<ProjectThoth> Does Atlas V have disproportionately heavy propellant tanks?
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<wb99999999> hey
<Bornholio> ho
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<Bornholio> project thoth the tank is isogrid aluminum instead of baloon, plus it needs plenty of insulation for the lox
<Bornholio> projectthoth
<ProjectThoth> Bornholio: It seems rather weighty.
<Bornholio> well it is designed to have three cores and 5 side boostes strapped on in various places
<ProjectThoth> Fair 'nuff.
<Bornholio> oh and Oxygen ratio is higher than most western rockets, so tad bit more for that
<Bornholio> wish they had not cancelled the GX version
<wb99999999> are we talking about Atlas v?
<wb99999999> Bornholio can you think of any way to make a proc "doughnut" tank?
<Bornholio> I wish, convince Taniwha to do it?
<Bornholio> and yes Atlas V having Heavy tanks
<wb99999999> how heavy? do you mean it's heavier than the traditional steel balloon or heavier than other rigid rocket?
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<Bornholio> yes.
<Bornholio> Hey lamont liking peg10, did see the weirdness that starwaster and 9's talked about
<Bornholio> I'll update some pics in the wiki soon
<Bornholio> 9's have you looked at modelling at all?
<ProjectThoth> Heavier than other rockets, pmf is like .93.
<Starwaster> omg.... just read an old 2009 article talking about the space hotel that was going to accept its first guests in 2014....
<Starwaster> I think that just maybe they're not going to meet that deadline
<ProjectThoth> I mean, we're all a little tardy once in a while, aren't we?
<ProjectThoth> What's six months away for six years between friends?
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<Bornholio> same article in 1972 ;p
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<UmbralRaptor> SS2's development has been almost as long as the entire X-15 program now,
<ProjectThoth> UmbralRaptor: SS2's development is longer than the entirety of Apollo at this point, I'm pretty sure.
* ProjectThoth checks.
<ProjectThoth> 1976 - 1961 = 15, 2004 + 15 = 2019.
<ProjectThoth> Not quite, but damn close.
<ProjectThoth> Who would win: A multi-billion dollar corporation with nearly unlimited resources and some of the brightest minds on the planet, or a W I N G B O I with a friend?
<wb99999999> Manley says in one video that adding boosters to Atlas V is an afterthought
<wb99999999> what?
<wb99999999> I have doubt over this statement ever since
<ProjectThoth> wb99999999: That doesn't seem right.
<wb99999999> he had a video explaining why the boosters on Atlas V is all off-set and weirdly angled
<ProjectThoth> I mean, if memory serves me right, Atlas V maintains a lot of the same umbilical and fuel line connections from the older-Atlas days, and that makes it tricky to mount solids evenly.
<Bornholio> it was spose to be a triple booster in plan not snubby little solids
<wb99999999> okay, this sounds a lot more logical
<wb99999999> AJ60s are not snubby boosters though
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<wb99999999> they're quiet large for an Atlas sized rocket
<Bornholio> SSRB's thats boosters :P
<ProjectThoth> Triple-stick rockets: Great on paper, bad in practice.
<Bornholio> we get to se a real try soon
<wb99999999> well only if cross-feeding is easier
<wb99999999> oh wait, the Tesla SpaceX guy gave up on cross-feeding, too.
* ProjectThoth pokes Bornholio with a Delta IV Heavy
<ProjectThoth> I have a theory that it's probably about the same cost to pull a Saturn I/IB and build a clustered-tank first stage rather than try any multi-core shenanigans.
<wb99999999> one of my astronomy professor literally said "...that spaceX guy tesla person"
<wb99999999> he just can't recall the name
<wb99999999> multi-core structure works when you launch a lot of different variant of it
<wb99999999> Delta IV almost made it, but its base variant had too few launches
<ProjectThoth> Well, yeah, case in point Atlas V.
<ProjectThoth> Atlas V is a wonderfully flexible rocket, and it's paid off well for ULA.
<wb99999999> yes
<wb99999999> I mean the flight profile of that thing is insane
<ProjectThoth> But there's no intermediate size between F9 and FH, which means that every component of the rocket is unique to FH.
<ProjectThoth> Like, I doubt SpaceX will fly FH cores as F9s. (If they do, I'll eat my licorice hat).
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<wb99999999> in SpaceX's plane the "intermediates" are filled with options on whether or not the boosters are recovered
<wb99999999> plan*
<wb99999999> I don't believe this is going to work
<wb99999999> Falcon 9 is a good rocket, but not a smart one
<ProjectThoth> Arguably, SpaceX could have/should have pursued solid strap-ons as a halfway step between F9 and FH.
<ProjectThoth> And either expended them (while recovering the first stage) or gone fishing.
<wb99999999> I think for their strategy pulling used solids out of the sea and refurb+reload them is too expensive and too time-consuming
<ProjectThoth> Yeah, they probably would have pitched them.
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<ProjectThoth> But, certainly, the cost of a F9's first stage is way more than the cost of buying new solids every time.
<ProjectThoth> I also think they should have put effort into developing a high-energy upper stage for GEO/GTO missions.
<wb99999999> guess for them the F9H is good enough
<wb99999999> who needs high-energy stage when you can boost a HUGE second stage to almost orbital velocity?
<wb99999999> oh and I speculate that Elon hates hydrolox
<ProjectThoth> (frankly, a hydrolox upper would probably make it possible for S1 to RTLS on almost every flight)
<wb99999999> but if you look at F9's shape you'll know that's not a rocket for hydrolox
<ProjectThoth> F9 is a very distorted rocket in general because of the insistence on roadability.
<ProjectThoth> And the fact that it wasn't originally designed for the reuse mode it uses.
<wb99999999> this is why I like New Glenn
<wb99999999> it look...to be honest, a bit Von Braunian to me
<wb99999999> it has that Saturn-era American vibe
<ProjectThoth> NG will be interesting to see.
<ProjectThoth> It's designed to be reused, has a high-energy upper stage, and offers a pretty large payload.
<wb99999999> I like its cluster of large engines
<wb99999999> well BE-4 is not PARTICULARLY large but still
<ProjectThoth> I do worry that it might be *too* big, but we'll just have to wait and see.
<wb99999999> watched the animation again
<wb99999999> the baseline design really do have some Saturn vibe
<wb99999999> hard to verbalize, but I got the feeling
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<ProjectThoth> I wish stage-and-a-half would make a comeback.
<ProjectThoth> I think that's what I'd wind up building in the real world, a light-lift reusable 1.5STO.
<wb99999999> man...will SLS ever fly?
<ProjectThoth> Eventually, yes.
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<blowfish> I suspect some of the F9's whacky proportions have to do with not anticipating how much more powerful later Merlin variants would be, and then not wanting to redo tank tooling
<ProjectThoth> blowfish: My pet theory is that it has to do with the way SpaceX moved towards reuse.
<ProjectThoth> First-gen F9 was supposed to use parachutes and get fished out of the Atlantic. http://i.imgur.com/PGXIqKX.jpg
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<ProjectThoth> But it tended to break up before they could fire the chutes, so they decided to move on to SSRP and then powered landing.
<ProjectThoth> My sneaking suspicion is that they didn't *have* to go this route, but American design philosophy favors high propellant mass fractions over high-performance engines.
<ProjectThoth> Which is interesting. Merlin 1D still only gets a specific impulse in the 310-320 second range in vacuum, but the upper stage variant is on par with the NK-43.
<blowfish> yeah, American engineering also seems to like insanely large vacuum nozzles
<blowfish> at least in the post-apollo era
<blowfish> well, even Apollo ... look at the SPS and lunar module engines
<ProjectThoth> blowfish: Post von Braun, emphasis was put on airframes over engines because we had the metallurgy tech to do so. (And we also developed solid motors pretty heavily because of ICBM tech).
<ProjectThoth> The Soviets didn't (that's part of the reason why the N-1 looks so weird, they didn't have the ability to produce aluminum on the scale we did), so they turned to improving engine performance by diving into ORSC.
<stratochief> the nozzle on the service module was at least somewhat oversized
<ProjectThoth> The Soviets didn't need large vacuum nozzles because their engines were just that high-performance. The NK-33 was considered to be borderline pixie dust until after the Cold War ended.
<ProjectThoth> (Though the flipside of this is that we developed the best hydrolox engines in the world)
<stratochief> ProjectThoth: then strap them on the rocket to nowhere, and dump them in the ocean :P
<ProjectThoth> stratochief: I think I get the reference.
<stratochief> SLS, RS-25. RIP
<ProjectThoth> Oh, yup, I do - duh.
<stratochief> that's alright, I shouldn't speak in riddles, wrapped in fried chiken
<ProjectThoth> et moar chikn
<stratochief> IMO, Ares V would've been so cool, even if they had to do some redevelopment to the RS-68 nozzles to they could be clustered
<stratochief> throwing away RS-25 engines as expendables seems like sacralige
<ProjectThoth> Also an interesting write-up on the RD-0120. http://www.astronautix.com/r/rd-0120.html
<ProjectThoth> stratochief: Recoverable engine pods or nothin'!
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<stratochief> I dunno, I have dreams where the RS-68 got a redevelopment over ~2 years while the rest of the Ares tooling and manufactor was being worked out, and we got cheap and expendable heavy lift again for a bit, to compete against the new space re-users
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<ProjectThoth> stratochief: I have dreams of SLS being based around a stage-and-a-half launcher.
<stratochief> ? got drawings?
<ProjectThoth> With Orion being derived from an enhanced CST-100.
<stratochief> sweet buddy christ, 6x SSMEs per shebang?
<stratochief> they'd have to get some cheap manufacture down for that
<ProjectThoth> stratochief: The outboard four could be recovered.
<stratochief> ahh. nice. recovered engine pods are a bit of a leap, though. I'm still skeptical that can be done reliably and cost effectively
<stratochief> also, I have a distate for pure LH2 vehicles for some reason. just so much.. volume.
<stratochief> maybe because the RS-25 is so damn expensive and Delta IV isn't cheap either
<ProjectThoth> But, I mean, something like that could be brought online relatively quickly and enter operational service *without* the upper stage.
<ProjectThoth> Which is why I like stage-and-a-half.
<ProjectThoth> stratochief: It doesn't sit right with me, either, like eating green beans with ketchup.
<blowfish> Ariane V is supposed to be expensive too (though not as bad as Delta IV)
<blowfish> not sure about H-II
<ProjectThoth> I prefer kerolox.
<ProjectThoth> Hydrolox/methalox for an upper stage.
<blowfish> both kerolox and hydrolox present challenges for reusability
<stratochief> blowfish: true. I expect anything out of Europe to be expensive, though :)
<blowfish> coking or hydrogen embrittlement ... take your pick
<blowfish> probably why everyone's looking into methalox these days
<ProjectThoth> Meh, coking isn't a *horrible* issue to deal with, the F-1s were flushed with industrial solvent after being test-fired.
<stratochief> something about the F-1B fueled boosters for SLS makes me giddy. possibly, brinigng F-1 technology back on the scene. giant kerolox
<UmbralRaptor> blowfish: So if one uses Aerozine-50 and N2O4…?
<stratochief> blowfish: does methalox deal with either of those problems?
<ProjectThoth> Methalox does coke a hell of a lot less.
<blowfish> it cokes less than kerolox IIRC
<stratochief> coke, meth... not even once.
<stratochief> I've long been a methalox fan, largely because of Zubrin and Mars Direct ISRU ideas.
<stratochief> plus its basically natural gas, so easy to source and conceptualize
<ProjectThoth> The vehicle I'm currently looking at uses five NK-33s, four on the half-stage and one sustainer.
<blowfish> IIRC the NK-43 works at sea level, might be a better sustainer
<stratochief> like the original Atlas design, before they realized how light they could make tankage and how much they could miniaturaize nuclear death
<ProjectThoth> Target payload is about 2,000 kg to LEO.
<stratochief> should be able to do more than that, no? with 5x engines? IIRC, Atlas was nearly 2T to LEO
<ProjectThoth> stratochief: Craptacular pmf and payload reserve is intentional.
<stratochief> ahh. da. russia-like?
<ProjectThoth> It's *technically* capable of doing about 8.5 tons to LEO, but I kinda need landing propellant.
<ProjectThoth> (about 6.5 tons, landing plus 10 seconds of hover reserve)
<stratochief> as god and robert heinlein intended?
<ProjectThoth> Well, it comes in sideways and then does a half-flip for the landing approach.
<wb99999999> you could certainly use some spoilers for this
<wb99999999> if you can increase the drag of the top end of the booster
<wb99999999> the flip would be child play
<ProjectThoth> wb99999999: Winrar!
<ProjectThoth> Double-articulating drag flaps... grid fins nestled behind drag brakes that flip out after the vehicle goes transonic.
<ProjectThoth> So they don't get all melty.
<Bornholio> one of these times i'll hunt down the silly missing texture notes in fasa
<ProjectThoth> missing texture: all
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<stewartx> Starwaster: was it you who was asking about g-dot
<stewartx> i was reading through "how apollo flew to the moon" (great book) and it mention h-dot as being the change in height, so i'm assuming g-dot is similar but for gravity?
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<Starwaster> stewartx yes I was asking about it
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<Oneiros> ping already perturbed his orbit and he crashed on the irc surface
<Bornholio> amazingly his G-dot is now zero, what a good navigator
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<Mike_> does anybody know if the dev versions of ro/rp-0 work on 1.3.1 without a recompile?
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<soundnfury> Mike_: fairly sure they don't.
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<Probus> Been playing DCS World. Maybe I can translate some of my "Skillz" to flying spaceplanes. Probably not...
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<Probus> Talk about Skillz. I can cold start an A-10C now Rokker.
<stewartx> it's on sale if anyone is interested
<stewartx> 7kg
<stewartx> damnn
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<Pap> o/
<stewartx> o7
<stewartx> 550t to get 2000kg to orbit
<stewartx> efficiency
<Pap> How heavy is the Zuma satellite that is being launched? Any best guesses?
<Pap> Bornholio: What needs to be fixed in order for RP-1 to be ready for release?
<Pap> I want to get that doen
<Pap> *done
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<wb99999999> aye
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<Rokker> Probus: psh
<Rokker> Probus: we all know that th OV-10 is better than the A-10C
<Mike_> soundnfury, thanks. guess no testing for me, then. :)
<soundnfury> Mike_: unfortunately I seem to be the only one doing RP-0 builds at the moment, and I'm using 1.2.2 so... ;)
<Mike_> i probably could try to build it myself, if i wouldnt be so lazy and afraid of that huge unity download. :)
<soundnfury> oh you don't need Unity to build it
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<soundnfury> just a C# compiler (I use monodevelop, though it's a bit grody)
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<Mike_> oh, great. if the cfg files should work with 1.3, i might try to build it some time.
<Bornholio> pap some bugs in pads adisapearing, training needs clarification and probably a fix to keep it from getting messed up
<Bornholio> everything else is pretty good shape, late game isn't very well tested from what i've seen
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<Bornholio> mike_ let me get the sheet
<Mike_> thanks Bornholio, might try those.
<Mike_> really like the new tech tree from the looks of it, good job pap and everybody else involved.