Northstar1989

OK, so the recovery of my Nuclear Thermal Spaceplane Mk2 (so-named because of the earlier failed design I did not show) went smoothly: This thing flew like a dream- much better than any other spaceplane I had ever built before... And with Bill Kerman safely back on the ground after a nice, slow, low-G re-entry aboard the NTR Spaceplane, I decided to continue with the mission of my Minmus probe... With a single burn during a Munar gravity-assist, the Minmus probe set itself on an impact-trajectory with Minmus. Although tiny course-correction was necessary after leaving the Mun's SOI, due to game errors when switching SOI during time-warp... After which I followed on with ANOTHER spaceplane mission: This was the launch of my NTR Spaceplane Mk3, which featured a reduction in its number of wing-pairs from 3 to 2- a main wing and a canard; as well as an increase in wing-sweep and an increase in the length of the cargo hold (made using Procedural Fairings inline-fairings). This actually somehow moved the Center of Lift forward relative to the Center of Mass (one possible explanation is that FAR seems to generate too much lift from fairings...) made the spaceplane MUCH harder to control, though, and although its Lift/Drag was improved by the increased wing-sweep, it barely made it to orbit due to control-issues... (a number of quickloads were required...) The payload of this mission was the first (and larger) half of a Propulsive Fluid Accumulator satellite, and after deploying it the spaceplane returned to the runway at the KSC: Re-Entry and Landing was even more difficult for the Mk3 version of the NTR Spaceplane than the ascent, as the deployment of the payload and loss of fuel and one of the cargo hold fairing sections (necessary to deploy the payload without a proper cargo bay...) moved the Center of Mass backwards and increased the drag at the forward end of the spaceplane... The spaceplane DID eventually end up making a successful landing, though (after *MANY* quickloads) and the mission controllers were able to breathe a sigh of relief at the recovery of the 990,000 Fund vessel... The next mission was the launch of a Control Section for the Propulsive Fluid Accumulator (due to limitations of the length of the cargo hold on the NTR Mk3 Spaceplane, the Propulsive Fluid Accumulator section launched this way lacked a probe core or as much empty tankage as was desired for efficient propulsive fluid-accumulation operations...) The payload for this mission weighed less than 200 kg (more than half of the weight being in a probe core, and the rest being in empty Procedural Parts ballooncryo tanks and two Clamp-O-Tron Jr. docking ports) this was my lightest launch vehicle yet. The LV was still recovered at sea though using a small parachute... Ideally, I would have saved a bit more fuel on the launch-stage to fly it back to the launchpad, but I cut so many corners on this mission that I was having a difficult time getting the upper stage high enough and fast enough to circularize without either losing control during the ascent due to dynamic pressure in the gravity-turn, or falling back into the atmosphere with the upper stage before circularization or ending up on a sub-orbital trajectory... Thus, I had to use every gram of propellant aboard the launch-stage possible, and could save none for recovery... (note to self: give more consideration to developing a Space-X style barge for recoveries at sea...) In hindsight, I probably would have been better off giving the launch stage even more fuel-capacity, or launching this module as a secondary payload on a larger rocket... Anyways, after the successful recovery of the launch-stage, I then proceeded to rendezvous and dock the Control Module with the other half of the Propulsive Fluid Accumulator, using the upper stage for propulsion: The only reason I didn't launch this payload as another spaceplane-cargo (besides being completely worn out with spaceplanes for a little while) was that I needed the upper stage for propulsion to rendezvous and dock with the other half of the Propulsive Fluid Accumulator... (my other option would have been to perform TWO additional spaceplane missions- one to launch the Control Module and another to launch a small tug capable of carrying it to the rest of the Propulsive Fluid Accumulator...) My first Propulsive Fluid Accumulator is now assembled and ready to operate in orbit! The only reason I have not yet showed it off in action is because of a resource-naming bug with KSP-Interstellar Extended I had to clear up first (it was collecting Nitrogen, but the wrong resource-definition for Nitrogen due to a naming issue: rest assured this has now been cleared up as of the latest update of KSP-I Extended...) Regards, Northstar

FreeThinker, Another AWESOME update as always! You even included some changes that I had meant to suggest, but can't remember ever mentioning yet... Like extending the altitude Propulsive Fluid Accumulators work up until a spacecraft hits "high orbit" around a body (I assume you are using the Low/High boundary- so it will adjust correctly with Real Solar System 6.4x installs?) In real life, the Thermosphere extends up to 500-1000 km (depending on levels of solar activity) so the low/high boundary is a convenient place to draw the line on where PFA's work in KSP as it will make it so players can easily determine if their PFA works with a simple Thermometer part (which will work in Low, but not High Orbit...) Increasing Hydrogen/Helium abundance in the Thermosphere (above the KSP atmosphere line, but before High Orbit) is both realistic and a good idea from a balance-perspective as well... Also, what Ec/s values did you use for Liquid Hydrogen and CO2? The Ec/s demands for Hydrogen should be one of the *highest* of any of the cryostat storeable fuels- higher than anything but Helium (which has an even lower boiling-point than Hydrogen: -268.9 C vs. -252.9 C) whereas CO2 has its triple-point at -56.6 C and requires *far less* cooling even than Nitrogen, which boils at -197.795 C (although CO2 has to be pressurized to at least 5.12 atm to remain as a liquid- which should increase tank-mass in direct proportion to the pressure-levels, although the cryostat is already so heavy compared to real life we can probably assume it is already storing fuels at 30-40 atm pressure or more... Even RealFuels Service Modules, which store fuels at 20+ atm of pressure are *much* lighter per liter of volume...) Regards, Northstar - - - Updated - - - P.S. Would still love to get started on those ISRU reactions... I understand you're still waiting to get data from me on the energy of combustion of Methane and LOX at a temperature of 3000 Kelvin (or a general equation that applies to all temperature-ranges?) I'll be working on that- but could we get started on the ISRU reactions I listed before? I really want to get as many of these in as possible before the 1.0 release, as once 1.0 comes out we'll just be scrambling to make sure everything is ported over correctly for the update to the base-game... There are several of these that are low-hanging fruit. Especially #7, which is just a matter of implementing a name-change from Monopropellant--> Hydrazine when RealFuels is installed (but in turn enables #8, as Hydrazine can then be easily processed into MMH, UDMH, and Aerozine; which can all be burned with easily-produced N2O4...) Please let me know your thoughts on this. Regards, Northstar

Try posting on the 0.90 port thread for support. Most mods are up-to-date for 0.90 by now- I'm really surprised you're still having issues with any of them! Also, KSP-I Extended will probably eventually come as a standalone that includes all the 0.90 port files, if I can convince FreeThinker to eventually come around to this perspective... It includes some bug-fixes even vs. the 0.90 port, so I suggest giving the Extended config a try even now, or especially once it comes as a standalone... Regards, Northstar

I'm surprised to see people still posting here when KSP-I is current outdated... I assume you guys are using the 0.90 port? Or KSP-Interstellar Extended? (link in my signature) Also, FreeThinker, we really ought to think about making KSP-I Extended a standalone that doesn't require players to first install the 0.90 port and then overwrite certain files with ones from Extended... That would make the installation process much easier and probably lead to us getting a lot more players downloading the mod... Regards, Northstar

Hi Freethinker, I've seen a lot of updates/fixes lately, but nothing about fixing the resource-naming issue with Propulsive Fluid Accumulators... Are you planning on fixing this soon? The current code prevents me from using them effectively to collect Nitrogen for propelling nuclear-electric missions to Duna and beyond... (where I plan to deploy another Propulsive Fluid Accumulator to collect LiquidCO2 for the return trip- I assume I won't run into any issues with PFA's there as well? Or with performing the Sabatier Reaction on-orbit using LiquidCO2 and LqdHydrogen stored aboard a refinery vessel?) Also, will I find that my Propulsive Fluid Accumulator tries to accumulate "Oxidizer" instead of "LqdOxygen"? Or is that fixed for players using RealFuels? Regards, Northstar

I already provided values for Ammonia and Hydrazine (no time now, but I can go back and re-post these later: but it might be simpler for you to search the thread for them). Water and CO2 do not spontaneously decompose at the temperature ranges of a fission reactor- they actually *absorb* energy when they decompose, and an electric current is required to force those reactions to happen. By decomposition energy of Meth/LOX, I assume you mean the energy of combustion when Methane burns with LOX? Also, good catch about the Nitrogen-naming. It will break existing vessels (including the PFA I just launched to orbit you saw a screenshot of before) to re-name the resources though, so could you hold off until 1.0 and the release of CRP 2.0 with it (when most saves will break anyways). In the meantime, can we get it so the Propulsive Fluid Accumulators scoop "LiquidNitrogen" properly instead of "Nitrogen"? Regards, Northstar

@FreeThinker Haven't had time to take a look at that code/explanation yet (will get to it), but it seems we have other issues with existing systems not working right yet as well: This Propulsive Fluid Accumulator may *SEEM* to be working correctly, but notice the resource-name. "Nitrogen", not "LqdNitrogen". The quantity of LqdNitrogen already in the tanks was launched from the ground to allow the PFA to use its plasma thrusters to position into a properly low circular orbit for collection. No new LqdNitrogen was accumulated after more than 5 days unloaded in an appropriate orbit (for RSS 6.4x, where the atmosphere begins at 91 km) and with a 18 MW reactor (and attached generator at 20% efficiency) powering the Atmospheric Scoop... Could we get this working so that the Atmosphere Scoop stops trying to collect RealFuels "Nitrogen" when no tanks for it are present, and starts collecting the usable KSP-I "LqdNitrogen" instead? Regards, Northstar

Also, a reminder, HERE is a link to a list of some of the ISRU reactions I suggest we include... Regards, Northstar

Freethinker, After we fix the Plasma Thrusters (which don't currently work, *at all*), we need to refocus on ISRU. I suggest we start with including more resources that can be harvested, and then move into including more ISRU reactions... Once again, I recommend looking at THIS list I drew up. Except for the nuclear resources, and any abundances given for Jool/Jupiter (as I may or may not have badly mis-interpreted a table of planetary resource abundances on Jupiter when obtaining these) this list is entirely correct and accurate. Some of the more interesting additions we should make (all of which have basis/support in real life) include: Water-ice in the polar craters of Moho (like on Mercury- where we have better evidence of water-ice than on the Moon/Luna!) Nitrogen and methane-ice common on Eeloo (like on Pluto) Water-ice covering between 30 and 70% of the surface of Dres and Eeloo (like Ceres and Pluto) Lithium deposits on Duna (Mars) and in oceans of Eve/Laythe (no real life counterpart as no water-oceans outside Earth) Methane in atmosphere of Laythe (Titan has atmospheric Methane and hydrocarbon-lakes) Fluorine on Eve (like Hydrogen Fluoride is found on Venus) Helium and Helium-3 in Munar regolith (like on Luna- Earth's moon) Ammonia-ice richly abundant in Laythe's soil (like on Titan- where makes up up to 50% of planetary mass) and oceans, and perhaps in liquid form in Eve's oceans (most plausible liquid for that temperature/pressure range) Trace amounts of Ammonia, Nitrogen, and Methane in atmosphere of Jool (like on Jupiter- although some of these are only found at very high pressures) There's also the noble gasses we don't use in KSP-I yet (Neon and Krypton), but these aren't such a high priority unless we give Plasma Thrusters the ability to use them as propellant (which should be feasible, but requires some research to determine accurate Thrust/MW and ISP values...) Regards, Northstar

The ability to store both Alumina and Aluminum in more places would be strongly desirable. At the very least we should have a MM patch so players using RealFuels or Modular Fuel Tanks can store it in the modular tank types that mod provides (or, to add a RealFuels tank type specifically to hold Alumina/Aluminum and other solid resources such as Lithium, as they are solid resources unlike most resources stored in the current RealFuels tank-types...) - - - Updated - - - Also, FreeThinker, why did you do this? I can understand your wanting to change the performance of LFO, which is a made-up resource used by most players that we could give any performance we like, but I don't understand what your fixation is/was on changing HydroLOX. We already had good, physically accurate data on what the Thrust/MW should have been for HydroLOX reflected in the config, which you now replaced with an entirely arbitrary value that makes no physical sense... The only players who use HydroLOX (as opposed to LFO) are those who have RealFuels installed. Such players (including myself) will want realistic performance rather than performance that is entirely unrelated to reality, so could we please restore this Thrust multiplier back to its previous value of 1.977 instead of 2.22? It's true that with realistic values for Thrust/MW and ISP, Hydro/LOX is pretty much in all ways surpassed by Ammonia (which makes up for its slightly lower ISP and Thrust/MW with a higher density and thus reduced tank dry-mass requirements), but it's based on a pair of resources that are MUCH more prevalent in the solar system than Ammonia- the Water ice needed to produce HydroLOX shoudl be readily available on Vall, Dres, Eeloo, the Mun and Minmus- all places where the Nitrogen needed to produce Ammonia is not readily available. Speaking of which, can we go and update the resource definitions to include widespread water-ice on Dres and Eeloo? As I already posted research on before, Ceres and Pluto (their real-world analogs) are pretty much made of water-ice: in fact they are both rock+ice planetoids with poor differentiation and water-ice that penetrates all the way to the core of these "planets" as well as making up much of the visible surface! Thus, they should both provide a virtually-inexhaustible supply of Water ice for use in ISRU both in KSP-I and in real life... All we need for this is a file that maps the Water-ice deposits onto the surface of these planetoids (I'm guessing it should preferentially be found in the low-lying areas that receive a bit less sunlight, although not to the exclusion of highlands or ridge-lines...) Would anybody like to try their hand at drawing one of these up for Dres and Eeloo? Regards, Northstar

Ladies and gentlemen, I present a TRUE, REAL, AUTHENTIC spaceplane for Real Solar System 6.4x, and I can promise you- this is no April Fool's joke! The ascent of this thing was rather tricky, I must say (as would be expected of a spaceplane with this much Delta-V: in fact with use of all the reserve Nitrogen it might have even been capable of making orbit on full-scale Earth...) This design only became possible with a radical paradigm-shift: instead of trying to build the spaceplane like a plane, I needed to design it like a winged rocket. As such, it makes use of very large diameters (for the high Ballistic Coefficient- which is invaluable once switching into rocket-propulsion and pushing out of the atmosphere), very lightweight fuel-tank construction (in fact the fuselage is comprised of an insulated balloon-tank, which actually had problems with sometimes imploding due to aerodynamic stresses it was so incredibly weak... Realistically this only would have worked because the weight was hung below wings spread out along the length of the craft, so no part of the fueselage had to support much weight other than its own cross-section...), and relatively high Thrust for a plane (in the lower atmosphere, the spaceplane was capable of an almost-vertical ascent before it started to run out of atmosphere for its Thermal Turbojets and had to level out for speed...) All this aside, there was still room for improvement... For one, I made use of a tri-wing design as the front two wings were actually both giant canards that evolved from an earlier failed design (which had only one pair of canards instead of two). However I would like to try enlarging the front canards and rear wings, and doing away with the middle canards altogether so that I can make use of larger, more highly-swept wings for the improve Lift/Drag ratio that they would offer at hypersonic speeds (the Lift/Drag fell below 1.00 soon after switching to rocket-propulsion, due to the 45-degree delta shapes used for the wings instead of something more highly-swept...) Additionally, I would love to figure out how to pre-cool more of my air intakes, as Thermal Turbojets are theoretically capable of operating up to a bit over Mach 5 (both in-game and in real life) with sufficiently powerful and advanced pre-coolers, but I was forced to rely on a combination of precooled inline-intakes and radial intakes that were not attached to any precooler (KSP-Interstellar Extended makes it possible to pre-cool radial intakes, but they still have to be attached directly to a precooler to receive its benefits...) limiting their operation up to about Mach 4.3 (which, in practice, meant I could operate them up to my maximum speed before activating the rockets, but could not take much advantage of the ram-effect that operating a mixture of rockets and jets provides to shove more air into the intakes and allow higher Thrust-production by jets under intake-limited operating conditions...) due to compression-heating in the Thermal Turbojet's compressors forcing a shutdown at around Mach 4.4 to avoid the Thermal Turbojets failing (read: exploding) due to overheating! Regardless, it was a highly-successful ascent (read: the plane made orbit in one piece, even if the ascent was not the most fuel-optimal possible- in fact it fell back into the atmosphere after apoapsis before circularizing...) and the spaceplane soon began with its mission-objective for its virgin flight: which was to recover Bill Kerman form the Munar-1 Lander, where he had been waiting in orbit for over 24 hours... (and 4 days of total mission-time) All the fuel-balancing shown was about keeping the remaining Hydrogen in the smallest tanks possible that could hold the entire volume to minimize boil-off during wait-periods, or as far forward as possible to maximize stability during burns, by the way... You'll also notice I had significant amounts of LqdNitrogen leftover- which was my highest Thrust and lowest ISP propellant- upon reaching orbit. This was kept both to act as an emergency reserve-fuel during the virgin flight, and can be exchanged for more useful payload in future design iterations with a larger inline fairing at the nose of the craft... The inline-fairing acts as a kind of simple lightweight cargo-bay, (and will protect Bill Kerman and a magnetometer from re-entry heat this mission...) and as forward-ballast during re-entry. In future missions, I intend to have a Propulsive Fluid Accumulator in orbit that will supply an orbital fuel depot with unlimited quantities of Liquid Nitrogen, and will refuel the spaceplane with Nitrogen before re-entry: allowing me to use this Nitrogen reserve earlier in the ascent, and deploy larger payloads as a result... (future design-iterations will include a longer and possibly wider inline-faring at the front of the spaceplane, allowing the existing Nitrogen-tanks to be elongated and pushed lower in the fairing, and providing more room for payloads- which I estimate could reach up to 2.5 meters in diameter...) Regards, Northstar

In the spirit of recovering as many mission-components as possible, I designed recovery-capabilities into the tanker itself, and attempted to recoup some of my costs by recovering it... Unfortunately, the tanker recovery-systems *did not* pay for themselves... The tanker ended up splashing down on the opposite side of Kerbin, and the recovery-factor was so low that the parachute (cost of 400 Funds) barely ended up paying for its own part-cost, and certainly did not pay for the reduction in payload-capacity of the rocket that including the parachute entailed... I guess I should have been a bit more careful about the re-entry trajectory the Nuclear Thermal Tug dumped the tanker on... However I was *extremely* tight for fuel at this point, and more concerned with simply stabilizing the orbit of the NTR Tug (which is worth a LOT more Funds than the tanker) at all than where the tanker ended up... Anyways, it wouldn't be fair to burden you guys with all these screenshots of a simple refueling mission without showing you why I wanted the Hypergolic Tug refueled in the first place... So, I present the launch of my Minmus Probe: Launching atop a rather odd launch platform designed to complete a contract to test a Novapunch2 Aerospike Engine at a certain speed and altitude, the Minmus Probe actually rode to orbit atop a vertical-takeoff rocket SSTO... (rocket SSTO's are actually quite easy to develop compared to spaceplanes, both in Real Solar System with RealFuels, and in the real world- where numerous plausible designs have been suggested, unlike HTHL spaceplanes where most of the proposed spaceplane designs have been barely-feasible at best...) Anyways, after setting up the Minmus Probe on a trajectory that took it reasonably close to the Munar-1 Lander (more on that later) the launch-stage turned around and performed a de-orbit burn to take it back as close to the KSC as possible... Unlike with the Hypergolic Refueler Tanker, the upper stage was large and expensive enough to make a controlled re-entry desirable: both for getting a more precise re-entry trajectory that could take the craft close to the KSC (maximizing recovery-factor) and for a landing-burn (which I turned out not to have enough fuel for- the leftover fuel boiled-off before landing, which was luckily *just* slow enough not to cause any damage to this rocket-design without a landing-burn...) The controlled re-entry was desirable for a landing-burn during splash-down (where water-pressure on the sides of the rocket can cause a rocket to explode even at splashdown speeds as low as 10 m/s... Which is a bit too much and is fixed by Ferram4's Better Buoyancy mod, but is not as unrealistic as you might *think*- water pressure on the sides of the rocket really would be an issue in real life...) However IF the touchdown had been on land, the rocket could have safely touched down at even faster speeds- up to 100 m/s (the crash-tolerance of the boosters, which extended below the aerospike engines) would have been possible, so long as bouncing didn't manage to cause a part other than the boosters to hit the ground... So, the real benefit of the controlled re-entry was getting a trajectory that very precisely took the rocket near the KSC (and the increased recovery-factor), not the landing-burn... The Minmus Probe, meanwhile had several sets of orbital maneuvers to carry out... First, rendezvous was necessary with the Munar-1 Lander to pick up scientific equipment I would be re-using (a thermometer and an accelerometer- as I have decided not to use the lander again as I have no need for a 5-Kerbal lander with engine-technology that has now become outdated by newer, higher tech-levels of RealFuels engines I've unlocked...) Then, the Minmus Probe rendezvoused with the Hypergolic Tug in a higher orbit, taking advantage of my lowering the periapsis before to match velocities near pariapsis and thus take maximum advantage of the Oberth Effect... (matching velocities with a craft in an elliptical orbit is the same thing as boosting into that exact elliptical orbit without the other craft being there- and necessarily is most efficiently performed by performing as much of the burn as possible at high speeds and in the prograde direction...) Finally, the two craft began their burn towards the Mun together (where I will be making use of a gravity-assist to curve the orbit towards Minmus, which is currently on the wrong side of Kerbin relative to the orbital axes of the Hypergolic Tug's elliptical orbit...) The Minmus Probe still had some fuel left in its supplementary fuel-tank (which provided the fuel to rendezvous with the Hypergolic Tug, and doubled as a nosecone during ascent from Kerbin...) so it made sense to have the two craft start their burns separately and then rendezvous partway through the transfer-burn after the Minmus Probe had emptied and ejected its supplementary fuel-tank... (the relative positions of the Mun, Minmus, and Hypergolic Tug's orbit dictated that I perform the transfer-burn at apoapsis of the Hypergolic Tug's orbit, meaning I wouldn't be able to take advantage of the Oberth Effect, but would have more time to perform tricky maneuvers like this without messing up the transfer-trajectory to the Mun...) If it seems like I just rushed through rather complicated and impressive set of orbital maneuvers you're right- because I've got something even MORE impressive I want to showcase to you guys in the form of my first ever (and possibly *THE* first ever) RSS 6.4x Horizontal Takeoff Horizontal Landing spaceplane! I also only have so much time I can or wish to dedicate to posting screenshots and explanations instead of playing (or recently, watching or broadcasting on Steam) KSP... Regards, Northstar

I present the launch of my "Hypergolic Refueler" Seeking to make use of the remaining fuel onboard the Nuclear Thermal Tug used for the Munar-1 mission, as well as the Hypergolic Tug (previously a Kerbosynchronous satellite- rather then deploy a separate satellite the transfer-stage was not staged from the probe core+ solar panels + antenna...) currently in orbit, this vehicle contained a quantity of hypergolic fuel destined for the Hypergolic Tug... As with most of my missions, it was carried out with a recoverable launch-stage: I really ought to start packing more extra fuel into these launch-stages, or build a barge to land them on out at sea, Space-X style. Because I am losing a LOT of Funds by splashing down so far down-range of the KSC instead of flying these back to the Space Center like Space-X plans to do with their launch-stages... Then again, the recovery percentages are already unrealistically high in KSP (refurbishment and/or inspections are going to cost SOME money, even if you land back on the launchpad), so I'm somewhat OK with what I'm doing now... The upper stage also safely recovered after an orbit: The upper stage had its parachutes pre-configured, and de-orbited via a set of retro-rockets rather than an onboard probe core and retrograde-burn with the main engines as it was cheaper to use retro-rockets rather than a probe core for a rocket in this size-range... Larger rockets still need a probe core because a single small parachute is not enough to slow them to a safe touchdown speed, and the main engines are needed for a landing-burn, however... (and if even smaller/cheaper parachutes had been available, I would have done the same with this rocket...) The upper stage DID splash down with excess LOX onboard, however- which tells me I should have packed more LqdHydrogen before. Not that I will get the chance to fix this in future launches- this was a one-off mission anyways: I will be retiring the Hypergolic Tug in the near future... The Nuclear Thermal Tug then proceeded to undock from the Munar-1 Lander, and rendezvous+dock with the Hypergolic Reueler tanker: This went smoothly enough- but after here things started to go wrong... I didn't notice that the Nuclear Thermal Tug lacked sufficient Delta-V to rendezvous with my Hypergolic Tug in a much higher elliptical orbit, and ended up having to install TAC Fuel Balancer and dump more than half the hypergolic fuel onboard the tanker just before rendezvous in order to have enough Delta-V to match velocity with the tug... This also didn't leave me with quite enough fuel to aerobrake the Nuclear Thermal Tug back into a low Kerbin orbit, although I came up with a creative solution to the latter of these problems... My solution to the Nuclear Thermal Tug lacking sufficient Delta-V to aerobrake back to a lower orbit on its own was to have the Hypergolic Tug complete a portion of the retrograde burn, detaching just before the periapsis fell within the atmosphere... Overall this was not a BAD solution, as I needed to lower the Hypergolic Tug's periapsis as well for easier rendezvous in the future (and greater utilization of the Oberth Effect when departing for destinations further out). However IDEALLY I would have dumped just a bit more of the hypergolic fuel, and had the Hypergolic Tug and NTR Tug each lower their orbits separately. This way I wouldn't have been hauling any hypergolic fuel all the way out to the Hypergolic Tug's orbit just to use it to help lower the orbit of the NTR Tug again (where using Hydrogen onboard the NTR Tug for that would have been lighter and more efficient...) This isn't the end of my recent missions I have to catch you guys up on, but for the sake of post brevity (and my own sanity) I think this is a good place to cut this update for now... Regards, Northstar

The best way to document that would be screenshots- but I haven't got any. What I *DO* have are plenty of screenshots of the my first SUCCESSFUL spaceplane design- which I think might actually be the first successful Horizontal Takeoff Horizontal Landing spaceplane anybody has *EVER* managed to build in RealSolarSystem 6.4x + FAR (although it's worth pointing out it was only made possible by TweakScale, Procedural Parts, Procedural Wings, and KSP-Interstellar: I couldn't IMAGINE having done it without those four mods...) First, though, I've got some other missions to catch you guys up on... Regards, Northstar

Lovely April Fool's prank. As a temporary moderator I must close this thread now, though. LOL (apparently we're all "moderators" for a day- let the chaos ensue!) Regards, Northstar

I'm only reporting what I observed. The coding reasons for it are beyond me (since I don't have any software that can open .cs files...) Regards, Northstar

Ack, Hydro/LOX (the RealFuels fuel-mode) not LFO. I don't use the stock fuel modes for anything anymore! Like I said, its ISP should be higher. One of the primary advantages of Hydro/LOX is its widespread ISRU availability. Whereas Ammonia can only be manufactured where a source of Nitrogen is available, and Methane with a ready source of CO2, Hydro/LOX can be obtained wherever there's Hydrogen+Oxygen (in gaseous form) *OR* water/ice. The other high-ISP fuels are much harder to obtain (excepting of course, pure Hydrogen- which has very low density and thrust, and is only a fraction of the mass-makeup of water/ice...) The thrust multiplier is currently correct (0.6289), but for some reason the ISP ends up much lower in-game than Ammonia, which has a HIGHLY similar ISP multiplier (0.6303). We already have good real-world date for the Thrust, ISP, and fuel-mixture of Hydro/LOX LANTR, and use it for the config. You just need to figure out why ISP is only about 2/3rd what would be expected for the ISP multiplier (around 400 instead of 600 seconds) and Thrust/Mw is so much higher. My suspicion is that, despite your attempting to deactivate it, the "is LFO" code is still being applied... Should be simple enough to test- I'll delete that line from the config tonight, and see if it changes the ISP in the Spaceplane Hanger... Regards, Northstar - - - Updated - - - FreeThinker, I can officially confirm that the "is LFO" code is *NOT* disabled. I went and deleted the code from the entry for Hyro/LOX, and only the entry from Hydro/LOX, without changing anything else, and it set the Thrust and ISP of Hydro/LOX equal to the values for Water! It also showed a new, incorrect ISP multiplier in the context menu for Water in the Spaceplane Hanger- those associated with Hydro/LOX! (so, in summary, Hydro/LOX got Water's Thrust and ISP but kept its displayed ISP multiplier, whereas Water got Hydro/LOX's displayed Thrust and ISP multiplier values, but kept its original Thrust and ISP...) So, it's almost certain that this code is what is, somehow, messing up the Thrust/MW and ISP of Hydro/LOX. I'll have to see if changing "is LFO" to "false" instead of deleting it entirely fixes the issue instead of making the problem worse by messing up other fuels... It's worth noting that I rearranged my EnginePropellants file to list the fuel-modes in order of ISP multipliers, and deleted the entries for LiquidFuel, Kethane, LFO, and "LiquidHydrogen" (the NearFuture version of LqdHydrogen" from my config. Water was the entry directly above Hydro/LOX in my config. So, if you delete the "is LFO" line from YOUR Hydro/LOX entry it would likely mess up a different fuel-mode than Water... Regards, Northstar - - - Updated - - - OK, so changing "is LFO" from "true" to "false" DID fix the ISP and Thrust/MW for Hydro/LOX to the proper/realistic values: Now we just need to make this fix part of the next update, and do the same for Meth/LOX (which also has a much lower ISP and much higher Thrust/MW than it ought to based on its ISP multiplier and Thrust multiplier...) until we can figure out why the "is LFO" code was not deactivating properly... Regards, Northstar

One last thing- did you look at what I talked about before, regarding giving Water some ability to clean soot out of the reactors as well? Pressurized steam is quite effective at cleaning Carbon-deposits from the interior of furnaces and boilers in real life: there's no reason to think it wouldn't be able to do so in a Thermal Rocket as well... I know part of the cleaning is mechanical- but there may also be a chemical reaction that occurs and helps the process as well... EDIT: It appears, according to numerous different sources, the following reaction occurs: H2O(g) + C(s) --> CO(g) + H2 (g) This is actually a closely-related reaction to the Reverse Water Gas-Shift Reaction: H2(g) + CO2 (g) --> CO(g) + H2O(g) Which can be used on Duna/Mars to obtain Oxygen directly from atmospheric CO2, by condensation and eletrolysis of the water vapor (the reaction is carried out in a closed reaction-chamber to avoid loss of the valuable Hydrogen in the form of steam...) and which is STILL an ISRU reaction we need to add to KSP-Interstellar Extended... Both reactions are Endothermic, and only spontaneous under high-temperature conditions, meaning they both require external energy to drive them to occur... This means that using Water to clean soot deposits should reduce the Thrust and ISP just like using Carbon Dioxide to clean soot deposits does... Regards, Northstar

The base ISP values of Ammonia, Methane, and Water already give accurate ISP compared to real-world projected values within 5% deviation. If the thrust multiplier code were fixed to actually affect ISP, you would have to divide the base ISP by the Thrust multiplier values- so maybe it's actually easier to leave the thrust multiplier in its current state. If we leave Thrust multiplier alone, no changes whatsoever need to be made to Ammonia, Water, or Methane (except possible tweaks to the SootFactor rate of accumulation for Methane). I still need to take a look at Meth/LOX, and I can confirm that the ISP of HydroLOX is too low and the Thrust/MW is currently too high- apparently due to the "LFO = true" code, which I would recommend deleting entirely... Given the way the Thrust multiplier is actually currently working in-game (it increases Thrust, but leaves ISP unaffected, regardless of how it was intended to work- and this may actually be easier to create configs around... My guess is the system automatically reduces the ISP when you increase the Thrust/MW, so the increase to Thrust/MW only balances that auto-reduction and leads to no net change in ISP...) I will need to come up with new configs for Hydrazine with a higher base ISP. Will post those shortly... Regards, Northstar - - - Updated - - - Well then I've no idea why LFO currently gives so much of a lower ISP than Ammonia. The ISP values should currently be nearly-identical (62.89% vs. 63.03% of Hydrogen), with the major difference being that Hydro/LOX gives slightly better Thrust/MW but lower ISP and is harder to store due to fuel boil-off... Making it a superior fuel for launch-stages (using Microwave Thermal Rockets- you would be silly to use a NTR for a launch-stage if playing with RealFuels...) and upper-stages that don't need a lot of insulation or to be stored for long periods of time, but inferior for orbital stages where the Hydrogen has a lot more time to boil-off... - - - Updated - - - OK, here are the new config values for Hydrazine, adjusted to the way that the Thrustmultiplier is currently working (in practice, it is increasing Thrust, but leaving ISP unaffected) as it's easier to code around the oddly-working Thrust multiplier system than to fix it and have to go back and fix all the ISP multiplier values at this point... BASIC_NTR_PROPELLANT { name = Hydrazine guiName = Hydrazine ispMultiplier = 0.744 thrustMultiplier = 1.806 isLFO = false PROPELLANT { name = Hydrazine ratio = 1 DrawGauge = True } } You'll notice that basically I just multiplied the old ISP multiplier (0.412) by the Thrust multiplier (1.806). The previous config was giving an ISP that was too low, but a Thrust/MW that was much too high. Increasing the ISP multiplier as above should fix both of these issues... Hydraazine should now appropriately give an ISP that is higher than Hydro/LOX (but lower than Methane), but a Thrust/MW that is lower. Note that the higher ISP is not due to the molecular mass of the exhaust-gasses (which, at 2 parts Hydrogen and 1 part Nitrogen by volume, average a higher molecular weight than those of Hydro/LOX: which are 2 parts Hydrogen and 1 part Water by volume) but likely to the fact that the Hydrazine-decomposition reaction occurs inside the heat exchanger rather than inside the rocket-nozzle, and thus is more effectively converted to Thrust (and by increasing Thrust for the same fuel-flow, increasing ISP) than the energy released by the actually technically more-energetic (by mass of propellant- not by volume) Hydro/LOX combustion reaction (the values for Hydrazine are based off known reaction energies and 75% thermal efficiency- the values for Hydro/LOX are based off actual measured values: thus the Hydro/LOX must have a thermal efficiency of 40-50% or less due to where the LOX-augmentation takes place in the nozzle rather than before the exhaust aperture... Note that this is only an *estimate* of the Hydro/LOX thermal efficiency- I haven't actually bothered to do out the numbers to see why the Thrust-augmentation is so weak or how low the thermal efficiency actually is when adding LOX in the exhaust nozzle...) Regards, Northstar

This is how it should be done- but the code is not working at intended. Otherwise HydroLOX (base ISP 0.6289, Thrust/ISP multiplier 1.977) would have a higher ISP than Ammonia (base ISP 0.6303, Thrust/ISP multiplier 1.832) as currently coded. This is not currently the case- Ammonia has a MUCH higher ISP than HydroLOX in the Thermal Rocket Nozzle parts right now... (around 600 seconds for Ammonia vs. around 400 seconds for HydroLOX- specifics depending on whether you use a Particle Bed or Molten Salt Reactor...) Also, like I already discussed HERE the current base ISP values yield the correct ISP values if the thrust multiplier doesn't affect the ISP- as is currently the case is KSP-I Extended (otherwise, as I pointed out, HydroLOX would have a higher ISP in-game than Ammonia, which is *NOT* currently the case...) *IF* you could fix the thrust multiplier code so that it increases both ISP and Thrust/MW as intended, then the new ISP values would simply be calculated by dividing the current ISP multiplier by the Thrust multiplier... So a propellant with base ISP of 600 seconds but thrust multiplier of 2 would have a base ISP of 300 seconds- for 600 seconds ISP in-game... You know what, maybe it's simpler just to keep the system as-is. And I have a theory about why HydroLOX currently has an ISP so much lower than Ammonia when the actual, realistic ISP values should be EXTREMELY close (63.03% of Hydrogen for Ammonia, 62.89% of Hydrogen for HydroLOX). The code says: isLFO = true Didn't Fractal_UK already include code that automatically reduced the ISP but increased the Thrust/MW of any propellant with this line of code? If so, we need to remove the LFO code altogether- as the new Thrustmultipliers currently accurately reflect what the ISP and Thrust/MW should be for each propellant (and apply to more than just LANTR fuels- Ammonia benefits from one due to its breakdown into Hydrogen and Nitrogen gasses, for instance...) It is currently leading to an ISP value that is too low for Hydro/LOX and Meth/LOX, and a Thrust/MW value that is much too high for these fuels... (as the "LFO = true" code is stacking on top of the current thrust multipliers- which are more predictable and easier to understand...) - - - Updated - - - I'm having the same issue with the Thermal Turbojets- so confirm this as a known bug FreeThinker... EDIT: Looks like you already fixed this in the next update! - - - Updated - - - I can also confirm this bug- plasma thrusters don't currently work on the launchpad *at all*, no matter what fuel-mode you swap to. - - - Updated - - - This is AWESOME! I was actually talking about doing this before! We'll have to get this included in the next release of KSP-Interstellar Extended somehow! (FreeThinker, the question is, does this code need to only activate when RealFuels is installed- or will it be harmless if it activates without?) - - - Updated - - - Oh. Forgot about that... Never mind that bit about the radiator-code ABZB... Regards, Northstar

Indeed. I'll just need to watch out for little green men that AREN'T Kerbals, and want to donate their metal armor to my cause by way of falling into traps.. I've got a significant backlog of screenshots to post at this point, but I just thought I'd tide you guys over with one small mission I carried out in the meantime (and DIDN'T revert- for those of you who watched my latest ultimately-unsuccessful attempts at a RSS 64K spaceplane on Steam recently... Something about trying to fly at only Mach 2.4 at 42 km didn't sit too well with my control-surfaces' ability to control a monstrously large spaceplane...) I present, my High Altitude Research Plane: Mostly, this was just a proof-of-concept to see if I could really use Stanford Torus mod's over-sized solar panels as wings (turns out I could- with some very small Procedural Wings hidden underneath as supports, and struts!) - but this plane could also very well have utility for flying around on Duna... Yep, that's right, I *STILL* haven't given up on the Flying Duna Challenge- in fact that was part of the motivation for my recent focus on planes and aircraft... I also designed an ultra-light helicopter at about the same time (which, with a bit more refinement, will probably have enough TWR to fly around Duna...) I might try out on Duna someday first... (helicopters are *much* easier to launch on a rocket because they don't have huge wings to destabilize a rocket, obviously...) Geschosskopf, if you're reading this- I know it's been more than a year (almost 2 years!) since I first posted on your thread- but my entry is still coming someday, even if it doesn't end up being until after 1.x! Regards, Northstar

I just want to explain the bit about Thrust multiplier a little more clearly: It is imperative that Thrust multiplier increase both the Thrust and the ISP by the same factor, as what it represents is an increase in Thrust for the same fuel-flow and MW of reactor power. Otherwise what you have is just the turbopump magically pumping more propellant through the rocket. If you double Thrust without doubling ISP, then your rocket will simply pass twice as much fuel through the nozzle per minute at exactly the same energy-level, which is not what Thrust multiplier is meant to represent. Simply assuming that the Exhaust Velocity remained fixed and the extra energy from a reaction was used to accelerate more mass (resulting in more Thrust) would, in theory, require us to square all our current Thrust multiplier values. So a fuel-mode with a Thrust multiplier of 2 must now have a Thrust multiplier of 4, a fuel-mode with a Thrust multiplier of 3 must now have a Thrust multiplier of 9, etc. However this does not actually work in practice- because many of these reactions actually add energy to the exhaust-stream not by increasing the exhaust temperature, but mainly by increasing the exhaust pressure (by increasing the number of moles of gas- for instance Ammonia breakdown doubles the moles of gas, and Hydrazine breakdown triples the number of moles of gas and thus the exhaust pressure before nozzle-expansion...) One of these reactions, Ammonia-breakdown, actually *decreases* the temperature of the exhaust stream, and adds energy to the exhaust for the same mass-flow rate solely by increasing the exhaust pressure (which is later converted into Exhaust Velocity in the rocket nozzle). These reactions add less energy to the exhaust stream the lower the exhaust temperature (as exhaust energy is proportional to temperature * pressure), so increasing the mass flow rate instead of keeping it fixed would lead to a decrease in the exhaust temperature and thus a decrease in the total exhaust energy... Regards, Northstar

OK, here's the code: BASIC_NTR_PROPELLANT { name = Hydrazine guiName = Hydrazine ispMultiplier = 0.412 thrustMultiplier = 1.806 isLFO = false PROPELLANT { name = Hydrazine ratio = 1 DrawGauge = True } } Note that after ordering the propellants by ISP (after taking the Thrust multipliers into account- as they improve ISP as well as Thrust/MW, as they should realsitically do and was intended...) it comes out intermediate between Water and Ammonia. Here is the fuel-modes I use (so no stock LiquidFuel, LFO, NFT "LiquidHydrogen", or Kethane), ordered from lowest to highest ISP: 1. LiquidCO2cleaning 2. LiquidNitrogen 3. LiquidCO2 4. Water 5. Hydrazine 6. Ammonia 7. Methalox 8. Hydrolox 9. Methane 10. LqdHydrogen Note that the Thrust/MW generally decreases as you down this list- with three exceptions: LiquidCO2 has a higher Thrust/MW *and* ISP (and fuel-density for that matter) than LiquidNitrogen or the the LiquidCO2 "cleaning" mode thanks to its Thrust multiplier... Hydrazine has a higher Thrust/MW than Water and LiquidCO2 (also due to its higher Thrust multiplier). Meth/LOX has higher Thrust/MW than Ammonia. All of these exceptions are realistic, and follow real-world chemistry, so I'm not really too concerned about them... (although Atomic Rockets confirms the Thrust/ISP for Carbon Dioxide, it undergoes no reaction- so this is the only one that is a mystery to me... It's probably due to its heat capacity being more optimal for thermal rocketry or something...) They also all make sense for balance reasons- the fuels that fall out-of-order in the ISP vs. Thrust/MW lists (Meth/LOX, CO2, and Hydrazine) all require substantially greater effort to produce via ISRU (Hydraazine especially- which requires 3-4 separate reactions to produce, and 2-3 different raw resources) or have limited availability- Carbon Dioxide (and Methane, by extension- through the Sabatier Reaction) is only really abundant on Duna after all- you can't get it easily in the Kerbin or Jool systems in any significant quantity as it is a very minor atmospheric component... EDIT: I listed the propellants as they SHOULD be based on their base ISP, and additional Thrust obtained from the Thrust multiplier. It appears the thrust multiplier is currently not being applied correctly in-game: for instance in the SPH, Ammonia is listed as having a higher ISP than Meth/LOX (should not be the case- due to how much more energetic Methane combustion is than Ammonia-decomposition, and the much higher Thrust multiplier that results...) and Hydrazine has a lower ISP than Water (should be the other way around... If applied correctly, a fuel with a base ISP of 500 seconds and a Thrust multiplier of 2 should have a higher effective ISP (1000 seconds) than a fuel with a base ISP of 800 seconds and no Thrust multiplier... This is not currently the case- so I'd go back and check the code for the Thrust multiplier and try and figure out what is going wrong... Basically, a Thrust multiplier of 2 indicates a doubling of the exhaust velocity vs. what you would expect from the molecular mass alone- without a decrease in mass flow rate, i.e. a 4x increase in the energy of exhaust gasses... (E = 1/2 m v2) Regards, Northstar

Hi FreeThinker, Still no word on the Hydrazine fuel-mode for Thermal Rockets, are you working on that? I already provided the numbers for ISP multiplier and Thrust multiplier- which is all that should be needed to add it... I'll even write up the code for the fuel mode and post it here so all you have to do is copy+paste into the appropriate file... Also, just a little perspective as your faithful co-developer of this mod- this is a mod that started out with a Warp Drive- which by any account was OP'd compared to stock- and only later added things like reactors, antimatter, and an energy-intensive process to create ExoticMatter... Thus, by all means, I don't think we should by shying away from any technology- especially when it exists in real life. Hydrazine is already a commonly-used rocket propellant for resistojets and RCS- which are basically just simple thermal rockets that rely on the increase in gas volume created by Hydrazine decomposition and either heat from that reaction or additional added heat with resistojets, to generate thrust... The only difference with putting it through a Nuclear Thermal Rocket is that the temperatures it is exposed to are much higher- which creates more complete decomposition and improved the Gibbs Free Energy of the reaction and energy released by an increase in the volume of gas... I don't think you should try penalizing or punishing players for using it somehow either. Players could already use nuclear rockets (either KSP-I or stock) right off the launchpad anyways. While Hydrazine is much more toxic short-term, radiation is still much more dangerous in the long run... (whereas Hydrazine rapidly decays in the environment into harmless gasses) It's not up to us to make decisions for our players or our Kerbals about what sacrifices are or are not acceptable in the name of space exploration... Finally, I particularly strongly advise against any mechanic that steals away player's hard-earned Science. Not only is it much less realistic than losing Reputation (realistically, a Hydrazine rocket probably isn't going to kill anyone- it's just going to lead to the creation of a restricted-access zone around the launchpad to prevent exposure to residual Hydrazine shortly after launches... Also, even if a scientist or engineer DID die, science has never been set back too far by the loss of one individual. Their data and records remain intact, and it wouldn't be too long before somebody else picked them up and continued their work...) It's also a bad idea from a gameplay perspective... KSP is supposed to be !FUN!, and that necessarily means making some sacrifices of detail in realism to gameplay. While players might disagree about where the optimal balance between !FUN! and realism lies (for instance, I like using realistic fuel-densities and ISP values, and a larger solar system, other players might not like that...) I think everybody can agree that losing Science for making use of a certain type of fuel is NOT fun- and thus isn't something we should seriously consider adding to our mod (which has never before ventured to penalize players in Reputation of Science for any of their actions...) One more thing: you drastically underestimate the utility of Reputation as a resource, and have probably either been playing Science mode (which is supposed to be simpler/easier than Career Mode anyways) or not using enough strategies... Reputation not only affects the contracts you are awarded, it can always be traded off to increase your Science and Funds yields from missions, or DIRECTLY "burned" to get tech nodes cheaper through the "Aggressive Negotiations" strategy (which not only saves you Funds on rocket launches- it also saves Science on tech node purchases and Funds on entry-purchases...) Not that I think Reputation *should* take a hit for using Hydrazine rockets- but if it did it would ultimately still be quite damaging to players, and a lot more realistic than losing accumulated Science points... Regards, Northstar

FreeThinker, I've got a beautiful new spaceplane sitting in the Spaceplane Hanger, ready to launch and use Hydrazine to boost itself to orbit! (the trace amounts of Hydrazine not broken down by the heat of the nuclear reactor would have a short half-life in the upper atmosphere thanks to the high ultraviolet radiation above the ozone layer- as UV is *highly* effective at breaking down Hydrazine, so much so that high-powered UV lights are being looked at for use to explosively photolyze Hydrazine... Point being, no Kerbals would be directly harmed by its use in the upper atmosphere...) The only problem is, I can't use Hydrazine as a thermal rocket propellant yet! Could you so kindly push out an update to allow use of Hydrazine in thermal rockets using the numbers I provided earlier? You'll note that I cut out the part about "at a significantly higher Thrust/MW" from the quote. That's because ALL thermal rockets propellants that produce exhaust gasses with a higher molecular mass than Hydrogen will produce significantly higher Thrust/MW- and I thought that might be confusing you into thinking Hydrazine is more powerful than it really is.. Except for its density, Hydrazine is really not much better than Ammonia- and it's much more difficult to produce through In Situ Resource Utilization... You actually need to first produce Ammonia and Hydrogen Peroxide and then react the two in order to produce Hydrazine- which currently requires access to both Water and Oxygen as Hydrogen Peroxide can currently only be produced from Water and Oxygen in KSP-I... (Which reminds me- we still really need to fix that- Hydrogen and Oxygen are the normal feedstocks for producing Hydrogen Peroxide in real life, via the Anthraquinone Process- Water is not required...) The drawback is lower ISP, of course- even 74% ISP leads to GREATLY increased mass-requirements for large Delta-V gaps (say the 7-8 km/s it takes to orbit Kerbin in Real Solar System 64K, or 10 km/s for Earth/Kerbin in full-scale RSS...) thanks to the beauty that is the Rocket Equation... Hydrazine is great for upper stages (chemical rockets still have Hydrazine Nuclear Thermal Rockets beat for TWR, and thus are still preferable in launch-stages, at least if you're using RealFuels...) and landers thanks to its density, but for orbital stages you still really want to go with Hydrogen- because once you're in orbit ISP becomes the only thing that really matters... Regards, Northstar P.S. Note that just because you *can* build a Nuclear Thermal Rocket launch-stage doesn't mean you *should* build a Nuclear Thermal Rocket launch stage... The Thrust of a NTR is still drastically inferior to a realistic chemical rocket (like you get with RealFuels installed), and for Thrust Weight Ratio they lose out even worse (30 for the best Hydrogen Nuclear Thermal Rocket designs to have been proposed to date- in Project Timberwind- vs. anywhere from 60 to 120 for a chemical rocket...) thanks to the high weight of the reactor. Plus, nuclear reactors are EXPENSIVE! This is just one reason why Nuclear Thermal launch-stages, as embodied by designs like Project Timberwind, are a terrible idea and ultimately failed to ever be realized. High TWR nuclear thermal rockets (like the ones designed for Project Timberwind) *do* make for great launch-stages and possibly extra-atmospheric landers, however... Spaceplanes in particular could really benefit from them- because you don't have to lift the mass of the reactor with Thrust, but use Lift to keep it up instead (making lower TWR methods of propulsion more viable, and favoring ISP over TWR...)