit. I suggest the stage be spinned in order not to lose some parts to reentry heat, so extending the control surfaces is a good option.

A few issues are left, though:

• Staging of the parachutes is frequently lost when decoupling the first stage and its payload. As I use AGExt, I can assign action groups in-flight and this is not too annoying, but still.
• As I did not add landing gear at all, they are a bit unstable on landing and can topple over and break.
• Splash-down means that they will topple and break, unless one can click on the recover button quick enough.

Feel free to take them for a spin (dropbox links, subassemblies): Phaeton-R and Herakles-R.

[Edit 27.10.16:] So I overhauled the Phaeton-R for better efficiency and added some SRBs for increased payload; the new version, Phaeton-R1(V/6) is available on KerbalX, and can lift about 15 tons to LKO. Additionally, having the booster land on the tail fins means it is much less likely to lose its engine. 

[Edit 19.11.16:] Two versions of Herakles-R are now available on KerbalX, with and without the S2 intermediate stage.

 

Edited November 22, 2016 by valens
added mission badges & pictures, kerbalX links