Neptune 1 Mod 3: An Old School SSTO (full stock)

[Zeiss Ikon]

The Neptune series of launchers was named because the first iteration had a pickle-fork layout to launch two Mk. 1 Command Pods, each with its own LFO tank and Reliant engine, plus docking clamp (and parachute) in parallel -- that is, one alongside the other.  This was intended as an easy way to get two Command Pods, each with its pilot and ability to maneuver and navigate, into similar orbits with a single launch.

Experience led to some modifications: duplicating the parachute on each pod seemed a good idea after a seemingly minor collision during a docking attempt turned out to have destroyed the radial parachute -- a problem discovered only after reentry had begun.  Oops, sorry, Jeb.  Also, building the second capsule stack upward from an inverted bi-coupler caused staging issues, in that when the capsule was staged off the tank/engine module, the focus stayed on the uncrewed portion.  If that happens after you drop past 70 km, unfortunately, KSP won't let you switch to controlling the occupied Command Pod, but forces you to watch until the engine/tank stage crashes, leaving too little time to then go via Tracking Center to start "flying" the Command Pod and still deploy the parachute before impact.  Valentina, you're a hero before all of Kerbin.

Eventually, this led to changing to a stacked/tandem arrangement.  RCS fuel shortages prompted addition of in-stack monopropellant tanks, the need to control (very cranky) early booster iterations during launch resulted in doubling up the RCS quads, taking advantage of the more than adequate RCS propellant supply.  Heat shields prevent the RCS tank from exploding during reentry, after it was found that it was best to keep it with the Command Pod after staging off the LFO tank and engine.  Excessive stack flex was controlled with struts -- both joining the lower Command Pod to the upper service module, and bracing that upper module to the top of the large diameter booster tank.  Finally, with the stiffer stack now much more controllable, it was possible to add a fairing to neaten up the appearance on the pad and cut down on drag during boost, which could now be accomplished without RCS.

The last modification to date was stretching the booster fuel tanks to a full 19,200 units (Twin Boar engine/tank unit, plus two orange 64 tanks), which gives the full stack "barely" SSTO performance -- in fact, there's just enough fuel to circularize, and still deorbit the booster (though the Command Pods must then recircularize, either together of individually; I need to come up with a way to extend the battery life of the probe controller in the booster long enough to handle the deorbit after staging).  That's 16 T (the two Command Pod stacks and their fairing) orbited by a single booster.  I'm pretty happy with that, given I've been playing the full version for about two weeks, and I'm still on Year 1, Day 4 game time (which includes a fair amount of warping waiting for maneuver nodes and such).

Next upgrade on this is likely to be conversion of the uppermost orange tank to a stage, which ought to give enough additional dV to send the upper section to Mun and hopefully even do the Munar capture burn.  That will be accompanied by conversion of the lower Command pod to a lander, while the upper command pod stage will push itself and the lander's Command Pod back to Kerbin after descent, ascent, and docking.

Neptune One Mod. 3  Craft File

71 parts

132.8 T liftoff mass (including launch clamps?)

38.4 m high

2.6 m wide (2.5 m booster diameter, plus Twin Boar skirt)

3.6 m "long" (Twin Boar engine setup and skirt)

Inline images don't seem to want to work from Dropbox -- but this is the first time I've tried to share from there, so it's probably me missing something.

Edited January 21, 2017 by Zeiss Ikon

[qzgy]

As the saying (apparently) goes, no pics, no clicks

[Zeiss Ikon]

The pictures are on the "naked" links.  I'd welcome assistance on how to edit them to show inline.

[qzgy]

Ah, ok. Copy and paste maybe?

[Zeiss Ikon]

I tried the "insert other media" as instructed in the "how to post your rockets" thread, but the insertion doesn't seem to take with the Dropbox links.  If I don't get a suggestion how to get Dropbox links to work, I may move the images to my Photobucket and leave only the craft file in Dropbox.

[septemberWaves]

Best way I know of: upload the images to Imgur (or a similar free image sharing website, Imgur is the only one I know of). Then, once uploaded, right click on the image, click "open image in new tab", and copypaste the url of that new tab. Then paste that into the forum and it will automatically embed.

[Zeiss Ikon]

Well, apparently the board software doesn't like Dropbox -- but it works fine with Photobucket.  Images fixed.