A good starter could be a study to identify the worlds disused mine shafts to test the concept of long barrels firing shells made of supercooled sulphuric acid. The shell casing could be considerably reduced, but ultimately these shafts would have to be dug into mountains to make the benefit of altitude and thin atmosphere to help them carry payloads higher and to right areas of atmosphere.
Date: Mon, 4 Apr 2011 18:08:24 -0700 Subject: Re: [geo] Another look at gunnery? From: [email protected] To: [email protected] CC: [email protected]; [email protected] Hi Andrew, the Space Fountain Concept could give us very important multiple benefits in one project. Here is the Wiki primer on the concept. http://en.wikipedia.org/wiki/Space_fountain As you can see, this is an advanced concept which can be built with todays technology. By focusing on a multi use project, the cost of SRM becomes almost an after thought. If we are to use stratospheric injection as the main SRM tool, keeping the injection going for many decades will be needed. By backing a multi use commercial space delivery system, the SRM cost would simply be absorbed as a cost of doing business. My earliest submission to this group was on the subject of a similar concept and it was a clumsy effort. I was too focused on nuts and bolts and not on theory. At that time, I had not found the concept of the Space Fountain, yet there are some similarities. I did call for a vacuum tube extending up into the stratosphere and the use of High Temp. Super Conductive Magnetic in a coil gun fashion. The main difference was that I proposed a more mechanical lift system than that of the Space Fountain concept. We do need all of the benefits that the Space Fountain has to offer to launch us beyond this time of critical energy/pollution problems. Huge amounts of capital are going to be spent one way or the other to deal with the issues we face. A concept like the Space Fountain can be a focus for that investment and it can be a net benefit as opposed to a net loss. I am not an expert on any aspect of this issue, however, I believe this type of multi problem solving approach is something that might be supported by most sides in this debate. Thanks, On Mon, Apr 4, 2011 at 4:43 PM, Andrew Lockley <[email protected]> wrote: Hi I've been going over some reports and notes recently, notably the Aurora report http://people.ucalgary.ca/~keith/Misc/AuroraGeoReport.pdf The report makes it pretty clear that they've not done a huge amount to expand on gunnery as a tool. Specifically, the report states that: " In the 80-100 kft range, the relative simplicity of the gun system begins to look attractive despite the high recuring cost of shells, if the payload fraction can be increased" Back to basics here. Gunnery was developed by the military. Navies need portable guns that aren't fired often - the exact opposite design criteria that geoengineers need. Sailors therefore have short thick barrels with massive overpressures, and robust shells to withstand the high g forces a short barrel requires.. This is absolutely nothing like what we need for geoengineering. We need long guns that work at low overpressure. Low overpressure means a lightweight shell casing, a less tight barrel seal leading to lower friction and hence lower wear and thus lower costs. I think we need to look at completely different gunnery technologies, as well as just looking at gun redesign. My favorite is the ram launcher. This works with a loose (sub calibre) shell as it doesn't rely on barrel friction, so there's not the wear and cooling problem you get with a gun. It doesn't require expensive propellants, as you can run it on a cheap fuel/air mix. The acceleration is continuous, not declining like with a gun - so it's much gentler. In fact, accelerations as low as 600g with a 1.2km barrel are possible - and that still gives you 8kms/s launch speed - well over what's needed for accessing the stratosphere. That's 1/10th the acceleration in a conventional gun (although you do need to initiate the projectile with a primary launcher - a ram accelerator can't self start). In case people need a reminder, the ram projectile works by firing a loose-fitting projectile which relies on aerodynamic effects to ingnite fuel behind it by compression ignition, like a ramjet. It travels through the propellant, rather than being pushed in front of it. As a result of the loose fit and low launch stresses, the shells are likely to be very much thinner, cheaper and less well-engineered than conventional shells, and it may even be possible to make the shells reusable or at least recyclable. What do other people think of this? For more info on the technology, check the following links: http://www.tbfg.org/papers/Ram%20Accelerator%20Technical%20Risks%20ISDC07.pdf and for an improved version, check http://www.galcit.caltech.edu/~jeshep/icders/cd-rom/EXTABS/178_20TH.PDF A -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en. -- Michael Hayes 360-708-4976 http://www.wix.com/voglerlake/vogler-lake-web-site -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
