ddewees Posted January 23, 2015 Share Posted January 23, 2015 Gonna hate missing this one... http://www.prnewswire.com/news-releases/atk-completes-installation-of-worlds-largest-solid-rocket-motor-for-ground-test-300024596.html Link to comment Share on other sites More sharing options...
gregh Posted January 23, 2015 Share Posted January 23, 2015 That's a little bigger than what your new press can handle I think. Link to comment Share on other sites More sharing options...
taiwanluthiers Posted January 23, 2015 Share Posted January 23, 2015 They are probably APCP, so it's cast, not pressed. Link to comment Share on other sites More sharing options...
ddewees Posted January 23, 2015 Author Share Posted January 23, 2015 Captain Obvious... Link to comment Share on other sites More sharing options...
dagabu Posted January 23, 2015 Share Posted January 23, 2015 (edited) It WAS made in 5 increments... Edited January 23, 2015 by dagabu 1 Link to comment Share on other sites More sharing options...
MrB Posted January 24, 2015 Share Posted January 24, 2015 Speaking of casted fuels. I read a small writeup on "improvised" rocketry, and the fuels were casted as long square slugs, rather then tubes. This allowed for a lot higher burnrates, but of course meant they need stronger casings. I suppose part of the reason might have been that the higher surface area would allow you to use a slower fuel and still get enough initial thrust to get of the ground. Now then... Boosters like the one linked to. Do they the "traditional" round core elements, or do they use some more exotic design to increase the surface area, and burn rate? I've read about starlike patterns and stuff, but i'm not sure if they actually would turn to such, since they all mean you spend the fuel at a much higher rate as well, and spaceflight sort of needs a long burn-time to get there... And your wasting space that could have been used for more fuel. Not really having any reason for the question outside what killed the cat... curiosity.B! Link to comment Share on other sites More sharing options...
ddewees Posted January 24, 2015 Author Share Posted January 24, 2015 http://www.nakka-rocketry.net/th_pix/grains4.gif Link to comment Share on other sites More sharing options...
dagabu Posted January 24, 2015 Share Posted January 24, 2015 Here you are: http://www.nasaspaceflight.com/2014/09/atk-making-progress-srb-propellant-void-issue/ Link to comment Share on other sites More sharing options...
Arthur Posted January 24, 2015 Share Posted January 24, 2015 Space flight usually needs controllable thrust so pyrogolic mixtures of liquids are often used. Launch is different! There is the need to raise a small tower block sized rocket to flying speed in less time than it takes to start to topple over. The shaped cores are chosen to chose the thrust time profile of the rocket engine. Casting a complicated core design is much easier than pressing a core design. Cored rocket motors are sometimes fired from the TOP away from the nozzle, this ensures that all the core catches fire as fast as possible 1 Link to comment Share on other sites More sharing options...
ddewees Posted January 24, 2015 Author Share Posted January 24, 2015 I wonder why they paint the cardboard tube. Link to comment Share on other sites More sharing options...
MrB Posted January 24, 2015 Share Posted January 24, 2015 Visibility. It's much easier to figure out what happened on the highspeed video of the cato, if the inside and outside has different colors. Painting it gives a high contrast between the scorched inside, and the painted outside...Yeah, thats it, i'm sure.B! 1 Link to comment Share on other sites More sharing options...
ddewees Posted March 12, 2015 Author Share Posted March 12, 2015 (edited) [Video] Edited March 12, 2015 by ddewees Link to comment Share on other sites More sharing options...
stix Posted March 12, 2015 Share Posted March 12, 2015 (edited) Great video - but don't those NASA guys realize that they were meant to attach it to a huge stick and point it vertical? - No wonder it didn't take off!! Edited March 12, 2015 by stix Link to comment Share on other sites More sharing options...
gregh Posted March 12, 2015 Share Posted March 12, 2015 Yeah, and they completely forgot the report too! 1 Link to comment Share on other sites More sharing options...
Peret Posted March 12, 2015 Share Posted March 12, 2015 The reason this has to be made in five segments is that it's made in Utah but fired in Florida, and a full size booster won't go round the curves on the railroad journey east. I'm a bit bothered that they're still doing this, since the segmentation is what caused the Challenger disaster. For something this important I would think it was worth building an assembly plant at the Cape and making the damn things in one piece on site. Link to comment Share on other sites More sharing options...
Sparx88 Posted March 13, 2015 Share Posted March 13, 2015 That thing just burns and burns. I'm impressed at how long it is able to maintain its thrust. Link to comment Share on other sites More sharing options...
Oinikis Posted March 14, 2015 Share Posted March 14, 2015 The reason this has to be made in five segments is that it's made in Utah but fired in Florida, and a full size booster won't go round the curves on the railroad journey east. I'm a bit bothered that they're still doing this, since the segmentation is what caused the Challenger disaster. For something this important I would think it was worth building an assembly plant at the Cape and making the damn things in one piece on site.They use segments to get the thrust curve that they want (as we do with BATES grain), and according to wikipedia the segments are different from each other(one is 11 star shaped, others are cone core etc.). Also if you look at a thrust curve of traditional 4 segment SRB right here, you can see it has quite sharp changes in thrust, suggesting some segments burn faster than others at certain stages of the burn. They just added 5th segment to ramp it up. As far as I know, Challenger disaster was caused by cold temperatures during launch, because it was like -1C outside. Richard Feynman proved it to be the cause by putting a piece of O ring into some ice water, and showing that it hardened and lost it's sealing properties. Later the footage has been reviewed, and that SRB was seen leaking gray smoke during liftoff, as seen right here. Manufacturing near the launch site of course makes sense, but for some reason neither NASA, nor Roskosmos (former Soviet Space Program) does this. Soyuz rockets are manufactured near Moscow, then brought to Baikonour by railroad, and they still are most reliable, safest and cheapest way of getting humans to orbit. However, SpaceX saves incredible amount of money by making all parts and assembling the stages under the same roof, and testing engines just around the corner. Link to comment Share on other sites More sharing options...
Arthur Posted March 14, 2015 Share Posted March 14, 2015 I'm quite certain that I wouldn't want my precision engineering company anywhere near the site of a potential thousand tonne CATO, Also you couldn't house all the skilled managers and workers near enough to a firing site without creating a "Work Camp" environment like Peenemunde or Los Alamos in WW2. Link to comment Share on other sites More sharing options...
Peret Posted March 15, 2015 Share Posted March 15, 2015 As far as I know, Challenger disaster was caused by cold temperatures during launch, because it was like -1C outside. Richard Feynman proved it to be the cause by putting a piece of O ring into some ice water, and showing that it hardened and lost it's sealing properties. Later the footage has been reviewed, and that SRB was seen leaking gray smoke during liftoff, as seen right here.Yes, the O-ring failed. But if the casing had been made in one piece, as it should have been, there wouldn't have been an O-ring to fail. The segments do have different profiles, yes, but it could still be loaded that way. The igniter is at the nose end so the whole core burns at once, not one after the other. The various manufacturing jobs on the boosters were spread around 20 different congressional districts for political reasons. It happens that Utah was the place that got to load the fuel. If that were not the case, the segments could have been shipped empty to Florida and welded together before the fuel was loaded, and nobody need have died. Link to comment Share on other sites More sharing options...
ddewees Posted March 15, 2015 Author Share Posted March 15, 2015 That's a pretty big reach. A lot of accidents in life should have, could have, would have turned out differently "if". What happens when someone dies because of a welding accident putting the pieces together? How many people die in cars and trucks everyday? Should we stop making them or using them? Link to comment Share on other sites More sharing options...
Ubehage Posted March 15, 2015 Share Posted March 15, 2015 Space flight usually needs controllable thrust so pyrogolic mixtures of liquids are often used. Launch is different! There is the need to raise a small tower block sized rocket to flying speed in less time than it takes to start to topple over.I just learned some physics the other day, and so I know that without active stabilization, you will topple over within 3.1 seconds.Nothing can stay upright Link to comment Share on other sites More sharing options...
stix Posted March 15, 2015 Share Posted March 15, 2015 (edited) As far back as I can remember I always wanted to be a Cosmonaut/Astronaut - I'm sure there's plenty of people on this forum that share my childhood dreams, desires and sentiments. It would be the ULTIMATE CAREER. Failing that, just to be an engineer working on those huge motors would be of great satisfaction. Accidents happen, and there have been many, but when you consider that you are at the "cutting edge" well, what do you expect? SpaceX have also had their problems too. It's not easy. A great man once said... We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win. JFK circa 1963. btw. I grew up reading books: Tom Swift and Isaac Asimov. Cheers. [EDIT] Whoops, made a few errors. Edited March 15, 2015 by stix Link to comment Share on other sites More sharing options...
dagabu Posted March 19, 2015 Share Posted March 19, 2015 "For the fully evolved 130mt SLS vehicle, source notes claim a future static DM test could be provided by ATK as a pathfinder test for an upgraded booster, which would be in competition with the liquid counterpart. Such an upgraded booster may include recently proposed change to a HTPB (Hydroxyl-terminated polybutadiene) fueled solid in “composite over wrapped steel cases” thus allowing higher MEOP (Maximum Expected Operating Pressure) – to as much as 1500 psi." Source: http://www.nasaspaceflight.com/2011/09/atk-and-nasa-ground-test-five-segment-motor/ Link to comment Share on other sites More sharing options...
FlaMtnBkr Posted March 19, 2015 Share Posted March 19, 2015 I just skimmed the thread and links so may have missed it. Is this an AP based motor? I wonder if AP may become easier to find and at a more reasonable price. If anyone knows of a source I would appreciate a heads up. Link to comment Share on other sites More sharing options...
ddewees Posted March 19, 2015 Author Share Posted March 19, 2015 You already go through that ten pounds? I've been considering buying from RCS, buy the TCP makes me hesitant. http://www.rocketmotorparts.com/200_Micron_Ammonium_Perchlorate_Oxidizer/p1577809_7835906.aspx Link to comment Share on other sites More sharing options...
Recommended Posts