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I for one am sad! But also, hasn't this been one of the most successful NASA missions ever? And I think now they're planning to go to Jupiter's Europa as a result of things they learned on this mission.
― Dominique, Thursday, 14 September 2017 21:48 (six years ago) link
For calstars, copied from an actually useful yahoo answers page:
By radio waves. The transmission is programmed into the computers on Cassini at a particular time and the receiving stations of the Deeps Space network are ready to receive the data stream 46 hours later.
"...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.
― Mince Pramthwart (James Morrison), Saturday, 16 September 2017 02:39 (six years ago) link
Oops, 14400 kbit/s.
By comparison, New Horizons, sending back the data from its Pluto flyby, and using both antennas, was limited to 2000 bits per second. Your 1995 AOL dial-up was 28 times faster. Space porn requires patience.
― Special Egyptian Guest Star (Sanpaku), Saturday, 16 September 2017 05:25 (six years ago) link
one year passes...
two years pass...