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OVERVIEW
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NASCOM USER COMMUNITY
The NASA Communications (Nascom) Division is one of six institutional support divisions within the Mission Operations and Data Systems Directorate (M0&DSD) at the Goddard Space Flight Center (GSFC). The Division is responsible for planning, budgeting, design, engineering, implementation, operation, and maintenance of two principal telecommunications networks: the Nascom Network, supporting all planetary, Earth-orbiting, and manned spaceflight missions; and the GSFC Telecommunications Network.
The Nascom Network is a worldwide complex of communications services that include data, voice, teletype, and television systems. This network consists of approximately 850 satellite and terrestrial circuits, and provides data transport, switching, and control facilities that link approximately 140 domestic and foreign terminals. The GSFC Telecommunications Network is based at the GSFC and the Wallops Flight Facility (WFF) to provide local users with telecommunications services.
Nascom provides communications support for NASA's Ground Network, a system of tracking and communications
stations located around the world, and its Space Network, which includes the Tracking and Data Relay Satellites and an Earth station facility in White Sands, New Mexico.
Communications support is also provided to the Deep Space Network (DSN). The DSN comprises the deep space communications complexes, compatibility test areas at the Jet Propulsion Laboratory (JPL), and launch compatibility test station at the Kennedy Space Center (KSC). The Deep Space Communications complexes at Tidbinbilla, Australia; Madrid, Spain; and the launch compatibility test station at KSC have real-time interfaces with the Nascom Network and are connected with the JPL center communications terminal via voice, teletype, and data communications facilities of the Nascom Network. The DSN is under the system management and technical direction of the JPL in Pasadena, California.
The Nascom user community is very diverse and geographically distributed worldwide. Many NASA missions carry instruments from both national and foreign users for which Nascom provides a variety of communication services. These users interface with the Nascom Network to obtain transport services for their data, voice, and video communications requirements.
The user community consists of personnel, projects, and missions from NASA centers, the Department of Defense (DoD), the National Oceanic and Atmospheric Administration (NOAA), and commercial and foreign entities. Significant events from these users, such as planetary missions, spacecraft launches, and shuttle missions, are seen on home TV through the facilities of the Nascom Network. The institutional users at the GSFC and WFF are served by the GSFC Telecommunications Network.
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U.S. AND OVERSEAS FACILITIES
The Nascom Network interconnects various communica tion systems globally with a variety of U.S. and overseas circuit facilities that are operationally controlled at Nascom's primary switching center at the GSFC. This center, located in Greenbelt, Maryland, provides centralized technical control and switching capabilities.
Intermediate switching centers are located at Canberra, Australia; Madrid, Spain; Pasadena, California; Eastern Space and Missile Center, Cape Canaveral Air Force Station, Florida; and Western Space and Missile Center, Vandenberg Air Force Base, California. These facilities afford flexible circuit sharing on costly overseas and domestic communication channels and first-line alternate routing, testing, and circuit restoration capabilities. Use is made of various commercial carriers via communications relay satellites and terrestrial facilities (e.g., cable, fiber optics, submarine cables, and microwave) to obtain maximum diversity and reliability. Nascom has unique communications support arrangements for the Space Shuttle, which include facilities of other cooperating agency systems such as those under the DoD and NOAA.
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OPERATIONAL COMMUNICATIONS SYSTEMS
Nascom operates and maintains various communications systems and facilities to perform its function and responsibility to the users. The loss or degradation of these systems and facilities, in many instances, can directly affect mission success and the safety of life and/or property.
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Nascom Technical Control is responsible for low speed, high-speed, and wideband data operations. It is the central point for configuring user support, controlling circuits, and monitoring and testing Nascom circuits and equipment.
Nascom Voice Control, known as the Switching, Conferencing, and Monitoring Arrangement (SCAMA), provides high-quality local and long-haul circuits. The primary purpose is to provide air-to-ground voice and analog data operational support to NASA's manned flight missions, scientific satellite projects, and deep space programs. Network circuits originate at the GSFC and terminate at the tracking stations either directly or through a Nascom switching center.
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The Message Switching System is a computer-based system that performs a switching function on incoming wideband, high-speed, and low-speed digital data and teletype. The system is a software-controlled switching computer designed and programmed specifically to switch digital data automatically and control network traffic.
The Communications Manager is the head of the Nascom Operations Management Branch. He is responsible for the operation and control of the Nascom Network. To ensure the efficiency of a 24-hour-per-day, 7-day-per-week operational network, the Communications Manager's responsibility is delegated to the position of Shift Communications Manager. This position functions as the centralized point of coordination for the Nascom Network.••• ss
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Nascom's broad experience in network management has contributed immensely to the success of NASA missions. Nascom operates a technical facility to maintain the network for optimum performance and efficiency. The facility conducts monitoring, measuring, status reporting, diagnostics, and testing. Nascom ensures that availability and reliability goals are met or exceeded.
The Nascom mission planners perform a liaison function between the technical implementing organization and the flight projects to coordinate and ensure that their communication requirements are met.
An important service that Nascom provides to the user is procurement and contract management. Nascom coordinates this service with the user and performs the review, negotiation, and fulfillment of domestic and/or foreign leases for communications services. Because of the significant importance of data and voice to the users, full-period private line services are provided. Nascom, however, attempts to gain multiple-user utilization of a system or service for economical efficiency.
Nascom provides engineering services, such as system study, research and development, system design, and installation of communications systems. If necessary, Nascom tailors the system to the user specifications. Nascom also provides ongoing support services, such as preventive maintenance, testing, monitoring, and restoration of the communications lines and equipment associated with a given system. These services may require Nascom to closely coordinate with the common carrier, provide spare parts and logistics, and conduct equipment repair to maintain required system availability.
Nascom offers a variety of telecommunications services for users of the GSFC Telecommunications Network at the GSFC and WFF. The services, primarily directed to institutional users, include the ROLM telephone system, electronic mail, local area communications networking, video and closed-circuit TV, and access to NASA's Program Support Communications Network and Packet Switching System, and U.S. Sprint's Telenet. Nascom operates and maintains video services at NASA Headquarters in Washington, D.C.
The ROLM telephone system provides switched voice and data services to approximately 9000 GSFC and WFF civil service and contractor personnel. The system is computer-controlled to provide subscribers with not only fully integrated switching of voice, data, facsimile, and other digitized information, but also with direct access to local and foreign exchange services and other NASA locations using the Federal Telephone System.
The electronic mail system is basically an electronic mailbox that allows computer terminal users to read, compose, and send messages online. Considering that nearly 75 percent of all business calls are requests for information or result in messages, electronic mail improves the efficiency of communications throughout the Center.
The local area communications network is an institutional system providing interbuilding connectivity for the GSFC's many computer networks. Using established protocols, this system uses a network of underground cables to interconnect computers and terminals in 24 buildings throughout the Center. The computer users are able to perform intercomputer file transfer, remote batch job submission, electronic mail, remote logons, and other terminal support applications.
In the 1990s, the most demanding requirements are associated with the Space Station Program. The communication requirements of space station payloads will differ significantly from those of current users. Major changes in Nascom's capabilities and architecture may be required because of their potential impact on system design, operation, and cost. To prepare for this role, the current Nascom Network will be upgraded with state-of-the-art systems. An entirely new system will be implemented to transmit data rates up to 300 megabits per second using established protocols. During the next 10 years, Nascom will continue to support near-Earth applications, scientific projects, and the DSN using the existing protocol of the Nascom Network.
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National Aeronautics and Spacc Administration
Goddard Space Flight Center
Greenbelt Maryland 20771
NASA Communications Division (301) 286 7337