Yaivenov

Hydrazine is a fairly simple molecule, N2H4. Just do a Fischer-Tropsch synthesis, except instead of using carbon as your primary building block you use nitrogen. Liquid fuel (assuming LH2) plus nitrogen ice, plus a lot of heat and electricity equals hydrazine. Now most used mono-propellant isn't straight hyrazine, it's actually a mixture of hydrazine and unsymetrical dimethylhydrazine, usually in a 50/50 mix called Aerozine 50. USDH has a molecular formula of C2H8N2. Still smack-dab in the realm of a FT fuel synthesis, just add CO2 ice to the mix and shake well. Warning: Hydrazine and USDH is hypergolic when in contact with nearly all organic material: oxidizers, textiles, rocket technicians, etc. ETA: Just a side note, with FT synthesis, you can make any chain hydrocarbon you want with nothing more than CO2, H2O, and a butt load of electricity. RP-1 anybody?

Thank you, regarding the strut feet. And as for Jool/Jupiter, yeah, it was just kind of a let down not to get that final "crunch" of atmospheric pressure or an impact. Lots of excellent science made on the way down though! I usually go with some Saturn-1C boosters for the really heavy lift jobs, but I'm assuming you want a stock solution. Here's my fuel tanker I sent to Jool, it has a slightly greater mass of around 86.75 tons, boosted fully to a 100km parking orbit using 14 mainsails and 21 SRB's. This was done without touching any of the payload's own fuel, either mono-prop or liquid fuel. Fair warning, this is a 335 part count booster, but it sheds parts pretty quickly. After having trouble of getting the towers to release reliably and not hang-fire due to lag, I finally just made a tower-less assembly. That's right, it just sits on the pad until launch! The payload: The booster: Hard to see but important, there are radial RCS mono-propellent tanks mounted to the final mainsail booster so I don't have to dip into the payload's maneuvering fuel during launch. Noted launch events. Launch preparation note: The outer mainsails are starting with their gimbals locked, and the payload's mono-propellant tank is locked out to prevent use. A gravity turn starting at 8km and proceeding at 100% until 70km is utilized. Target apogee is 100km 1: All SRB's and the Stage-1 mainsails are fired. These mainsails are not asparagus stacked and are treated as a unitary booster (I know, I probably could have made this more efficient, but I did this for simplicity of the assembly at this point. 2: Stage 1 SRB Separation: Using terminal velocity limitation, the stage 1 mainsails will throttle back and allow them to save enough fuel to outlast the SRB's by a few seconds. 3: Stage 1 Separation: Stage 2 asparagus stacked mainsails fire. 4/5: Stage 2-4, 2-3 are shed during climb to 100km apogee. 6/7: During coast to apogee stage 2-1 mainsail engine is gimbal locked and RCS takes over attitude control. Stage 2-2 is shed during circularization burn. 8:Stage 2-1 is shed after fine-tuning orbit, with a surplus of 70m/s dV remaining. (Note: thrust was not limited to 20m/s, only to terminal velocity.) The clock is running! Max-Q (for my purposes anyway). SRB sep. and throttle up. Stage 1 sep. Stage 2-1 sep. proceeding through the turn nicely. Stage 2-2 sep. Main engine shut down and coast to apogee. Circularization burn. Sorry, missed the stage 2-3 seperation. Final orbit established, and not a drop of payload fuel expended!

I shall test and report back. Thus far whenever I try to strut TO the reactor it has acted as if I'm clicking on thin air. Also another concern is I don't want a bunch of expended strut feet excessively adding to the part count of my completed craft. ETA: Huh, the struts worked that time.

Fair enough on the fuel material. Any thought on the third "expended fuel" category so a player can easily tell how much fuel has been permanently used? Also, I need to ask as I'm having trouble with this right now, exactly how does one get a 3.25m reactor off the ground? The problem I'm facing is that the reactor model in game has NO attachment points on it's surface for reinforcement struts, thus it's only attachment to the lifter is the single point which immediately snaps under the 43 ton burden at even the slightest hint of acceleration (I attempted a slow take off throttle up with a mechjeb limited acceleration of 15m/s, and even that was too much for the single attachment point and on a few occasions just loading in was enough stress to collapse it).

Well that was fun! Decided to bring that research ship back home to Kerbal to collect the final Science from it's trip to Jool. Kind of disappointed though, the expendable probe I dropped into Jool's atmo worked great....except there was no land/impact, it just fell through the surface. Anyways, I just wanted to chime back in regarding the nuclear reactor since I asked a question about it just a little while ago... the 2.5m reactor, after approximately 14 years of operation (approximately because a docking/undocking of a resupply ship reset the flight clock) had permanently expended one quarter of it's fissile material. Talk about some nice life expectancy. Now, just some thoughts and suggestions I thought I'd toss your way, if you don't mind Fractal. Uranium Hexafluoride (UF6) is a Uranium compound used primarily during the enrichment process, but is not the form used as fuel. The form "burned" in reactors is Uranium Dioxide. That is kind of neither here nor there however as the process you have in the game, of reprocessing your fuel for continued use, seems closest to the real world counter-part of Mixed Oxide (MOX) fuel, where spent fuel rods are reprocessed and subsequently contain both Uranium and Plutonium isotopes which are re-burnt, reprocessed, and so on. So the first suggestion is that the fuel in the reactors be renamed from UF6 to MOX Fuel. The second suggestion, which may be more trouble that it's worth as I'm not sure how you have the code for this written at the moment, is in regards to being able to tell the current life-state of the reactor core in a more readable form. Simply put, adding a third fuel measure if you will, for the permanently expended fuel. The readouts thus would be: "MOX Fuel", "Depleted Fuel", and "Waste Isotopes". As the MOX is expended it converts to Depleted, from this the player can immediately infer that 20% of that will be lost during reprocessing to the "Waste" category. The "Waste Isotopes" (or perhaps "Fuel Waste"?) measure will give an immediate and easily discerned measure of how much of the reactor's life has been expended. *shrug* Just something I thought I'd toss out there, hope it can be of use.

Alright, I'll keep that in mind for future construction. As this was my earliest exploration ship I didn't have the available parts to make it as modular as I would have liked. Guess it'll be getting parked permanently in Jool orbit then.

First off, thanks for this awesome mod! Been having a blast with it, and I haven't even progressed very far past thermal rockets yet (career mode). Now for my silly question that has probably already been asked, please forgive me; Is it possible to refuel the nuclear reactors at the end of their useable life to include reprocessing operations? I've got one exploration ship that has racked up 10 years of flight time and I was curious if I'd eventually have to permanently park it (so that I could dock a fresh reactor to it and keep its labs running) or otherwise dispose of it.