h a l f b a k e r yCogito, ergo sumthin'
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Micro-Shuttle
Why was the Shuttle so dang big in the first place? | |
Low cost access to space is not going to happen with big, SEMI-reusable systems like the soon-to-be-retired Shuttle. What is needed is a smaller-scale system that flies without (permanently) throwing away hardware.
I am not talking about single-stage orbiters. I happen to think they can be built,
but there is still some argument about this. . .mostly from NASA.
What I mean is something like the Orion/Ares I where you have a first stage that is recovered and reused and an orbiter that is so small that a fairly modest sized first stage will get it to the proper velocity so it can perform its own orbit insertion. Such a system, if built as small as possible, could be turned around very quickly and launched very frequently. A metric tonne of payload would be typical.
N-Prize
http://www.n-prize.com/
[MisterQED, Jun 02 2008]
Nebula Prize entrant to N-Prize
http://www.nebula-prize.com/
[MisterQED, Jun 02 2008]
Titan II - Top stage will theoretically do SSTO
http://en.wikipedia.org/wiki/Titan_II
[MisterQED, Jun 02 2008]
[link]
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something tells me [Moonguy] is no rocket scientist. Neither am I, thats why I don't question NASA |
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// I don't question NASA // |
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Rightly so. After all, they have powerful friends in Washington DC, and lots of satellites in orbit. In fact, they're probably watching you right now....... |
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well considering that Columbus had to get the Queen of Spain to hock her jewels for something that today can almost be achieved from pocket change... in favour of manned boosters over here, btw. |
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Well, a couple of things, first, I am also no rocket scientist, but I've done a lot of research on this due to the n-prize, see links. SSTO is possible, it just isn't cheap or at least it is tough to do cheap. Your idea isn't new and I don't think it's even an idea unless you give a hint as to how the first stage will be recovered. I included a link to the Titan II because it's second stage has the theoretical ability to do a light mass to SSTO. |
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Check out the Nebula-prize link. He is planning on doing SSTO for the N-prize and if he is BSing, it is at least the finest BSing I have seen in years. |
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(MisterQED) Thanks for the link! No, I am not a rocket scientist. I am just another atavistic soul who believes EVERYONE who wants to should be able to go into space. My attempt here was to describe low-cost access via small-scale, rather than a specific design, per se. |
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There is not enough info storage capacity at the Halfbakery for me to get into discussing NASA and its effect on non-government space travel. Besides, there are probably limits to the kind of language we can use. . . |
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Frankly, I wouldn't care if the tech involved was squirrels on flywheels; what matters is the cost-per-mass-to-orbit. My attempt here was to make a case for 'smaller-is-better'. |
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// With you on that one // |
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"FLASH IMMEDIATE: Dateline LONDON, UK: 2008-05-02: MaxCo press release announces plans for manned space shot using innovative "squrrels on flywheels" reactionless propulsion system. Executors of Salvador Dali's estate issue writ for infringement of coptright." |
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The rocket equation doesn't care what it weighs, just the fuel to mass ratio. To do that you generally need pressure containment and insulation. These things don't get much easier with miniaturization. If anything they get a bit harder. Smaller is better only works if you avoid the rocket equation and do scram jets or something. |
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Once you get to space smaller isn't really better either. Certain things can't be miniturized like antennas or life support, so small things have to be assembled into bigger things. So if anything, I'd say bigger is better. Bring back the Saturn 5s or make some Saturn 6s. |
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//The rocket equation doesn't care what it weighs, just the fuel to mass ratio// |
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Bingo! The micro-shuttle concept is not based on mass optimizing as has been the preoccupation of rocket engineers since the days of K. Tsiolkovskii. It is based on using a rugged, even 'kludgy' design that aims for small payloads being launched on a lot of flights. A horribly inefficient rocket is one that rquires huge amounts of propellant (hence tankage, structure etc.) to deliver a small payload. The result is a cost-per-unit-mass-of payload that would impress even a Senator. |
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HOWEVER, if the kludgy, horribly inefficient system was able to fly, say, 100 times, the cost of its construction would be 1% of each flight's cost. The costs associated with refurbishing units in between flights begins to be the real dominant part of the cost equation. |
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The Orion/Ares I system is based on the idea that refurbishing one solid rocket is cheaper than refurbishing two as is currently done with Shuttle. The upper stage to be used with Orion is essentially a replacement for the Shuttle External Tank and will almost certainly exceed its cost. |
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By comparison, micro-shuttle uses one solid booster for the first stage and integrates the payload with the propelling 'stage' into one unit - my choice would be a ballistic cone-shaped design instead of winged, but I can accept there are issues with that. To accomplish that sort of 'integration' you have to trade off payload capability. |
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//FLASH IMMEDIATE: Dateline LONDON,
UK: 2008-05-02: MaxCo press release
announces plans.....// Shhhh. Wait til you
see what comes after the N-Prize. |
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So [Moonguy], how is your idea any different than the new Orion system? |
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Much smaller. . much faster turn-arounds. . .more frequent flights per time period. . .two systems to process (booster & payload/stage vehicle) instead of three (booster, upper stage, Orion module). . . one metric tonne payload (or four passengers). . . |
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