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Zero Gravitas posted:I think I've hijacked the thread for long enough now. When I wrote the OP I did say that DIY Projects are ok, mostly due to my support of Copenhagen Sub-orbitals but hey someone building the "GOONTHRUSTER ULTIMAX 9000" (9000 is the amount of explosions I expect to happen  ) is fine in my books!
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| # ? Feb 19, 2013 16:52 |
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| # ? May 26, 2013 06:20 |
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Zero Gravitas posted:Aerospike cooling might be one of the backup ideas. Like I say, its all early stages and I want to have all my ducks in a row in terms of calculations and shitton of CFD before I start making it. http://www.ukrocketman.com/rocketry/index.shtml I think this is the right guy, I was at a UKSEDS conference and he had a miniature rocket engine running in a lecture hall. Even if he isn't that crazy man, at least there is a lot of useful info linked for you. Check for the next SEDS conference http://ukseds.org/ Well worth a trip for space interested students.
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| # ? Feb 19, 2013 17:56 |
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) with my fiancee and get the initial design calculations done for a reasonably small thrust.
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3 posters remain from the previous thread. The 6 claimed posters are in tubes ready to take to the post office, then I'll get estimates etc for you. Right now the tubes cost 2 pounds each so that's your starting point   - This is a smaller poster, A4 I think. Let me know in here and message me if possible as well so I have a record of who wants what. thehustler fucked around with this message at Feb 19, 2013 around 19:36 |
| # ? Feb 19, 2013 18:32 |
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Deteriorata posted:It will work if they can get a vast array of theoretically possible, but untested, technologies all to work on the first try without the incremental development normally associated with spaceflight. Propellant Mine Ingredients: 2 liquid water storage depots with optional on-board electrolysis unit 3 polyurethane microspine anchors 1 NSTAR ion engine 1 Canadarm2 with scoop attachment 1 parabolic mirror 1 pressure chamber 1 condenser Directions: Purchase and integrate one microspine anchor and ion engine, then attach carefully to the surface of a NEO of your choosing. Burn until the object's rotation has been reduced to a suitable minimum. Purchase and integrate another microspine anchor with a Canadarm2 and attach to a suitable location near high concentrations of water ice. Meanwhile, purchase one more microspine anchor and integrate with your pressure chamber, mirror, and condenser suite. Teleoperate the Canadarm2 to scoop regolith into the pressure chamber, being careful to avoid complications that may arise from signal latency. When the chamber is full, use your mirror to distill the water contents into vapor, and then condense into liquid phase for storage. You may wish to dock your depot with the processing unit for easy transfer, though a small tug launched as a secondary payload may do in a pinch. If your civilization has advanced to steam rockets you may remove the electrolysis units and directly use the water for propellant. Vast array of untested technologies indeed.
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| # ? Feb 19, 2013 18:39 |
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NASA lost contact with the ISS this morning. http://cosmiclog.nbcnews.com/_news/...computer-glitch It's fixed now but it sounds like their only backup was radio contact with ground stations in Russia.
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| # ? Feb 19, 2013 19:34 |
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Optus poster gone. Two left!
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| # ? Feb 19, 2013 19:37 |
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ISS crew have requested a private conversation with MCC-H to get a debrief on the events of this afternoon and also to raise some concerns they had. Interesting.
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| # ? Feb 19, 2013 20:13 |
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It might be pretty melodramatic at times, but I really love October Sky. edit: except for the streak of anti-union sentiment. Didn't really remember that aspect of it. Admiral Bosch fucked around with this message at Feb 19, 2013 around 21:31 |
| # ? Feb 19, 2013 20:29 |
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The DE-STAR Threes a Fox news link at the bottom that describes it as mullti-functional; destruction/deflection of incoming meteors, could be used for interstellar propulsion... Sounds fun but I wouldn't bet on it happening. (I couldn't bring myself to link directly to the Fox page) Interview in LA Times
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| # ? Feb 19, 2013 21:26 |
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DiHK posted:The DE-STAR Yeah, we don't really need to destroy incoming asteroids. Just a bit of a push to change their trajectories, so that they either miss Earth completely or land in Tuscaloosa.
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| # ? Feb 19, 2013 21:37 |
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it can do that too, they propose, for large asteroids. And in doing it for large asteroids you are made capable of completely vaporizing the small ones (over time). a third function is determining asteroid content for mining by analyzing the vapor. e: what really impresses me is that it's effective range would be 1 AU.
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| # ? Feb 19, 2013 22:49 |
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CombatInformatiker posted:On the contrary, their approach is very much incremental (http://www.planetaryresources.com/technology/): Are Planetary Resources telescopes restricted to the visible band? It would seem like they would be a lot more useful for remote sensing, both for NEO hunting and Earth observation if they had infrared. A lot of space objects are dim in visible and bright in infrared, especially small asteroids (which is why WISE was good at finding them), while most of the useful wavelengths for tracking vegetation and discovering mineral deposits are in the infrared. This is just the near infrared, too, so it's not like they'd have to integrate a complex cooling design into the telescope as well.
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| # ? Feb 19, 2013 23:14 |
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They're designing them to be all-purpose optical telescopes, so they'd be stupid not to extend to at least the infrared and ultraviolet wavelengths. They've already stated they want them to be flexible and versatile, and considering how much research can be done in the infrared (both Earth observation and in space) I'd be willing to bet money they're including that in their base design.
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| # ? Feb 20, 2013 00:02 |
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I figured. By the way, am I correct in understanding that they wanted to use the inside of their telescope tube for equipment to save space? If so that doesn't seem like a great idea - not only are you obscuring parts of the mirror and affecting your light-gathering capability, you'd be be losing resolution through the introduction of diffraction. The diffraction would be an especially bad problem if the telescope ends up using the ultraviolet.
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| # ? Feb 20, 2013 00:54 |
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Is there a generaly accepted best way to deflect a large asteroid? As they only "space guy" my relatives and coworkers know, they all want to know how we would stop a dinosaur killing asteroid.
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| # ? Feb 20, 2013 01:00 |
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Xenoborg posted:Is there a generaly accepted best way to deflect a large asteroid? As they only "space guy" my relatives and coworkers know, they all want to know how we would stop a dinosaur killing asteroid. Depends on how much warning you have. If you have many years warning, then a small impulse applied over a long period of time would be plenty. Even something as small as just sending a satellite to orbit alongside the thing could do the trick, as the gravity of the satellite acting on the asteroid would change its orbit. That would be the safest way, as with that sort of small gentle acceleration you avoid doing something like breaking the body up into smaller pieces which would be worse than a single big impact.
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| # ? Feb 20, 2013 01:06 |
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Xenoborg posted:Is there a generaly accepted best way to deflect a large asteroid? As they only "space guy" my relatives and coworkers know, they all want to know how we would stop a dinosaur killing asteroid. That depends on the asteroid, and especially on how much lead time we have. If the rock isn't going to hit for many decades, it might be enough to just wrap the thing in reflective foil and let the tiny (but constant) solar-sail effect add up and push it off course. Or you could paint it a different color to have the Yarkovsky effect shove it around a little differently. But if it's going to impact in, say, a year or two? Well, I suppose we could throw some nukes at it and hope for the best. It may or may not work, and might actually make things worse, but it's really the only thing we could try in the near-term. No promises. The real problem is that we've never moved asteroids around before and we have ZERO practical experience with any of the proposed methods. So we honestly don't know what the "best way" is for any specific situation. Hopefully we'll have done some sort of dress rehearsal well before we have to do it for real...
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| # ? Feb 20, 2013 01:17 |
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This might be a better question for the physics thread. If you were able to spot it before it reaches the highest or lowest point in it's orbit (and have enough time to send a probe to adjust it's orbit) you would have a good chance of changing it's orbit appreciably. You might have to burn an entire Saturn V (which weighed 2500 tons on the pad) worth of fuel to move a rock (which weighed ~10,000 tons) like the one that burnt up over Russia. You would need decades to move that rock with an ion engine and a tow rope, if you could overcome the inertia.
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| # ? Feb 20, 2013 01:21 |
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Hadlock posted:This might be a better question for the physics thread. If you were able to spot it before it reaches the highest or lowest point in it's orbit (and have enough time to send a probe to adjust it's orbit) you would have a good chance of changing it's orbit appreciably. You might have to burn an entire Saturn V (which weighed 2500 tons on the pad) worth of fuel to move a rock (which weighed ~10,000 tons) like the one that burnt up over Russia. You would need decades to move that rock with an ion engine and a tow rope, if you could overcome the inertia. But you don't actually have to move it very much. A tiny change in its orbit is enough to cause it to miss the earth - particularly if you've got a long lead time. A very small force may be all that's needed, if applied in the right way.
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| # ? Feb 20, 2013 01:26 |
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Xenoborg posted:Is there a generaly accepted best way to deflect a large asteroid? As they only "space guy" my relatives and coworkers know, they all want to know how we would stop a dinosaur killing asteroid. You tell it all the dinosaurs are already dead, and it fucks off to find somewhere that does have dinosaurs.
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| # ? Feb 20, 2013 03:21 |
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Deteriorata posted:But you don't actually have to move it very much. A tiny change in its orbit is enough to cause it to miss the earth - particularly if you've got a long lead time. A very small force may be all that's needed, if applied in the right way. Oh, sure; The difference between Earth and Mars' orbital speeds is "only" about 6,500 m/s (Voyager 2 is cruising along at around 17,000m/s) . To more or less solve the problem you only need to adjust the delta-v perhaps 10m/s, maybe even as little as 2-3m/s. The problem is accelerating 10,000 tons of mass + the weight of the fuel (2,500 tons) by that amount, and getting the fuel in to orbit.
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| # ? Feb 20, 2013 04:14 |
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I was having a good browse at http://www.secretprojects.co.uk (sign up and log in to see the pictures in the threads!) and I came across this jaw-dropper:  Yes, this is a Saturn V first stage with giant wings, this 'flyback booster' concept would have landed on a runway. Note the blister on the leading edge of the left wing. That is a cockpit.
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| # ? Feb 20, 2013 04:17 |
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That's some crazy Thunderbirds shenanigans right there.
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| # ? Feb 20, 2013 04:32 |
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Hadlock posted:Oh, sure; The difference between Earth and Mars' orbital speeds is "only" about 6,500 m/s (Voyager 2 is cruising along at around 17,000m/s) . To more or less solve the problem you only need to adjust the delta-v perhaps 10m/s, maybe even as little as 2-3m/s. The problem is accelerating 10,000 tons of mass + the weight of the fuel (2,500 tons) by that amount, and getting the fuel in to orbit. That's where the lasers, pusher satellites, solar sails and even paint ideas come in. If you've got enough lead time, the small forces you can get from those can be enough to deflect it. A small force exerted continuously for a few years may be enough to do the job. The less time you have, the more force you need to apply. Strapping a Saturn V to it is what you do when you don't have the time for more subtle methods. That's why it's important to get NEO asteroids mapped out and their orbits plotted far into the future, so if we can see one will intersect the Earth in 2046 or something we can get to work on it quickly.
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| # ? Feb 20, 2013 04:38 |
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Deteriorata posted:That's where the lasers, pusher satellites, solar sails and even paint ideas come in. If you've got enough lead time, the small forces you can get from those can be enough to deflect it. A small force exerted continuously for a few years may be enough to do the job. Phil Plait talks about it in his TED talk on intercepting asteroids. Applying MAXIMUM STRENGTH to an asteroid can even throw it into a future keyhole. It's a much more spray and pray approach, even if the worst case side effect is unlikely. The talk is more overview than detail, but it's lots of fun and touches on the long-term effect a probe's gravitational field can have on a comparatively large asteroid. The Big One heading on a beeline for Earth would be immune to that approach but a multi-decade slow approach is much more likely, as Deteriorata pointed out.
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| # ? Feb 20, 2013 05:21 |
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Venusian Weasel posted:I figured. By the way, am I correct in understanding that they wanted to use the inside of their telescope tube for equipment to save space? If so that doesn't seem like a great idea - not only are you obscuring parts of the mirror and affecting your light-gathering capability, you'd be be losing resolution through the introduction of diffraction. The diffraction would be an especially bad problem if the telescope ends up using the ultraviolet.
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| # ? Feb 20, 2013 07:10 |
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CombatInformatiker posted:It is my understanding that they want to use the telescope for communication using laser signals. I guess they must just have a lot of data storage on them to compensate?
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| # ? Feb 20, 2013 08:16 |
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Woden posted:How much fuel would that waste though? You'd have it look at a rock, then turn to send the data to where ever, then back again on the rock. It would probably just turn using reaction wheels using no fuel. Of course that has other issues. In fact I don't think I even saw an RCS system on the demo craft so far. Also yeah they're planning on putting a lot of processing and storage onto them so that they don't need to send huge amounts of raw data but instead the processed final results (3D map, albedo, composition, etc) with redundancy by having multiple craft. Shanakin fucked around with this message at Feb 20, 2013 around 08:27 |
| # ? Feb 20, 2013 08:25 |
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Zero Gravitas posted:Well, slightly premature Protip: Keep it simple as you can. Undergraduates always bite off more than they can chew for their thesis topics. Start simple and add on to it as you go. Nothing is worse than having 'Discussion: I didn't get any results because...' as part of your thesis. Forget aerospikes, etc. Just get something that burns consistently enough to go straight without exploding. Also, a completely blind lead here as I haven't looked, but check out the guys on the left of this page and have a look at some of their publications like journal papers, etc. May be nothing of interest but at the same time they may also be of use. They're the guys who do a lot of Scramjet research alongside DARPA/NASA and have a fair body of expertese in the whole rocket flight/hypersonics arena. edit: Also, this and this (which you probs have covered already judging by your CFD screenshot). Nam Taf fucked around with this message at Feb 20, 2013 around 09:34 |
| # ? Feb 20, 2013 09:26 |
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Schindler's Fist posted:I was having a good browse at http://www.secretprojects.co.uk (sign up and log in to see the pictures in the threads!) and I came across this jaw-dropper: Yes, the early Space Shuttle concept had the entire system being fully reusable, and incorporated both a manned orbiter and a manned flyback booster. Supposedly, just as there were OV-101, OV-102 etc for Orbiter Vehicle, there were also to be BV-101, BV-102 etc for Booster Vehicle. But flyback boosters were deemed too expensive to develop... which isn't saying much. They didn't have enough money to even properly test the SSMEs during development, which probably helped contribute to engine development delays. MattD1zzl3 posted:I dont say the "b-u-r" word, but i reject the opinion that the worlds only operational manned spaceplane in history can be considered a mistake. If compromises had to be made to get it funded, that can only be considered a failure if you share how else exactly they should have paid to get the thing built and beyond the prototype/testing phase. Ultimately this is a political failure and not a technical one. Space Shuttle represents the best that could be done with the resources the nation was willing to allocate, and even then largely on the basis of wildly over-optimistic projections and possibly with an eye towards throwing some money at an otherwise beleaguered aerospace industry. Either more money should have been allocated to the project to permit the reusable concept to be fully developed (and also not forced NASA to go hat in hand to USAF), or the project should have been aborted in favor of more Saturn rockets, Apollo spacecraft, and Skylab stations.
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| # ? Feb 20, 2013 14:04 |
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Shanakin posted:It would probably just turn using reaction wheels using no fuel. Of course that has other issues. In fact I don't think I even saw an RCS system on the demo craft so far. You lose a lot of reliability and increase per-part complexity that way with such high part integration, but you greatly reduce your overall part count, weight, and complexity. They recoup their reliability by launching a ton of them for redundancy.
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| # ? Feb 20, 2013 18:05 |
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Farmer Crack-rear end posted:Ultimately this is a political failure and not a technical one. Space Shuttle represents the best that could be done with the resources the nation was willing to allocate, and even then largely on the basis of wildly over-optimistic projections and possibly with an eye towards throwing some money at an otherwise beleaguered aerospace industry. Either more money should have been allocated to the project to permit the reusable concept to be fully developed (and also not forced NASA to go hat in hand to USAF), or the project should have been aborted in favor of more Saturn rockets, Apollo spacecraft, and Skylab stations.  
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| # ? Feb 20, 2013 18:37 |
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GWBBQ posted:and the general public would have received the pleasure of watching this monstrosity being launched And two billion-dollar shuttles and 14 human beings wouldn't have been blown the gently caress up due to a combination of stupid design decisions and awful communication/management philosophies.
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| # ? Feb 20, 2013 19:00 |
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GWBBQ posted:Should have gone with the Saturn Shuttle design. The Air Force could have gotten their new toy, NASA could have used the shuttle when needed without having to give up their moon rockets, and the general public would have received the pleasure of watching this monstrosity being launched Wait, was this actually a Real Idea? Were they really going to just slap a 250,000 lb orbiter on the side of a Saturn V?
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| # ? Feb 20, 2013 22:21 |
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spacetimecontinuu posted:Wait, was this actually a Real Idea? Were they really going to just slap a 250,000 lb orbiter on the side of a Saturn V? Nope, they were going to put it on top!. 
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| # ? Feb 20, 2013 22:29 |
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Well, at the very least I thought the Space Shuttle was cool, even if not very efficient it did help NASA survive. Also, the astronauts going from Military test pilots to scientists and other non-mil folk.
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| # ? Feb 20, 2013 22:33 |
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GWBBQ posted:Should have gone with the Saturn Shuttle design. The Air Force could have gotten their new toy, NASA could have used the shuttle when needed without having to give up their moon rockets, and the general public would have received the pleasure of watching this monstrosity being launched Is that a huge sheet of glass on the front?
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| # ? Feb 20, 2013 22:34 |
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GWBBQ posted:Should have gone with the Saturn Shuttle design. The Air Force could have gotten their new toy, NASA could have used the shuttle when needed without having to give up their moon rockets, and the general public would have received the pleasure of watching this monstrosity being launched Here's another mock-up version from 1970:  From a balance and ease-of-launch standpoint, this would have been highly preferable. The limitation would be that the Shuttle would have no main engines of its own and just thrusters. The decision to have the Shuttle's main engines be reusable and provide thrust for ascent meant that the Saturn booster had to go, and the Shuttle then had to be piggy-backed on a huge external fuel tank. This complicated things enormously, as it shifted the center of mass off the main axis of the launch (and the CoM would then shift as the tank drained), and ice accumulations on the tank could damage the Shuttle's tiles, among many other things. It also meant the additional complication of solid-rocket boosters, as the Shuttle's main engines would not be powerful enough to get it to orbit on its own. All part of the design compromise process that left the Shuttle far less useful and much more expensive than was originally envisioned.
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| # ? Feb 20, 2013 22:52 |
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I think being a flyback booster driver would be a really cool job. All of the zoom and boom, and none of the making GBS threads in bags or doing experiments suggested my ms. crabapple's 3rd grade class.
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| # ? Feb 20, 2013 22:55 |
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| # ? May 26, 2013 06:20 |
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Deteriorata posted:Here's another mock-up version from 1970: So basically everything that ever happened to the Shuttle (from foam to SRBs) was brought on by this design choice? Why did the orbiter need to have main engines anyway? Even the version we got couldn't use them on orbit or landing, they're just there for thrust during ascent.
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| # ? Feb 20, 2013 22:56 |
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