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The Space Communications and Navigation (SCaN) program places the three prime NASA space communications networks, Space Network (SN), Near Earth Network (NEN) (previously known as the Ground Network or GN), and the Deep Space Network (DSN), under one Management and Systems Engineering umbrella. It was established in 2006. It was previously known as the Space Communications & Data Systems (SCDS) Program.
Before NASA's administrator Michael D. Griffin created SCaN to direct an integrated networks program, different organizations at NASA Headquarters have managed the Agency's space communications capabilities and functions under separate Programs using a variety of administrative approaches. [2]
The SCaN Office was established by direction of Griffin in a Memorandum entitled "Establishment of a Space Communications and Navigation Office," dated July 19, 2006. [3] SCaN operates as a central organization within the Human Exploration and Operations Mission Directorate (HEOMD):
The Office's responsibilities encompass the management of existing space networks including the Tracking and Data Relay Satellite system, the Deep Space Network, the Ground Network, the NASA Integrated Services Network; implementing any improvements and upgrades to those systems and networks; and developing any future NASA communications and navigation architectures.
The Ground Network (GN) has since been renamed the Near Earth Network.
SCaN is viewed as a service provider supporting interfaces and performing a standard set of functions, including: [4]
Communications with spaceborne platforms is performed by RF, with a selection of spectra, modulation, and encoding methods, enumerated below.
The Space Network communicates with spacecraft using S-band, Ku-band, [5] and Ka-band with planned laser/optical communications.
The Deep Space Network communicates with spacecraft using S-band, X-band, and Ka-band.
SN uses phase-shift keying and phase modulation of the carrier signal. [6]
The Space Network (used for near-Earth communications) supports the following encoding schemes: [7]
The Reed–Solomon method is used as the initial error-correcting block code prior to the selected secondary encoding scheme.
The NASA Deep Space Network (DSN) is a worldwide network of spacecraft communication ground segment facilities, located in the United States (California), Spain (Madrid), and Australia (Canberra), that supports NASA's interplanetary spacecraft missions. It also performs radio and radar astronomy observations for the exploration of the Solar System and the universe, and supports selected Earth-orbiting missions. DSN is part of the NASA Jet Propulsion Laboratory (JPL).
The Goddard Space Flight Center (GSFC) is a major NASA space research laboratory located approximately 6.5 miles (10.5 km) northeast of Washington, D.C. in Greenbelt, Maryland, United States. Established on May 1, 1959 as NASA's first space flight center, GSFC employs about 10,000 civil servants and contractors. Named for American rocket propulsion pioneer Robert H. Goddard, it is one of ten major NASA field centers. GSFC is partially within the former Goddard census-designated place; it has a Greenbelt mailing address.
The Goldstone Deep Space Communications Complex (GDSCC), commonly called the Goldstone Observatory, is a satellite ground station located in Fort Irwin in the U.S. state of California. Operated by NASA's Jet Propulsion Laboratory (JPL), its main purpose is to track and communicate with interplanetary space missions. It is named after Goldstone, California, a nearby gold-mining ghost town.
The U.S. Tracking and Data Relay Satellite System is a network of American communications satellites and ground stations used by NASA for space communications. The system was designed to replace an existing network of ground stations that had supported all of NASA's crewed flight missions. The prime design goal was to increase the time spacecraft were in communication with the ground and improve the amount of data that could be transferred. Many Tracking and Data Relay Satellites were launched in the 1980s and 1990s with the Space Shuttle and made use of the Inertial Upper Stage, a two-stage solid rocket booster developed for the shuttle. Other TDRS were launched by Atlas IIa and Atlas V rockets.
The Canberra Deep Space Communication Complex (CDSCC) is a satellite communication station, part of the Deep Space Network of NASA's Jet Propulsion Laboratory (JPL), located at Tidbinbilla in the Australian Capital Territory. Opened in 1965, the complex was used for tracking the Apollo Lunar Module, and along with its two sister stations at Goldstone, California and Madrid, Spain is now used for tracking and communicating with NASA's spacecraft, particularly interplanetary missions. Its DSS-43 antenna is the only antenna on Earth that can send commands to Voyager 2. It is managed in Australia by the Commonwealth Scientific and Industrial Research Organisation (CSIRO) for NASA’s Space Communications and Navigation program (SCaN) at NASA Headquarters in Washington, D.C.
SpaceWire is a spacecraft communication network based in part on the IEEE 1355 standard of communications. It is coordinated by the European Space Agency (ESA) in collaboration with international space agencies including NASA, JAXA, and RKA.
A tracking and data relay satellite (TDRS) is a type of communications satellite that forms part of the Tracking and Data Relay Satellite System (TDRSS) used by NASA and other United States government agencies for communications to and from independent "User Platforms" such as satellites, balloons, aircraft, the International Space Station, and remote bases like the Amundsen-Scott South Pole Station. This system was designed to replace an existing worldwide network of ground stations that had supported all of NASA's crewed flight missions and uncrewed satellites in low-Earth orbits. The primary system design goal was to increase the amount of time that these spacecraft were in communication with the ground and improve the amount of data that could be transferred. These TDRSS satellites are all designed and built to be launched to and function in geosynchronous orbit, 35,786 km (22,236 mi) above the surface of the Earth.
Space Technology 5 (ST5) of the NASA New Millennium program was a test of ten new technologies aboard a group of microsatellites. Developed by NASA Goddard Space Flight Center, the three individual small spacecraft were launched together from the belly of a Lockheed L-1011 aboard the Pegasus XL rocket, on 22 March 2006. One technology involved antennas that were designed by computers using an evolutionary AI system developed at NASA Ames Research Center. The ST5 on-board flight computer, the C&DH system, was based on a Mongoose-V radiation-hardened microprocessor.
The Madrid Deep Space Communications Complex (MDSCC), in Spanish and officially Complejo de Comunicaciones de Espacio Profundo de Madrid, is a satellite ground station located in Robledo de Chavela, Spain, and operated by the Instituto Nacional de Técnica Aeroespacial (INTA). Part of the Deep Space Network (DSN) of NASA's Jet Propulsion Laboratory (JPL), along with its two sister stations at Goldstone, California and Canberra, Australia it is used for tracking and communicating with NASA's spacecraft, particularly interplanetary missions. The DSN and the Near Space Network (NSN) are services of the NASA Space Communications and Navigation program (SCaN).
The Manned Space Flight Network was a set of tracking stations built to support the American Mercury, Gemini, Apollo, and Skylab space programs.
Space Network (SN) is a NASA program that combines space and ground elements to support spacecraft communications in Earth vicinity. The SN Project Office at Goddard Space Flight Center (GSFC) manages the SN, which consists of:
The Near Earth Network provides orbital communications support for near-Earth orbiting customer platforms via various ground stations, operated by NASA and other space agencies. It uses a number of different dishes scattered around the globe. The antennas must be able to move fast for tracking of objects in low Earth orbit (LEO). The NEN and Space Network (SN) combined were previously referred to as the Spaceflight Tracking and Data Network (STDN).
The Merritt Island Spaceflight Tracking and Data Network station, known in NASA parlance as MILA, was a radio communications and spacecraft tracking complex located on 61 acres (0.25 km2) at the Kennedy Space Center (KSC) in Florida. The name MILA was an acronym for the "Merritt Island Launch Annex" to Cape Canaveral Air Force Station, which was how the site was referred to when spacecraft launches were primarily originating from the adjacent military installation. MILA's arrays of antennas provided various communications and data services between spacecraft and NASA centers, as well as tracked and ranged moving spacecraft. In its final years, it served as the primary voice and data link during the first 7½ minutes of Space Shuttle launches, and the final 13 minutes of shuttle landings at KSC. Though it occupied land at KSC, MILA was operated and managed by the Goddard Space Flight Center.
The NASA (Ground) Communications System (NASCOM) manages terrestrial communications between ground stations, mission control centers, and other elements of spacecraft ground segments. Established in 1964, NASCOM provides worldwide, near real-time, transmission of commands, telemetry, voice, and television signals. It is managed out of NASA's Goddard Space Flight Center in Greenbelt, Maryland.
The Unified S-band (USB) system is a tracking and communication system developed for the Apollo program by NASA and the Jet Propulsion Laboratory (JPL). It operated in the S band portion of the microwave spectrum, unifying voice communications, television, telemetry, command, tracking and ranging into a single system to save size and weight and simplify operations. The USB ground network was managed by the Goddard Space Flight Center (GSFC). Commercial contractors included Collins Radio, Blaw-Knox, Motorola and Energy Systems.
There are NASA facilities across the United States and around the world. NASA Headquarters in Washington, DC provides overall guidance and political leadership to the agency. There are 10 NASA field centers, which provide leadership for and execution of NASA's work. All other facilities fall under the leadership of at least one of these field centers. Some facilities serve more than one application for historic or administrative reasons. NASA has used or supported various observatories and telescopes, and an example of this is the NASA Infrared Telescope Facility. In 2013 a NASA Office of the Inspector General's (OIG) Report recommended a Base Realignment and Closure Commission (BRAC) style organization to consolidate NASA's little used facilities. The OIG determined at least 33 of NASA's 155 facilities were underutilized.
The forerunner of the Deep Space Network was established in January 1958, when JPL, then under contract to the U.S. Army, deployed portable radio tracking stations in Nigeria, Singapore, and California to receive telemetry and plot the orbit of the Army-launched Explorer 1, the first successful U.S. satellite.
A ground segment consists of all the ground-based elements of a space system used by operators and support personnel, as opposed to the space segment and user segment. The ground segment enables management of a spacecraft, and distribution of payload data and telemetry among interested parties on the ground. The primary elements of a ground segment are:
The Deep Space Atomic Clock (DSAC) was a miniaturized, ultra-precise mercury-ion atomic clock for precise radio navigation in deep space. DSAC was designed to be orders of magnitude more stable than existing navigation clocks, with a drift of no more than 1 nanosecond in 10 days. It is expected that a DSAC would incur no more than 1 microsecond of error in 10 years of operations. Data from DSAC is expected to improve the precision of deep space navigation, and enable more efficient use of tracking networks. The project was managed by NASA's Jet Propulsion Laboratory and it was deployed as part of the U.S. Air Force's Space Test Program 2 (STP-2) mission aboard a SpaceX Falcon Heavy rocket on 25 June 2019.
The Lunar Exploration Ground Sites, or LEGS, are several NASA space communication complexes created to support lunar exploration. They are in addition to the existing NASA Deep Space Network and the Near Earth Network. The LEGS mission is to provide direct-to earth communication and navigation services for missions operating from 36,000 kilometers (km) in the GEO to cis-Lunar and other orbits out to 2 million km. To fully support distant orbits there will be three LEGS sites roughly equally spaced around the Earth.