Digital Commons Network^™

Probability Of A Clear Line-Of-Sight Through The Atmosphere For A Satellite Based Laser Communications System: A Feasibility Study, Richard A. Brintzenhofe, James L. Cox, Charles J. Neumann, James T. Williams

Space Congress® Proceedings

The NASA Earth Resources Technology Satellite (ERTS) program is considering the possible use of laser communications to transmit data between a satellite and earth. Such a transmission requires a relatively clear line-of-sight between the satellite and a receiving station on earth. This study considers the effect of clouds on laser transmissions from space.

To get an indication of the receiving capabilities for a selection of ground receiving stations, the authors made a preliminary evaluation of the monthly mean percentage-of-possible-sunshine statistics. With a network of six stations optimally placed, a satellite passing over the contiguous United States would generally be within …

Air Pollution: Our Ecological Alarm And Blessing In Disguise, Hugh W. Ellsaesser

Space Congress® Proceedings

Air pollution is the one feedback signal of nan's overgrazing of his ecological niche on the planet Earth capable of sptreading an alarm throughout the encapsulated cities and suburbs and hopefully in time to allow preventive action. It has already stimulated a greater awareness of and interest in man's total environment and his impact on other species. If air pollution does, indeed, arouse man to come to a planned, as opposed to a catastrophically imposed, equilibrium with the ecology of Earth no one can deny that it will truly have been a blessing in disguise.

Hurricane Seedlings, Neil L. Frank

Space Congress® Proceedings

It is generally recognized that hurricane formation occurs within a pre-existing region of disturbed weather and the dynamical and thermodynamical processes responsible for the disturbed weather are of several different types depending upon the source of energy that feeds the system. Disturbances in which air motion results from cold air underriding and displacing warm air are known as "Baroclinic systems". These are common over subtropical portions of the oceans and are more frequent in the spring and fall. A more common system in the tropics is similar to a simple mechanic heat engine and is driven by the release of …

A Critical Point Anomaly In Saturation Curves Of Reduced Temperatures -Compressibility Planes Of Pure Substances, Joseph W. Bursik

Space Congress® Proceedings

Lines of striction are obtained in 9, x, Tr and Z, x, Tr spaces of one component, two-phase regions; 9 being the reduced pressure volume product, pr vr ; Z, pr vr /Tr and x the quality. Using the concept of smoothly joined saturation curves at the critical points of Tr , 9 and Tr , Z planes and a transformation of the striction curves into the 9, Z plane results in an impossible anomaly at the critical point. Removal of the anomaly necessitates abondoning the concept of smooth, saturation curves at the critical points of all of these planes.

Skylab Consumables Computer Simulation, E. G. Howard, R. C. Scott

Space Congress® Proceedings

A computer program has been developed to calculate resources expended on a NASA Skylab mission and to identify mission incompatibilities,, The program works by modeling engineering subsystems of the Skylab cluster* The computer program does not compensate for problems found, but locates and identifies them. It does permit the evaluation of the impact of one subsystem upon another 0 An output of consumable usage as a function of mission time is supplied on a fixed time interval basis as specified by the user, with a minimum time interval of six minutes.

Facilities Planning Approach For The Space Shuttle, J. T. Rose

Space Congress® Proceedings

In developing an overall facilities plan for the Space Shuttle program, it is important to recognize that manufacturing, development, and operations requirements cannot be independently developed. While it is true that specific requirements for each element can be developed independently, applying these requirements to candidate locations can only result in an optimized facilities plan when the appropriate interrelationships of all program elements are properly assessed. Starting with an understanding both of the Shuttle vehicles and of the overall assembly flow, this paper discusses the MDC study of the overall manufacturing, test, and operations requirements for facilities. It also demonstrates the …

Progress In The Dissipation Of Fog, Robert D. Fletcher

Space Congress® Proceedings

The first part of this presentation concentrates on operational programs in the dissipation of supercooled fog as conducted by U. S. commercial and military agencies with emphasis on that of the U. S. Air Force f s Air Weather Service (AWS). This program involves airborne dissipation systems at Elmendorf Air Force Base, Alaska, and at U. S, "bases in Germany, as well as ground-based propane systems at Fair child Air Force Base, Washington, and Hahn Air Base, Germany.

The second part reviews progress in warm-fog dissipation which is mostly in the research and development stage. The French jet-engine installation is …

Integration Of Techniques For Problem Formulation And Solution, Ivan Bratt

Space Congress® Proceedings

The problem solving process covering problem identification until implementation of a solution should be regarded as a multiple feed-back process. This paper suggests a technique for problem formulation which can be put into a computer for evaluation with a minimum of programming. The technique is designed to facilitate evaluation of a restructured problem to encourage optimization of systems by iterativly exchanging parts of the system.

Space Station Utilization In Lunar Orbit, Fritz C. Runge

Space Congress® Proceedings

An effective lunar exploration system can be created by flying a modified earth-orbit space station in polar lunar orbit as a remote sensor platform and lander deployment base.

Objectives of such a lunar station can be categorized by (1) science, (2) technology and (3) operational experimentation. A plan for orbital investigations and surface exploration is presented.

The lunar environment, as well as interactions with the lunar landers, logistics shuttles, and a propellant depot levy unique requirements for the conversion of an earth station to lunar applications.

It appears feasible and highly economical to use a modified earth-orbit station for major …

Application Of Reliability And System Safety Analytical Techniques To A Civic Need, Thomas G. Goss

Space Congress® Proceedings

Many billions of tax payer dollars have been spent on aerospace programs. In order to continue further expenditures for the exploration of space, the American people demand a payoff which is beneficial to the average citizen. This paper will outline one such "spin-off"; VIZ, the application of reliability and system safety analytical techniques to a civic need.

A Low-Power Magnetic Torquer For Satellite Attitude Control, Michael E. Polites, Charles A. Gibson

Space Congress® Proceedings

This paper analyzes a magnetic torquer for satellite attitude control which requires very little energy, or average power, to control its magnetic moment. The magnetic torquer consists of a solenoid with a hard magnetic-material core that has a large residual intensity of magnetization. Discharging capacitors through the solenoid winding generates current pulses to switch the polarity of the residual intensity of magnetization in order to control the magnetic moment of the magnetic torquer. A mathematical model and design equations are presented for the magnetic torquer.

First Underwater Artic Winter Expedition, Andres Pruna, J. Macinnis

Space Congress® Proceedings

Perhaps I should start off by stating the reasons for having an underwater expedition in the arctic. Recent human activities in the arctic have focused attention on mans poverty of knowledge in this area, morover there is a particular lack of understanding of ecosystem relationships within the Arctic Ocean. What we do know indicates that arctic marine biomass may be extremely "fragile 11 even to minor pollution stress. Complicating this situation is the fact that issues such as arctic progress, preservation and sovernity are gaining increasing national importance. The Canadian Government as well as other governments who posses territory in …

Thermal Ground Testing Of Concorde And Veras Or Improvement In French Test Methods And Facilities, G. L. Leroy, N'Guyen, M. Perrais, H. Loiseau

Space Congress® Proceedings

The more numerous the requirements are in aerospace vehicle operations, the more the ground test facility have to improve both the nature and the quality of the equipment as well as the volume and the size of the sites, for the importance of ground testing cannot be over emphasized.

As an example, two ground test programs are reviewed in this presentation, namely CONCORDE and VERAS. Special emphasis is given to the facility implementations due respectively to the static and fatigue test of CONCORDE in heat environment and to the dynamic test of VERAS in high level and transient temperature conditions.

Reliability's Role In Key Project Decisions, Haggai Cohen

Space Congress® Proceedings

Tb present a brief -summary of the role played by reliability in the key project decision' Making process, this paper is arranged in an outline form. We will discuss the Establishment of Early RequireHents, Preliminary FMEA T s During Conceptual Design, Design Trade-off Studies and Participation in Baseline Meetings and Milestone Reviews, Periodic Beliability Assessment - Long Poles in the Tent, Selection of Candidates for Inflight maintenance, Special Reliability Analyses - Suspected Trouble Areas, Hardware Storage and Refurbishment Problems, Special Requirements on Experiments, Reliability Data Base - Functional Notebooks, Utilization of FMEA/SFP Data, and the "Lessons Learned" Report.

Radio Amateur Satellites: A Means For Relating The Advances In The Space Program To The Public, William I. Dunkerley

Space Congress® Proceedings

Five amateur satellites in the Oscar series have been launched. They provide the radio amateur with an opportunity for a direct experience with space technology. Schools and educational organizations have used amateur satellites to aid in the instruction of space science. The planned Amsat-Oscar B spacecraft will involve an organized program to promote the educational utilization of Oscar satellites. In these ways sections of the general public receive personal contact with space technology.

Pan American's Planned Maintenance Control System, Sam Stallone

Space Congress® Proceedings

Pan American World Airways is proceeding with a modular development program from the foundation and framework designed in the "Maintenance Control System" (MCS) Master Plan. Pan Am began to anticipate and be prepared for the growing services that will be required by the increasing fleet, particularly the 747's and prospects of the Concorde and the U.S.-SST.

MCS is a management information system that incorporates all the control functions of maintenance into an integrated operation. MCS encompasses 12 major functional subsystems supporting scheduling, forecasting, performance evaluation, modifications, and improvement functions at all levels of maintenance management from the Production Foreman to …

Geodetic Application Of Satellite Data, Thomas O. Seppelin

Space Congress® Proceedings

The Aeronautical Chart and Information Center has used the data obtained from the Geodetic Satellite Program in a number of ways. Our investigations are divided into two separate categories which support the development of a World Geodetic System both directly and indirectly. The geometric application has been specific point positioning for the Test Ranges and the densification of geodetic control in South America. The dynamic application has been concerned primarily with determination of an earth gravitational model and tracking station locations from a combination of optical and electronic data supplemented with existing surface gravity anomalies. The status of the various …

Titanium And Superalloy Heat Shield Design For Space Shuttle Application, B. V. Groninger

Space Congress® Proceedings

Thermal protection systems for large reentry vehicles, such as a Space Shuttle booster or orbiter, comprise a significant percentage of the total weight of the vehicle and the total cost of the program. Therefore, to achieve a Shuttle system that is cost- and weight-effective, it is imperative to select an optimized thermal protection system.

One type of thermal protection system considered for the Space Shuttle consists of radiative heat shield panels, or "shingles," supported from the primary structure. This paper summarizes the results of a design and analytical study of five such titaniumsuperalloy thermal protection systems for the Space Shuttle …

Use Of Scientific Experiment Data In Preliminary Design Of A Post-Skylab Space Station, Ronald I. Miller

Space Congress® Proceedings

A computer simulation model with accompanying input and analysis techniques has been developed which will generate Phase A spacecraft preliminary design data using a minimum of computer time, allowing maximum flexibility, and requiring a minimum of learning effort by the user. The application of this model to Space Station design, the construction of a data base for earth orbit experiments, and the Candidate Experiment Program for Manned Space Stations (Blue Book) are dis- cussed.The Blue Book was the primary reference for experiment data, and its contents, organization and current status are described.

Communication In The Technical Organization, Robert W. Moyer

Space Congress® Proceedings

Virtually all businesses and organizations have communication problems * The aerospace business is no exception and has its share of normal as well as peculiar communication problems. With reasonable attention to communication problems and weaknesses, basic causes can be identified and appropriate solutions provided. This paper addresses itself to communication concerning the technical organization as well as the individual. Analysis is made of the cause of communication problems with both the organization and the individual within the organization. Causes of miscommunication are identified, and corrective as well as preventive remedies are presented.

Potential Effects Of Using Guaranteed Premium In Lieu Of Minimum Guaranteed Mechanical Properties Of Materials, G. L. Palcheff

Space Congress® Proceedings

The use of premium mechanical properties for materials, in lieu of minimum guaranteed properties, will result in substantial weight and overall Shuttle program cost savings. To obtain materials with premium mechanical properties (properties that exceed present minimum guaranteed values) will require negotiation with the material suppliers; the prime objective is to obtain the highest supplier guaranteed mechanical properties at an acceptable additional raw material cost. To illustrate the potential benefits of typical properties a study involving a Space Shuttle orbiter wing resulted in a total program cost reduction of $39.3 million, and a weight saving of 1414 Ibs. Suggested means …

Hadamard Source Encoding Techniques Applied To Apollo Telemetry Links: An Evaluation, Neil M. Schmitt, Carroll T. Dawson

Space Congress® Proceedings

The effort described in this paper is an investigation of the possible improvement in performance of the Apollo Unified S-Band Telemetry links due to the use of the Hadamard transform as a means of source encoding. Both rapidly and slowly varying telemetry signals were considered and three sizes of the Hadamard matrix were used. Results indicate that as much as 3-db improvement in system performance may be obtained in systems operating at a 2% RMS error level.

Centaur/Shuttle Integration And Operations, Carl F. Peters

Space Congress® Proceedings

One of the major pay loads to be considered for delivery to orbit by the Space Shuttle is a cryogenic propulsion stage.

An investigation was conducted, in conjunction with North American Rockwell, to investigate the interfaces between the Centaur and the Shuttle and the various possible operational modes of launching the Centaur in the Shuttle, The Centaur vehicle was used as the design model since its characteristics are presently well defined and it accommodates all the unmanned missions in the time period of interest.

The results of the study showed Centaur integration into the Space Shuttle to be feasible with …

A Survey Of Large Propellant Tank Quantity Gaging Methods In Zero-G, Clyde Wiley

Space Congress® Proceedings

This zero-g gaging survey excludes methods used with tanks small enough for positive expulsion. Gaging prototypes have been developed, but no satisfactory method was devised that could meet the Apollo/Saturn design deadline. Advanced space systems designs, such as the Space Shuttle, have generated a new interest in zero-g gaging. The operating principles of developed concepts are analyzed for application to cryogens and kerosenes and for accuracy comparison to conventional gaging. Actual need for zero-g gaging is also analyzed for design compromises to allow a realistic choice from concepts that have yet to be tested in a zero-g environment.

Kennedy Launch Processing System, Walter E. Parsons

Space Congress® Proceedings

The foremost challenge facing the aerospace industry during this decade is to develop the management, design and operational techniques required to reduce hardware development and operational costs. The concept of merging space technology with airline maintenance and operational philosophies enjoys considerable favor at this time; however, additional effort must be expended to develop a conforming system of hardware, supporting software and procedures. Vehicle launch with an attendant requirement for massive preparation and coordination can no longer be considered self justifying. The success of the Space Transportation System will be measured by the cost per pound of payload successfully delivered into …

The Space Shuttle Booster, Robert A. Lynch

Space Congress® Proceedings

An analysis and status report of Space Shuttle booster configuration design features is presented. In comparing stowed, fixed straight, and "delta" wing basic configurations; the "delta" wing approach with a canard has been selected. Wing planform shape and cross-section is strongly influenced by air breathing engine installation requirements rather than purely aerodynamic performance optimization.

Attitude Control And Orbit Maneuver System Selection For The Space Shuttle, Dali F. Stone, Edward C. Fox

Space Congress® Proceedings

The propulsion system studies made to select the Attitude Control Propulsion System (ACPS) and Orbit Maneuver System (QMS) for the. McDonnell Douglas - Martin Marietta Space Shuttle Vehicle are summarized in the paper. Both high chamber pressure and low chamber pressure gaseous 02/H2 ACPS concepts are considered in conjunction with ACPS, RL-10, and new development engines for the OMS function. Weights, performance, reliability, maintainability, mission flexibility data are combined with overall system/ vehicle costs to complete the evaluation and the final selection of a high chamber pressure (500 psia) ACPS and liquid pump fed RL-10 OMS.

Shuttle Test And Operations Approach, W. F. Edson

Space Congress® Proceedings

The Shuttle Program presently under development is one which challenges our ingenuity. In its infancy we see that old and tried test techniques and approaches may no longer "be valid and that in order to meet program goals of minimum cost and high reliability, new test and operation plans and methods must be conceived. This paper presents an over view of the Space Shuttle Test and Operations Program. I will briefly touch on today's test/ operations requirements, the concept under which they have been developed and their implementation. Several of the concepts presented are a direct result of our Phase …

Readiness For The Tools Of Automation, Robert B. Miller

Space Congress® Proceedings

Any information system (manual or automatic or a combination) should be a construction of intelligent design to serve—rather than dilute—human intelligence in the performance of purposeful tasks. Any automatic system or tool can only implement order: it cannot create it.

Atmospheric Electricity Problems, Lothar H. Ruhnke

Space Congress® Proceedings

The problems encountered when protecting rockets and launch operations from the dangers of lightning are discussed. This reveals the need for a mesoscale network for observing important parameters that indicate lightning danger, as well as the need to develop a set of rules for forecasting potential lightning danger. Before developing methods to inhibit the generation of electricity inside thunderclouds, it is imperative that the charge seperation mechanism be thoroughly understood. The present state-of-the-art of lightning suppression uses either metallic chaff fibers to produce a continuous discharge current or rocket propelled projectiles to discharge the thundercloud with artificially triggered lightning.