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  1. Those points read like it has to discarded a lot of equipment. My initial though was: an extended upper stage, a.k. larger volume kerlox fuel tanks + ignition fluids, to give it enough D/v and restarts for both: 1) push "a" payload (D2 + D2 lander version) to it's TLI point, and 2) make it back alone to LEO, to be reused for some next mission. About the fuel transfer problem, the following idea passed through my head (and I know it sounds rather Kerbal-ish). Mate two upper stages (designed this purpose, pusher and refueler), docked nose to nose, then tumble them to generate a centrifugal force and use electrical pumps to pump fluids from one upper stage tanks the another? Rinse and repeat until the pusher stage it fueled up. Then: Dock with what ever needs to be delivered from LEO to LLO Extended upper stage performs the TLI burn Releases payload - the payload does it's own burn to get into LLO to do it's mission ExUS adjust orbit, to put it's Pe back into LEO At Pe the pusher stage does it's LEO circularization burn Refuel etc About the D2 stages and their reusability. How to go about making th D2 lander, more reusable? That's a thing I was pondering as well. Might need an orbiting Lunar station for that.
  2. I really watching enjoyed this and it made me wonder if it were remotely possible with some redesigning of F9 2nd stage and D2 trunk. Been building Munar mission in my 6.4x KSP install with SSTU and real fuels. On that scale it in KSP it seems doable. So, funding issues for such endeavor aside. Could it be technically feasible for SpaceX to: a) rework their second stage into a multiple reusable and refuel-able TLI tug?; and b) add fuel tanks + propulsion to the D2 trunk to make it capable to do trans Lunar injection burn with a lander and the TEI burn to get home?
  3. What I am still wondering, what also has been mentioned on astrobiology.com, have astronomers already figured it's outbound heading, or are investigating this aspect of Oumuamua. Everything that is published about it does not go into that, or what it's inbound heading was. I think these two pieces of information would be rather interesting to investigate and could give insight in to solar formation. As it might well be a planetary shard from a collision in some pro-solar system out there..
  4. Yes indeed. But that still leaves in system travel distance and time (game time) Lore wise: it would not be "far fetched" that a few decades later in the story line, a breakthrough propulsion technology is invented, that is back engineered from protomolecule tech. This would be the FTL "plot device" that is needed, to make long in system distances vs time, viable in an MMO setting. "Epstein plot device" would be suited for all distances maneuvers. Couple that with a scaled down universe (regretfully needed imo) and one can make it MMO viable.
  5. Bit off topic, my apologies! I do not think this would mutually exclusive. But a plot device for "faster than light travel" is needed (albeit a logically limited mechanic) to make a The Expanse MMO environment work. Like you say, speeding up time is a no-go solution for a semi-realistic space-sim MMO. I say logically limited, with a good background story (you read the books I hope so you know what I'm pointing at), otherwise it will become too much of an arcade like mechanics as we see in SC. This would not do honors to The Expanse universe and where it came from.
  6. Don;t know if you are talking about current day levels of technology or if you meant near future levels of technology (+100 years). In my opinion if we become technologically evolved enough to a point where we can build (manned) large scale missions to Saturn, probably using (SC/GC) NTR propulsion, using local methane as the reaction mass would be very beneficial (ignoring the engineering issues of soot buildup for a second). Even if humanity skipped NTR propulsion and got straight to fusion drives. Using methane as a reaction mass would imo still be better than needing to skim a gas giants atmosphere, with all inherent risks in doing so, in order to refill the reaction mass tanks. Other thing to take note of, if we ever reach that level of technology where reaching Saturn is not a death warrent, harvesting methane from Titan would then already have become relatively easy. Landing on solar bodies would have become common place, Titan would be not much of a challenge. But if you are talking about current tech levels, than I fully agree it's ludicrous and not feasible.
  7. Yes yes I know That's why I asked the question, cause they want to develop such refueling tech for their Mars space ship concept. So maybe they could start of small, with this by developing such tech and adopting it to current F9 upper stage.
  8. Probably an impossible idea: but couldn't they rework the the upper stage, to be able to be robotically refueled? And device a way to make the the Merlin 1D Vac not freeze up so it can be easily restarted. Launch a refueling craft to GTO (or what is useful) and let the Moon mission rendezvous with it. Robotically refuel it's second stage and progress with the mission.
  9. Hellion alpha is finally released! I have been watching a lot of Twitch streamers over the past 24 hours, one thing stands out and that is the game is indeed still very alpha. Graphics wise the solar system looks absolutely superb, the model textures as well and the sense of scale seems very vast. Seeing were the orbital mechanics of objects around solar bodies in navigation views was very nice and also the maneuver nodes and node execution time is a nice addition. But now for the negatives (from what I have seen) if you have a KSP back ground, like most of us here, a lot is still left to be desired TBH. The big downside IMO in this iteration being: the only means to get from A to B is using the warp mechanics and RCS to do approaches targets. There seems no convention "engine" implemented yet, I read this will be added upcoming patches. The warp mechanics is rather simplistic and does not take conservation of local momentum (you initial orbital velocity) into account. So your ships relative velocity vs your targets relative velocity does not need to be cut before warping to target and is magically adjusted when getting out of " warp". For me this method of implementing such plot device is rather immersion breaking tbh. Further more the UI, icons for Pg/Rg/NM/aNM/R/aR have not been implemented! Nor are there any indicators of you ships orbital velocity vs reference body, or relative velocity vs a target. I hope this will be implemented asap when the conventional engines are released in the future, otherwise I can't see how one could ever do more complex navigation outside of point, click and warp.
  10. It has some super nice features, although I don't like the combat focus and the scenario type missions. The ship building feature would be fantastic IMO, if they expand on that and made it bigger than a pure space combat sim. About Terminus, I read about it on SpaceSimCentral forums. For it's time it looks like a really nice game. It's a shame really that most game development studio's choose to not develop a realistic Newtonian space environment, or more or less with correct physics (within the limitations of their engines). Using The Expanse universe as a basis to build a game upon is immense IMO. Like for instance 100>200 years in it's future, has great potential to make a single or MMO game environment. The world building opportunities, revealed in book three, would be a great basis for a game.
  11. Helion is on my to watch list for some time now! The graphics look stunning and the physics look really promising. The 1st person survival and building part as well add to the things I like. Though, since I began playing KSP and reading the Exapanse (excluding the what the molecule is doing), things in scifi games that generally really put me off are: magic artificial gravity, submarine/boat-like space ship design (unless we talk about atmospheric crafts) and warp drive devices wokring in gravity wells and not needing to get far far away from any gravity well. If they made Helion like: The Expanse is to KSP, than they would have really hyped me. But I am keeping a eye out on it, for what I see it is really good.
  12. Really a wonderful video by Scott Manley's, gave much to talk about with friends who also follow the Expanse. Good stuff! --- Done some digging regarding the confusion about "teakettling" vs RCS propulsion. Teakettling has to do with steam, but not with RCS propulsion. In book 5 Nemesis Games, I won't spoiler the story, a ship will be used for a couple of chapters in the plot. The ship itself dates back to the pre-epstein era, an oltimer so to say. It's main drive is an old style fusion-torch-drive (stuff like described on Projectrho site). The ship mentioned in book 5 needed to 'coast from A to B', due to it's fusion drive, leaving the crew in zero-g for most of the trip. It ran on it's fusion plasma only (high efficiency/low thrust), or augmented with a reaction mass (more thrust/much lower efficiency). This oldskool fusion propulsion was mentioned as a teakettle drive (a short description was also given in book one if i'm not mistaken) --- Way back The Expanse started out as a tabletop rpg and that made me wonder what other games besides KSP are in the making. Since I began reading the books, I have been looking for a new Sci/fi game which combines the Expanse in feel, scope and in technological development, with KSP like features. A game like: KSP's ship construction/design, proper Newtonian physics, a large (full) scale solar system to explore, trade and walk around in. But not orientated on building/launching rockets, like in KSP. I haven't been able to find any title besides KSP that checks most boxes. Most titles have unrealistic physics, submarine ship design, or artificial gravity mumbo-jumbo/propulsion/etc. Helion and Helium Rain seem to come close, though both have also have elements I really dislike. KSP's 'realism' can really spoiled you , so is there anyone else who is looking for a similar type of game and know of something in development at this moment?
  13. I think a normal designed "shadow shield" would suffice, maybe it would need a slight adjustment in material composition/desntity, but far from an expert. I could be wrong.
  14. Cause it maybe is a 'plot device'? Regarding technologies that are in the realm of being technically feasible in the near future (Nuclear Thermal Rockets), IMO a major aspect is political willingness to put funds into development of said technology. That willingness became very biased, also to the public, because of the former cold war nuclear arms race, the fear of it, it's effects and the few nuclear disasters/incidents the world has seen. All tainted the idea of having nuclear tech used for something good. For the more short term timescale I think PB666 really explained it excellently, with what is needed and what can be done now with what we have.
  15. Haven't read the proloque yet regretfully. But I understood the 'tea-kettle' drives where, as a plot mechanic, fusions reactors where the plasma exhaust was fed 'a' reaction mass (water/LH2/NH3/etc). Giving about the same thrust levels as an Epstein, but far far less Dv. Remember reading in one of the books those 'tea-kettle drives' where the technical norm for propulsion in the early days, when humanity started to colonise Mars and the belt. The were only used for orbital insertions/escape and the rest of the journey the ships coasted.
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