Pipcard

"3-stages/4-stages are best for high-energy destinations," but there will probably be just a single upper stage because: The MCT system would have to involve refueling on Mars (I'm guessing with pre-established ISRU capability at the landing site) anyway, and orbital refueling is also their way of not pushing the rocket equation to its limits. With refueling, you don't need to design, manufacture, and operate any more than two types of reusable stages (BFR's "monster boost stage," and the "Big [Freaking] Spaceship" itself). A two-stage system with refueling actually reduces complexity and cost compared to a three-stage or four-stage system without refueling. _____ Regarding staged combustion methane: _____ A reusable rocket gains more complexity with multi-core configurations than an expendable one because those separate cores also have to be recovered and serviced. Those arguments can also apply to 5-core FH, not just 3-core BFR, because both the BFR and FH are intended to have reusable first stages. Notice how they said you would have to land and service three separate vehicles instead of one? That is made much worse with a five core reusable launcher. Yes, FH is 3-core already, but 5-core would only make reuse operations worse.

The bolded part of the quote had to do with the difficulty of managing the simultaneous return of four separate boosters. These "difficulties" are the same whether it's folded wings or propulsive boost-back. There is nothing really wrong about Atlas and Soyuz, but simpler configurations are what SpaceX prefers. It has everything to do with it, whether it's F9 or future plans for Mars rockets, because Musk decided to go with a "single monster boost stage [+ one upper stage]" for BFR instead of a reusable three-stage, or three-core or five-core configuration, implying that it's because of the philosophy of operational simplicity. Three-core/two-booster reusable FH probably stretches that philosophy to its limit. I might accept a five-core/four-booster FH with smaller baseline cores, if it was only going to be expendable. http://forum.nasaspaceflight.com/index.php?topic=33494.msg1153752#msg1153752 https://forum.nasaspaceflight.com/index.php?topic=35424.msg1282608#msg1282608 And BFR/MCT doesn't need to be more than two reusable stages when the upper stage that would carry people and cargo to Mars can be refueled in orbit with multiple tankers (which would be a variant of that upper stage).

The boosters of Delta II, Atlas V, and Angara aren't designed for reuse (i.e. SpaceX style). That's the difference. I know that the Baikal flyback booster was proposed for Angara but... "However, the use of two to four reusable boosters on one LV may cause a number of problems. Thus in case of Angara A5-V and An­gara A4-V, the tailplanes of two out of four boosters have to be made folding. Besides, there may be serious difficulties when four RBs sepa­rating from the LV simultaneously return to the airdrome of the space center [sic]." And 3-stage rockets have more separation events, which increase the risk of failure, and you also add additional production lines. It's not that a 3-stage is a bad idea, but a 2-stage is better for reliability and production cost optimization (however, 1-stage goes too far and you lose a lot of your payload capacity because of the nature of the rocket equation). Thus, there are a significant amount of people (such as on the NASASpaceflight forum or r/spacex) who speculate that the BFR/MCT plan will be unveiled as a two stage system with the MCT essentially being a reusable upper stage and refueling in orbit before going to Mars. I've seen some others speculate that there might be in-space solar electric stages involved, though.

Soon? It's been almost two months... You don't need a source to understand that coordinating the almost-simultaneous landing of four or five cores is much harder than landing two or three. A five-core FH would also mean more complex pad integration, more separate avionics systems, more points of failure, and possibly diminishing returns as well. But anyways, back to the topic at hand. If SpaceX actually gets the BFR to work, and for much less cost than SLS, NASA might use that. I have some skepticism but let's wait for the announcement in September and see what happens then. Actually, Musk's decision to go with a "single monster boost stage" for BFR instead of a three-core implies that he ultimately prefers the simplicity of fewer cores especially when reuse is involved.

That's just the poll question. The OP said " in terms of planetary exploration" but they also defined it as "quite possibly how they do things different which makes them better." And Dragon is delivering cargo to the ISS much cheaper than Shuttle+MPLM ever did. At least they're planning to do Red Dragon in the near future, I mean that NASA list also includes JWST which hasn't launched yet.

Indeed, NASA has a much longer history, but saying SpaceX has "nothing" is a bit disingenuous, don't you think? And SpaceX is doing better than NASA at cost-efficiency.

Reuse is their planned modus operandi and recovering 4-5 cores is much more complex operationally than recovering 2-3. Falcon Heavy is intended to launch in large comsats (up to 7 tonnes) in full reuse mode, which explains the relatively small fairing. Also, the three-core Falcon Heavy already needs the manufacture of a "buffed-up" version of the central core. As for Mars, I expect them to get there in the 2030s (late 2020s if I was thinking more optimistically) in cooperation with NASA.

Do you have a source for this?

To those saying "manned spaceflight is never worth it": is that the same philosophy you hold when you play KSP?

Maybe it is a mistake? 28800 lbs = 13063 kg; 13150 kg = 28991 lbs.

My country's called Hatsunia, you've seen it if you saw my HASDA/Hatsunese Space Program thread. (I don't consider the info on that page to be "canon," though, especially the population. Hatsunia has a stable population of 139 million, not 8.655 billion and counting. But I sometimes like to decide on issues especially if they might increase my "scientific advancement" ranking) -and please remember not to get into political debates here- (Considering that Nationstates is a tongue-in-cheek political "game" that also has roleplaying forums, which I only participate in very rarely.)

Your "realism" really looks like pessimism, though.

They are known as "alt-text."

edit: You know what, that's enough arguing. The Unmanned Transfer Vehicle "Hikyaku" berthed to Space Station Mirai.

and neither will you, it seems.

Everyone does, because Musk has already stated why. Musk thinks the "slight" Isp increase is worth it, and considers it along with "energy cost" to be the "main driver" for that choice. Methane could be made using carbon from Mars's atmosphere (+ hydrogen that was brought along or mined from water ice deposits), and you might be able to make methane on the Moon as LCROSS detected carbon (in carbon monoxide) in the impact ejecta. You cannot make RP-1 using ISRU on Mars or the Moon. Because it provides commonality with the UTV (HTV analog). Long term storage also applies to a depot at Earth-Moon L1, as well as a lander staying at a lunar base for several months. A reusable lunar lander will also have less coking problems when it is using methane instead of RP-1. And please say "M-III," as we are not talking about the H-III. M-III revolves around taking humans to many places, including Earth orbit, the Moon, and even Mars (although a successor to the M-III might be used for the human Mars missions. But still, even if that happens, M-III is being used to gain experience with methalox propulsion technology.) You know what, I feel the exact same way towards you. I'm tired of arguing too, and I just wanted this thread to be something to show my Orbiter add-on developments in, and now this page has gotten really long because we both keep having to respond to each other. It is designed for commercial use and government-led human activities beyond Earth's orbit (which may become commercialized as well if companies such as SpaceX have their way). Vulcan is using methane (liquified natural gas is almost entirely comprised of methane) as well, even though it does not revolve around Mars missions, because it is better for engine reuse. SpaceX only preferred RP-1 because they were just starting out. "except the aforementioned development costs" - And that's exactly why. Developing a single larger engine costs an arm and a leg compared to developing a smaller engine that can be clustered multiple times. Having 7-9 engines also means more mass production of that engine rather than a single large engine, as well as engine-out capability (although engine failures won't be simulated in the Orbiter add-on). And you can have a vacuum-optimized variant of that same first stage engine for the second stage. Okay, let me say this for the last time: the benefits (even with "apples to apples" engine comparisons) are more synergy and commonality with ISRU systems in future Mars missions (and possibly lunar propellant mining operations as well), in addition to space-storability (RP-1 is harder to store due to greater temperature difference between oxidizer and fuel), and little-to-no coking (better maintenance when reusing engines). HASDA will be going to many places, and it is important to plan for the future. You are only thinking short-term while I am thinking about the long-term development of space. Not apples to apples, as Ariane 6 launches much closer to the equator than Angara-5 (so it gets the speed boost from the Earth's rotation, and the upper stage and/or satellite need less delta-V to change inclination in order to get to a geosynchronous orbit of 0 degrees). M-II could carry RCV without needing boosters. As you can see here, the RCV adapter is substantially smaller than the PMA (and yes, I know the stock ISS in Orbiter has the wrong kind of docking petals). And that statement in bold is why M-III single core will have a capacity of 14 tonnes to LEO in RTLS mode, compared to your "5 tonnes in RTLS mode." Insulated tanks add more mass. Although this animation for ULA's Vulcan is sub-par quality for professional work, it shows the entire first stage of Vulcan frosting up (for kerolox, only the oxidizer section frosts), which only happens when it isn't insulated like a hydrolox stage. This is the only official depiction of a orbital launch vehicle using methalox propellant. (until SpaceX unveils the BFR) RCV has PICA-X style heatshields, which are capable of re-entry from the Moon and even Mars. An entirely separate re-entry vehicle to develop and operate sounds much more costly than an extra appended habitation and service module that doesn't need to re-enter intact or operate separately from the RCV. Negi-5 was that. It did have a monolithic SRB like Epsilon as the first stage and I already told you that but you didn't listen. Now it is being replaced by M-III for the same reasons that Falcon 9 replaced Falcon 1, and Falcon 9R will be the same price as Epsilon for a lot more payload capacity (and could spread launch costs even further by carrying multiple small payloads, thus undercutting Vega). Using the same launcher means less separate stage production lines for less manufacturing costs. And that is one of the reasons why M-III has a maximum of three cores, as you increase the amount of cores, more structural mods will be needed to support them. For HLV option 3, having 7 cores and 7 second stages joined up like that results in diminishing returns in performance (because the mass of the outer skin of each core adds up, launchers in the real world aren't designed the same way as in KSP). HLV option 2 is not preferred due to lack of commonality. 175-tonnes to LEO = lower flight rate than multiple launches of a 60-tonne launcher (actually ~30 tonnes with two boosters RTLS & central core landing on barge, or ~40-50 tonnes with two boosters RTLS & and central core expended) that also uses common components with a 20-tonne launcher. For M-III, there will be 3 cores/2 boosters (simpler [i.e. less costly] integration and handling process in the VAB than a 7-core or 5-core version) to handle 60-tonne payloads (like Falcon Heavy, but slightly better); the single core will provide launches of ~4-tonne satellites to GTO in RTLS mode and ~6-tonne satellites in barge landing mode (haven't really tested barge landings yet, but the fully expendable GTO capacity is ~8 tonnes, so the barge mode capacity is somewhere in between 4 and 8). With the 5.39-m diameter, the rocket would also be too short if it were to carry only 8-10 tonnes to LEO. I am sorry, too.

The last thing I would want to do is add to the view count of that nonsense.

[1] Actually, I'm thinking of doing a "frosted-over" effect in the texture. But I might not because it won't look like that when it is mostly empty of propellant (e.g. when landing). Although I've never downloaded the Real Solar System mod*, tanks with liquid oxygen don't seem to get the frosting effect either. *because I'm waiting to get a better computer - KSP is already somewhat sluggish with a planet about 10 times smaller than Earth. [2] Speculation that was denied when Musk said "At first, I was thinking we would just scale up Falcon Heavy, but it looks like it probably makes more sense just to have a single monster boost stage." [3] It won't launch 3 times a year. In the future, there will be at least two manned lunar missions per year, with a reusable lunar lander going between the Earth-Moon L1 point and the lunar surface. Thus, each mission would need to bring up the RCV with extra habitation and propulsion modules (as the regular RCV can't last more than ~2 days by itself), Earth Departure Stages, as well as propellant tankers (propellant is relatively cheap) to refuel the lander. Also, it uses mostly-common hardware with the single-core variant of the M-III, so that isn't only being used for lunar missions. [4] And Hatsunia will have manned Mars missions in the future as well. [5] "before SpaceX came along." Now the hydrogen first+second stage approach won't be as competitive. The point that they're trying to say is that hydrogen will result in more expense for the same payload capacity. M-II would have been able to compete well during the 1990s and 2000s, but with the rise of a launch provider that follows a philosophy of "optimizing for total systems cost" instead of Isp, the next-generation rocket will have to adapt in order to stay competitive. [6] Because even if you treat it as an "apples to apples" issue in terms of Isp, methane fuel doesn't leave as much residue in the engines, making for much better maintenance when reusing them. Methane is also being used instead of kerosene/RP-1 because it enables easier long-term storage in space (due to the oxidizer and fuel being close in temperature). Don't forget about operational/recurring costs, and those tend to be higher with liquid hydrogen. [7] It had to be brought up to the station on a separate mission that occurred after the launch of the core, using a HTV (UTV)-bus disposable tug. [8] Doesn't matter if the rocket can still carry it. The total price of a launch is fixed, not determined by the mass of the spacecraft on each mission. The RCV adapter is also somewhat smaller and lighter than the PMA. [9] It wasn't. It is similar to the disposable HTV propulsion and avionics bus. [10] Negi-5 already had a monolithic SRB first stage, and is more like Epsilon although its first launch took place earlier, like Mu-V. And there will be no Negi-6 (although Hatsunia will have a different negi-themed vehicle in-universe, similar to this, but I'm not planning on making an Orbiter add-on for that any time soon), because the savings from reuse will allow M-III to supplant light-lift launch vehicles. An Epsilon launch: $38 million for 1.2 tonnes to LEO. SpaceX intends to sell F9 in reusable mode for a price of ~$40 million for ~10 tonnes to LEO (their advertised payload capacity has already taken reusability margins into account). [11] Why do you keep wanting to make "apples to apples" comparisons to support your argument when SpaceX isn't doing that when considering Raptor development? They were considering hydrogen too, but realized that pad handling and engines would become more expensive due to hydrogen's deep cryogenic nature, so thus it was not worth the higher Isp. [12] Didn't you read that whole array of quotes that say that it is better to have common rocket propellants than different fuel types in order to have optimization of recurring costs, and that hydrogen isn't a good common propellant because of low density and thrust in the first stage? Methane is the next best thing in terms of Isp, but with less of the "pain in the (butt)" factor (i.e. costly operations and engine manufacturing) that hydrolox has. Here's another reason why: it makes reuse more effective at saving costs. "The thing is, reusability the way SpaceX has been working on has been technologically possible for decades, but it requires the foresight and the daring to actually try it. More importantly, it requires building the rocket with reusability in mind from the outset. There are several aspects behind that. First, it's important that the majority of the cost of the vehicle be in the first stage, which is the easiest to reuse. This runs counter to conventional expendable rocket design optimization, which has resulted in a lineup of existing launchers where the upper stage is the majority of the cost (due to using light-weight alloys and materials and LOX/LH2 propellant, for example)." -rocketsocks and here's another reason why M-III doesn't have a hydrogen upper stage: "If you look at other rocket designs you see the influence of the siren song of "efficiency" or "advanced design" and so forth creeping in. One of the common historical routes to increasing rocket performance is to replace the upper stage with a more "advanced" one using higher ISP propellants (typically LOX/Hydrogen). This is possible because a LOX/Hydrogen stage will have a lower fueled mass than a LOX/Kerosene stage with better delta-V performance. But the end result of this is often that the upper stage becomes a much larger part of the overall cost of the rocket. So you've improved the performance of the launcher, but at the cost of inflating its price tag a great deal." - same person as above

(Okay this is annoying, pressing ctrl+z here reverts everything, and I can't redo) [1] During the start of Mirai's construction, there were no Canadarm-style robotic arms, and they couldn't have been launched with the module as they would not fit in the fairing. A Skylab-like mechanism is more mechanical complexity. [2] Because that would introduce extra complexity in avionics and detachment operations. [3] It can't be a reusable space tug because it is designed to carry modules with berthing ports and can't redock or refuel. [4] But it is based on post-WWII Japanese society. [5] Okay, so M-III's engines will be like those figurative "oranges." A significant improvement. [5a] and you need even larger tanks for hydrogen [6] If you read this thread on NASASpaceflight starting from here, you'd see how methalox or kerolox are better than hydrolox for "cost optimization," despite their lower Isp. [7] Let us wait and see. If SpaceX unveils the BFR with unpainted insulation, I will change it. A speculative render of the BFR made by a NASASpaceflight member seems to show it painted. Methane and LOX also have similar boiling points (110 K and 90 K, respectively, while hydrogen has a boiling point of 20 K) [8] M-III won't have a reusable second stage, but an M-IV probably would. [9] It is implied that with BFR/MCT, they will transition to a single all-methane system in the future for simplicity reasons. [10] hit "current" prices. [11] Yeah, -you- calculated. SpaceX may have different factors. [12] And yet they are planning a BFR anyway. The simple reason why M-III will not have a five-core/four-booster variant is because it makes recovery more complicated, which is the same reason why BFR will have a "single monster boost stage." So Falcon Heavy's three cores/two boosters are the upper limit for that.

[1] M-II Heavy isn't going to be used for a Moon mission, multiple launches of M-III Heavy (~60 tonnes to LEO expendable) will. There are a few reasons why Falcon 9 won't have a four core variant: it's more complex to reuse, and the second stage would be underpowered for launching heavy payloads anyway (diminishing returns). They will not create an extra variants of the second stage (like Angara), and neither will I. [2] Falcon 9 is thought to have a capacity of a few tonnes greater than the advertised capacity of 13 tonnes to LEO (something like 16-17 tonnes). Dragon has a mass of 4 tonnes, and Dragon V2 might be the same. If that is just the mass of the capsule, the trunk can't weigh much more than that. [3] I don't know, Delta II and Falcon are both painted (I know, they don't have liquid methane). Let's see if BFR is painted. [4] Well, M-III will have the same kind of engine as Raptor, so it will have a better increase in efficiency. [5] Exactly why the rocket is all-methane. [6] And yet they're switching to all-methane anyway. Helium is an extra fluid to deal with. [7] At most, they might only be competitive with F9 as it is today. [8] and they abandoned that idea. [9] It won't be a 10 s Isp increase. SpaceX is developing Raptor anyway, despite the R&D costs. [10] If the adapters were launched with the core module, it wouldn't fit in the fairing. [11] Like this. And if you're going to say something about the detachment process being too risky, I just really needed to have RCS thrusters at the front in order for it to not generate too much torque when making translational maneuvers. [12] About the same size as hatches on Soyuz. [13] I already know about that. [14] But is Japan really willing to make a nuclear weapon? Even it they did, it would probably be an unpopular decision with the public. [15] Thank you.

[1] I meant Epsilon seeing as Epsilon is basically a Mu-V but with the H-IIA SRB as its first stage. But in-universe, Negi-5 was introduced in the 90s, like Mu-V. [2] Whatever you want to do. [3] Negishima | M-II/Negi-5 | Reusable Crew Vehicle | Space Station Mirai | M-III Launch Vehicle (a lot of the older posts have defunct images because of imageshack, ugh) [4] Stage masses (a lot of that was guesstimated based on real stage propellant fractions) and payload capacities [5] The adapter needs to be brought up there in the first place. The interface between the docking adapter and the RCV doesn't have proper docking mechanisms, similar to how the Soyuz descent module can't re-dock with the orbital module. Making the adapter wider at the top would have made it too tall for the back of the RCV. The issue with a Dream Chaser style adapter for RCV is that the docking port wouldn't fit through the front end. [6] Downmass is a few hundred kilograms. [7] They are supposed to be radiators, and that was not the final design. I wanted to combine form and function in a way that seemed somewhat plausible. [8] Yes it is. [9] I moved the cupola so that there could be a free berthing port for a UTV at the nadir. [10] That was not the final design. One of the docking ports is supposed to be used for temporary visits or crew rotations. [11] Eh, it's okay. [12] It is getting a bit excessive.

Okay, this is a lot to reply to, but... 1. I like Miku and space. And there is a precedent for associating Miku with space and rocketry. The Negi-5 is the Epsilon-equivalent. 2. At one point I was planning to make sounding rockets, but I decided to focus on things such as crew vehicles and space stations instead. 3. It's several threads in the "add-on development" section of the forum, not a single thread. 4. The M-II core is kerosene (RP-1) /LOX. 5. See this as an example. I wanted to have a docking adapter built in (so it wouldn't need to dock to a PMA-style adapter that stuck out of a space station), but couldn't do a Dream Chaser-style adapter because the docking adapter would get in the way when jettisoning. I also wanted to save (virtual, guesstimated) mass. 6. No cargo version, however, there is an HTV-equivalent called the UTV (Unmanned Transfer Vehicle) "Hikyaku" 7. The windows are the circular things, and are there for the astronauts to look out when in orbit. It doesn't have front-facing windows, Kliper wasn't going to have front-facing windows either. 8. It's really for aesthetic reasons, I wanted the shape to be reminiscent of 未来 (Mirai). And if you look really closely, there is a station construction arm. 9. Which is why I moved it up in a later design. That was only preliminary. There was also a cupola at the bottom. 10. Not really that complex. They "look more complicated despite being more efficient to build with (a hexagon has a greater area for the length of its sides than a square, hence why bees use hexagonal honeycombs for storage)" (TVTropes link) 11. The trusses need to rendezvous with the station by themselves. 12. Raptor (first stage) - 363 s Isp in vacuum (321 at sea level). Merlin (first stage) - 311 s in vacuum (282 s at sea level). Elon Musk made the compelling argument that "Using three kinds of rockets in the same vehicle may optimize its performance, but at a price: 'To a first-order approximation, you’ve just tripled your factory costs and all your operational costs'." Hydrogen/LOX is not a good common propellant for both stages for the reasons you mentioned in [4.]. Switching to an all-methane rocket will "optimize for cost" (per kg) instead of "optimizing for pure performance." Yes, there are R&D costs, but SpaceX is doing it anyway (It is good for reusability because there is less residue buildup, a.k.a. coking). The M-II was designed in the late 1980s (in-universe), decades before SpaceX disrupted the launch industry. 13. I need the larger diameter for really heavy payloads. (There will be a three-core version later) 14. It won't have SRBs, as it is planned to have scalability through reuse modes, just like Falcon 9. It will have a three-core variant sometime later. Landing more than 3 boosters (including central core) is complex operationally, which is why Falcon Heavy will only have 3 cores, and the future BFR will only have one. Small boosters (like what you seem to be proposing) will result in extra production lines and more manufacturing costs. 15. The plan is to use multiple launches of the 3-core M-II Heavy. And it does not need a solid upper stage when it can scale through reusability. 16. About 10-11 tonnes. 17. It's painted. See Vulcan with it's 'Murican decals on the LNG (liquid natural gas, mostly methane) first stage

I would like to, but there were a combination of things: - my current PC can only run KSP on low graphics settings and low FPS, which was detrimental to my enjoyment when playing. I am planning on getting a new PC this summer, and might continue to play on 1.0.5 for this once that happens seeing that 1.1 is likely to actually break my save this time. - I was busy doing other stuff (like projects for Orbiter, school work, etc. - but I wanted to do that Duna mission to coincide with the release of The Martian movie) Also, I regret this but I had tried to migrate all my images to imgur after imageshack became really terrible and started deleted all of their old images, but when the new forum updated, the posts per page had been doubled. I was too lazy to convert all of the posts that I had migrated so far into a imgur slideshow post, and so the images from missions 35-41 are lost forever. I am very sorry for this. I have the images starting from Mission 42 stored on my PC.

Falcon 9 is already competing against Soyuz, "Falcon 5" and VEGA-class launchers would only result in extra manufacturing costs (different production lines) and they would rather carry small satellites as secondary payloads on Falcon 9, which is why they aren't making Falcon 1s anymore.

no, I instantly recognized it as being about transhumanism.