They tested it about a year ago. Not a complete success. The test projectile wobbled as it left the launch tube. I do not know if they solved this problem in later tests, but they will have to in order to ensure a reliable system.
They need to do some kind of controlled release while still in vacuum, with no air resistance there can't be any aerodynamic stabilization. Maybe spin the vehicle up on the long axis just before release.
Look up "centrifugal gun". In the Civil War, and again in WWI, there were attempts to develop machine guns that did not use gunpowder but launched the bullets from a spinning disk, powered by steam or electricity. The expected advantages were no smoke, saving on propellant (WWI exceeded the production capacity of smokeless propellants and other high explosives so much that it fell into a cycle of great battles followed by a pause of several months while the ammunition stocks were replenished), and supposedly less noise to reveal your position. (That's dubious unless you hold the muzzle velocity under the speed of sound; in the Civil War that meant you matched the lowest muzzle velocities of the common Minie ball rifle cartridges but the steam engine would be noisy, and in WWI it would mean a muzzle velocity around 1,000 feet per second against 2,500 fps or higher for the standard bolt-action rifles.)
Both times they failed because they could not achieve sufficient accuracy - for a bullet-sprayer. A consistent release from a spinning launcher is difficult, and it gets worse as the RPM's increase, because the angle changes with any variation in time. If the projectile comes out wobbling, that's even worse. With the spinner in a vacuum chamber, the projectile must also be crashing through a window
Kinda reminds me of wind turbines..using outdated technology that's just updated but still inefficient. One day they'll figure out that an electromagnetic system is more efficient and faster than the electric motor to rotate the centrifuge. Just an obvious observation from an ignorant conservative out here in flyover country...
It was around the mid 1960's that a magazine (Popular Mechanics??) showed how to make a spin launcher that could propel BBs. This is the same thing, just on an enormous scale.
The sling was a deadly weapon if you happened to hit the right spot. But accuracy requires not only a perfectly repeatable release, but timing the release to a few milliseconds, with the timing becoming more critical the faster you're spinning the sling. In the ancient world, Balearic slingers were often hired as mercenaries, and considered more effective against light armor than arrows - the bows weren't particularly powerful and arrows had to penetrate or did nothing, but slingstones could carry enough energy to break bones under the armor. But there's a reason that only one little group of islands produced masses of professional slingers; to be sufficiently accurate, you had to start practicing when you were a small child and keep it up for over a decade. No doubt David had been using a sling just as long to keep wolves away from the sheep, as well as to bag rabbits and birds for dinner.
As compared to the English and Welsh longbow, which is apparently the most powerful simple bow (not a crossbow or with cams and gears) ever used: Both took a decade to learn, beginning in childhood. Slingers spent that time learning accuracy. Longbowmen mainly spent it building up muscles so heavy that their skeletons grew lopsided, and incidentally learned better accuracy than is possible with a sling. Longbowmen used 120 pound bows and yard-long arrows pulled back to the ear, maximizing the energy. Besides the high energy, the sectional density was very high, and the tip could be shaped to burst through armor. You couldn't put a tip on a sling bullet, so the longbow was more apt to inflict serious injuries through the heavy armor and thick padding of medieval knights. OTOH, if you were a longbowman, you would run out of arrows; in the quiver, the arrows must be held apart so the feathers weren't damaged, and the quivers were quite bulky. Carrying a bow about as long as you were tall meant you were limited in your choice of backup weapons. A slinger carried his ammo jumbled together in a bag so he was only limited by how much weight he could handle, and he could carry any backup weapon he liked, even the same pike or shield and spear as the standard infantryman.
Or they could do as the ancient Roman army often did: using slings as a secondary weapon, that added hardly anything to the soldier's burden. They weren't trained to hit anything smaller than the enemy equivalent of a century in dense formation, but massive volleys somewhat compensated for the inaccuracy.
This needs a VERY hard vacuum in an enormous space to be really feasible. Add up the energy budgets. I betcha buring LOX and hydrogen is cheaper. Even with the discount for cool factor.
One: Trading rocket propellant "pollution" for natural gas and or coal-fired electricity, or nuclear power; doubtful they can store energy in a (hazmat) battery from (a hazmat) solar and wind for a launch. Two: What ever happened to the rail "gun" or launch programs? Three: Such an electric launch mechanism would eliminate - or at least make difficult - satellite detection of a visual plume or heat signature of launching missiles and rockets.
Couple things came to mind... it can only launch payloads that would be able to withstand the g forces placed on them by the spin. Heat mitigation might be an issue, also, as a hypersonic projectile would heat just through atmospheric friction... and they're pushing (flinging?) the thing through the thickest part of the atmosphere, first, at hypersonic speeds. Whitestone
They tested it about a year ago. Not a complete success. The test projectile wobbled as it left the launch tube. I do not know if they solved this problem in later tests, but they will have to in order to ensure a reliable system.
ReplyDeleteThey need to do some kind of controlled release while still in vacuum, with no air resistance there can't be any aerodynamic stabilization. Maybe spin the vehicle up on the long axis just before release.
DeleteIsn't that what rifling was developed for?
DeleteHow does the vehicle tolerate the required "G's" for launch?
DeleteLook up "centrifugal gun". In the Civil War, and again in WWI, there were attempts to develop machine guns that did not use gunpowder but launched the bullets from a spinning disk, powered by steam or electricity. The expected advantages were no smoke, saving on propellant (WWI exceeded the production capacity of smokeless propellants and other high explosives so much that it fell into a cycle of great battles followed by a pause of several months while the ammunition stocks were replenished), and supposedly less noise to reveal your position. (That's dubious unless you hold the muzzle velocity under the speed of sound; in the Civil War that meant you matched the lowest muzzle velocities of the common Minie ball rifle cartridges but the steam engine would be noisy, and in WWI it would mean a muzzle velocity around 1,000 feet per second against 2,500 fps or higher for the standard bolt-action rifles.)
DeleteBoth times they failed because they could not achieve sufficient accuracy - for a bullet-sprayer. A consistent release from a spinning launcher is difficult, and it gets worse as the RPM's increase, because the angle changes with any variation in time. If the projectile comes out wobbling, that's even worse. With the spinner in a vacuum chamber, the projectile must also be crashing through a window
Yah. That'll work about as well as EV's immersed in salt water and green power when the wind isn't blowing and the sun isn't shining.
ReplyDeleteNemo
Interesting process. Keep it it up.
ReplyDeleteGreat story!
ReplyDeleteKinda reminds me of wind turbines..using outdated technology that's just updated but still inefficient.
ReplyDeleteOne day they'll figure out that an electromagnetic system is more efficient and faster than the electric motor to rotate the centrifuge.
Just an obvious observation from an ignorant conservative out here in flyover country...
The trebuchet was rendered useless after gun powder. This newest version offers a solution to a problem that does not exist.
ReplyDeleteIt was around the mid 1960's that a magazine (Popular Mechanics??) showed how to make a spin launcher that could propel BBs. This is the same thing, just on an enormous scale.
ReplyDeleteWell, sorta. On an industrial scale, that BB spin launcher is called a wheelabrator. AKA "shotblasting".
DeleteGreat. An even cheaper way for the government to launch arrays of spy satellites to violate our rights, freedoms, and privacy.
ReplyDeleteI smell "boondoggle".
ReplyDeleteCool but was thinking the same, almost anything can be done with other peoples money
DeleteDidn't David take out Goliath with a spinning slingshot?? New technology, yeah right...
ReplyDeleteThe sling was a deadly weapon if you happened to hit the right spot. But accuracy requires not only a perfectly repeatable release, but timing the release to a few milliseconds, with the timing becoming more critical the faster you're spinning the sling. In the ancient world, Balearic slingers were often hired as mercenaries, and considered more effective against light armor than arrows - the bows weren't particularly powerful and arrows had to penetrate or did nothing, but slingstones could carry enough energy to break bones under the armor. But there's a reason that only one little group of islands produced masses of professional slingers; to be sufficiently accurate, you had to start practicing when you were a small child and keep it up for over a decade. No doubt David had been using a sling just as long to keep wolves away from the sheep, as well as to bag rabbits and birds for dinner.
DeleteAs compared to the English and Welsh longbow, which is apparently the most powerful simple bow (not a crossbow or with cams and gears) ever used: Both took a decade to learn, beginning in childhood. Slingers spent that time learning accuracy. Longbowmen mainly spent it building up muscles so heavy that their skeletons grew lopsided, and incidentally learned better accuracy than is possible with a sling. Longbowmen used 120 pound bows and yard-long arrows pulled back to the ear, maximizing the energy. Besides the high energy, the sectional density was very high, and the tip could be shaped to burst through armor. You couldn't put a tip on a sling bullet, so the longbow was more apt to inflict serious injuries through the heavy armor and thick padding of medieval knights. OTOH, if you were a longbowman, you would run out of arrows; in the quiver, the arrows must be held apart so the feathers weren't damaged, and the quivers were quite bulky. Carrying a bow about as long as you were tall meant you were limited in your choice of backup weapons. A slinger carried his ammo jumbled together in a bag so he was only limited by how much weight he could handle, and he could carry any backup weapon he liked, even the same pike or shield and spear as the standard infantryman.
Or they could do as the ancient Roman army often did: using slings as a secondary weapon, that added hardly anything to the soldier's burden. They weren't trained to hit anything smaller than the enemy equivalent of a century in dense formation, but massive volleys somewhat compensated for the inaccuracy.
FTX laundromat for the geeky liberal mindset. Let me know what the centrifuge carbon footprint is in comparison to rocket propulsion.
ReplyDelete-Ερωτοκριτος
This needs a VERY hard vacuum in an enormous space to be really feasible. Add up the energy budgets. I betcha buring LOX and hydrogen is cheaper. Even with the discount for cool factor.
ReplyDeleteOne: Trading rocket propellant "pollution" for natural gas and or coal-fired electricity, or nuclear power; doubtful they can store energy in a (hazmat) battery from (a hazmat) solar and wind for a launch.
ReplyDeleteTwo: What ever happened to the rail "gun" or launch programs?
Three: Such an electric launch mechanism would eliminate - or at least make difficult - satellite detection of a visual plume or heat signature of launching missiles and rockets.
Couple things came to mind... it can only launch payloads that would be able to withstand the g forces placed on them by the spin. Heat mitigation might be an issue, also, as a hypersonic projectile would heat just through atmospheric friction... and they're pushing (flinging?) the thing through the thickest part of the atmosphere, first, at hypersonic speeds.
ReplyDeleteWhitestone