Duke MelTdoWn

May I recommend getting some mining gear to the Mun, makes refueling landers so much easier. Here are some of the refueling solutions I have developed, feel free to adapt them to your needs. Refueling Rover 'Samaritan': refueling on the Mun surface Ore Miner 'Reginn' + Orbital Refinery 'Fafnir': 2,100 Ore to Mun orbit 'Leviathan' Heavy Miner: 12,000 Ore to LKO 'Behemoth' Mining System: 12,000 Ore to LKO 'Gargantua' Mining System: 18,000 Ore to LKO A 'Gargantua' Ore Freighter (on its Ascent/Descent Stage) is being loaded with 180 tons of ore by a 'Gargantua' Mining Rover. Matbart Kerman in foreground for scale.

Today during testing of the 'Brokkr' Light Mining Rover, German Kerman got his head barbequed in the flame of a Spark. After this horrible accident I decided to modify a 'Gladr' Light Lander to serve as interplanetary transfer stage instead. It can be refueled by 'Brokkr', but the way of connecting the two looks sketchy I am tempted to use a robotic refueling arm for more flexibility. Should I?

Oh and I remembered how to embed images! Here are some of a Gargantua Freighter bringing 180 tons of ore to the Refinery in LKO. Gargantua Mining System Mining Rover + 2x Ore Freighter + A/D Stage + Refinery Station Ore capacity: 18,000 per Freighter Payload Mass (launch confguration): 238 tons Total launch mass incl. ExHeReLau launcher: 1779 tons Total price: 988,233 https://steamcommunity.com/sharedfiles/filedetails/?id=3380142778

Based on experience gained from the Air Speed Challenge, I built a SSTO with minimal frontal area. 'Gisl' Light Shuttle Passenger SSTO 1x Rapier, 1x Nerva Launch mass: 15.1 tons Price: 34,232 Delta-V: 2950 m/s left after insertion into 80x80 km Kerbin Orbit TWR: 0.52 in Low Kerbin Orbit Crew capacity: 2 Cargo capacity: 650 L + 100 L Docking: 1x Clamp-O-Tron Jr. port, RCS https://steamcommunity.com/sharedfiles/filedetails/?id=3380933491 The low drag design improves the aerodynamic performance dramatically. Low weight allows for rapid acceleration on the single Rapier. A Nerva Engine hides under the front cowl. You need to flip the plane around at 45 km altitude. I built the 'Gladr' derivate to land on the Mun. The Spark landing engines did not perform as expected. Therefore landing was performed on Nerva. VTOL on Spark worked after correcting thrust levels. I found that I needed to decrease thrust in the front Spark to 50%. 3 more Kerbonauts stranded in Mun orbit! 'Gladr' has insufficient delta-v to return from Mun orbit to Kerbin, so I will not post the craft file at this time.

Hi, after a year away from the game I was motivated to deal with some unfinished business. The 'Gargantua' Mining System has entered production after I completed two more test flights! If you feel the urge to haul 180 tons of ore from the Mun to Kerbin orbit, here is the model: https://steamcommunity.com/sharedfiles/filedetails/?id=3380142778 The main advance compared to Behemoth is that the mining gear now stays permanently on the Mun surface in a Rover. This improves the payload fraction of the system.

Did you know there are 32 mini biomes around Kerbal Space Center, not only the Runway and Launch Pad? You can almost max out the tech tree without ever going to space. Some biomes only become available after you upgrade the building. Map by justintnelson taken from https://imgur.com/gallery/lKWuTu9 List of biomes can be found here: https://wiki.kerbalspaceprogram.com/wiki/Biome#Kerbin I like to use a compact plane to explore these biomes. This can be done before rover wheels become available. E.g. Science Junkie 3000

I made a puny submission to the Air Speed Challenge (below 10,000 m). I am not sure if the weird placement of the heat shields in front is considered cheating ^^. 1937 m/s is not bad for a days work. I saw some old threads with higher altitude ceilings, you can go much faster it seems Workshop: https://steamcommunity.com/sharedfiles/filedetails/?id=3041717110

Hi, good challenge, I will try to tackle this! May I ask why no Mk1 parts? They might be more aerodynamic than Mk2 or Mk3. ___ Highest Speed over Land: 1558 m/s I used Engine Pre-Coolers to attach two Whiplash in addition to the two Rapiers, I hope that is OK? Main problem is heating, next version will get a heat shield. If we are allowed to fly higher we could go faster (less drag and heating). Thanks to the Pre-Coolers I was able to still accelerate a little after the Shock Cone Intake boiled off. ___ Highest Speed over Land: 1750 m/s Is rotating the heatshield 90° into the airstream so that it has less drag considered cheating? If it is in normal position my max speed is 1193 m/s. I am in a slight dive here. And I crashed into the sea. ____ Highest Speed over Land: 1936 m/s Use a fairing in front for ultra low drag. Two Small Heatshields rotated 90° in front to protect it. Wings mounted at 0° instead of 5° so you don't have to push down to stay very flat. I crashed this one on landing. Workshop: https://steamcommunity.com/sharedfiles/filedetails/?id=3041717110

Return of Morgaine Fuel Fairy to Kerbin orbit was successful. I wanted to see how much LF can be transported at most, so I made 10 aerobraking passes to lower my apoapsis. In the end it took me 5 days to ferry 36,065 LF (180 tons) out of the original 40,800 back to the Behemoth Orbital Refinery . This can be quicker if you are prepared to use some fuel for braking. About 1600 LF will be needed to return Morgaine to the Mun. One issue I did not anticipate was the UI for fuel transfer. With a stock game you would need to select over 100 individual LF tanks in Morgaine as source for the transfer, some of which are not even visible from the outside. So I guess a fuel transfer mod is in order.

A prototype of the 'Gargantua' Mining System did a test flight to the Mun. Seems to work well in principle, I need to tweak some minor things like initial fuel load. Also need to continue with a return to Kerbin test. The new design incorporates the findings from https://forum.kerbalspaceprogram.com/topic/208074-ore-vs-fuel-which-is-more-efficient/. Improvements compared to the 'Behemoth' Mining System include: More payload: the 'Morgaine' Fuel Fairy now transports 40,800 LF, of which about 33,600 (168 tons) are estimated to be usable payload to LKO. This is up from 120 tons of ore in the Leviathan Mk.3 Ore Freighter. Total mass 245 tons. Morgaine now uses Mk1 LF tanks which have less dry mass than ore tanks. Dry mass is only 42 tons (up from 37 tons in Leviathan Mk.3). This also boosts the range of Morgaine to 13959 m/s. Mining gear stays in constant use because it stays permanently on the surface in the 'Sindri' Refinery Rover. This allows you to buffer 3000 ore while waiting for the next ship to be refueled. More efficient Mun takeoff/landing because we do not need to lug around the mining gear. Instead we use a dedicated Descent/Ascent Stage. Only one engineer required - stays permanently with Sindri. Drawbacks: Lost flexibility - only LF can be transported. Should be fine because nobody runs their interplanetary ships on LF+OX anyways? You need to land 'Morgaine' close to Sindri. Can only transport 2 tourists in 'Morgaine' , but more cabins could be added easily. Requires Breaking Ground parts to connect Sindri to Morgaine. Connection with stock parts will result in Kraken attack. Pictures of the full flight:

I was doing some math regarding the optimal setup for orbital refueling after seeing the huge Eve ship of Tony Swallow. tldr: use Mk0 or Mk1 LF tanks instead of ore tanks, and convert the ore to fuel on the surface. Details here: These results made me think about possible improvements to the 'Behemoth' Mining System. Quick prototyping shows I could build a new orbital fuel ferry out of lots of MK1 tanks that is compatible with the Leviathan Mk.3 Miner. This Miner stage holds the drills, converter and the strong engines (Darts) and OX needed for takeoff; also some excess LF for landing on Nervas. On further thought, I decided to split the whole process into three stages instead of two for even more optimization: Orbital Fuel Fairy: will bring the fuel to the target ship: 4x Nerva, lots of Mk1 LF tanks, airbrakes for efficient return to Kerbin orbit, maybe small crew compartment to ferry tourists to the Mun and back. Mun descend/ascend stage: Landing legs + excess LF for landing; high TWR + OX tanks for takeoff and getting the payload back into Mun orbit; will be left in Mun orbit waiting for next Fairy Refueling Rover: This should be a Samaritan like Rover so that it can easily connect to the landed Fairy. Drills, converter, thermal, solar, fuel cells, science experiments etc. Maybe buffer some ore here while we wait for the next Fairy? All this heavy equipment can be left permanently on the surface. This way all the gear stays where it is needed and not lugged around unnecessarily. I will continue to refine this ___ 'Sindri' Refinery Rover is coming along nicely, I used a Sandworm chassis as basis, switched out the lab for ore tanks and added 4 additional drills. It uses Breaking Ground parts (robotic refueling arm) and can only run 3/6 drills with a 5* engineer before running out of electricity. Do you think I should build a full stock version and go for 5*? I only got 2* engineers in my campaign. Orbital Fuel Fairy next.

I am reviving this thread , here are some of my observations. 1) You need a converter somewhere for sustained operations. I like to put it on the Miner because of the convenience already mentioned by others. Land with almost empty tanks, refuel Miner on the surface. The drawback that you have to lug around the drills and converter can be mitigated by splitting the Miner into two stages, one with all the equipment needed on the surface (drills, converter, landing legs) and one with only the tanks to hold the ore or fuel meant for other ships. Another benefit of split into two stages is that you can tune the TWR of the Miner stage for takeoff (landing should be no problem because you land almost empty) and that of the Fuel/Ore Ferry for orbital operations. I implemented this two stage concept in the 'Behemoth' Mining System (https://kerbalx.com/Meltdown/Behemoth-Mining-System). First note that if we use a Convert-O-Tron 125 we must convert on the surface because of its poor conversion efficiency. Lets look at the two variants assuming 100% efficiency: we want to go from orbit to the surface, gather ore or fuel, and return it to orbit. Then start this cycle again. We need to look at both landing and takeoff to get the full picture. A) Haul around the converter. Refuel Miner on the surface. B) Haul around extra fuel for takeoff. Refuel Miner in orbit. Mass budget comparison A Orbit before landing B Orbit before landing A Surface before takeoff B Surface before takeoff dry mass of vessel (incl. dry payload tanks) dry mass of vessel (incl. dry payload tanks) dry mass of vessel (incl. dry payload tanks) dry mass of vessel (incl. dry payload tanks) fuel for landing fuel for landing fuel for next landing fuel for next landing (in the form of ore) dry mass of fuel tanks for landing dry mass of fuel tanks for landing dry mass of fuel tanks for landing dry mass of fuel tanks for landing dry mass ore tanks for next landing dry mass ore tanks for next landing fuel for ascend fuel for ascend fuel for ascend dry mass of fuel tanks for ascent dry mass of fuel tanks for ascent dry mass of fuel tanks for ascent dry mass of fuel tanks for ascent fuel for next ascent (in the form of ore) dry mass ore tanks for next ascent dry mass ore tanks for next ascent converter mass converter mass payload mass payload mass Note that fuel needed for ascent will be much larger than fuel needed for landing, because we want to lift additional payload to orbit. -> Using no converter on the Miner only makes sense if mass of fuel for ascent is less than half of the mass of the converter. At 4.25 tons for the Convert-O-Tron 250 this break even point will be reached for any practical vessel. 2) The question I want to investigate now is: Is it better to ferry the fuel meant for other ships around in the form of raw ore or already converted? Lets start by looking at the dry mass to fuel capacity ratio of some tanks. I assume 100% efficiency when converting ore to fuel (i.e. Convert-O-Tron 250 at optimal temperature). Mass stays constant during conversion. Conversion ratio: 1 ore = 2 LF [1] Tank data taken from [2]. Dry mass / LF ratio Tank LF capacity Dry mass (t) Wet mass (t) Dry mass / unit of LF (kg) Large Holding Tank 1500 ore = 3000 LF 2.0 17.0 0.666... Small Holding Tank 300 ore = 600 LF 0.5 3.5 0.833... Radial Holding Tank 75 ore = 150 LF 0.125 0.875 0.833... MK3 LF Fuselage 5000 3.57 28.57 0.714 MK2 LF Fuselage 800 0.57 4.57 0.7125 Mk1 LF Fuselage 400 0.25 2.25 0.625 MK0 LF Fuselage 50 0.025 0.275 0.5 So if compactness or flexibility is of no concern, and if you use the right tanks, it is more efficient to ferry around the converted LF instead of the ore. If part count is of no concern, go for Mk0 LF tanks. Otherwise go for Mk1 LF tanks or Large Holding tanks. ___ Well ... in theory. Practically compactness is a concern. E.g. I would need to replace the 8 Large Holding Tanks on the Leviathan Mk.3 Ore Freighter with 60 MK1 LF tanks to achieve the same refueling capacity of 120 tons. I am not sure I could fit all those tanks in such a way that they would not cause problems during landing (e.g. tendency to topple over because too tall). This would save 1 ton of dry mass on a vessel that weights ~190 tons when fully loaded. Current dry mass of Mk.3 is 37.435 tons, so it might be worth it - I will investigate further ___ Quick prototyping shows I could build a new orbital LF Ferry that is compatible with the Leviathan Mk.3 Miner. This Miner stage holds the drills, converter and the strong engines (Darts) and OX needed for takeoff; also some excess LF for landing on Nervas. On further thought, I decided to split the whole process into three stages instead of two: Orbital Fuel Fairy: will bring the fuel to the target ship: 4x Nerva, lots of Mk1 LF tanks, airbrakes for efficient return to Kerbin orbit, maybe small crew compartment to ferry tourists to the Mun and back. Mun descend/ascend stage: Landing legs + excess LF for landing; high TWR + OX tanks for takeoff and getting the payload back into Mun orbit; will be left in Mun orbit waiting for next Fairy Refueling Rover: This should be a Samaritan like Rover so that it can easily connect to the landed Fairy. Drills, converter, thermal, solar, fuel cells, science experiments etc. Maybe buffer some ore here while we wait for the next Fairy? All this heavy equipment can be left permanently on the surface.

Gilly ... to be continued

As Vanamonde said, what a huge ship! That is a good amount of Nervas, I guess you have pretty decent thrust/weight ratio for an interplanetary ship? I try to get away with much less TWR, for example my Gilly ship Pannychis only has 5 Nervas in total (TWR 0.23). Are you using split burns/periapsis kicks to reduce the time needed for the Kerbin escape burn? I saw a good tutorial here: Kerbal University: Maneuver Splitting And I might have something for you to shorten the time needed for orbital refueling. A month ago I constructed the 'Behemoth' Mining System. It allows you to ferry 120 tons of ore from the Mun to Kerbin orbit in one go. https://kerbalx.com/Meltdown/Behemoth-Mining-System

Moho ... if they can make their capture burns. 'Maia' Moho Exploration Stack "We have come to stay, and we brought toys." Maia was the first interplanetary stack launched in this career. I hope I packed everything I need. Launched on day 32; VeHeReLau recovered day 33; day 33 - 40 periapsis kicks; Kerbin escape burn day 43 From left to right: VeHeReLau Launcher, Icarus Lander, Hermes Station, Hephaistos Miner, Nabu Depot with Antlion and Scarab Rovers attached, Phaethon Relay Carrier 'Sandworm' Exploration Rover "The best part is no part and the less parts the better." Sandworm was flown as an insurance policy if Maia runs into trouble. Prototype is currently at Minmus. 'Sancus' Long Range Shuttle "I did not read the fine print." Sancus was flown as an insurance policy if one of the Kerbals gets homesick.