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Aviation History
1957
1957 - 1808.PDF
898 FLIGHT, to December 1957 Missiles 1957 . . . ( U. S.A continued) been planned for several years by Cqnvair andthe Radio Corporation of America. The U.S.A.F. awarded Phase I studies to Boeing/G.E. / Ramo-Wooldridge, Lockheed / Raytheon, and Douglas/B.T.L., but Convair/R.C.A. arethe only group going ahead with the work and their system has been endorsed by the JointChiefs of Staff as the future defensive system for the whole of the U.S.A. Fundamental to the successful interceptionof any ballistic warhead is its early detection, and the "break-through" which has made theWizard concept practicable is the development of "fine structure analysis" radar by ColumbiaUniversity and Rome A.D.C. since March 1954. This permits target range and velocityto be measured with unprecedented accuracy even when the signal strength is still below the(unprocessed) background noise level. Exist- ing radars can see up to 300 miles (one minute'sICBM flight), but the Columbia Omnirange Digital Radar extends this to fifteen minutes,a distance of some thousands of miles. The intention is that the Wizard anti-missile shouldmeet the on-coming ICBM near the apogee. The missile itself will have a nuclear warheadand a range of approximately 1,000 miles and a flight performance appreciably in advance ofthat of Hercules. Our American contemporary, Aviation Week, states that sub-contractors onWizard are: G.E. (MOSD) for the warhead; Sanders Associates for a special multi-lobeaerial system, resistant to point-source jam- ming; D. S. Kennedy, Inc., for research intolarge parabolas; and Avco for aerial steering devices. SURFACE-TO-SURFACE Atlas As the first intercontinental ballisticmissile in the Western world, this weapon has required an unprecedented amount of funda-mental research into previously unexplored realms of science. It is logical that a very greatdeal of the work carried out for Atlas, as well as numerous items of "hardware," should havebeen carried across to accelerate progress with the later Titan and Thor. A full account of the background to thegenesis of Atlas was given in our 1956 Missiles issue. The original U.S.A.F. project numberwas MX-1593; the weapon-system number is WS-107A-1, the missile itself is SM-65A(Strategic Missile) and to Convair, the prime contractor, it is Model 7. Initial design and pro-totype fabrication was done at Convair"s San Diego division, but during the past few monthsit has been transferred to a completely new $40m facility north-east of San Diego. Theheadquarters of the Astronautics division, this plant will be fully occupied by the middle ofnext month with a staff of 7,000. Chief pro- ject engineer is Charles S. Ames. One of the areas in which the design of theAtlas has broken new ground is that of air- frame design. Unlike the Army ballistic mis-siles, Atlas has an airframe with a skin so thin that the interior (integral tanks) has to bepressurized in order to preserve the shape of the body as the propellants are consumedduring flight or when the missile is being transported on the ground. Structure weighthas thus been minimized and the mass-ratio is better than that of any previous ballisticweapon. Prime contractor for propulsion is North American's Rocketdyne division. There arethree powerplants, arranged in a unique fashion. The main body comprises integraltanks for JP-4 fuel and liquid oxygen, and these propellants are fed by turbopump to a singlegimbal-mounted chamber, rated at 65,000 lb thrust, mounted centrally at the lower end*.On either side of this motor is pivoted an additional single-chamber motor rated at135,000 lb thrust, providing boost propulsion. These boost motors burn for 180 sec and arethen jettisoned as a package, taking the large flared body skirt—which provides increaseddirectional stability—with them. All three motors are fired on the ground, so that Atlascan reasonably be called a "lj-stage missile." Following cancellation of the ballistic A.C."Achiever" system, prime contractor for guid- ance is General Electric, whose Heavy Mili-tary Electronic Department (Syracuse) received an $83m contract in April to continue thiswork to the production stage (the H.M.E.D. guidance section is unique in that it conductsits own design, manufacturing, selling, finance and employee relations). The system is of ahybrid radio-inertial variety, functioning in conjunction with G.E. ground radar of veryhigh power, together with a Burroughs com- puter. Such a system does not require a trueinertial platform, and a contract originally let to Minneapolis-Honeywell was therefore can-celled. The latter firm's HIG floating gyros are, however, proving so reliable that thefinal Atlas guidance may well be the pure- inertial system developed for Titan (q.v.). Theguidance controls the trajectory solely by changing the axis of the sustainer motor. Third of the major problems of any ICBMis the nose cone, and here again the prime con- tractor is General Electric (in this case theMissile and Ordnance Systems Division). A contract for $l58m was agreed for this workand the nose-cone section of MOSD have evolved a curious design with a very smoothnose of some 3ft radius, faired into a corru- gated re-entry body about 6ft deep with a metalbase coated with special laminated plastic (here again, this may not be the final configuration).Such is the pace of development that 3-4 days is the maximum allowed for processing the 300types of information available from each nose- cone test, and MOSD Philadelphia operate a$3m automatic computation facility equipped with an I.B.M. 704 and auto analogue/digitalconverters and switching equipment. Tape containing data from nose-cone tests bygovernment and industrial centres—and, now, from flight tests—are handled with un-paralleled speed and reports are then made up for the 1,100 MOSD scientists involved. Asub-contractor for assembled nose-cone hard- ware is Republic Aviation's guided missilesdivision. Contractor responsible for the warhead isthe Sandia Corpn., a subsidiary of Western Electric. The warhead will weigh at least3,000 lb and will, of course, have a megaton yield and very advanced fuzing. The electricalsystem is energized by an A.M.F. (American Machine and Foundry) turbo-alternator run-ning on the main liquid-oxygen/fuel mixture. Gas pressure for the propulsion system isobtained from a manifold fed with the pro- ducts of combustion of a controllable cartridge.As the drawing indicates, a number of pipes * All descriptions of ballistic, tail-standingweapons are worded to conform with the missile in the vertical (firing) position. Raytheon Hawk Surface-to-air. Solid internal boost and sustainer motors. Length, 16ft 4in; span, 47in;body diameter, 16in; firing weight, rather more than 1,000 Ib; burn-out speed, more than Mach 2.8; slant range, about 15 miles. ig IM-99 Bomarc Surface-to-air. Liquid-propellant boost motor with gimbal-mounted chamber (retained>ard) and twin Fiarquardt RJ43 ramjets for cruise propulsion. Length, 46ft 8in; span, 18ft 2in; body lameter, 36in; launching weight, 15,000 Ib; cruising speed, Mach 2.7; ultimate range, over 250 miles. Boein Surface-to-aon bo di and controls are run outside the liquid-oxygentank in a faired conduit. Convair hold a $145m contract for airframefabrication and testing. Twelve XSM-65s are reported to have been manufactured at Plant Iin San Diego. The first was static tested at the Convair facility in Sycamore Canyon (p. 883)in March of this year. Component testing is handled by a facility on Point Loma—also nearSan Diego—and further ground tests, includ- ing static firing, are being undertaken on Leuh-man Ridge, within the perimeter of Edwards A.F.B. No aircraft can reasonably carry Atlasand all are at present being moved on 35ft steel-tube trailers, provided with elevatingrams for placing the empty missiles on their tails. Each trailer has electronic test-gear byHallamore (Siegler Corpn.). Tank pressure- tests are carried out vertically in ad hocbuildings. The first XSM-65 to reach the firing pad atPatrick was scheduled to be launched on May 29, but it was delayed by malfunctioningground-gear until June 11—by which time static-firing time had reached 700 sec. Thefirst flight-prototype comprised an airframe with a simple, pointed nose, together with thetwo boost motors: absent were the sustainer and the operational guidance system. Simpleprogrammed guidance was incorporated to keep the Atlas climbing to a height of 400miles (long after burn-out) followed by a con- trolled flight to a point 200 miles distant. Pre-flight checks on June 10 were satisfac-tory and, following a 10i-hour count-down, the prototype was fired on June 11. Ignitionwas good, as was thrust-balance between the two motors. After only a few seconds, how-ever, a failure to a turbopump valve almost completely shut off the liquid-oxygen supplyto one motor. The flame from this side changed from yellow to a dirty orange, leaving a longsmoke trail of burning fuel. The sudden loss of thrust on one side caused a violent yaw; acomplete loop followed, after which the hard- pressed guidance effected some correction byfully gimballing both motors. Yet vertical flight could not be held, and two more loopsfollowed, until finally the erring vehicle was detonated by Patrick's range safety officer. Theflight ended at about 6,000ft, after 32 seconds' firing time (10 on the pad and 22 in the air).Telemetry was perfect and 95 per cent of the programmed data was actually obtained.Moreover the Atlas proved that its airframe could withstand lateral accelerations of up to22 g—an incredible demonstration of struc- tural strength outside any original design case. A second flight-test was conducted onSeptember 25. On this occasion all three engines were installed, and a curious flight-plan was programmed: vertical climb for a few seconds followed by push-over at 15,000ftand level flight at that extremely low altitude for 2,000 miles down-range until detonationover the outer Bahamas. Such a flight was scheduled to produce aerodynamic datarequired for advanced testing. In the event, a malfunction—presumably similar to that of thefirst prototype, since there was an excess of fuel—led to detonation as soon as cruisingheight was reached. Once again telemetering was perfect and valuable information wasgained. Production SM-65s are beginning to takeform in the new factory. Each will probably be priced at about $lm, exclusive of weapon-system supporting equipment, which is about half the cost of any of the prototypes. Atlasmotors are manufactured at Rocketdyne's new facility near Neosho, Missouri. Turbopumpsbuilt there went on test in September, and the first production Atlas powerplant beganstatic trials last month. This proved the stands, and current running is on a normal produc-tion-acceptance basis. Total SM-65 programme costs now amountto more than $500m—a relatively very modest figure. It will probably be the first ICBMin service in the West, the schedule being 40 operational SM-65s on the pads of StrategicAir Command by 1959. It is, however, per- tinent to point out that an SM-65 is a vervtight fit in a C-133A transport (no other air craft can take it), and that trucking a sing!;weapon from San Diego to Patrick takes 1 days. Much must be done before it becomeoperational. Corporal This lofty spindle of a weapon ;probably so well known by now that little nee :
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