I disagree that the pilotless conversion is simple. The trajectory comment was comparing shells with shells, not shells with aircraft
A On Mar 20, 2012 8:36 PM, "Michael Hayes" <[email protected]> wrote: > > 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 > <[email protected]>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 <[email protected]> >> 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: >> > [[email protected]] >> > Good to hear from you, John. >> > >> > ************************************** >> > John Latham >> > Address: P.O. Box 3000,MMM,NCAR,Boulder,CO 80307-3000 >> > Email: [email protected] or [email protected] >> > 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 [[email protected]] >> > 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: [email protected] or [email protected] >> >> 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: [email protected] [[email protected]] >> on behalf of Andrew Lockley [[email protected]] >> >> 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 [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. >> > >> >> >> >> -- >> 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 [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.voglerlake.com > > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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