Deep Space Network Supports Cassini on its Way to Saturn
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The Cassini spacecraft is supported by two major components of the JPL's Interplanetary Network Directorate (IND).
Telecommunications and data acquisition support is provided by the NASA Deep Space Network, the world's largest, most sensitive spacecraft communications network. The DSN consists of three deep space communications complexes located approximately 120 degrees of longitude apart around the world: at Goldstone, California; near Madrid, Spain; and near Canberra, Australia. This placement permits continuous communication with deep space spacecraft. The DSN supports Earth orbiter spacecraft communications, as well as, radio and radar astronomy observations for the exploraton of the solar system and the universe.
The DSN provides the vital two-way communications link that guides and controls the Cassini spacecraft. The DSN 34-meter-diameter (112-foot) and 70-meter-diameter antennas are precision pointed, high-gain, parabolic reflector antennas with high power transmitters and ultra low noise (3 Kelvin operating temperature) amplifiers. Each deep space communication complex provides capabilities required to perform telemetry data processing including signal reception and amplification, signal demodulation and decoding, and data packet extraction. A capability to control the spacecraft via commands received from the Cassini project and transmitted from the DSN using 20 kilowatt transmitters is provided. Precision navigation is provided by measurements of signal phase and generation of range data which make use of the ultrastable frequency and timing capabilities of the DSN. All DSN complexes are linked to JPL via a world-wide communications network.
Cassini is also supported by IND's Advanced Multimission Operations System. Known as AMMOS, this system provides a common set of mission operations services and tools to the Cassini mission, as well as to other JPL spaceflight projects. They include capabilities which enable Cassini engineers to do mission planning and analysis, develop pre-planned sets of commands to the spacecraft, perform trajectory calculations for navigating the spacecraft, and process telemetry data (i.e., downlink data from the spacecraft). The AMMOS also provides capabilities for the Cassini Flight team to display and analyze key measurements, such as readings of temperature, pressure, and power, from the spacecraft. Other mission operations services include simulation of telemetry and command data, data management and retrieval of all data types used by the Cassini project, and data archiving.
Dr. Peter Poon and Mr. Ron Gillette are the Telecommunications and Mission Services Managers for Cassini who provide key IND management interface functions to Cassini, and ensure that IND supports the Cassini Launch, Cruise and Saturn Tour successfully.
