Deep Space Station 43 in the foreground with the Beam Wave Guide antennas in the background

The Big Dishes

The Canberra Deep Space Communication Complex (CDSCC) features a number of 'big dish' antennas that are required daily to receive data from; and transmit commands to; a wide variety of spacecraft.

Deep Space Stations

The antennas are known as Deep Space Stations (DSS) and are identified by a number. Each location around the world has it own set of similar antennas: In the United States, antennas are numbered in the 10s and 20s series; in Australia antennas are in the 30s and 40s and in Spain the 50s and 60s. This is a simple shorthand way to easily identify an antenna at each site.

CDSCC currently has four active antennas:

DSS-43 (70-metre)	DSS-34 (34-metre)	DSS-35 (34-metre)	DSS-36 (34-metre)

Retired from Service

There are also several antennas that have either been dismantled or decommissioned at the Complex over the years. The original antenna on site - Deep Space Station 42 - was dismantled in December 2000, and Deep Space Station 33 (an 11-metre antenna) was decommissioned in February 2002 and in 2009 dismantled and transported to Norway to start a new role in atmospheric research. A 5-metre dish that was used to support an Earth-orbiting space telescope is now decommissioned and is still on site but no longer in use.

The most recent retirement was the closure of Deep Space Station 45 . After 30 years of service, the HEF (High Efficiency) antenna was decommissioned in November 2016. DSS-45 makes way for the newer generation of 34 metre, beam waveguide dishes that will be the type of antennas that the Deep Space Network will use going forward.

One Small Step

One other dish - the first you come by as you enter the station - is Deep Space Station 46 . This 26-metre antenna was originally located at the Honeysuckle Creek Tracking Station between 1967 and 1981. It was moved to CDSCC as part of a consolidation of tracking station sites in Canberra.

DSS46 is most famous for being the antenna which received and relayed to the world the first historic TV images of astronaut Neil Armstrong setting foot on the Moon in July 1969.

Having tracked hundreds of missions - both human and robotic - DSS-46 was retired from service in November 2009 and now remains at CDSCC as a celebrated and recognised historic monument.

Lending a Helping Ear

To assist in the busy period in spaceflight at the end of 2003, early 2004, the Complex incorporated the 64-metre dish at Parkes in central New South Wales. This antenna was upgraded by NASA through the Canberra Complex with new receivers and equipment capable of handling transmissions received from robotic spacecraft.

The 64-metre wide radio telescope is one of the world's best and most active facilities for radio astronomy. When its research time permits, Parkes can act as a spare 'ear' for CDSCC at times of high scheduled activity. When it is being used for this purpose it is designated as DSS-49.

Primary Antenna Roles

The role of the antennas can be broken into four key areas; Telemetry, Tracking, Control and Monitor.

Telemetry

The purpose of the Telemetry System is to provide the capability to acquire, process, decode and distribute deep space probe and Earth orbiter telemetry data. Telemetry data consists of science and engineering information modulated on radio signals transmitted from the spacecraft. The Telemetry System performs three main functions: Telemetry data acquisition, telemetry data conditioning and transmission to projects and telemetry system validation.

Radiometric Tracking

The purpose of the Tracking System is to provide two-way communication between Earth based equipment and spacecraft, to make measurements that will allow the state vector (position and velocity) of spacecraft to be determined.

Spacecraft Command

The purpose of the Command System is to provide the means by which a Project controls the activities of its spacecraft. Control information (Command Data), provided by the Project, is modulated on the RF carrier and transmitted to a spacecraft by a Deep Space Network (DSN) station. The Command System functions as a transfer medium between the Project Control Centre and its spacecraft.

Monitor and Control

The purpose of the Monitor and Control System is two-fold: to provide real time monitor data to projects which reflect the status of project support by DSN systems, and to provide monitor and control capabilities to operators of DSN systems' components.

Antenna Scientific Research

In addition to serving as a communications instrument for deep space exploration, the Deep Space Network (DSN) may be used as an advanced technological instrument for scientific research and development. The DSN makes its facilities available to any qualified scientist on a non-interference basis with spacecraft mission support. The DSN encourages the use of its facilities for those scientific observations that exploit its unique elements and capabilities. This includes collaboration with other NASA and non-NASA observatories.

The DSN anticipates and responds to user needs. The DSN maintains and upgrades its facilities to accommodate all of its users. This includes not only the implementation of enhancements to improve the scientific return from current experiments and observations, but also long-range research and development to meet the needs of future scientific endeavours.

• Interferometry

  The accurate measurement of radio source positions; includes astrometry, very long baseline interferometry, connected element interferometry, interferometry arrays and orbiting interferometry. Measurement of station locations and Earth orientation for studies of the Earth.

• Very Long Baseline Interferometry

  The purpose of the Very Long Baseline Interferometry (VLBI) System is to provide the means of directly measuring plane-of-the-sky angular positions of radio sources (natural or spacecraft), DSN station locations, interstation time and frequency offsets, and Earth orientation parameters.

• Radio Science

  The field of Radio Science improves our knowledge of the solar system and the theory of general relativity through radio frequency experiments performed between spacecraft and the Deep Space Network's (DSN) Radio Science System. In the past, Radio Science has performed experiments which have allowed scientists to characterise planetary atmospheres and ionospheres, characterise planetary surfaces, characterise the planetary rings, characterise the Solar corona, confirm general relativity, characterise interplanetary plasma, search for gravitational waves, characterise planetary gravity and determine the mass of the planets, moons, and asteroids.

• Radio and Radar Astronomy

  The acquisition and extraction of information from signals emitted or reflected by natural celestial sources; includes studies in the fields of astrophysics, Earth physics, planetary radar, gravitation and relativity.

• Earth Dynamics

  The measurement of station locations and Earth orientation. The Global Positioning System (GPS) is a constellation of 24 satellites which is used for navigation and precise geodetic position measurements. The GPS, originally developed by the U.S. Department of Defence, has been applied recently to the study of earthquakes.

• Sky Surveys

  Identification and mapping of radio sources to create radio position reference frames; includes radiometry, polarimetry, spectroscopy and enhanced spectral analysis. The DSN has built a subnetwork of 11-meter antennas whose primary purpose is to support two orbiting Very Long Baseline Interferometry (VLBI) Satellites. Both satellite missions are radio astronomy projects designed to provide high resolution maps of radio emissions from natural sources using the technique of VLBI.