KerikBalm

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  1. KerikBalm

    If I ever make it back from Eve

    This is because if it is the same shape, it is also taller. That means that you are stacking more stuff above the same frontal area. Try testing a 4xstack of 1.25m tanks, compared to a single 1.25m tank... Of corse with fins and nose caps, and the same mass. You want the tallest stacks possible, and you get that with 1.25 tanks, and the vector, like foxster said.
  2. KerikBalm

    If I ever make it back from Eve

    This is a factor of how *tall* the stack is. If you just have 1 tank, the wider tank is also taller, so it has less drag per unit mass. It has more mass per frontal area. But you can stack parts, and a tall thin stack is better than a shorter fatter one. Thus you should use the tallest stack that your engine can lift. The vector is the king of lifting tall stacks... that's a lot of power for a 1.25m diameter. It can lift a lot of 1.25m tanks above it. I think we need another thread for this SSTO... There are many design changes that could be made, and you could change your ascent profile to get a lot more out of it.
  3. KerikBalm

    If I ever make it back from Eve

    Yes, if your payload is that light... but if on the other hand you're trying to lift ore off the surface for a contract (and not abusing an exploit for those sort of contracts), or trying to lift many kerbals at once (with life support mods, so a chair isn't exactly very viable) to get many kerbals leveled up in one flight, or making an Eve SSTO that uses ISRU (its just barely possible), then the wolfhound starts to look appealing again Well, I was wondering about the mastadon's smallest variant. It has more thrust than the Vector, but I'm not sure its smallest variant fits on a 1.25m stack. Also the variants have weird drag properties, but it was one of the ones I was unsure about As for 4) you've just made #2 again silly - that is why its in seconds :p Burn time is fuel consumption / amount of fuel it can lift. The amount of fuel it can lift is determined by its thrust. An engine with 2x the thrust lifts 2x the fuel, but if the fuel consumption is 2x as high, then you've got the same burn time. Thrust is roughly equivalent to fuel consumption (adjusted for Isp), total impulse is roughly equivalent to fuel consumed (adjusted for Isp differences). 3, the total impulse, is essentially burn time * thrust, adjusted for Isp. Then by dividing that by thrust for #4, you're essentially getting an Isp normalized/weighted burn time - I think. A don't find graph 3 to be very useful, because it weights all stacks the same, regardless of if they are 1.25m stacks, or 3.75m stacks, they should be weighted by cross sectional area. As for the aerospike, graphs 1,2, and 4 make it look like the best engine below the first 4-5km of Eve, and again after about 25-30km on Eve. So the lesson here would be to land at a relatively high altitude, and them use mammoths/vectors to get you up to about 25-30km, and then aerospike stages after that (or since aerospikes are OK in between that, what I personally like is an asparagus rocket with an aerospike as the core engine, so the aerospike is firing the whole ascent). In my hellhole modded eve with 10 Atms, the aerospike is the only option for surface ascents... I don't think I've actually managed an ascent from sea level on my modded eve yet, but I've got suborbital in space. 10 Atms is really really hard to deal with using stock parts. The aerospike is the only option. The same would go if you were trying to ascend from a low altitude on Jool: no option but the aerospike (or sort of cheaty stock propellors)
  4. KerikBalm

    ultimate shuttle challenge

    Define a shuttle? Orbiter with engines, 2 SRBs, and an external tank? Would a Buran/energia style craft count? A Hermes style craft? Are airbreathers allowed? Are LFO boosters instead of SRBs allowed? Is an engine under the main tank allowed?
  5. KerikBalm

    If I ever make it back from Eve

    Well, foxster's exploity craft do well here. Eve is a bit like the pre-1.0 ascents: you may actually have to throttle down to avoid excessive drag if you reach terminal velocity (cannot be reached if TWR < 2.0)... that said, a problem with many designs is excessive gravity drag. Eve's high gravity takes a design that would be about 2.5 on Kerbin down to less than 1.5 on Eve. On top of that, the thick atmosphere further reduces thrust of the engines (some more than others, most vacuum engines don't do anything, intermediate engines like the skipper are horrible on Eve). Even Mainsails don't do well. You basically want mastadons, vectors, and aerospikes. Aerospikes are kind bad too for the lower stages. Even on Kerbin at 1 atm, they only have a 15:1 TWR... eve's gravity reduces that to only 9.2:1. Then the atmosphere reduces it even further.... Its worse than using spider engines or a rapier in closed cycle (the whole way) to launch a payload to kerbin orbit. Even worse is the poor thrust per node/stack. The thrust to cross section ratio means that to get a decent TWR, your drag goes way up, and thus your terminal velocity comes way down. This is why you want the vector, its thrust/cross section size is by far the best in the game (at least it was, I'm not sure on how the MH engine variant switching factors into this now, but I think they can be quite draggy despite their appearances). I play on a 3x rescaled game, and Eve is super punishing there. I further modified it to be more venus like... I dropped the gravity from 1.7 to 1.25 G, but then doubled the atmospheric pressure to 10 atms... big mistake... at that density, even Vectors and mammoths have Isp too low to be usable. Aerospikes were the only option... and... good lord did I need a lot of them because each one couldn't lift much fuel... 3x eve was ridonculous
  6. KerikBalm

    So what is Serenity?

    Source? Also note: "not currently"... their phrasing leaves open the possibility that it will be coming to PC
  7. KerikBalm

    If I ever make it back from Eve

    It also depends on your engines, some get really bad Isp at 5 atm, and the difference between sea level and vacuum is worse than on Kerbin. from my experience, you want vectors, as they have a really high thrust to cross section ratio, so your rocket can be really tall and thin
  8. KerikBalm

    Do you think Tau Ceti e is inhabited?

    You haven't defined your acronym BIF (Biologically induced Formation... of clouds?). Anyway, it need not exclude the presence of life... I'm just saying what you cited there doesn't argue that life was responsible for the warming. And as for the radiogenic heating: note it was never argued that radiogenic heating was providing the heating to keep the Earth from freezing. The argument was that radiogenic heating was driving the outgassing and other geological processes that lead to a larger greenhouse effect, that trapped more heat from the sun's rays.
  9. KerikBalm

    Good MK1 Mun SSTO

    Are you ok with a detachable lander? One thing you can do if you want re-usability, is to make a small single stage Mun lander, and then have your Re-usable single stage craft from kerbin just bring fuel for the Mun lander. Sometimes I'd do that with a single craft mk2 or mk3, that deploys the mun lander and recovers it to take it back to kerbin, but its more efficient to leave the lander at Mun for future use and refueling. A small basic mun lander is also going to be lower parts than an single stage vehicle that goes all the way from kerbin to the surface of Mun. 3 landing legs, 1 fuel tank, 1 pod, 1 engine, 1 docking port (not needed if the other vessel has a claw), one solar panel... 8 parts. If you land on the engine (if the base is on flat enough terrain), you can bring that down to 5 parts, and using a claw, you're down to 4 parts.
  10. KerikBalm

    What Career build are you most proud of?

    I'd say either my heavy SSTOs (which I first build in sandbox), my modular stations/long range exploration vessels (life support and stock centrifuges), or my modular and relocatable surface bases.
  11. KerikBalm

    Do you think Tau Ceti e is inhabited?

    Well, U238 has a halflife of about 4.5 billion years, so the early earth ad 2x as much as it. For elements with even shorter halflives, early Earth had a loooooot more. At the moment radiogenic heat only replaces about half the heat lost by earth, so primordial heat is still playing a role*. About 2.1 billion years ago, the U235 concentration was high enough for natural nuclear reactors. We only have the one example, but 4 billion years ago? who knows, there isn't much rock left from back then, its hard to say what role that played. Early Earth had a lot more primordial heat, a lot more tidal heating, and a lot more radiogenic heating. I *assume* that the scientists take that into account when discussing this paradox, and that something funky with the sun, or a much stronger greenhouse effect was needed. Also I'll note that your second link actually argues against biological factors: First, they disbute that methanogens, for example, were responsible for greenhouse effects: Then the argue it was actually the lack or paucity of life: Its very complex. Life increases the complexity, but I'm not convinced that it increased the stability. I wouldn't dare argue that it didn't play a large role on the climate and environment, of course. Of course, Earth would have been all good and hot right after formation, and after the moon formation event, and probably the LHB. But for how long? could life have started fast enough to solve the paradox? I'm thinking no, but I don't know. I'd guess that something abiotic was going on to keep Earth warm enough for life to even start. Also, if the snowball episodes are confirmed, it shows that life didn't stabilize the climate all that well, and it needed to be geologic events to break out of the snowball condition. * Interestingly, I recently read that Kelvin's calculations on the age of the Earth weren't so wrong because be didn't know about radioactivity, but rather because he didn't consider convection within the Earth. One of his friends used a convection model, and came to about 2 billion years (or am I remembering wrong, and these were modern calculations, and he just wanted to model again with convection), but he didn't push hard because he was friends with Kelvin.
  12. KerikBalm

    Do you think Tau Ceti e is inhabited?

    Yes, which is affected by outgassing, which is affected by the heat gradient, which is affected by radioactive heating... read the quote: "but rather the establishment of the high geothermal gradient of the crust, resulting in greater out-gassing rate and therefore the higher concentration of greenhouse gases in early Earth atmosphere. Additionally, a hotter deep crust would limit the water absorption by crustal minerals, resulting in a smaller amount of high-albedo land protruding from the early oceans, causing more solar energy to be absorbed." Supposedly about 2.7 billion years ago... about, from the wiki article on faint young sun https://faculty.washington.edu/dcatling/Som2016_Earths_Low_Air_Pressure_w_supplemental.pdf " Our data indicate a surprisingly low surface atmospheric pressure of Patm= 0.23± 0.23 (2σ) bar, and combined with previous studies suggests ∼0.5 bar as an upper limit to late Archaean Patm. The result implies that the thin atmosphere was rich in auxiliary greenhouse gases and that Patm fluctuated over geologic time to a previously unrecognized extent." Yes, but the planet still has to orbit too close, gets tidally locked, experiences a very strong solar wind/great disruption from flares... I find the arguments that they are very bad candidates for life to be convincing. It certainly has an effect, and will affect the stable states/equilibirum... but overall, I'm not convinced it makes the climate any more stable. The great oxygenation event was a huge disruption to the climate. The colonization of land had a huge effect. The only stabilization you get is if life is doing something that makes the environment worse for life... when it does it too much, life starts to die, and it stops making the environment worse for life (a negative feedback loop). It can also participate in positive feedback loops. Like imagine life that is on a world that is a bit too cold, evolves a dark pigment to help warm it up in the day... spreads, the whole planet's albedo warms... life thrives... fine... but that's a positive feedback loop, and those typically have 2 steady states, and a switch can still happen between them. Now suppose there is a bad event, the life starts to die, the planet's albedo increased due to less life increasing the albedo... the life doesn't stabilize this, as more of it dies off, the planet cools further, and snowballs. Life affects the climate/environment, for sure, but I'm not at all convinced that it will form a system that actively maintains the climate/environment to be suitable for itself. Look at the GOE, that destroyed the environment for life at that time. It resulted in a massive dieoff, a permenant change in the environment. Life didn't stabilize the environment, it changed it and then adapted to the new one. Oh, for sure. There is so much we don't know because we have just Earth. I'm a bit of a Rare-Earther, I would love to see another planet that looks well suited for life, or life on Europa/mars, etc... even martian fossils from 2.5-3.5 billion years ago... but we should also look at these planets objectively, and not try to think of a way thhat they could be what we want them to be, but try to make our best guess as to what they actually are. Earth's history itself is very unclear. Understanding the real story behind the putative snowball episodes, and the solution to the fain early sun paradox, would help a lot in evaluating the prospects that detected exoplanets are suitable for life as we know it or not
  13. KerikBalm

    Do you think Tau Ceti e is inhabited?

    Well, one explanation of the faint young sun thing, was tidal and radiogenic heating of the Earth. Would Earth have been in a permanent snowball state for billions of years if it weren't for the (seemingly uncommon event, based on our solar system, and Earth's moon being huge relative to the planet) event that created our moon? Its remarkable that our climate has been as stable as it has been (but snowball episodes are worth noting, as well as some evidence that at some points the atmosphere was only about 1/4 the current pressure). Larger stars move through their lifecycle faster. Smaller stars go through it slower, but too small and its a Red Dwarf. And then you've got to figure old planets have their cores cool, lose magnetic fields, plate tectonics stop, so you need a young-ish star (star and planet being about the same age), that starts already bright enough for the planet, and stays not too bright for billions of years (or something special happening on the planet to stabilize its temperature even as stellar output changes). And I don't want to hear any Gaea hypothesis about life stabilizign the atmosphere to maintain that... the fossil record shows otherwise. We've got the carboniferous rain forest collapse (plants colonized land, sucked all the CO2 out of the air, caused global cooling, then died off as a result of the climate change), wildly fluctuating O2 levels (from the GOE, to big swings in O2 after that, including periods of very high O2). Earth's gone from no O2 to over 30% O2, to about 20, from snowball, to ice-less polar caps (nearly the whole mesozoic), etc, all while life has been around
  14. KerikBalm

    Do you think Tau Ceti e is inhabited?

    Generally speaking to the topic title: no, I have no reason to think that is more likely than not. I think there's a small chance that it is... very small. Its at least 4.3 x the mass of earth, this means it can hold on to a thick atmosphere. At over 4x the mass of earth, it may hold on to helium too (it could be partway between a terrestrial planet and an ice giant). Its more likely to be a super-Venus than a super-Earth. The problem with Red Dwarves is that the habitable zone is so close to them, that all planets in that zone become tidally locked in short order. Without thick atmosphere, you then have a hot side and a cold side. The problem with a cold side is that if the atmosphere is thin enough, it gets very very cold. The atmosphere can then start to liquefy and freeze on the cold side. Then there is even less convection, and more freezing, and the atmosphere collapses. With a thick enough atmosphere, there is enough convection to prevent freezing on the cold side. Venus, for example, doesn't have a cold side in its extremely long nights (it rotates very slowly). So there's then a narrow range of possible atmospheric thickness that lies between "runaway greenhouse" and "atmospheric collapse". Luyten b, having 3 earth masses, likely held on to a thick atmosphere, and is a venus analogue. Even a 10% increase in the brightness of our sun will lead to loss of hydrogen, and the evaporation of our oceans. The suns brightness increases over time, and we've got about 1 billion years before its too bright. On the other end, there's this: https://en.wikipedia.org/wiki/Faint_young_Sun_paradox Maybe something special happened to keep Earth warm enough earlier, giving us time to evolve. If life started a billion years later, it may have been too late for something like us. And then there's the flar activity of red dwarves coupled with the close proximity of the habitable zone. They thought Proxima might have a habitable planet, then they detected a flare from Proxima that would have devestated any life on the planet. Its flare activity was high enough that it was concluded that any atmosphere was stripped away long ago. Red Dwarves have planets that orbit close, their atmosphere gets pummeled by the solar wind/flares, and has a high escape rate. Once the atmosphere is too thin, it freezes out on the dark side. I'm quite pessimistic about any reddwarf having a terrestrial planet with water on its surface.
  15. Warp drive technology does not exist today... only a vague concept and some math about how they could work if you had certain things which we don't have (such as large quantities of negative mass/energy) Space is not an ocean, and your "thus" statement is a non-sequitur because you're using a bad analogy. Also if you were using warp technology, your ship would be stationary within the local bubble. Collision danger would be miniscule. For just moving at 0.2c (no warp shenanigans, just ridiculously powerful fusion engine or anti-matter), there'd be dust collisions that are a threat, but it would be so dispered that it would be unlikely to be a threat anywhere, and even after 1000 journeys ("establishing a safe course") you could still suffer a catastrophic collision... because space is big, and stuff in inter stellar space is sparse. Current warp tech is non-existent. Your explanation of how it would propel the ship is wrong, but the conclusion (no splat against the wall) is right. Ummm, no. #1) Alpha centauri is 4.37 light years away, at 0.2c, that takes 21.85 years to get there. #2) The warp "ring" (concept art shows a ring, no reason afaik it actually needs such a structure, since no actual tech exists yet) would have to be inside the bubble, and would experience the same relative time Warp travel, if it works, would not involve relativistic effects, even though its effectively covering distance at relativistic speeds. The passage of time on board the ship at a warp equivalent to moving at 0.2c would be the same as for an observer on Earth, and it would take 21.85 years to reach A Cent. Support what? The games are completely different. As far as I know, Space engineers doesn't have orbital mechanics in it as a core gameplay element. KSP does.