Deep Space Network upgrades and new antennas increase vital communication capabilities

by Mihir Neal

NASA’s Deep Space Network, commonly referred to as the DSN, has welcomed a new dish, Deep Space Station 56, to its family of powerful ground listening stations around the world.

The now-operational 34-meter antenna joins the network’s Madrid Deep Space Communications Complex located 60 kilometers west of Madrid, Spain while other dishes within the network undergo critical upgrades.

The new dish is part of an ongoing series of enhancements to the DSN, which traces its roots back to January 1958 when the U.S. Army’s Jet Propulsion Lab was tasked with standing up a series of communications stations in Nigeria, Singapore, and the U.S. state of California to support orbital telemetry operations for the Explorer 1 mission.

This precursor to the Deep Space Network was transferred to NASA along with the Jet Propulsion Lab on 3 December 1958.  The DSN was then formally commissioned by the U.S. space agency as a way to consolidate the pending deep space communication needs through centralized locations to avoid each mission having to create its own ground listening station(s).

The three Deep Space Network ground locations are spaced roughly 120 degrees from each other in Canberra, Australia; Goldstone, California; and Madrid, Spain. The location of the three facilities ensures deep space missions with a line of sight to Earth can communicate with at least one of the locations at any time.

Updates throughout the decades have increased the network’s capabilities, most notably for the two Voyager probes that continue to operate and send back science data having both long-passed out of the heliosphere and into the interstellar medium.

The network, nonetheless, is showing its age, with upgrades and refurbishments needed to ensure continuous operations. Part of this initiative is the recent addition of the new dish, Deep Space Station 56 (DSS-56), at the Madrid complex.

“After the lengthy process of commissioning, the DSN’s most-capable 34-meter antenna is now talking with our spacecraft,” said Bradford Arnold, DSN project manager at the Jet Propulsion Laboratory.

(Click here to see which dishes of the Deep Space Network are talking to which spacecraft.)

The new antenna is a Beam WaveGuide dish and underwent a far more complex commissioning phase than its predecessors due to its novel nature of being the first “all-in-one” antenna capable of communicating with all missions/probes that use the DSN.

All other DSN dishes have limited frequency ranges, meaning they cannot communicate with every Network-using mission.

That changes with DSS-56, which utilizes the DSN’s full range of communication frequencies. This has an added benefit of allowing the new dish to serve as a backup for any of the Madrid complex’s other antennas regardless of the mission they’re talking to.

Workers at the Madrid Deep Space Communications Complex (MDSCC) carry a symbolic key to celebrate the successful commissioning of the new DSS-56 antenna. (Credit: MDSCC, Robledo de Chavela)

That backup would not be instantaneous and could take between 30 minutes to an hour, minimum, to take effect depending on DSS-56’s condition at the time it were suddenly needed.

In response to NASASpaceflight inquiries, Mr. Arnold related that “The configuration of the antenna is agreed to and set prior to [a] pass with [a] mission. It takes some time (maybe an hour) for a ‘cold’ antenna [one not being used] to come up prior to performing the track.”

However, he added that “Switching between one mission and another, back to back, does take some time… maybe 30 minutes” and would involve properly positioning the antenna and calibrating it to the new mission specifics.

DSS-56 is the fourth 34-meter antenna at Madrid, giving the site the most 34-meter dishes of the three locations.  Goldstone and Canberra each have three. A fifth 34-meter dish, DSS-53, will also join Madrid later this year as the second all-in-one antenna of the network, noted Mr. Arnold.

This new all-in-one capability represents a significant upgrade to the DSN’s capability; however, work is also ongoing to upgrade other antennas in the DSN, most notably DSS-43 at the Canberra complex. 

NASA announced in March 2020 that DSS-43 would undergo critical upgrades as some of its components were nearly 50 years old and increasingly unreliable.

The Canberra Deep Space Communications Complex outside the Australian capital. (Credit: CSIRO)

Highlighting the sometimes difficult nature of the DSN to support both new and “legacy” missions, the 70-meter DSS-43 dish is the only antenna in the network capable of sending commands to Voyager 2, located approximately 18.9 billion kilometers (or 126.8 AU) away from Earth as of publication.

Taking the dish offline for upgrades, while necessary, meant no communications from Earth could be sent to the probe. Data transmissions from Voyager 2 back to Earth, however, would remain uninterrupted as those channels use the smaller, 34-meter dishes at Canberra, DSS-34, -35 and -36.

As part of the refurbishment, DSS-43 received two new transmitters while its heating and cooling, power supply, and other electronic equipment was upgraded as well.

In May 2020, the new X-band cone in the center of the dish was installed. Two months later, the water coolant pumphouse, also known as “Caravan,” was reinstalled after refurbishment. 

In September, the dish underwent azimuth and elevation drive system tests, followed by further testing and commissioning of new equipment and antenna pointing calibrations.

At the end of October, a critical series of test commands were sent to Voyager 2. After 34 hours and 48 minutes, the team received a “hello” from deep space as the craft returned a signal confirming it had received the call and executed the test commands without issue.

In November, teams commissioned each of the DSS-43’s systems and performed precision pointing calibrations for the antenna’s 4,000 tonne moving structure. 

The 70-meter dish is now in final testing and calibration before returning to service in early February.

“The Deep Space Network is vital to so much of what we do – and to what we plan to do – throughout the solar system,”said Thomas Zurbuchen, NASA associate administrator of the Science Mission Directorate. 

“It’s what connects us here on Earth to our distant robotic explorers, and, with the improvements that we’re making to the network, it connects us to the future as well, expanding our capabilities as we prepare human missions for the Moon and beyond.” 

“This latest antenna was built as an international partnership and will ultimately benefit all of humanity as we continue to explore deep space.”

Lead image credit: NASA

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