The statement of *"there are no unmanned transport aircraft at present"* is misleading. Virtually all modern aircraft can be quickly modified for automation.
The statement of *"The closer to vertical it's sent, and the less vehicle which is sent up to transport it, the lower the energy."* is also misleading in that a slow climb rate is the most efficient rate of climb. A shallow climb rate, weather on a straight or circular coarse is the most efficient for a mass effort if fixed wing craft are used. If Andrew wishes to devalue all other forms of aviation in support of ballistics, I would advise reading up..on..aviation. Michael On Wed, Mar 14, 2012 at 6:29 PM, Andrew Lockley <and...@andrewlockley.com>wrote: > Thanks for that, Roger. I'm aware of the issue with frictional losses > - but the only way to send the payload up with little 'dead metal' is > to propel it from the ground. The closer to vertical it's sent, and > the less vehicle which is sent up to transport it, the lower the > energy. > > Labour costs are also a big deal - there are no unmanned transport > aircraft at present, other than research planes. (AFAIK). > > This seems to make sense to me. Am I missing something? > > A > > On 15 March 2012 01:09, John Latham <john.latha...@manchester.ac.uk> > wrote: > > Hello All, > > Please see below message from Roger Angel > > All Best John (Latham) > > > > ************************************ > > > > Hello Roger, > > I've sent on yr message (below), as requested, to: > > [geoengineering@googlegroups.com] > > Good to hear from you, John. > > > > ************************************** > > John Latham > > Address: P.O. Box 3000,MMM,NCAR,Boulder,CO 80307-3000 > > Email: lat...@ucar.edu or john.latha...@manchester.ac.uk > > Tel: (US-Work) 303-497-8182 or (US-Home) 303-444-2429 > > or (US-Cell) 303-882-0724 or (UK) 01928-730-002 > > http://www.mmm.ucar.edu/people/latham > > ________________________________________ > > > > > > From: Roger Angel [ang...@email.arizona.edu] > > Sent: Wednesday, March 14, 2012 11:59 PM > > To: John Latham > > Subject: Re: [geo] Ballistics - failure to distinguish > > > > Hi John, > > > > I sent the following reply to the geo group, but I don't think it went > > through. I have not sent anything for a long while, though I get it > > all. You may want to circulate it. > > > > Thanks, > > > > Roger Angel > > > > > > Re: Ballistics - failure to distinguish > > > > Another reason to distinguish carefully - the lowest energy solution to > > get sulphur to the stratosphere will get there with zero velocity. > > Technology for orbiting will in general be mismatched because of the > > premium on very high velocities. > > > > - Roger Angel > > > > On 3/14/2012 12:46 PM, John Latham wrote: > >> Hello Andrew., > >> > >> You say "Ballistic delivery of materials for the purpose of Solar > Radiation Management", > >> but unless I'm misunderstanding you, you mean Stratospheric Sulphur > Seeding, not SRM. > >> > >> Stratospheric Sulphur Seeding is certainly the SRM scheme that has > attracted most > >> attention, and I wish it well, but it is only one of several. Others > include sunshades in > >> space, Russell Seitz's micro-bubbles, painting roofs white& cloud > brightening. > >> > >> It is good to distinguish clearly between the all-embracing term SRM, > and individual > >> techniques in that category. I wouldnt have written at this point, but > this lack of distinction > >> has been made recently by others, too. > >> > >> Good luck with yr poster. > >> > >> All Best, John. > >> > >> > >> > >> John Latham > >> Address: P.O. Box 3000,MMM,NCAR,Boulder,CO 80307-3000 > >> Email: lat...@ucar.edu or john.latha...@manchester.ac.uk > >> Tel: (US-Work) 303-497-8182 or (US-Home) 303-444-2429 > >> or (US-Cell) 303-882-0724 or (UK) 01928-730-002 > >> http://www.mmm.ucar.edu/people/latham > >> ________________________________________ > >> From: geoengineering@googlegroups.com [geoengineering@googlegroups.com] > on behalf of Andrew Lockley [andrew.lock...@gmail.com] > >> Sent: Monday, March 12, 2012 11:55 PM > >> To: geoengineering > >> Subject: [geo] Ballistics > >> > >> The below will form the basis of my poster at PUP, and the subsequent > >> paper. It's at a relatively early stage, and references haven't yet > >> been added. Comments on or off list would be appreciated. > >> > >> Thanks > >> > >> A > >> > >> -------------------------- > >> > >> Ballistics for delivery of SRM materials - an engineering principles > approach > >> > >> Introduction > >> ------------ > >> > >> Ballistic delivery of materials for the purpose of Solar Radiation > >> Management has been proposed and appraised by various authors. > >> Evaluation of technologies has been generally limited to redeployed > >> military hardware, such as tank or battleship guns. Such technologies > >> were not designed to deliver SRM materials, and are poorly suited to > >> the purpose, leading to high cost estimates in previous analyses. The > >> design of ballistic systems is reappraised with geoengineering use in > >> mind, and a literature review of alternative launch technologies is > >> given. The intent is to inform later engineering studies and cost > >> analyses which may seek to design in detail, or to cost, a suitable > >> gunnery system. > >> > >> Design requirements > >> -------------------- > >> > >> Modern military weapons > >> *Infrequent firing > >> *Portable/vehicle mounted > >> *Operating costs relatively unimportant > >> *Accuracy critical > >> *Shells never recovered > >> > >> Geoengineering guns > >> *Frequent or continuous firing > >> *Potentially static > >> *Operating costs relatively important > >> *Accuracy relatively unimportant > >> *Shells may be recovered > >> > >> Engineering differences > >> ----------------------- > >> > >> The objectives listed above will result in geoengineering guns being > >> very different from military weapons. Below are detailed a range of > >> design principles to guide the development of appropriate guns. > >> > >> *Large calibre: Energy costs are reduced substantially by the lower > >> aerodynamic drag per payload kilo on larger rounds (assuming constant > >> shape). > >> *Static installation: Guns will likely be stationary, but may rotate > >> to disperse projectiles widely. > >> *Elevated, mid latitude firing position: Firing from a tall tower or > >> mountain top will reduce muzzle velocities significantly, both by > >> increasing altitude and limiting aerodynamic drag. It will therefore > >> reduce propellant costs and require a less robust shell. Inserting > >> precursors into the ascending arm of the Brewer-Dobson circulation may > >> also reduce insertion altitudes, as well as aiding dispersion. As an > >> alternative, an ocean-submerged gun could be used, which will allow > >> easy repositioning and reorientation, as well as a very long barrel. > >> However, submerged guns will necessarily require a longer trajectory > >> through thicker atmospheric strata to attain the same elevations. > >> *Barrel length unrestricted: Static guns can use long barrels. This > >> means lower pressures are needed, as the propellant can act for > >> longer. This will permit less robust shell designs. > >> *Barrel wear costs are significant: Conventional barrels need > >> relining or replacing regularly due to the friction between the > >> projectile and the barrel. System design which minimises barrel wear > >> is important. (See projectile design, below) > >> *Propellant costs are significant: Hydrocarbon fuel/air mixtures are > >> alternatives for evaluation. > >> *Accuracy is unimportant: Minor trajectory changes resulting from > >> barrel distortions and sub-calibre projectile designs are largely > >> irrelevant. This allows a lighter barrel with a lower-friction fit. > >> *Shell costs are significant: Within the limits of a given > >> manufacturing technique, costs generally fall with a larger shell, as > >> the ratio of volume/surface area changes with size. Further, lower > >> pressures resulting from a longer barrel allow the use of less robust > >> shells than would otherwise be the case. > >> *Externally stabilised barrel: Military barrels are typically > >> self-supporting, whereas a scaffolding can be built to stabilise a > >> geoengineering gun. Where available, the gun may be built against > >> terrain. This additionally has the advantage of allowing easy access > >> to all barrel sections for maintenance. > >> > >> Projectile design > >> ---------------- > >> > >> *Lighter shell casings: Geoengineering projectile casings perform no > >> direct function, which differs from military uses where the casing is > >> itself a weapon. Casing contains the payload (which may be under > >> pressure), allows the propellant to act on it, and acts as a faring > >> during its travel through the atmosphere. The need to reduce casing > >> cost/weight suggests a more fragile casing, requiring lower propellant > >> pressures, and necessitating a longer barrel. > >> *Gradual payload release: Military guns rely on a momentary > >> detonation; geoengineering guns will likely benefit from a > >> 'slow-bleed' release of payload, to better aid dispersal. To this end, > >> a small dispersal aperture may be preferable to a fully frangible > >> casing. > >> *Low frontal area to volume ratio: Longer, thinner projectiles > >> experience less drag per unit mass. This has to be traded off against > >> higher casing costs from a relatively larger surface area. > >> *Payload dispersal: If explosive dispersal is not used, a similarly > >> cheap design for payload dispersal will be required. High-pressure > >> gases will self-disperse through any aperture. Liquids will need to > >> be forced through nozzles to achieve controlled particle size and > >> payload delivery at the desired location. Liquid-filled projectiles > >> will require a significant force to evacuate the payload from a large > >> shell on a short flight time, especially if fine droplet control is > >> required. Where rifling is practicable, centrifugal force may assist > >> dispersal. However, not all launch technologies permit rifling or > >> equivalent (eg railguns). Throughflow of external air in the payload > >> chamber could provide pressure to distribute the payload. A > >> propellant charge could alternatively be used. A simpler alternative > >> would be to dissolve gas into the propellant, allowing it to generate > >> its own force by effervescence. > >> *Shell recycling: Projectiles would ideally be recovered for recycling > >> or reuse. Predictable fall patterns from a static gun may make this > >> practical. More complex shell designs are harder to recycle, so a > >> simple design with few materials and components is preferable. > >> *Low-friction driving bands: Swaging bands are used to seal > >> projectiles to the barrel, maintaining a pressure differential. They > >> are usually metal, but plastic bands are used, such as in the GAU-8/A > >> Avenger fitted to the A-10. A low acceleration, long-barrel gun will > >> require a less demanding band design. Some guns, eg GC-45, do not > >> require driving bands at all. > >> *Base bleed: A slow-burning propellant can be added to the base of a > >> projectile in order to stabilise airflow over the rear of the shell. > >> This 'base bleed' technology improves aerodynamics to improve range at > >> a given muzzle energy. > >> > >> Alternative Technologies > >> ---------------------------------- > >> > >> A broad range of alternative technologies has previously been proposed > >> for gunnery, much of which has been motivated by a desire to allow > >> ballistic space launch. Below some technologies are considered which > >> superficially appear suitable for geoengineering. > >> > >> Light gas gun: This uses a tapering combustion chamber filled with > >> light gas (eg H2 or He) to provide potentially high muzzle velocities. > >> The mechanism of action is the same as that of a pellet gun (ie a > >> hydraulic force converter), but with a gas pressure (eg explosive) > >> propellant rather than a spring. This would be of interest were long > >> flight paths required, as the high muzzle velocity would allow low > >> angles of elevation to be used whilst still enabling the projectile to > >> reach the stratosphere. This would result in low payload ejection > >> rates and better dispersion. Cheap fossil fuels can be used, with > >> methane being deployed in experimental systems. Accelerations are > >> high, complicating projectile design. > >> > >> Ram accelerator: This launch system relies on a teardrop shaped, > >> sub-calibre projectile, which passes through a fuel/air mix. Due to > >> aerodynamic effects, the passage of the projectile controls the > >> combustion of the surrounding fuel, resulting in a zone of combustion > >> behind the projectile. This has two crucial advantages: very low > >> barrel wear (only stabilising fins contact the barrel) and very cheap > >> propellant (fuel-air mixture). However, the projectile has to be > >> launched into the ram accelerator at supersonic speeds, necessitating > >> a secondary launch system and increasing both complexity and cost. > >> > >> Coilgun: Electrically powered coilguns rely on electromagnets to > >> attract and accelerate a ferromagnetic projectile. This would require > >> the use of a significant mass of ferromagnetic material in the > >> projectile, increasing energy costs and making recovery/recycling more > >> important. Nevertheless, the frictionless design, and entirely > >> electrical power system, makes this an attractive system. Coilguns > >> are well researched, and various military uses are envisaged with some > >> space-launch projects specified. > >> > >> Ablative laser propulsion: A sulphur mass can be lifted and gasified > >> by the action of a ground based laser. This propulsion technology > >> could be combined with alternative lifting technologies, such as > >> gunnery. It has the advantage of potentially being made to work with > >> a solid sulfur projectile, thus eliminating the need to loft other > >> chemical species, which can instead be sourced from atmospheric air. > >> > >> > >> Other projects > >> ------------------- > >> Various supergun projects have been tested, which indicate some useful > >> design features and principles: > >> *V3: German WWII V3 gun designs used a smooth-bore barrel and an > >> aerodynamically-stabilised projectile. Propellant was multi-stage > >> solid rocket boosters, inserted into the barrel and fired against the > >> projectile as it passed. > >> *Startram: This proposed space launch project relies on MAGLEV > >> propulsion to accelerate craft to orbital velocities. Acceleration > >> takes place in a vacuum, with a plasma window protecting the open end. > >> *Superguns: Conventional artillery pieces, such as Big Bertha, Dora > >> and Project Babylon have all demonstrated heavy lift capability with > >> extended range. > >> > >> > >> Conclusions > >> ------------ > >> > >> Previous evaluation of gunnery for geoengineering use is inadequate, > >> as the military technology evaluated is wholly different in design > >> objectives from custom-build geoengineering equipment. > >> > >> The design of geoengineering guns will likely be based on alternative > >> design principles and may use alternative propellant technologies. > >> > >> Of the alternative gunnery technologies presented, ram accelerators > >> appear to have particular promise because: > >> *Low barrel wear > >> *Very cheap propellant > >> *Low acceleration allows a cheaper, less robust shell > >> > >> A secondary launch system would be required, and a conventional gun > >> could be used. A light gas gun or coilgun would be likely to reduce > >> costs, once developed, due to low propellant costs. > >> > >> Laser-ablation systems are worthy of consideration, but are at an > >> early research stage. > >> > >> A typical geoengineering gunnery system may therefore be a large > >> 'supergun' style design, based on a two-stage system with ram > >> accelerator technology providing the terminal stage. The angle of > >> elevation would be non-vertical, to enable bleed-dispersal of payload. > >> One design variant would rely on terrain support, being built against > >> the slope of a mountain. An alternative would be a rotating turntable > >> on a high plateau, which would give broader dispersal but would be > >> more costly per gun. > >> > >> Projectiles would likely be lightweight and substantially less robust > >> than military designs. An effervescent liquid, or high pressure gas, > >> will likely be the cheapest dispersal technology, should a slow > >> release be preferred. It is likely that spent projectiles would be > >> recovered and recycled. Base bleed technology may reduce costs, > >> although there is a tradeoff between energy and complexity costs. > >> > >> -- > >> You received this message because you are subscribed to the Google > Groups "geoengineering" group. > >> To post to this group, send email to geoengineering@googlegroups.com. > >> To unsubscribe from this group, send email to > geoengineering+unsubscr...@googlegroups.com. > >> 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 geoengineering@googlegroups.com. > > To unsubscribe from this group, send email to > geoengineering+unsubscr...@googlegroups.com. > > For more options, visit this group at > http://groups.google.com/group/geoengineering?hl=en. > > > > > > -- > twitter @andrewjlockley > 07813979322 > andrewlockley.com > skype: andrewjlockley > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To post to this group, send email to geoengineering@googlegroups.com. > To unsubscribe from this group, send email to > geoengineering+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/geoengineering?hl=en. > > -- *Michael Hayes* *360-708-4976* http://www.voglerlake.com -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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