October 2, 2016 – NASA has reached another milestone in building a new generation of Deep Space Network antennas. Deep Space Station 36 (DSS36) has joined the network in Canberra, Australia, and conducted its first official communication with the Mars Odyssey spacecraft on September 30.
The new antenna spans 34 meters (112 feet) in diameter and uses an advanced design called “beam waveguide,” which funnels the gathered radio signals through a series of mirrors to a protected, underground electronics room. Once captured, the signals undergo a complex cryogenic process that separates and extracts the desired signals from the remaining space noise and processes it through powerful computers. The waveguide design provides more reliable operation than the older antenna design and is easier to maintain.
The Deep Space Network (DSN) has provided a critical lifeline to space missions for over fifty years. The network sends commands to spacecraft and receives telemetry, engineering, and scientific data. The ground stations initiate course corrections, provide software updates, and allow scientific observations to be made.
There are three large deep-space communications facilities strategically placed approximately 120 degrees apart around the world – at Goldstone, California; Madrid, Spain; and Canberra, Australia. Each antenna dish needs a direct line of sight to “speak” with a spacecraft, and the placement allows stations to take turns linking with various spacecraft as the Earth rotates, ensuring communication with at least one station at all times.
The DSN is also used to make direct science observations of asteroids and celestial objects. It’s used for radar science, in which waves are bounced off objects such as passing asteroids to create radar images; radio science, where changes in the steady radio link between a spacecraft and the DSN reveal the internal structure of another world; radio astronomy, which looks at naturally occurring radio sources such as pulsars and quasars; and geodetic measurements, which reveal changes in the crust of the Earth by tracking how long it takes a radio signal from a quasar or other astronomical source to reach different telescopes.
The diameter of the DSN antennas range in size from 34 meters (112 feet) to 70 meters (230 feet) – equivalent to the height of a 20-story building. The antennas catch radioed information from spacecraft as near as Earth orbit and as far away as more than twice the distance to Pluto.
Historically, the larger dishes were necessary to capture the faint signals sent from millions, or even billions, of miles away, but DSS36 is part of a series of upgrades NASA is undertaking to eventually retire the network’s aging antennas and also provide coverage for the unprecedented peak in demand for deep-space communication. The 70 meter (230 foot) antennas are the most sensitive of the DSN antennas, but the network is operated 24 hours a day, seven days a week, 365 days per year, which puts a lot of wear and tear on the antennas. Even with regular maintenance, the 70 meter antennas — which are now more than 40 years old — are showing signs of surface deterioration from constant use.
Several studies determined that the best replacement for the 70 meter antennas is an array of 34 meter beam waveguide antennas. Each DSN complex will have four of the 34 meter antennas when the upgrade is complete, which will supply a downlink capability similar to the larger antennas. The arrays are scalable, which frees assets when the full capability isn’t needed and they also provide the flexibility to operate on multiple frequencies, including the wider-bandwidth Ka-band signal required for missions approved after 2009. Additional frequencies can be added in the electronics room as they’re needed.
History Of The Deep Space Network
The Deep Space Network first existed in the form of a few small antennas at the Deep Space Instrumentation Facility. That facility, originally operated by the U.S. Army in the 1950’s, was used to receive telemetry and to plot the orbit of NASA’s Explorer 1, the first successful U.S. satellite.
Soon after, NASA established the concept of the Deep Space Network as a separately managed and operated communications facility to accommodate all deep space missions. This avoided the need for each flight to acquire its own specialized space communications network. During its first year of operation, the network communicated with three spacecraft – Mariner 2, IMP-A and Atlas Centaur 2.
During the Apollo period (1967-1972), the DSN supported America’s missions to the moon, including the historic steps taken by Neil Armstrong in 1969. “That’s one small step for man. One giant leap for mankind.” The infamous words were captured by the Goldstone antenna, while a station in Australia captured the video of Neil and Buzz that would play on television sets across the U.S.
The DSN also supports less favorable missions, like the nerve-wracking Apollo 13. After a ruptured oxygen tank forced NASA to abort the planned lunar landing, it was essential that engineers on the ground maintain contact with the astronauts on board during re-entry of the capsule. The spacecraft’s minimal power was needed for re-entry, with little left over for communications, but the DSN was able to capture the “whispers from space,” and helped bring Jim Lovell, Jack Swigert and Fred Haise safely home.
The Deep Space Network enabled the first-ever image of Mars, obtained by NASA’s Mariner 4 spacecraft in 1965. Mariner 10 returned images of Mercury’s surface in 1974. NASA’s twin Voyager spacecraft were the first to fly by Jupiter, Saturn, Neptune and Uranus, capturing the first close-up images of these planets, plus some of their rings and moons. Last year, the Canberra complex was the first place on Earth to receive the closest encounter images from the New Horizons mission to Pluto. The DSN also relayed Voyager I’s portrait of Earth from 6 billion miles away, the iconic image Carl Sagan called “The Pale Blue Dot,” as well as the spacecraft’s entry into interstellar space.
Today, the DSN supports NASA’s Mars Exploration Rovers, the Hubble Space Telescope, Cassini, MRO, MAVEN, New Horizons, Juno, OSIRIS-REx and a host of other NASA spacecraft. The network has also supported deep space missions for the European, Russian, Japanese and Indian space agencies.
The Jet Propulsion Laboratory in Pasadena, California, manages the operations of the Deep Space Network. The Canberra Deep Space Network complex is managed by the Commonwealth Scientific and Industrial Research Organization (CSIRO).
You can see what all of the deep space antennas are tracking using Deep Space Network Now.