h a l f b a k e r yI CAN HAZ CROISSANTZ?
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The major cost of space launch is the vehicle, not the fuel.
That's why Elon Musk is trying to build rockets that get back
to earth in one piece.
In general - the trend has always been to build robust rockets
that can deliver the payload almost every time.
But what if we went another way?
What if we cut corners
here and there, and we were able to build a rocket that
succeeds only 10% of the time (and even then it doesn't
always get to the right orbit), but is 100 times cheaper to
produce?
Obviously, it would be no good to deliver humans or
expensive equipment to the orbit, but cheap things, like
water or other 3d-printing material?
n prise
http://en.wikipedia.org/wiki/N-Prize
what is an N-Prize (qv) ? [popbottle, Feb 22 2015]
3D Printer in Orbit
http://www.collects...tation-ratchet.html
[MechE, Feb 26 2015]
Kessler Cascade
http://en.wikipedia...ki/Kessler_syndrome
Why large bits of space junk are bad. [MechE, Feb 27 2015]
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Annotation:
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The N-Prize (qv) was made for you, [kolinko]. |
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The // 100 times cheaper // target is going to be tough to hit,
because of the economies of scale of building larger launch
vehicles. |
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But it might be possible, using very simple solid-fuel motors. |
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@8th it wouldn't be cheaper because the rocket would be
smaller, but because corners would be cut when building
one. If anything, the economies of the scale would work for
(not against) the idea, because hundreds of cheap rockets
would be built. |
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@MaxwellBuchanan - good idea :) |
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[kolinko], welcome to the Halfbakery. |
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Ooops - how rude of me! I hadn't noticed that
[kolinko] was new here. Welcome, [kolinko] - wear
these square brackets with pride. But don't tell your
employer. |
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Hahah, what do the square brackets mean? :) Or is it just a
way to mention the users? :) |
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^ More like quarantine. Isn't that right
[[[MaxwellBuchanan]]]?! Welcome to the HalfBakery
[kolinko] |
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By convention, [kolinko], usernames are enclosed in square brackets. |
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Quoted text is shown using the C and C++ convention of a double slash , as in // how rude of me! // |
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Using the @ symbol is considered somewhat gauche |
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It is traditional for newcomers to be welcomed in a friendly manner, allowed to post a few ideas, and then be mercilessly savaged by the existing members for some trivial error of grammar, mathematics, logic, or trangressing one of the numerous "unwritten rules" but mostly just for cheap amusememt. |
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Those without a rhinoceros -like hide need not apply ; "Can't take a joke, shouldn't have joined." |
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Because if we used curly brackets like this - {kolinko} - we'd be in the area of Set Theory and saying that there was a set of users which contained only "kolinko" - clearly nonsense, whereas square brackets usually denote a matrix or, in programming, an array, which makes a lot more sense. |
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Also, the HalfBakery has links to a manufacturer of
square brackets, so we get them at cost. |
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I think the problem is that the cost to build the rocket is
only a small portion of the total launch cost. Even if your
cargo is low value, fueling the rocket is not cheap. |
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Also some things, even in a disposable rocket, can't be
scrimped on. You're still going to need range safety
officers and functionality, in fact you're probably going to
need more of it. Likewise, your docking and transfer
functionality needs to be 100% reliable, or at least
completely fail safe, so it doesn't damage whatever you
are delivering to. |
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Not to mention if a bunch of these reach the wrong orbit,
you're adding to the space-junk issue, and increasing the
risk of a Kessler cascade. |
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// 100% reliable, or at least completely fail safe, // |
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You're no fun any more ... |
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// the HalfBakery has links to a manufacturer of square brackets // |
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Beware ! "the HalfBakery has links to a manufacturer of square brackets" would be more honest if it read "M'lord Buchanan's family have extensive financial interests in a vast, greedy, bloated, exploitative commercial empire of very dubious legality and non-existent ethics, who have obtained control - no doubt by underhand means - of resources in an impoverished third world country, where small children can be forced to work very long hours in appalling conditions almost indistinguishable from slavery, manufacturing minimum-spec product - including square brackets - at a fraction of the normal manufacturing cost of the item, then getting them imported duty-free into Western markets by greasing the palms of customs officials, and then sold at slightly below the going rate in counterfeit packaging, thus garnering enormous profits, which are then laundered through a complex chain of holding companies before being converted into either cash, precious metals or uncut jewels and surreptitiously added to the Smaug-like hoard of treasure in the basement of Buchanan Towers." |
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Well, yes, admittedly your version is concise, pithy and to the point, but [kolinko] is new here. |
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// for some trivial error of grammar // |
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No error of grammar is ever trivial. |
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I will be watching you, [kolinko]. Welcome. |
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On a less important note . . . |
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I agree with [MechE] about the cost of fuel being a large percentage
of the cost, as well as the costs of staging a launch - especially if it
might fail. I'd vote for as many safety features as possible - which is
usually the point at which a failure of the safety system becomes
more likely than the failure of the base system, and on a rocket is
when the weight of the safeties exceeds the lifting power of the
rocket. |
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But there could be something to be said for a dead-basic rocket, like
solid-fuel, ceramic-nozzle, and wrapped-body, that failed only 10% of
the time. I realize that is just an Estes model rocket motor, and the
sounding-rocket people are probably already doing something much
like that . . . |
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Well, as the last part of the original idea says, it is for water or raw
materials, not expensive things. |
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Resin for a 3D printer is interesting, but in that case I'd argue for
building ten copies of the desired part down on Earth, and slapping
them into ten of the maybe-make-it rockets. You can send the file for
printing a part via radio, and get a crappy rocket under way pretty
quickly. (Not that a printer in space would be bad - if it was needed, it
would be needed bad. And a crappy rocket might not be best for
docking with the station.) |
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Hmm. How about this idea as posted, for the first two stages of a
rocket, with the final stage made really well? If the first two stages
went boom, the final stage would have the guts to get up and away,
then make a good landing with the expensive cargo (which would
probably be shards after that, so never mind). |
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The other cargo for a maybe rocket could be fuel. (After all I said
about fuel cost.) Tanks of liquid fuel in orbit would be of great value.
And if the rocket starts to blow, the fuel would be self-disposing, if
you got the self-destruct signal in time. Heck fire, you could launch
fuel carriers and charge people to watch them blow up - the
occasional dud that made it to orbit would pay for the refunds. |
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Except that the 3d printer is already in orbit (see
link). The advantages are A) that it's a lot more
flexible to have some resin around if you aren't sure
which tool or part you'll need, and B) in theory the
resin could be reprocessed multiple times, although I
don't know if that capability is actually in place. |
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//I think the problem is that the cost to build the rocket is
only a small portion of the total launch cost. // |
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It's not really. E.g. the fuel cost for Falcon 9 is just $200k,
while the total launch cost is around $50M. (according to
Wikipedia) |
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«MaxwellBuchanan» «hippo» - what about those? :) |
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Very nice, except that (1) they make my eyes go funny, and (2) I don't know how to type them. |
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Fuel was only one example. However, if you're trying to
get your launch cost down to 10% of the current, then
that 200k of fuel just ate up about 4% of your total
available funds. |
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That being said, my point is that a lot of things don't
scale. |
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Let's say most systems on rocket are triply redundant. If
you cut out all redundancy, say you cut the material
costs to 1/3 (you don't, but as an approximation). That
cuts your reliability far more, because you go from only
having a problem when three identical systems fail to
having a problem when any single system fails. Being
generous, lets say this gets you to your 10% reliability. |
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You still need at least 70-80% of the personnel for each
launch, even cutting corners, although I'll allow some
economies of scale, call it 50%. |
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Now add back in 10% for the extra range safety
personnel. Then add back in 10% of material costs for
the systems that are critical for the safety of the delivery
point (your approach and docking systems, mostly). |
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I don't have real numbers for any of this, but it should be
fairly clear that reliability falls much more quickly than
cost. |
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And I repeat my point about space junk and a Kessler
cascade. |
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// in theory the resin could be reprocessed multiple times, although I don't know if that capability is actually in place. // |
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Hmmm, 3D-printed resin rocket ? |
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[MechE] those are some good points, thanks. |
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