Lothaar

Been playing a bit again, but now that 1.1.2 has fairly stable RO and RSS, I have not done much mars mission stuff as there is no ISRU yet for the latest kerbal build. I did have a bit of luck refining my close proximity landings and I have that version of kerbal client with my craft in its current state to refer to later when I am ready to start Mars works again in the up to date client. I also looked closer at bringing CO2 from the surface to orbit for processing. While you could do this, you would expend 3 times the fuel produced to supply the needed CO2 from the surface. Bringing fuel precursors from earth is a better paradigm for orbital fuel production around Mars. More resources, yes, but from a much more available pool of resources. Spending 3 units of energy to make one unit of energy in orbit is just to high a price in the Mars system where resources are next to Zero in availability and harvest potential. Exploiting ice on the surface will make stockpiling fuel in orbit from ground derived fuel precursors a bit more attractive, but not much.

I will post any further updates in this thread. Landing update posted.

So I have been playing with trying to do precision landings so that I can have multiple craft in reasonable distance from one another. Mechjeb is not playing nice, even the dev version. It can manage a decent of sorts, but it can not land on a target in RSS/RO on my set up. I did a clean install with just RO/RSS and mecheb and I still could not get it working right. Regardless, it would have only given be basic metrics to plan my actual decent profile, so I starting making one to test. I can manage a fairly efficient landing from a 200km orbit with 3600-3700 deltaV, but this is just a freehand landing with no target, just controlling engines manually all the way down for best use of thrust. Many adjustments are made during this decent and it is too complex to replicate easily in game. So to start I have tried to make a decent profile that is a simple as possible with out wasting too much deltaV. My initial set up is keying off positional markers relative to the planet's surface and the suicide burn timer for "full burn" and "throttle back" near the surface. First, I land a ferry with the below decent profile from an equatorial orbit. Then I load in another ferry of the same specs, and run the same decent profile from the same starting orbit. So far my closest second landing is 840 m away from the first. I am not great at final maneuvers, and I imagine with more practice I can get much closer. As it stands I am using about 4000-4100 deltaV in this profile but I have a very simple decent profile that is manually repeatable. I could use sequencer and super custom action menus with timers and such to make a really exact decent profile on almost full automation, but it is hard to develop in that format. I would rather try to develop a profile in a manual environment and then much later on introduce automation. So here it is. Starting orbit is 0.000 inclination and 0.000 eccentricity or as close as I can get in a 200 kn orbit. Initial burn is 34% thrust starting at coordinate 0.00.00 N - 136.00.00 E (in future will be distance to target instead of position) I maintain this burn until suicide burn timer = 0 sec Then 100% thrust until suicide burn timer = +6 sec I hold suicide burn timer at 6 sec and manage the decent with 80-100% thrust depending on position of target. I maintain this until my velocity surface/vert = 100 or less Then I cut to 4 engines and max thrust to kill off last of unwanted speed. Modulate as needed to vector to target. Touchdown Average flight time 12.5 min Average deltaV used 4050 Average distance from MARK (made at initial burn) 1.45Mm First video is the initial burn http://stalkr.co/2O1u071t2H3R Second video is the final. http://stalkr.co/0e2W1H3Q2W3y Same craft file as before, no changes. So now I can land ferry craft within walking/light rover distance of a designated site. I will now develop the cargo variant of the ferry. Then I can try to set up and test the orbital production chain.

Page 83 outlines some larger solar orbital systems, that with a few advances will be more than possible. http://www.ece.mtu.edu/SSP/presentations.html Really interesting technology in general, and if proven to scale, will be a great way to support larger orbital and ground installations. Modding this and getting it into game is another thing. Im gonna try to get a better understanding if a smaller unit is possible. They have some great material breakdowns a bit after the output chart. Not a real solution to the current need for portable power, but long term...

So funny, I was looking in to the systems on this chart https://www.google.com/imgres?imgurl=http://a.static.trunity.net/images/121224/400x218/scale/&imgrefurl=http://www.eoearth.org/view/article/154970/&h=218&w=400&tbnid=tlgqdROn7ipgoM:&docid=A-2d5LnVUyB1_M&ei=z-jpVtbvNMTjmAGC8IzgAw&tbm=isch&ved=0ahUKEwiWk7flqsbLAhXEMSYKHQI4AzwQMwggKAMwAw and also the homer15/25 SAFE seems to be the best in terms of power and weight.

First off I can not say enough to thank all the great folks making some amazing mods for this game. The RO RSS community and its leaders/founders are just doing an amazing job and are really inspiring other people to new levels of exploration and mission planning. I recently came across stratochief66's thread "RSS - Challenges of Mars Missions" It involves using ISRU as a way to develop more feasible mission plans for Mars. I am trying to develop an orbital fuel/production station and a ferry for travel between the station and surface and for suborbital hops. These type of station and craft would be employed well down the road from the initial interactions with Mars like stratocheif66 is working on. I will start with one main station design and two ferry designs; one for crew transport and one for cargo/materials. Utilizing ISRU for production of additional fuel on the surface of the planet allows for much smaller craft with very reasonable round trip deltaV. Producing fuel in orbit also has its advantages that i will explore. Right now, I am working with a 70 tn prototype. It has about 4600 deltaV of fuel and can produce another 4600 deltV of fuel after landing over a period of 70 days. This is the crew variant and can support 3 persons for 210 days if needed. Crew, supplies, capsule come in about 7.5tn. So the cargo variant will have about the same capacity of 11% weight cargo for a 70 tn craft. This is a completely reusable craft, and will use a pure propulsion profile for ascent and decent. I may incorporate aero interactive devices of some sort to shave some deltaV requirements, but for now I am trying to keep it simple. I also do not want to use anything that I do not feel certain is modeled as closely as possible to a real life object. The orbital fuel station prototype is fairly simple and, when full, can refuel/restock a ferry twice, and has tank space to take on resources for fuel production in orbit. It will develop more as the ferry design is refined and we get a better understanding of the frequency of the initial transit scheduled. Even as it stands now it could be mirrored on a central hub or expanded to any radial degree desired. All resources are in color/pattern coded tanks so that I can get used to the proportions of volume and weight of the various resource components as I develop designs and test things. I am working with the basic RO RSS install and I only use RO modified stock and procedural parts. ISRU and Heat Pumps are my two part pack additions for my current testing. I use all sorts of visual stuff and control/metrics mods. Ill paste screen below with full mod folder. I have two videos of some of my initial flight tests. Ones is a decent from the orbital fuel station to the surface and the other is the ascent from the same location on the surface to the orbital fuel station after refueling with ISRU. Both trips had 500+ deltaV to spare so we are close to the set up that I will use. I would like to have 10% fuel reserve in the final design if possible. Mars Ferry Landing https://thumb2016.s3.amazonaws.com/1616/test/Mars Ferry Landing.mp4 Mars Ferry Takeoff https://thumb2016.s3.amazonaws.com/1616/test/Mars Ferry Takeoff.mp4 craft files for ferry and station as they are in these videos. https://thumb2016.s3.amazonaws.com/1616/test/Mars Ferry C1.craft https://thumb2016.s3.amazonaws.com/1616/test/Mars Station F1.craft I will always post the craft in the video so that anyone can try the same thing. I will also in the future include flight profile information to better help you get similar results. I have an educational background in math and physics, but I am a total newb to this game, community and rocket science in general. However, it is all about solving small problems and I love to do that. I am open to suggestions and alternative methods for what I am doing My next goal is to land two craft in close proximity. I will be installing scansat and researching to choose a good place on the equator for my landing site. Let me know if you are aware of a good spot. Right now I would like to be able to land +or- 0.5 km from a given target. Past close proximity landing, I have two areas I would like to address as I develop my station and ferry. One is to move away depending on the RTGs I am using for power. My current ferry prototype is using two of the largest chemical engines and will most likely be scaled back to one or two of the smaller units. This will increase the time on the surface and I will need to look at what my limits will be regarding that. In moving away from the RTGs, I need to develop a solar plan. At current, I am thinking solar panel systems that will be deployed/assembled by hand/robot once landed on the surface. While I could build a permanent large solar installation on the surface and use that to power the ferry's refueling process, I prefer to contain the solar harvesting potential in the ferry itself. Most all initial craft, I think, will need to be lifeboats, and all but stand alone systems. Relying only on permanent solar installations would also limit sub orbital hop range. Later these solar installations will be present, but for the initial ferries and surface infrastructure I want as much self sufficiency as possible. Two is to take another look at boil off and scaling for time and active craft in game. We have good hardware/mods to keep fuels at the right temp, but I would like to look at performance of cryo systems in martian atmosphere and power requirements. I know this will take a decent amount of power, and there may be limitations in direct exposure environments. Heat-sinking and other methods of local thermal stabilization may be needed, and long term, desired for efficiency. The station producing fuel in orbit will require the CO2 ferry and I have to really look at the fuel cost of bringing CO2 up. The savings in not bringing LqdHydrogen to the surface are small, but I think large solar solutions for processing will be easier in orbit. SO right now I'm going to scale down fuel production on the ferry and see if I can get a deployed solar solution to power it on the surface. Then based on a flight schedule of two ferries, on their new fuel period, I will see how much CO2 I can run to the station. Then I will make a fuel production schedule for the station. Then I can make a LqdHydrogen delivery schedule from earth. Then I can look at the whole chain and see the rough potential of two craft and one station, with LqdHydrogen support from earth. Then I can do a similar chain set up where all fuel is produced on the surface in a permanent surface installation. Fuel will be lifted via ferry to the station and LqdHydrogen brought to the surface via the same ferry. The station will still receive Hydrogen support from earth. In the end, I imagine, it will be a combination of the above that will take place for matters of convenience and complexity reduction as well as efficiency. While some of this can be explored by my rudimentary math, I find working models to really spell it out much better.

Can you imagine the added stress of always wondering and hoping your return vehicle will make it to your location. "Dangit Bob, stop using battery power to link in and check on the DAVs mobile progress; It will get here when it gets here."

Yes, I have tried with two engines at the end, but if you switch to only two too soon, control is an issue. I need more testing in that area. The station producing fuel in orbit will require the CO2 ferry and I have to really look at the fuel cost of bringing CO2 up. The savings in not bringing LqdHydrogen to the surface are small, but I think large solar solutions for processing will be easier in orbit. SO right now I'm going to scale down fuel production on the ferry and see if I can get a deployed solar solution to power it on the surface. Then based on a flight schedule of two ferries, on their new fuel period, I will see how much CO2 I can run to the station. Then I will make a fuel production schedule for the station. Then I can make a LqdHydrogen delivery schedule from earth. Then I can look at the whole chain and see the rough potential of two craft and one station, with LqdHydrogen support from earth. Then I can do a similar chain set up where all fuel is produced on the surface in a permanent surface installation. Fuel will be lifted via ferry to the station and LqdHydrogen brought to the surface via the same ferry. The station will still receive Hydrogen support from earth. In the end, I imagine, it will be a combination of the above that will take place for matters of convenience and complexity reduction as well as efficiency. While some of this can be explored by my rudimentary math, I find working models to really spell it out much better.

Past close proximity landing, I have two areas I would like to address as I develop my station and ferry. One is to move away depending on the RTGs I am using for power. My current ferry prototype is using two of the largest chemical engines and will most likely be scaled back to one or two of the smaller units. This will increase the time on the surface and I will need to look at what my limits will be regarding that. In moving away from the RTGs, I need to develop a solar plan. At current, I am thinking solar panel systems that will be deployed/assembled by hand/robot once landed on the surface. While I could build a permanent large solar installation on the surface and use that to power the ferry's refueling process, I prefer to contain the solar harvesting potential in the ferry itself. Most all initial craft, I think, will need to be lifeboats, and all but stand alone systems. Relying only on permanent solar installations would also limit sub orbital hop range. Later these solar installations will be present, but for the initial ferries and surface infrastructure I want as much self sufficiency as possible. Two is to take another look at boil off and scaling for time and active craft in game. We have good hardware/mods to keep fuels at the right temp, but I would like to look at performance of cryo systems in martian atmosphere and power requirements. I know this will take a decent amount of power, and there may be limitations in direct exposure environments. Heat-sinking and other methods of local thermal stabilization may be needed, and long term, desired for efficiency.

First off I can not say enough to thank all the great folks making some amazing mods for this game. The RO RSS community and its leaders/founders are just doing an amazing job and are really inspiring other people to new levels of exploration and mission planning. I recently came across stratochief66's thread "RSS - Challenges of Mars Missions" It involves using ISRU as a way to develop more feasible mission plans for Mars. I am trying to develop and orbital fuel/production station and a ferry for travel between the station and surface and for suborbital hops. These type of station and craft would be employed well down the road from the initial interactions with Mars like stratocheif66 is working on. I will start with one main station design and two ferry designs; one for crew transport and one for cargo/materials. Utilizing ISRU for production of additional fuel on the surface of the planet allows for much smaller craft with very reasonable round trip deltaV. Producing fuel in orbit also has its advantages that i will explore. Right now, I am working with a 70 tn prototype. It has about 4600 deltaV of fuel and can produce another 4600 deltV of fuel after landing over a period of 70 days. This is the crew variant and can support 3 persons for 210 days if needed. Crew, supplies, capsule come in about 7.5tn. So the cargo variant will have about the same capacity of 11% weight cargo for a 70 tn craft. This is a completely reusable craft, and will use a pure propulsion profile for ascent and decent. I may incorporate aero interactive devices of some sort to shave some deltaV requirements, but for now I am trying to keep it simple. I also do not want to use anything that I do not feel certain is modeled as closely as possible to a real life object. The orbital fuel station prototype is fairly simple and, when full, can refuel/restock a ferry twice, and has tank space to take on resources for fuel production in orbit. It will develop more as the ferry design is refined and we get a better understanding of the frequency of the initial transit scheduled. Even as it stands now it could be mirrored on a central hub or expanded to any radial degree desired. All resources are in color/pattern coded tanks so that I can get used to the proportions of volume and weight of the various resource components as I develop designs and test things. I am working with the basic RO RSS install and I only use RO modified stock and procedural parts. ISRU and Heat Pumps are my two part pack additions for my current testing. I use all sorts of visual stuff and control/metrics mods. Ill paste screen below with full mod folder. I have two videos of some of my initial flight tests. Ones is a decent from the orbital fuel station to the surface and the other is the ascent from the same location on the surface to the orbital fuel station after refueling with ISRU. Both trips had 500+ deltaV to spare so we are close to the set up that I will use. I would like to have 10% fuel reserve in the final design if possible. Mars Ferry Landing https://thumb2016.s3.amazonaws.com/1616/test/Mars Ferry Landing.mp4 Mars Ferry Takeoff https://thumb2016.s3.amazonaws.com/1616/test/Mars Ferry Takeoff.mp4 craft files for ferry and station as they are in these videos. https://thumb2016.s3.amazonaws.com/1616/test/Mars Ferry C1.craft https://thumb2016.s3.amazonaws.com/1616/test/Mars Station F1.craft I will always post the craft in the video so that anyone can try the same thing. I will also in the future include flight profile information to better help you get similar results. I have an educational background in math and physics, but I am a total newb to this game, community and rocket science in general. However, it is all about solving small problems and I love to do that. I am open to suggestions and alternative methods for what I am doing My next goal is to land two craft in close proximity. I will be installing scansat and researching to choose a good place on the equator for my landing site. Let me know if you are aware of a good spot. Right now I would like to be able to land +or- 0.5 km from a given target.

Yes, I have broken them into 4 pairs across a set of 8 and now I have the throttle control I need. I always forget about engine grouping. I did add extended action groups for ease of control, but I needed that anyway to finish out fully equipped craft operation. I'm just trying to keep mods to an absolute minimum. How is your progress on landing two craft in close proximity? Even with full propulsion decent profiles I am having trouble achieving this. This seems, to me, to be one of the most important problems in developing true surface infrastructure. I am curious how much the need for accuracy will influence craft design. I understand with center of mass offset and a large enough heat shield one can get a good amount of lift, L/D (0.3+) and with craft rotation can use that to kind of steer the craft. Will this be enough or do you think you will need to have a move evasive way of interacting with the atmosphere to achiever greater flight path control?

Yes I have noticed the utter lack of methane powered engines in current development. The raptor is a bit much. I am looking for a total thrust package in the 500-600 kn range. This would be for craft up to 70tn. I am going to poke around and see what other engines I can find. For now, your CECE is working great. A bit deeper throttle would be nice, but I don't want to start tinkering with every variable that is not to my liking. That will quickly take me into fantasy land. I am going to try to only use realistic stats, but man what I would not give for some higher isp. What do you think the isp of these types of methane engines will top out at over the next decade or two? high 300s or maybe break 400 or is that getting past limits inherit to the fuels themselves? I am very unfamiliar with the gains yet to be had in efficiency for modern spacecraft engines.

Yes, it would seem I have my own momentum now; I will make a thread later this week to record my progress. If I find any new setups or solutions to cryo ill post in here. I am trying to find a good way to share decent and ascent profiles so when craft are shared, people can have a good starting point for setting up fight profiles. I am trying to avoid gdoc and data entry methods for poster and user. Also, regarding the engines you are using. For those engines will there feasibly be more powerful variants in real life to model from, or are those 66kn version about a beefy as they will get, and larger craft will just need to use more of them? I am not finding this to be a major limitation, I just thought I would ask about multi ignition, deep throttle, methane/LqdOxygen, engines that will have100-200kn thrust capability. I know the RL-10 has a methane variant, but it is not much more powerful and has a less favorable ratio of methane/LqdOxygen to match ISRU production ratios.

Thanks for that snip Starwaster. This will remove a lot of constraints on design and allow for much better stowed positions for heat pumps. I have been playing with boil off and it is not an easy problem regarding game mechanics. The persistence of the boil off effect, cooling, and heat reduction/increase all perform differently at different time scales and active/inactive states. Often times, temps can be lowered, but then are stuck there and will not raise even when cooling is disengaged. While I can simulate a synchronized state of these variables, it is through cfg editing, and only pertains to one environment and does not scale. As such, I may just ignore and instead, adjust some temps in tank configs, and still design with radiators/heatpumps to the proportions/power needed. So when we get them working, it will not require major changes in layouts. With boil off on the back burner and station design not having any other major issues, I will now focus on refining the ferry design for LMO to surface, surface to LMO and surface to surface operations.The ferry design will also inform a lot on how the station will be set up. I started playing with your EDL craft setup stratochief66. It helped me with a few design elements in my ferry. It will have two variants; one for cargo/fuel/materials and one for crew. Both variants will have on-board ISRU and will use full propulsion ascent/decent profiles. I have played with balutes, chutes, heatshields, and air brakes. They all add complexity in, flight profile, design, parts, staging and utilization. They also are more difficult to employ where repeated trips to the same place on the planet surface will be required. A full propulsion set up will lend more to simplicity, safety and accuracy. Even with the need to import more fuel and fuel precursors to various gravity potentials, I think this will be a viable craft until ice/water can be produced on the surface. Then the ferry will either get an increase in payload with the removal of LqdHydrogen mass or a substantial reduction in overall mass while still maintaining current operational ranges. I have tested an 72 ton (10tn cargo or crew/LS) ferry. It has about 5k deltaV for testing (to be reduced later once flight profiles and fueling station locations are dialed in). I can land from an orbit of 200km fairly well now and have a few decent profiles worked out. It has enough LqdHydrogen to refuel with ISRU and then can easily attain 200km orbit again. I am working with the basic RO RSS install and I only use RO modified stock and procedural parts. ISRU and heat pumps are my two part pack additions for my current testing. Happy to share my fuel station and ferry craft files. So great to have all these modifications. I am so excited to be able to develop real martian infrastructure in Kerbal. ISRU has bridged some major gaps that until now I could only get past with honor-system/role play/hyper-edit.

I have been looking into Mars and the various plans to get there and stay there. I like the idea of orbital fuel storage/production stations and have been working on a few designs to use in LEO and LMO. As such. boil off is my first and foremost problem. Today I plan to play with Starwaster's heat pumps to get a feel for its default capabilities. I may as you did, adjust temp values for boil off to get a working model so I can then focus on the ideal size for the core module and component tanks. ISRU and its capabilities will inform a lot on the best type and size of an orbital fuel storage/production station for LMO. It is great to see someone is already working out how ISRU will function on the surface. Orbital fuel storage/production stations will only really reduce my launch weights on Earth and Mars. ISRU will still be essential to maintain the LMO station fuels stores. My hope is to have orbital fuel stations reduce needed complexity and weight of surface launched/landed systems to increase the safety and reliability of these systems. This will however require a specialist craft to ferry fuel from the surface to the LMO fuel station to bridge gaps in production. I may try to leave the majority of hydrogen in LMO and just ferry up carbon dioxide and do most of the processing in orbit. Just produce enough fuel on the surface to attain LMO for the transports and fuel ferries. It will increase start up time for the system, but once running, should be more efficient as a lot of hydrogen mass will not be delivered to the surface, nor the resulting fuel from its incorporation into fuel production lifted to LMO. I am still in early planning, but excited to see someone else working on things that will help my overall goals of stable Martian systems on the surface and in orbit.