REPORT FOR ANALYTICAL CHEMISTS
The
Mark
of Superior Craftsmanship IN SINTERED UIASS FILTER WARE Plus Economy and Service
MEN, MECHANISMS, AND MATERIALS
6130 CRUCIBLE - Gooch, high large form with Ace Fiber Glass Disc sealed in. Porosities A-B-C-D-E Oia. disc, mm
30
Ht. abv. disc, mm
45
Capacity, ml
30
THE FIRST AMERICAN MADE SINTERED GLASS FILTER (U.S. Pat. No. 2,136,170) STANDARD UNIFORMITY Each Filter Plate Is Individually Tested for Porosity and Hardness
FILTER OISCS-6142 In the following Millimeter Sizes 10-25-30-40-50-65-90-120-150 8570 TUBE for construction of special apparatus with Ace. fiber glass filter disc sealed in. Porosities A-B-C-D-E Dia. of Disc, mm
10 to 90
Total length, mm
200 to 250
PI 8600 FILTER TUBE for filtering and gas dispersion. Porosities A-B-C-D-E Dia. of Disc, m m . . . 25,30
Ask Dep't FW* F to send Brochure.
Also in stock at our Midwestern Division, Louisville, Ky.
ACE G L A S S I N C O R P O R A T E D VINELAND |;V
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In anticipation of the rocket fuels of the future the analytical chemist has been busy correlating the purity and stability of many substances of possible utility, such as liquid ozone. He is aware that man's ability to pioneer in the infinite may well be dependent upon his ability to probe into the finite.
NEW JERSEY
M i d w e s t e r n Division
•/ LOUISVILLE, K Y . - B o x 996 SpeeuUolU ta Indu-iÎTy and ^caea-iea
If it is true, as the adage affirms, that it takes all kinds of people to make a world, it is equally true that it takes all kinds of men to make a moon. For as one surveys the magnitude of the construction problems involved in a man-made satellite and its associated launching equipment and tracking devices, it suggests a cross-section sampling of all skills and sciences. A cursory inspection of these items is sufficient for the chemist in the field of materials analysis to identify his contribution. T h e satellite, a 20-inch-diameter sphere, weighing 21.5 pounds complete with instrumentation, is fabricated largely from magnesium and magnesium alloys. The choice of magnesium is particularly understandable when one considers that for every pound of satellite, a half-ton of rocket and propellants is required. The shell consists of two hemispheres of AZ31B magnesium alloy (96% Mg, 3% Al, and 1% Zn), fabricated by the metalworking operation known as "spinning," and held together by hundreds of stainless steel, jeweler-type screws. The AZ31B alloy has a very low calcium content and was chosen for its excellent weldability, and good working characteristics. The internal structure and support framework is magnesium tubing, except the antenna mounts, which are machined from solid magnesium stock. After stress relief of the welded framework, it is placed inside the hemispheres, which are then joined, machined, and polished to mirror brightness, and plated with successive layers of copper, silver, and gold. This basic structural portion of the satellite is produced by contract and is furnished to NRL for instrumentation and final application of the surface layers of temperature-regulating materials. Adjacent to the polished gold-plate is added a plate of chromium metal, then a coating of silicon monoxide, a vaporized film of aluminum, and a final coating of silicon monoxide. Although the first satellite cannot possibly contain all the devices that inquiring scientific minds would like to incorporate in a "space laboratory," it does contain a remarkable number, thanks to miniaturization and semicon-
ductor technology. Included in or on the satellite are two ionization chambers, a solar aspect cell, erosion gages, a cadmium sulfide cell for erosion studies, micrometer microphones, thermistors, a Minitrack radio transmitter, a telemetry system, and ultraviolet radiation (Lyman alpha) memory storage units. Eight pounds of chemical batteries are required. The launching vehicle or rocket mechanism is a conglomeration of construction compromises that is required to do a job of exacting specifications under intolerably difficult circumstances. The wide temperature range to which the materials of construction are subjected, the stresses and strains created by the development of energy at the rate of a quarter million horsepower, the corrosive and temperamental behavior of the propellants, and the relentless demands for minimum weight impose a set of restrictions and limitations upon the project that call for the closest of working relationships between chemist, metallurgist, and construction engineer. Minimum weight considerations along with advances in the state of the rocket art have removed the stabilizing fins from the first-stage rocket and eliminated structural reinforcements to the point that propellant tanks also form the walls of the rocket. All of which means that the rocket tanks must be loaded while the rocket is in a vertical position in the servicing gantry, for the loaded rocket cannot support its own weight in the horizontal position. The first-stage rocket operates for nearly 2.5 minutes, and generates temperatures many times in excess of the melting point of the combustion chamber materials. In addition, it must help to impart guidance to the entire structure by the direction of its thrust. To do this the gimbal rocket motor must move through as much as five degrees, with the necessary attendant flexibility of fuel lines. A steam turbine is required to operate the fuel pumps at the enormous capacity specified. It in turn is driven by the steam generated by the decomposition of carefully analyzed hydrogen peroxide. As the propellants are pumped from the tanks, helium from stainless steel reservoirs floods the volumes to maintain pressure and provide rigidity. Valving arrangements permit part of the helium and steam to be diverted to the external roll jets that assist in stabilizing flight. Thrust for the second stage is provided by the reaction between white fuming nitric acid and unsymmetrical dimethylhydrazine ; and an ingenious rocket motor makes use of the nitric
Circle No. 24 A on Readers' Service Card, page 83 A 24A
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ANALYTICAL CHEMISTRY For further information, circle numbers 25A-1, 25 A-2, 25 A-3 on Readers' Service Card, page 83 A-
