RE: The gun thing again
Title: Message Sundry clever primates around the world, OK, OK, I know. The gun thing won't work for orbital delivery of stuff to build Europan probes because one can't shave the big bump off of the resultant wobbling orbit ... or +- something like that. However if one were to cant the trajectory of an equatorial gun back a little to the west, a projectile could be delivered which would "die" into a geosynchronous orbit. Granted, you'd only get one shot per gun per day, but at say a ton per shot ... Then from this orbit, a finished product could be dropped and sling-shotted with Earth gravity assist to wherever. From another of my cerebral railroad sidings - an inflatable Mylar geosynchronous space station would be a pretty handy toy too - at say 95% gun delivered. I await the group's scorn. Jack
Re: The gun thing again
An alternative would be to send up smaller spaces that connect together like bubbles. I guess it really depends on what is considered small for launching. If to objective would be to have a living/working space of say a 10x10x10 feet, you could send it in a package as small as 4x4x4 and it will include all the materials to expand it, seal it and prepare it for the next one. If you build them with three hatches each, you can create some great combinations! Joe L. Joe Latrell writes: Having done some experiments in gun launching (nothing to orbit mind you) there are a lot of factors involved that make it very unattractive. Heat is a really big issue. I've read papers that suggest a dead-mass burden of about 15% for ablative shielding. I.e., in the same ballpark as reentry capsules. No showstopper, at least for the optimist. Launching from higher altitudes definitely helps, since even 14,000 feet gets you above over 25% of the atmosphere. However, the geosync inflatable station is a great idea. Using a transhab type design, you can launch a really big space station with only a few launches, assemble it (self assembly?) and then get to work building probes to wherever you want to send them. Engineering inflatables for gun launch is an interesting idea. There may be some kinks in it (as it were), but it seems ideal for solving many construction problems. If you perfected rendezvous, one approach that I think would be kinda cool is: 1. launch an inflatable 2. inflate it 3. launch another 4. rendezvous at some orifice 5. inflate the new one *inside* the current one (vent residual gas to a pressure tank, and reuse the gas for future inflation) 6. repeat from 3 until you have enough layers for whatever purpose desired. This is nice because it means you can build structures of considerable mass within small payload limitations, and because it's fault tolerant -- blow a launch or miss a rendezvous, and the relative cheapness of gun launch (amortized over many launches, anyway) means just planning for a few more launches than the absolute minimum. To Jack's questions: Sundry clever primates around the world Having met me recently, Jack, you know just how ridged a brow and prognathous a jaw you're dealing with, in talking to me. (Thanks for the back-shaving tips, by the way. ;-) OK, OK, I know. The gun thing won't work for orbital delivery of stuff to build Europan probes because one can't shave the big bump off of the resultant wobbling orbit ... or +- something like that. The big bump? If you mean that it starts out very elliptical, shaving the big bumps (which I'm better at now; my back isn't as red and sore as it used to be) amounts to circularizing the orbit. If you launch enough fuel into the same orbit as the original projectile, you can use it to circularize the orbit at perigee pretty efficiently, or even just head right on out of Earth orbit, I would think. (Joe? You're the guy who most recently did the orbital dynamics stuff, right?) However if one were to cant the trajectory of an equatorial gun back a little to the west, a projectile could be delivered which would die into a geosynchronous orbit. Granted, you'd only get one shot per gun per day, but at say a ton per shot ... Um. Hm. I did some rough calculations a while back, looking at shooting straight up and using the Earth's rotation as free vector, and I remember coming up with an orbit out past the moon. But you're proposing something else, I realize. Still, I don't think you can get GEO without a burn, no matter what. Everything I've looked at suggests that you need a kick stage at the top just to avoid grazing the atmosphere on the backswing. Of course, it's also possible to coast up to a libration point, I suppose. But that's a lo-oo-ong way out there. And means a bigger gun. How much bigger? Haven't figured it out. Probably not too much smaller than what you'd need for Earth escape velocity. Then from this orbit, a finished product could be dropped and sling-shotted with Earth gravity assist to wherever. Dropped? In some sense (a sense that drove Newton crazy until the light bulb went on in his head) GEO is *already* dropping - in a circle. My impression is that slingshotting works with moons planets. Dropping *does* sort of make sense if you talk about the Sun-facing Sun-Earth libration point: drop it toward Venus, or rather give it a little shove at just the right time. Not sure where that point is in relation to the Van Allen belts, but if you're already rad-hardened for near Jupiter, maybe the Van Allen belts are negligible anyway. Joe! Help! I'm talking barely-informed nonsense, right? From another of my cerebral railroad sidings - an inflatable Mylar geosynchronous space station would be a pretty handy toy too - at say 95% gun delivered. Reasonable enough, to my
RE: The gun thing again
Most August Simians, Interestingly, (from a standpoint of trying to avoid the waste of fuel-eating trajectory corrections) GS orbits need not be circular. Even with a circular orbit, it still appears doable via a Hohmann transfer. Equatorial mountain candidates for drilling the gun boreholes include Chimborazo in Ecuador at 20,700, Kenya's Mt Kenya at 17000 + and another in Sumatra at 12400 +. An example of the non-linear thinking which can be easily applied to the gun method is that with many cargoes, the entire projectile could be deep frozen (Say in liquid N or He) prior to launch, thereby extending the heat tolerance. I was of course backward with the orientation - the bore hole would actually be pointed a little eastward. GS (circular) orbital velocity is about 3440 mph, eastward, so there is a little delta V (about 1400 mph) to make up. Some portion of this would come from the vectored rocket firing in the Hohmann transfer maneuver. Jack -Original Message- From: Michael Turner [mailto:[EMAIL PROTECTED] Sent: Thursday 08 April 2004 11:48 To: [EMAIL PROTECTED] Subject: Re: The gun thing again Joe Latrell writes: Having done some experiments in gun launching (nothing to orbit mind you) there are a lot of factors involved that make it very unattractive. Heat is a really big issue. I've read papers that suggest a dead-mass burden of about 15% for ablative shielding. I.e., in the same ballpark as reentry capsules. No showstopper, at least for the optimist. Launching from higher altitudes definitely helps, since even 14,000 feet gets you above over 25% of the atmosphere. However, the geosync inflatable station is a great idea. Using a transhab type design, you can launch a really big space station with only a few launches, assemble it (self assembly?) and then get to work building probes to wherever you want to send them. Engineering inflatables for gun launch is an interesting idea. There may be some kinks in it (as it were), but it seems ideal for solving many construction problems. If you perfected rendezvous, one approach that I think would be kinda cool is: 1. launch an inflatable 2. inflate it 3. launch another 4. rendezvous at some orifice 5. inflate the new one *inside* the current one (vent residual gas to a pressure tank, and reuse the gas for future inflation) 6. repeat from 3 until you have enough layers for whatever purpose desired. This is nice because it means you can build structures of considerable mass within small payload limitations, and because it's fault tolerant -- blow a launch or miss a rendezvous, and the relative cheapness of gun launch (amortized over many launches, anyway) means just planning for a few more launches than the absolute minimum. To Jack's questions: Sundry clever primates around the world Having met me recently, Jack, you know just how ridged a brow and prognathous a jaw you're dealing with, in talking to me. (Thanks for the back-shaving tips, by the way. ;-) OK, OK, I know. The gun thing won't work for orbital delivery of stuff to build Europan probes because one can't shave the big bump off of the resultant wobbling orbit ... or +- something like that. The big bump? If you mean that it starts out very elliptical, shaving the big bumps (which I'm better at now; my back isn't as red and sore as it used to be) amounts to circularizing the orbit. If you launch enough fuel into the same orbit as the original projectile, you can use it to circularize the orbit at perigee pretty efficiently, or even just head right on out of Earth orbit, I would think. (Joe? You're the guy who most recently did the orbital dynamics stuff, right?) However if one were to cant the trajectory of an equatorial gun back a little to the west, a projectile could be delivered which would die into a geosynchronous orbit. Granted, you'd only get one shot per gun per day, but at say a ton per shot ... Um. Hm. I did some rough calculations a while back, looking at shooting straight up and using the Earth's rotation as free vector, and I remember coming up with an orbit out past the moon. But you're proposing something else, I realize. Still, I don't think you can get GEO without a burn, no matter what. Everything I've looked at suggests that you need a kick stage at the top just to avoid grazing the atmosphere on the backswing. Of course, it's also possible to coast up to a libration point, I suppose. But that's a lo-oo-ong way out there. And means a bigger gun. How much bigger? Haven't figured it out. Probably not too much smaller than what you'd need for Earth escape velocity. Then from this orbit, a finished product could be dropped and sling-shotted with Earth gravity assist to wherever. Dropped? In some sense (a sense that drove Newton crazy until the light bulb went on in his head) GEO is *already* dropping - in a circle. My impression is that
RE: The gun thing again [Off Topic]
One of the problems I encountered was how do you build circuitry to survive the launch. The forces involved will destroy most electronics as they are now built. Solids state is not very solid after 15x gravitational forces. I probably sound negative, but the only way to prove it is to build one (even a small one) and see what happens. Pulling this back to the topic (sort of), would building a gun of this type on the moon facilitate the launching of deep space probes? We would eliminate the atmospheric issues and most of the acceleration issues too. Comments? Joe L. Most August Simians, Interestingly, (from a standpoint of trying to avoid the waste of fuel-eating trajectory corrections) GS orbits need not be circular. Even with a circular orbit, it still appears doable via a Hohmann transfer. Equatorial mountain candidates for drilling the gun boreholes include Chimborazo in Ecuador at 20,700, Kenya's Mt Kenya at 17000 + and another in Sumatra at 12400 +. An example of the non-linear thinking which can be easily applied to the gun method is that with many cargoes, the entire projectile could be deep frozen (Say in liquid N or He) prior to launch, thereby extending the heat tolerance. I was of course backward with the orientation - the bore hole would actually be pointed a little eastward. GS (circular) orbital velocity is about 3440 mph, eastward, so there is a little delta V (about 1400 mph) to make up. Some portion of this would come from the vectored rocket firing in the Hohmann transfer maneuver. Jack -Original Message- From: Michael Turner [mailto:[EMAIL PROTECTED] Sent: Thursday 08 April 2004 11:48 To: [EMAIL PROTECTED] Subject: Re: The gun thing again Joe Latrell writes: Having done some experiments in gun launching (nothing to orbit mind you) there are a lot of factors involved that make it very unattractive. Heat is a really big issue. I've read papers that suggest a dead-mass burden of about 15% for ablative shielding. I.e., in the same ballpark as reentry capsules. No showstopper, at least for the optimist. Launching from higher altitudes definitely helps, since even 14,000 feet gets you above over 25% of the atmosphere. However, the geosync inflatable station is a great idea. Using a transhab type design, you can launch a really big space station with only a few launches, assemble it (self assembly?) and then get to work building probes to wherever you want to send them. Engineering inflatables for gun launch is an interesting idea. There may be some kinks in it (as it were), but it seems ideal for solving many construction problems. If you perfected rendezvous, one approach that I think would be kinda cool is: 1. launch an inflatable 2. inflate it 3. launch another 4. rendezvous at some orifice 5. inflate the new one *inside* the current one (vent residual gas to a pressure tank, and reuse the gas for future inflation) 6. repeat from 3 until you have enough layers for whatever purpose desired. This is nice because it means you can build structures of considerable mass within small payload limitations, and because it's fault tolerant -- blow a launch or miss a rendezvous, and the relative cheapness of gun launch (amortized over many launches, anyway) means just planning for a few more launches than the absolute minimum. To Jack's questions: Sundry clever primates around the world Having met me recently, Jack, you know just how ridged a brow and prognathous a jaw you're dealing with, in talking to me. (Thanks for the back-shaving tips, by the way. ;-) OK, OK, I know. The gun thing won't work for orbital delivery of stuff to build Europan probes because one can't shave the big bump off of the resultant wobbling orbit ... or +- something like that. The big bump? If you mean that it starts out very elliptical, shaving the big bumps (which I'm better at now; my back isn't as red and sore as it used to be) amounts to circularizing the orbit. If you launch enough fuel into the same orbit as the original projectile, you can use it to circularize the orbit at perigee pretty efficiently, or even just head right on out of Earth orbit, I would think. (Joe? You're the guy who most recently did the orbital dynamics stuff, right?) However if one were to cant the trajectory of an equatorial gun back a little to the west, a projectile could be delivered which would die into a geosynchronous orbit. Granted, you'd only get one shot per gun per day, but at say a ton per shot ... Um. Hm. I did some rough calculations a while back, looking at shooting straight up and using the Earth's rotation as free vector, and I remember coming up with an orbit out past the moon. But you're proposing something else, I realize. Still, I don't think you can get GEO without a burn, no matter what. Everything I've looked at suggests that you
RE: The gun thing again
Mauna Kea and Mauna Loa in Hawaii are both nearly 14,000 feet. Both have mostly paved roads to their summits, and both roads have been used to haul heavy equipment. The astronomers would not like lots of dust kicked up on Mauna Kea with space launches, however. Perhaps Mauna Loa would be OK, but it's still an active volcano. Gary Most August Simians, Interestingly, (from a standpoint of trying to avoid the waste of fuel-eating trajectory corrections) GS orbits need not be circular. Even with a circular orbit, it still appears doable via a Hohmann transfer. Equatorial mountain candidates for drilling the gun boreholes include Chimborazo in Ecuador at 20,700, Kenya's Mt Kenya at 17000 + and another in Sumatra at 12400 +. An example of the non-linear thinking which can be easily applied to the gun method is that with many cargoes, the entire projectile could be deep frozen (Say in liquid N or He) prior to launch, thereby extending the heat tolerance. I was of course backward with the orientation - the bore hole would actually be pointed a little eastward. GS (circular) orbital velocity is about 3440 mph, eastward, so there is a little delta V (about 1400 mph) to make up. Some portion of this would come from the vectored rocket firing in the Hohmann transfer maneuver. Jack -Original Message- From: Michael Turner [mailto:[EMAIL PROTECTED] Sent: Thursday 08 April 2004 11:48 To: [EMAIL PROTECTED] Subject: Re: The gun thing again Joe Latrell writes: Having done some experiments in gun launching (nothing to orbit mind you) there are a lot of factors involved that make it very unattractive. Heat is a really big issue. I've read papers that suggest a dead-mass burden of about 15% for ablative shielding. I.e., in the same ballpark as reentry capsules. No showstopper, at least for the optimist. Launching from higher altitudes definitely helps, since even 14,000 feet gets you above over 25% of the atmosphere. However, the geosync inflatable station is a great idea. Using a transhab type design, you can launch a really big space station with only a few launches, assemble it (self assembly?) and then get to work building probes to wherever you want to send them. Engineering inflatables for gun launch is an interesting idea. There may be some kinks in it (as it were), but it seems ideal for solving many construction problems. If you perfected rendezvous, one approach that I think would be kinda cool is: 1. launch an inflatable 2. inflate it 3. launch another 4. rendezvous at some orifice 5. inflate the new one *inside* the current one (vent residual gas to a pressure tank, and reuse the gas for future inflation) 6. repeat from 3 until you have enough layers for whatever purpose desired. This is nice because it means you can build structures of considerable mass within small payload limitations, and because it's fault tolerant -- blow a launch or miss a rendezvous, and the relative cheapness of gun launch (amortized over many launches, anyway) means just planning for a few more launches than the absolute minimum. To Jack's questions: Sundry clever primates around the world Having met me recently, Jack, you know just how ridged a brow and prognathous a jaw you're dealing with, in talking to me. (Thanks for the back-shaving tips, by the way. ;-) OK, OK, I know. The gun thing won't work for orbital delivery of stuff to build Europan probes because one can't shave the big bump off of the resultant wobbling orbit ... or +- something like that. The big bump? If you mean that it starts out very elliptical, shaving the big bumps (which I'm better at now; my back isn't as red and sore as it used to be) amounts to circularizing the orbit. If you launch enough fuel into the same orbit as the original projectile, you can use it to circularize the orbit at perigee pretty efficiently, or even just head right on out of Earth orbit, I would think. (Joe? You're the guy who most recently did the orbital dynamics stuff, right?) However if one were to cant the trajectory of an equatorial gun back a little to the west, a projectile could be delivered which would die into a geosynchronous orbit. Granted, you'd only get one shot per gun per day, but at say a ton per shot ... Um. Hm. I did some rough calculations a while back, looking at shooting straight up and using the Earth's rotation as free vector, and I remember coming up with an orbit out past the moon. But you're proposing something else, I realize. Still, I don't think you can get GEO without a burn, no matter what. Everything I've looked at suggests that you need a kick stage at the top just to avoid grazing the atmosphere on the backswing. Of course, it's also possible to coast up to a libration point, I suppose. But that's a lo-oo-ong way out there. And means a bigger gun. How much bigger? Haven't figured it out. Probably not too much smaller than what you'd need for
RE: The gun thing again [Off Topic]
One or our firm's product sets is electronic sensing tools for oil well drilling. These tools must tolerate tremendous heat, pressure and rather high acceleration loads. They are continually making headway. To withstand the rigors of a gun launch (remember too that my version of the gun is 4 kilometers in length so g's are maybe not quite as high as in whatever model you are quoting), my simple answer is to embed all electrics in some sort of liquid-turned-solid epoxy material. If encased in a rigid solid, they have nowhere to go. Also, my thinking on the gun has it delivering stuff that is not so delicate - liquids, gasses, structural materials, connectors, inflatables, solid fuels, rolled sheet metals, etc. Really delicate components could be sent by STS or rockets. Re the lunar gun, a very interesting idea. I have spoken a little to oil industry people about drilling the boreholes for the guns and the steel casing to line it. They generally see it as completely feasible in the here and now - just a question of $. Jack -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Thursday 08 April 2004 14:29 To: [EMAIL PROTECTED] Subject: RE: The gun thing again [Off Topic] One of the problems I encountered was how do you build circuitry to survive the launch. The forces involved will destroy most electronics as they are now built. Solids state is not very solid after 15x gravitational forces. I probably sound negative, but the only way to prove it is to build one (even a small one) and see what happens. Pulling this back to the topic (sort of), would building a gun of this type on the moon facilitate the launching of deep space probes? We would eliminate the atmospheric issues and most of the acceleration issues too. Comments? Joe L. Most August Simians, Interestingly, (from a standpoint of trying to avoid the waste of fuel-eating trajectory corrections) GS orbits need not be circular. Even with a circular orbit, it still appears doable via a Hohmann transfer. Equatorial mountain candidates for drilling the gun boreholes include Chimborazo in Ecuador at 20,700, Kenya's Mt Kenya at 17000 + and another in Sumatra at 12400 +. An example of the non-linear thinking which can be easily applied to the gun method is that with many cargoes, the entire projectile could be deep frozen (Say in liquid N or He) prior to launch, thereby extending the heat tolerance. I was of course backward with the orientation - the bore hole would actually be pointed a little eastward. GS (circular) orbital velocity is about 3440 mph, eastward, so there is a little delta V (about 1400 mph) to make up. Some portion of this would come from the vectored rocket firing in the Hohmann transfer maneuver. Jack -Original Message- From: Michael Turner [mailto:[EMAIL PROTECTED] Sent: Thursday 08 April 2004 11:48 To: [EMAIL PROTECTED] Subject: Re: The gun thing again Joe Latrell writes: Having done some experiments in gun launching (nothing to orbit mind you) there are a lot of factors involved that make it very unattractive. Heat is a really big issue. I've read papers that suggest a dead-mass burden of about 15% for ablative shielding. I.e., in the same ballpark as reentry capsules. No showstopper, at least for the optimist. Launching from higher altitudes definitely helps, since even 14,000 feet gets you above over 25% of the atmosphere. However, the geosync inflatable station is a great idea. Using a transhab type design, you can launch a really big space station with only a few launches, assemble it (self assembly?) and then get to work building probes to wherever you want to send them. Engineering inflatables for gun launch is an interesting idea. There may be some kinks in it (as it were), but it seems ideal for solving many construction problems. If you perfected rendezvous, one approach that I think would be kinda cool is: 1. launch an inflatable 2. inflate it 3. launch another 4. rendezvous at some orifice 5. inflate the new one *inside* the current one (vent residual gas to a pressure tank, and reuse the gas for future inflation) 6. repeat from 3 until you have enough layers for whatever purpose desired. This is nice because it means you can build structures of considerable mass within small payload limitations, and because it's fault tolerant -- blow a launch or miss a rendezvous, and the relative cheapness of gun launch (amortized over many launches, anyway) means just planning for a few more launches than the absolute minimum. To Jack's questions: Sundry clever primates around the world Having met me recently, Jack, you know just how ridged a brow and prognathous a jaw you're dealing with, in talking to me. (Thanks for the back-shaving tips, by the way. ;-) OK, OK, I know. The gun thing won't work for orbital
RE: The gun thing again
What if there is a puncture? -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Thursday, April 08, 2004 1:23 PM To: [EMAIL PROTECTED] Subject: Re: The gun thing again An alternative would be to send up smaller spaces that connect together like bubbles. I guess it really depends on what is considered small for launching. If to objective would be to have a living/working space of say a 10x10x10 feet, you could send it in a package as small as 4x4x4 and it will include all the materials to expand it, seal it and prepare it for the next one. If you build them with three hatches each, you can create some great combinations! Joe L. Joe Latrell writes: Having done some experiments in gun launching (nothing to orbit mind you) there are a lot of factors involved that make it very unattractive. Heat is a really big issue. I've read papers that suggest a dead-mass burden of about 15% for ablative shielding. I.e., in the same ballpark as reentry capsules. No showstopper, at least for the optimist. Launching from higher altitudes definitely helps, since even 14,000 feet gets you above over 25% of the atmosphere. However, the geosync inflatable station is a great idea. Using a transhab type design, you can launch a really big space station with only a few launches, assemble it (self assembly?) and then get to work building probes to wherever you want to send them. Engineering inflatables for gun launch is an interesting idea. There may be some kinks in it (as it were), but it seems ideal for solving many construction problems. If you perfected rendezvous, one approach that I think would be kinda cool is: 1. launch an inflatable 2. inflate it 3. launch another 4. rendezvous at some orifice 5. inflate the new one *inside* the current one (vent residual gas to a pressure tank, and reuse the gas for future inflation) 6. repeat from 3 until you have enough layers for whatever purpose desired. This is nice because it means you can build structures of considerable mass within small payload limitations, and because it's fault tolerant -- blow a launch or miss a rendezvous, and the relative cheapness of gun launch (amortized over many launches, anyway) means just planning for a few more launches than the absolute minimum. To Jack's questions: Sundry clever primates around the world Having met me recently, Jack, you know just how ridged a brow and prognathous a jaw you're dealing with, in talking to me. (Thanks for the back-shaving tips, by the way. ;-) OK, OK, I know. The gun thing won't work for orbital delivery of stuff to build Europan probes because one can't shave the big bump off of the resultant wobbling orbit ... or +- something like that. The big bump? If you mean that it starts out very elliptical, shaving the big bumps (which I'm better at now; my back isn't as red and sore as it used to be) amounts to circularizing the orbit. If you launch enough fuel into the same orbit as the original projectile, you can use it to circularize the orbit at perigee pretty efficiently, or even just head right on out of Earth orbit, I would think. (Joe? You're the guy who most recently did the orbital dynamics stuff, right?) However if one were to cant the trajectory of an equatorial gun back a little to the west, a projectile could be delivered which would die into a geosynchronous orbit. Granted, you'd only get one shot per gun per day, but at say a ton per shot ... Um. Hm. I did some rough calculations a while back, looking at shooting straight up and using the Earth's rotation as free vector, and I remember coming up with an orbit out past the moon. But you're proposing something else, I realize. Still, I don't think you can get GEO without a burn, no matter what. Everything I've looked at suggests that you need a kick stage at the top just to avoid grazing the atmosphere on the backswing. Of course, it's also possible to coast up to a libration point, I suppose. But that's a lo-oo-ong way out there. And means a bigger gun. How much bigger? Haven't figured it out. Probably not too much smaller than what you'd need for Earth escape velocity. Then from this orbit, a finished product could be dropped and sling-shotted with Earth gravity assist to wherever. Dropped? In some sense (a sense that drove Newton crazy until the light bulb went on in his head) GEO is *already* dropping - in a circle. My impression is that slingshotting works with moons planets. Dropping *does* sort of make sense if you talk about the Sun-facing Sun-Earth libration point: drop it toward Venus, or rather give it a little shove at just the right time. Not sure where that point is in relation to the Van Allen belts, but if you're already rad-hardened for near Jupiter, maybe the Van Allen belts are negligible anyway. Joe! Help!
RE: The gun thing again [Off Topic]
Jack, Do you have a paper on this proposal and a guess as to how much it will cost? Joe L. One or our firm's product sets is electronic sensing tools for oil well drilling. These tools must tolerate tremendous heat, pressure and rather high acceleration loads. They are continually making headway. To withstand the rigors of a gun launch (remember too that my version of the gun is 4 kilometers in length so g's are maybe not quite as high as in whatever model you are quoting), my simple answer is to embed all electrics in some sort of liquid-turned-solid epoxy material. If encased in a rigid solid, they have nowhere to go. Also, my thinking on the gun has it delivering stuff that is not so delicate - liquids, gasses, structural materials, connectors, inflatables, solid fuels, rolled sheet metals, etc. Really delicate components could be sent by STS or rockets. Re the lunar gun, a very interesting idea. I have spoken a little to oil industry people about drilling the boreholes for the guns and the steel casing to line it. They generally see it as completely feasible in the here and now - just a question of $. Jack -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Thursday 08 April 2004 14:29 To: [EMAIL PROTECTED] Subject: RE: The gun thing again [Off Topic] One of the problems I encountered was how do you build circuitry to survive the launch. The forces involved will destroy most electronics as they are now built. Solids state is not very solid after 15x gravitational forces. I probably sound negative, but the only way to prove it is to build one (even a small one) and see what happens. Pulling this back to the topic (sort of), would building a gun of this type on the moon facilitate the launching of deep space probes? We would eliminate the atmospheric issues and most of the acceleration issues too. Comments? Joe L. Most August Simians, Interestingly, (from a standpoint of trying to avoid the waste of fuel-eating trajectory corrections) GS orbits need not be circular. Even with a circular orbit, it still appears doable via a Hohmann transfer. Equatorial mountain candidates for drilling the gun boreholes include Chimborazo in Ecuador at 20,700, Kenya's Mt Kenya at 17000 + and another in Sumatra at 12400 +. An example of the non-linear thinking which can be easily applied to the gun method is that with many cargoes, the entire projectile could be deep frozen (Say in liquid N or He) prior to launch, thereby extending the heat tolerance. I was of course backward with the orientation - the bore hole would actually be pointed a little eastward. GS (circular) orbital velocity is about 3440 mph, eastward, so there is a little delta V (about 1400 mph) to make up. Some portion of this would come from the vectored rocket firing in the Hohmann transfer maneuver. Jack -Original Message- From: Michael Turner [mailto:[EMAIL PROTECTED] Sent: Thursday 08 April 2004 11:48 To: [EMAIL PROTECTED] Subject: Re: The gun thing again Joe Latrell writes: Having done some experiments in gun launching (nothing to orbit mind you) there are a lot of factors involved that make it very unattractive. Heat is a really big issue. I've read papers that suggest a dead-mass burden of about 15% for ablative shielding. I.e., in the same ballpark as reentry capsules. No showstopper, at least for the optimist. Launching from higher altitudes definitely helps, since even 14,000 feet gets you above over 25% of the atmosphere. However, the geosync inflatable station is a great idea. Using a transhab type design, you can launch a really big space station with only a few launches, assemble it (self assembly?) and then get to work building probes to wherever you want to send them. Engineering inflatables for gun launch is an interesting idea. There may be some kinks in it (as it were), but it seems ideal for solving many construction problems. If you perfected rendezvous, one approach that I think would be kinda cool is: 1. launch an inflatable 2. inflate it 3. launch another 4. rendezvous at some orifice 5. inflate the new one *inside* the current one (vent residual gas to a pressure tank, and reuse the gas for future inflation) 6. repeat from 3 until you have enough layers for whatever purpose desired. This is nice because it means you can build structures of considerable mass within small payload limitations, and because it's fault tolerant -- blow a launch or miss a rendezvous, and the relative cheapness of gun launch (amortized over many launches, anyway) means just planning for a few more launches than the absolute minimum. To Jack's questions: Sundry clever primates around the world Having met me recently, Jack, you know just how ridged a brow and prognathous a jaw you're dealing with, in talking to me. (Thanks
RE: The gun thing again
Gary, Yep, but drilling a deep gun borehole into an active volcano implies significant heat issues while drilling. Ideally we like to see temperatures staying below 300oF at 4000 m of measured depth of hole. That said, I haven't determined geothermal gradients for the other potential sites either. Also, Hawaii is still a full 20 o North, the correction of which to an equatorial alignment would require more fuel on the projectile. I have been involved many times in drilling deep holes in remote mountainous terrain in Canada, the US, and Peru. Road access is generally a small issue. Jack -Original Message- From: Gary McMurtry [mailto:[EMAIL PROTECTED] Sent: Thursday 08 April 2004 12:40 To: [EMAIL PROTECTED] Subject: RE: The gun thing again Mauna Kea and Mauna Loa in Hawaii are both nearly 14,000 feet. Both have mostly paved roads to their summits, and both roads have been used to haul heavy equipment. The astronomers would not like lots of dust kicked up on Mauna Kea with space launches, however. Perhaps Mauna Loa would be OK, but it's still an active volcano. Gary Most August Simians, Interestingly, (from a standpoint of trying to avoid the waste of fuel-eating trajectory corrections) GS orbits need not be circular. Even with a circular orbit, it still appears doable via a Hohmann transfer. Equatorial mountain candidates for drilling the gun boreholes include Chimborazo in Ecuador at 20,700, Kenya's Mt Kenya at 17000 + and another in Sumatra at 12400 +. An example of the non-linear thinking which can be easily applied to the gun method is that with many cargoes, the entire projectile could be deep frozen (Say in liquid N or He) prior to launch, thereby extending the heat tolerance. I was of course backward with the orientation - the bore hole would actually be pointed a little eastward. GS (circular) orbital velocity is about 3440 mph, eastward, so there is a little delta V (about 1400 mph) to make up. Some portion of this would come from the vectored rocket firing in the Hohmann transfer maneuver. Jack -Original Message- From: Michael Turner [mailto:[EMAIL PROTECTED] Sent: Thursday 08 April 2004 11:48 To: [EMAIL PROTECTED] Subject: Re: The gun thing again Joe Latrell writes: Having done some experiments in gun launching (nothing to orbit mind you) there are a lot of factors involved that make it very unattractive. Heat is a really big issue. I've read papers that suggest a dead-mass burden of about 15% for ablative shielding. I.e., in the same ballpark as reentry capsules. No showstopper, at least for the optimist. Launching from higher altitudes definitely helps, since even 14,000 feet gets you above over 25% of the atmosphere. However, the geosync inflatable station is a great idea. Using a transhab type design, you can launch a really big space station with only a few launches, assemble it (self assembly?) and then get to work building probes to wherever you want to send them. Engineering inflatables for gun launch is an interesting idea. There may be some kinks in it (as it were), but it seems ideal for solving many construction problems. If you perfected rendezvous, one approach that I think would be kinda cool is: 1. launch an inflatable 2. inflate it 3. launch another 4. rendezvous at some orifice 5. inflate the new one *inside* the current one (vent residual gas to a pressure tank, and reuse the gas for future inflation) 6. repeat from 3 until you have enough layers for whatever purpose desired. This is nice because it means you can build structures of considerable mass within small payload limitations, and because it's fault tolerant -- blow a launch or miss a rendezvous, and the relative cheapness of gun launch (amortized over many launches, anyway) means just planning for a few more launches than the absolute minimum. To Jack's questions: Sundry clever primates around the world Having met me recently, Jack, you know just how ridged a brow and prognathous a jaw you're dealing with, in talking to me. (Thanks for the back-shaving tips, by the way. ;-) OK, OK, I know. The gun thing won't work for orbital delivery of stuff to build Europan probes because one can't shave the big bump off of the resultant wobbling orbit ... or +- something like that. The big bump? If you mean that it starts out very elliptical, shaving the big bumps (which I'm better at now; my back isn't as red and sore as it used to be) amounts to circularizing the orbit. If you launch enough fuel into the same orbit as the original projectile, you can use it to circularize the orbit at perigee pretty efficiently, or even just head right on out of Earth orbit, I would think. (Joe? You're the guy who most recently did the orbital dynamics stuff, right?) However if one were to cant the trajectory of an equatorial gun back a little to the
RE: The gun thing again (of topic)
Double or triple layers, a few feet from each other, chambered. If the outer layer is breached, the inner layer of the chamber which was hit would stretch outward under impetus of the pressure delta, cover the hole and seal it off. It is unlikely that holes in the inner and outer layers would align. Even if so, punctures in a chambered inflatable are easy to plug with anything sheet-like. Jack -Original Message- From: Sean McCutcheon [mailto:[EMAIL PROTECTED] Sent: Thursday 08 April 2004 15:02 To: [EMAIL PROTECTED] Subject: RE: The gun thing again What if there is a puncture? -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Thursday, April 08, 2004 1:23 PM To: [EMAIL PROTECTED] Subject: Re: The gun thing again An alternative would be to send up smaller spaces that connect together like bubbles. I guess it really depends on what is considered small for launching. If to objective would be to have a living/working space of say a 10x10x10 feet, you could send it in a package as small as 4x4x4 and it will include all the materials to expand it, seal it and prepare it for the next one. If you build them with three hatches each, you can create some great combinations! Joe L. Joe Latrell writes: Having done some experiments in gun launching (nothing to orbit mind you) there are a lot of factors involved that make it very unattractive. Heat is a really big issue. I've read papers that suggest a dead-mass burden of about 15% for ablative shielding. I.e., in the same ballpark as reentry capsules. No showstopper, at least for the optimist. Launching from higher altitudes definitely helps, since even 14,000 feet gets you above over 25% of the atmosphere. However, the geosync inflatable station is a great idea. Using a transhab type design, you can launch a really big space station with only a few launches, assemble it (self assembly?) and then get to work building probes to wherever you want to send them. Engineering inflatables for gun launch is an interesting idea. There may be some kinks in it (as it were), but it seems ideal for solving many construction problems. If you perfected rendezvous, one approach that I think would be kinda cool is: 1. launch an inflatable 2. inflate it 3. launch another 4. rendezvous at some orifice 5. inflate the new one *inside* the current one (vent residual gas to a pressure tank, and reuse the gas for future inflation) 6. repeat from 3 until you have enough layers for whatever purpose desired. This is nice because it means you can build structures of considerable mass within small payload limitations, and because it's fault tolerant -- blow a launch or miss a rendezvous, and the relative cheapness of gun launch (amortized over many launches, anyway) means just planning for a few more launches than the absolute minimum. To Jack's questions: Sundry clever primates around the world Having met me recently, Jack, you know just how ridged a brow and prognathous a jaw you're dealing with, in talking to me. (Thanks for the back-shaving tips, by the way. ;-) OK, OK, I know. The gun thing won't work for orbital delivery of stuff to build Europan probes because one can't shave the big bump off of the resultant wobbling orbit ... or +- something like that. The big bump? If you mean that it starts out very elliptical, shaving the big bumps (which I'm better at now; my back isn't as red and sore as it used to be) amounts to circularizing the orbit. If you launch enough fuel into the same orbit as the original projectile, you can use it to circularize the orbit at perigee pretty efficiently, or even just head right on out of Earth orbit, I would think. (Joe? You're the guy who most recently did the orbital dynamics stuff, right?) However if one were to cant the trajectory of an equatorial gun back a little to the west, a projectile could be delivered which would die into a geosynchronous orbit. Granted, you'd only get one shot per gun per day, but at say a ton per shot ... Um. Hm. I did some rough calculations a while back, looking at shooting straight up and using the Earth's rotation as free vector, and I remember coming up with an orbit out past the moon. But you're proposing something else, I realize. Still, I don't think you can get GEO without a burn, no matter what. Everything I've looked at suggests that you need a kick stage at the top just to avoid grazing the atmosphere on the backswing. Of course, it's also possible to coast up to a libration point, I suppose. But that's a lo-oo-ong way out there. And means a bigger gun. How much bigger? Haven't figured it out. Probably not too much smaller than what you'd need for Earth escape velocity. Then from this orbit, a finished product could be dropped and
Re: The gun thing again [Off Topic]
One of the problems I encountered was how do you build circuitry to survive the launch. The forces involved will destroy most electronics as they are now built. Solids state is not very solid after 15x gravitational forces. As they are now built - for what? They've built nuclear explosives into artillery shells, and those devices require carefully-timed electronics. Artillery shells often have proximity fuzes. There's a lot you can do, and people have been doing it, for a long time. I probably sound negative, but the only way to prove it is to build one (even a small one) and see what happens. They have been built, and they have seen what happens. You can build things to take far more than 15g. Drop your watch onto a concrete floor. Keeps on ticking. Compute the likely acceleration it experienced on impact. You'll be amazed. (You probably don't have to compute it - it's probably written on the box it came in.) Gerald Bull found that wooden sabots work just fine. He also found that immersing a liquid fuel rocket in water inside the cancels almost all of the forces that you'd think would crush it. Intuitively, gun launch to space fails the intuition test. So much the worse for intuition. Do the math. Pulling this back to the topic (sort of), would building a gun of this type on the moon facilitate the launching of deep space probes? We would eliminate the atmospheric issues and most of the acceleration issues too. Anything that reduces launch cost dramatically facilitates almost anything you might want to do in space. Once you can get a lot of stuff up there cheaply, many problems go away. Launching living things is the one payload category that seems off the boards, though I wouldn't be surprised if you could launch frozen ova, seeds, spores, and microbiology that ecosystems depend on, with little trouble. Ditto for food ingredients. -michael turner [EMAIL PROTECTED] == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
