On 10/29/2014 6:07 PM, Home wrote: > As I understand it, those are (basically) the same engines that takes the > Soyuz rockets up still.. Truth be told (I'm no expert but have seen some > articles to this effect) the Russian rocket engines where much superior to > their American counterparts such that since Russia put some of there > political views up on the shelf, these motors have been imported into the > U.S. in fairly good numbers. > > Just 'cause it's old doesn't mean it won't work. Might not be as efficient as > new technology but if you factor in the cost of acquiring(creating) new > technology, sometimes the old stuff is still more efficient.
The engines are leftovers from the failed N1 moon rocket. It had 30 of those in the first stage. All four launch attempts failed, with only one almost making it through the first stage burn before something went kablooie. With 30 engines and all the plumbing and controls etc to go with them, there were just too many potential points of failure. There were 24 engines in an outer ring, using differential throttling for pitch and yaw, while the other 6 were gimbal mounted in the center for roll control. Communists being Communists, they tried to sweep the whole thing under the rug, "Failed manned moon program? What manned moon program?". The scientists and engineers were ordered to destroy everything but they hid the engines in a warehouse. With each N1 using 30 engines in the first stage, there were a lot of them left over. Forward to the early 90's, the USSR is crumbled and former rocket Comrades decide those engines should be used. What makes them sought after is they are more efficient for their size because they don't waste the turbopump exhaust. They use a staged combustion or closed cycle system. The people who developed these engines just kept throwing ideas at the wall until something stuck. ;) In Europe and the USA, the rocket scientists gave up on the idea after some failures (several of them explosive) and declared it "impossible" to route the turbopump exhaust back into the combustion chamber so as to not waste the energy and fuel. The closest a non-Soviet rocket engine came to such a design was the Aerojet M1. With a 32 inch combustion chamber throat and a nozzle skirt max diameter of 18 feet, the engines were huge. The turbopumps were rated at 75,000 and 27,000 horsepower. Their exhaust was used to cool the lower skirt, exiting through a ring of nozzles at the bottom where it contributed an additional 28,000 pounds of thrust to the main 1.5 to 2 million pounds. A complete M1 was never tested, though all the components to assemble at least one were built. NASA chose the Saturn with its LOX-RP1 (RP1 is simply JP1 made to a stricter standard, fancy diesel in which a hypergolic additive may be mixed to make it light upon contact with LOX) fuel over the Nova and its LOX-LH (Liquid Oxygen and Hydrogen) fuel. Liquid Hydrogen gives better performance than RP1 but its lower density requires a much larger tank. See the Shuttle's big tank for an example. The tanks would have been much smaller with RP1. There's a lot of info for rocket enthusiasts in John D. Clark's book "Ignition! An informal history of liquid rocket propellants." It covers quite a lot from the earliest liquid fueled rockets up through 1971. http://mikea.ath.cx/Ignition/ One rather amusing anecdote about Chlorine Trifluoride from the book... ”It is, of course, extremely toxic, but that's the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively. It can be kept in some of the ordinary structural metals-steel, copper, aluminium, etc.-because of the formation of a thin film of insoluble metal fluoride which protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.” Yet even with such a nasty reputation, a chemical company managed to spill a ton of it when a transport cask split. It ate through a foot thick concrete floor and another three feet of sand and gravel below that. The toxic and corrosive fumes damaged everything in the building. Amazingly there was only one casualty, one person suffered a heart attack running away as fast as he could move. Clark mentions many compounds that would make excellent fuels or oxidizers or monopropellants, if only they didn't explode violently at the slightest anything (bump, wiggle, temperature or pressure change, up or down, static discharge or even exposure to moderately bright light) or freeze solid at temperatures higher than water or have a high vapor pressure that made them unusable (and often explosive) in long term storage. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
