Need help testing a craft.

[StevieC]

I've built a modified version of the stock "Kerbal X" rocket, over the past couple of weeks, that only uses stock parts. I have used some mods to build it, but made it an explicit goal to build a craft that someone could download and use in a completely stock install of KSP.

This was motivated by several difficulties that have long undermined my attempts to fly missions with the stock Kerbal X, specifically:

1. The craft's part-count is unnecessarily high.
2. The asparagus boosters have an exasperating tendency to collide with parts of the core first-stage, especially the AV-R8 Winglets, often damaging or destroying said parts, which impairs vehicle control-authority, with increasing severity each time another booster collides with parts that previous boosters may have spared destruction
3. Inability to dock with another spacecraft in orbit means that I can't easily conduct rescue-missions.
4. Lack of RCS thrusters has long hindered Jeb's efforts to execute precision maneuvers whilst on-orbit.
5. The small fixed solar panels are woefully inadequate to replenish the craft's electrical charge. nd sine they're on opposite sides of the spacecraft, there's no way to get both solar-panels into full sunlight at the same time.
6. The spacecraft lacks communication with ground stations or other spacecraft.
7. There is no reliable mission-abort mode with assured crew survival.
8. There is no thermal protection for the command-capsule.
9. The first-stage remains in orbit as debris.

Seeking to address these shortcomings, I set to work on modifying the Kerbal X into a craft sporting remedies for the above issues. Thus far, I have made the following alterations:

1. I consolidated the first-stage's upper two Rockomax X200-32 fuel-tanks into a single Rockomax X200-64 "Orange Jumbo" fuel-tank, reducing part-count by one while retaining the exact same total fuel capacity. Similarly, I consolidated each asparagus booster's lower two FL-T400 fuel-tanks into single FL-T800 fuel-tanks. resulting in asparagus-boosters that are each one part smaller in count, but still have the exact same fuel-capacity as in the stock Kerbal X.
2. On the remaining X200-32 fuel-tank, I moved the asparagus boosters' six radial-decouplers as far forward as I could without letting them touch the "Orange Jumbo" tank, moving the asparagus boosters down so that their their engines are still in the same position relative to the first-stage's core engine as those of the stock craft. This has the benefit of pushing empty asparagus boosters slightly nose-out which generally means that aerodynamic forces will carry them clear of the first-stage core, without requiring use of a Sepratron.
3. I installed a Clamp-o-tron docking-port to the front attachment node of the command-capsule, so that the spacecraft can dock with other spacecraft and exchange crew.
4. I installed RCS thrusters to the upper-stage. This has the additional benefit of making the command-capsule's supply of monopropellant a useful resource, instead of merely dead-weight. To accommodate placement of the RCS-thrusters, I moved the two batteries (each with a storage capacity of 400 units of electric charge) to the dorsal and ventral sides of the uppermost stack-decoupler, so as not to clip into the upper-stages landing-struts.
5. I replaced the two OX-STAT fixed solar-panels with a pair of OX-4W 3x2 folded solar arrays which ca be deployed in orbit and which can turn to track the sun on one axis of motion.
6. I fitted a Communotron 16 antenna to the command-capsule, allowing crew to transmit and receive data to and from the ground or other spacecraft.
7. I attached a Kerbodyne Launch Escape System to the docking-port, with provision to jettison the escape-system once the vehicle's apoapsis is high enough to no longer need the additional burst of velocity to pull the command-capsule clear of the vehicle behind it.
8. I added an ablative heat-shield to the command-capsule to ensure crew-safety on higher speed re-entry profiles such as returning from either the Mün or Minmus. It can be jettisoned once the capsule has slowed down enough for air-friction heating to stop posing a threat to the capsule and crew.
9. I installed some Sepratrons to the inside of the decoupler that jettisons the first-stage's core upon fuel-depletion.

Unfortunately, some of these modifications have drawbacks, such as the position of the docking-port and escape-tower displacing the command-capsule's parachute, necessitating the use of radial parachutes attached to the capsule dorsally and ventrally. The addition of so many parts adds a lot of mass, which reduces the resulting craft's Delta-V capacity. The upper-stage alone is brought down from 2392 meters per second of vacuum Delta-V to a mere 2117 meters per second, thanks to the added mass of the ablative heat-shield, Communotron 16, Clamp-o-tron, twin-radial-chutes, and heavier folded solar-arrays. But, by strategically adding fuel-tanks nested within the decoupler that jettisons the upper-stage from the command-module and heat-shield, I managed to squeeze an octet of "Oscar-B" fuel-tanks encircling a 9th Oscar-B sandwiched betwixt twain Round-8 toroidal fuel-tanks inside that empty-space, resulting in an upper-stage that actually gives the vehicle 41 meters per second more delta-V than the stock Kerbal X gets from its upper-stage, despite my variant being heavier.

The resulting extra mass added to the upper-stage unfortunately gives the law-of-diminishing-returns some extra sting which means that I can't completely eliminate the delta-V penalty that the first-stage pays by adding extra fuel, but I can cut the penalty roughly in half, and eke out an extra dozen meters per second of delta-V from each pair of asparagus-boosters by sneaking an Oscar-B fuel-tank under each asparagus booster's nose-cone, allowing me to keep the whole rocket's total Delta-V juuuust north of 6 km per second (slightly above 6049 meters per second, the exact amount above that depends on when one chooses to jettison the launch abort/escape system) which puts it within 400 meters per second of the stock Kerbal X's total Delta-V of 6428 m/s which I think is fairly respectable.

The reason I've titled this thread as a request for help with testing is that I know the stock Kerbal X can return to Kerbin after landing on the Mün, but it takes a very, very skilled pilot to pull this off. What I want to determine is whether it is possible for my modified Kerbal X to get to the Mün using the Apollo-style free-return-trajectory transfer, land on the side of the Mün that faces Kerbin, and then return its crew to Kerbin, alive. Since this rocket has less total delta-V than the stock Kerbal X and the free-return-trajectory transfer consumes more fuel as the price of its increased safety for the crew, this will most-likely be harder than even making the simple round-trip in the stock Kerbal-X, but my reasoning is that the increased safety this model provides would be a major selling-point of this variant in-universe. I'm in the process of test-piloting this particular flight-profile right now but I'm not exactly the best pilot without MechJeb's aid, and I haven't got MechJeb on this KSP install. I have KER but not MJ.

Now, I will admit this craft has a higher part-count than the stock Kerbal-X but I consolidated parts where possible to keep the total part-count down.

You can download the craft itself here.

The in-game craft description is as follows:

Pronouncd "Kerbal X Prime", "X Prime" or simply "Prime" for short, this vehicle is intended as an improvement of the venerable X. Designers asked Kerbonauts for suggestions of things they would like to see added to the X, and then went to work seeing how many could be integrated into an enhanced version of the classic spacecraft and launch-vehicle. The result was the Prime: a vehicle boasting several amenities that were absent from its predecessor, such as deployable sun-tracking solar-panels, retractable comms antenna, RCS thruters, crew-passable docking port, ablative heat-shield, and a revolutionary "Abort and Escape Motor" from Kerbodyne which allows the crew to abort their mission even in the event of the most severe vehicular failures, AND which carries the command-capsule with crew inside a safe distance from any potential explosions, allowing the crew to escape the ailing launch-vehicle and live to fly another day.

Although it sacrifices almost 400 meters per second of vacuum delta-V (the exact amount sacrificed is dependent upon the timing of when the escape-motor is jettisoned), designers guarantee that it can still reach the Mun using a fancy "free-return-trajectory" which is somehow a safer way to travel to the Mun, and to put itself into a tight circular orbit around the Mun. Once in that orbit around the Mun, the designers also guarantee that it will still have enough Delta-V either to land on the Mun or to return to Kerbin. They warn, however, that they are unsure whether it will have enough delta-V to return to Kerbin, or even get back into orbit around the Mun, after a Munar landing. When designers told Jeb they didn't know if the Prime can get home to Kerbin after a Munar landing, he simply said, "Watch me."

I'm eager to hear what results yinz have with flying it, especially any success with the flight-profile I described above the picture.

Edited August 31, 2016 by StevieC
Added the text of the craft-description shown in game