SATELLITES

A satellite is any object that orbits something else. It is launched into orbit using a rocket and positioned at different heights while traveling at different tracks around the Earth at variable velocities. The International Space Station (ISS) orbits Earth once every 90 minutes. The ISS is the largest man-made satellite to orbit the Earth.

SEARCH: LIBRARY of CONGRESS SUBJECT HEADINGS

TECHNOLOGY - T

Subclass TL500 - 777: Aeronautical engineering.

Satellites - Geostationary

Satellites - Digital imagery

Satellites - Data processing

Satellites - Remote Sensing

Satellites - Communications

Satellites - Structural analysis

Satellites - Materials engineering

Satellites - Factory Architectural Design Plan

Satellites - Tracking Live Satellites Orbiting Earth

SUBJECT EXPERTS I

SUBJECT EXPERTS II

RESEARCH GUIDES

SATELLITE NEWS

Program Development

Program development of facility / satellite engineering typically involves the design of satellitesand related innovative technologies. The coordination of systems programming along with installing and testing of satellites is also essential to program implementation.

Design Aspects

The required specifications of satellite design engineering include such dynamics as: the shape, size and configuration of the device. Further considerations include: pointing, thermal control, power quantity, and duty cycle which all must satisfy mission requirements.

Design Constraints

Developing satellites and systems facilities involves several critical functions that must be considered such as: electrical / mechanical structuring techniques, design schematic(s), delivery option(s), launch schedule(s) and financing.

Design Optimization

Satellite manufacturing projects require the expertise of research/development personnel to initiate the design process. Once the process is initiated, the logistical aspects of program development are supervised by several groups comprised of mechanical / electrical / engineers along with technicians to assure and maintain synchronization of the processes.

Designing Satellite Systems

Computer software development programs can illustrate technical satellite design(s) and systems configuration(s) consisting of diagrams with specifications which should include annotated peripherals. Engineers and techical personnel can use the software for co-operating during the design process by verifying sepia renditions and schematic diagrams.

Design Process/Simulation

Satellite process simulators enable cableless radio frequency (RF) testing of mobile satellite communication systems through providing a loop-back test for Satcom terminals without the need to access the satellite.The underlying purpose of simulation is to define the structural mechanisms that control the behavior of a system.

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SATELLITES 2024

Hubble isn't just a satellite, it's about humanity's quest for knowledge.

- John M. Grunsfeld: 1958 -: AZ Quotes

Designing a Satellite

There are several factors that bring about the construction of a satellite. The structure, design, and cost are important characteristics of a satellite. Each one has different qualities which make up a satellite.

STRUCTURE

The structure is important in the construction of a satellite. The structure must be 15-25 per cent of the total spacecraft weight which is considered light. The structure must also avoid resonances which would amplify by a factor exceeding 4 to 6 the vibration communicated by the rocket. Spacecraft structures fall into 2 large categories. The one most often used consists of a rigid core. This rigid core is like a stiff torsion tube carrying all loads transmitted by plateau, which is what equipment is attached too, with outriggers to support the other structural elements such as solar panels. In the alternative, a box structure, most of the loads are carried by the outer surfaces. It is used when a lot of pressurized volumes are needed, such as for a manned flight. Second, thermal control which is to keep with in suitable limits the temperature of solar radiation and by internal power dissipation. Third, power supply. In almost every Earth satellite, silicon solar cells are used to change solar into electrical energy. Fourthly, attitude control which is to keep the satellite in the necessary attitude with respect to the Earth and the Sun. Fifth, satellite in the required direction, and the attitude must be known. The last is station-keeping for which, "a sub-system is required only when it is necessary to control closely the position of the satellite as with the geostationary satellites.

DESIGN

Satellites are usually made to meet the mission requirements of specific application. Their design is primarily influenced by the combination of the performance and characteristics of the launch vehicle, the characteristics of the useful equipment or payload, and the geometry of the selected orbit. The design of a Global Positioning System (GPS) satellite has three segments, a space segment, control segment, and a user segment. The space segment has over thirty (30+) Navstar satellites (2 active and 3 spare) orbiting the Earth. They serve as the radio beacons that users sight to determine their own positions and velocities. The control segment has five (5) monitoring stations and one (1) master control station. They provide updated error corrections to keep the systems accurate and they also monitor the system. The user segment has a radio receiver coupled with a signal-processing computer that finds its own location by searching for more of the GPS satellites.

COST

The cost of a satellite shows the value and expense in the construction of a satellite. The average overall costs for launching, developing, maintaining, and operating a single application satellite in orbit over a period of 5-10 years usually exceeds 10 million a year, and often reaches several times this figure. The manufacturing and development costs in industry of Earth satellites are proportional to their weight with the coefficient of proportionality lying between $200,000 and $260,000 per kg., depending upon various factors. These factors are past experience of contractors which is often all sub-systems already developed that can readily be adapted. The design complexity such as: spinning satellites with body mounted solar cells can be expected to be near the lower value, and 3-axis stabilized satellites near the higher. Payload complexity, costs increase rapidly with the complexity of payload instrumentation. Even when this does not influence the simplest design of a satellite. Project duration is when fast developments are likely to cost much less than long ones but they are also connected with higher risks of delays. The last factor is overall weight which is a second order of tendency that exists, nevertheless, towards a decrease in specific costs per kg. with increasing spacecraft weight, because several sub-systems are little affected by satellite size.

Some of the factors that drive the cost of satellites are the equipment and materials used to build them. Transponders alone hundreds of thousands of dollars a year to maintain, while bandwidth cost per MHz is priced at a minimum of about $3,500 a month. Maintaining a satellite at a 36MHz bandwidth will cost over $1.5 million a year. There are also additional technologies and equipment that have to be built into the satellite in order for it to perform its intended function. These can include computers, computer software and cameras.

Another factor that contributes to the expense associated with satellites is the cost of launching one into orbit. It is estimated that a single satellite launch can range in cost from a low of about $50 million to a high of about $400 million. Launching a space shuttle mission can easily cost $500 million dollars, although one mission is capable of carrying multiple satellites and send them into orbit.

Also to be considered in the cost of satellites is its maintenance. After getting one into orbit, it has to be monitored from a ground facility, which will require manpower. Satellites are also not impervious to damage or down times. Furthermore, if things don’t go too well during a launch, a multi-million endeavor can either end up in pieces or sustain damages that will cost more money to repair.

CONCLUSION

The structure, design, and cost all play important roles in the construction of a satellite. The structure consists of a light one and there are several factors that make up the spacecraft, such as thermal control, power supply, attitude control, attitude reference, and station-keeping. In a satellites design there are three segments which are, control segment, space segment, and user segment. There are also three influences in a design, characteristics of useful equipment, geometry, and performances of launch vehicle. The cost can also exceed 10 million a year. The cost is also proportional to their weight. It is between $100,000 and $160,000 per kg. and it depends on several factors, such as past experience of contractors, design complexity, payload complexity, project duration, and overall weight. The different characteristics of structure, design, and cost all serve important roles in the construction of a satellite.

SATELLITE PRODUCTION FACILITY

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DIMENSIONS

The parameters of a satellite production facility should possess an approximate field area of at least 90,000-square-feet. Financing in excess $24 million dollars is also required to implement a satellite design facility. The factory should consist of at least two bay launch processing high bay (252’ long by 201’ wide with a 76 ft. eave height), a flight hardware staging annex (252 ft. long by 101 ft. wide with a 52 ft. eave height) and a two story air conditioned support area (252’ long by 51’ wide with a 26’ eave height). The high bay has two 74 ft. wide by 34 ft. high doors on each end and two 25-ton ordnance rated bridge cranes with hook heights of 55 ft. The annex has one 74 ft. wide by 34’ high door at each end. Concrete paved aprons accommodate movement of flight hardware. The facility must have direct access to a 15,000 ft runway for a Shuttle Flight / Landing Facility as well as close proximity rocket launch pads. Finally, a parking lot or garage (with 150 / more spaces) will support personnel.

SPECIFICATIONS

• Low Bay

• Processing Area

• Main Door (95 ft. w x 35 ft. h)

• Two 30-Ton Bridge Cranes, 66 ft. max hook height

• Two High Bay: 30,000 sqft (197 ft. x 150 ft.w x 95 ft.h)

CONCLUSIONS:

A satellite production facility must be huge and expandable from the outset. It has to be able to accommodate the research, development, production, and operation of at least 20 spacecraft anually. Office space and areas of production should include a cafeteria, clean rooms, meeting spaces, electronic fabrication areas, mission operations center, and enormous high bay areas.

ARCTURUS

SATELLITE DESIGN