NASA is upgrading the Deep Space Network to help advance future space exploration

According to foreign media reports, NASA is upgrading the Deep Space Network (DSN) to communicate with more spacecraft than ever before and adapt to changing mission needs. When NASA's Mars 2020 Perseverance rover landed on the red planet, the agency's Deep Space Network (DSN) was there, enabling the mission to send and receive data to help make the event possible. Last year, when OSIRIS-REx collected samples from the asteroid Bennu, DSN played a key role, not only sending command sequences to the probe, but also transmitting its amazing photos back to Earth.

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The network has served as the backbone of NASA's deep space communications since 1963, regularly supporting 39 missions, with more than 30 more NASA missions in development. The team behind it is now working to increase capacity and make a number of improvements to the network that will help advance future space exploration.

A space communications and navigation program managed by NASA's Jet Propulsion Laboratory, housed within the Human Exploration and Operations Mission Directorate at NASA Headquarters, the DSN is what enables missions to track, send commands and receive science data from distant spacecraft.

The network consists of tracking antennas at three complexes around the world: Goldstone Complex near Barstow, California; Madrid, Spain; and Canberra, Australia. In addition to supporting missions, the antennas are routinely used to conduct radio science -- studying planets, black holes, and tracking near-Earth objects.

“Capacity is a big pressure, and our antenna enhancement program will help address that. This includes building two new antennas, increasing our number from 12 to 14,” said Michael Levesque, deputy director of the DSN program.

Network upgrade

In January 2021, DSN welcomed its 13th antenna. Named Deep Space Station 56 (DSS-56), this new 34-meter-wide (112-foot-wide) antenna in Madrid is an "all-in-one" antenna. Previously built antennas were limited in the frequency bands they could receive and transmit, often restricting them to communicating with specific spacecraft. Once online, DSS-56 became the first antenna to use all of DSN's communication frequencies, allowing it to communicate with all missions supported by DSN.

Shortly after bringing DSS-56 online, the DSN team completed a critical 11-month upgrade of Deep Space Station 43 (DSS-43), a giant 70-meter (230-foot) antenna in Canberra. DSS-43 is the only antenna in the Southern Hemisphere with a transmitter powerful enough and broadcasting the right frequencies to send commands to the distant Voyager 2 probe, now in interstellar space. With its rebuilt transmitter and upgraded facility equipment, DSS-43 will serve the network for decades to come.

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“The refresh of DSS-43 was a tremendous accomplishment, and we are now processing the next two 70-meter antennas at Goldstone and Madrid. And we continue to deliver new antennas to meet growing demand — all during COVID-19,” said Brad Arnold, DSN manager at JPL.

These improvements are part of a program to meet not only growing demands but also changing mission needs.

Missions are generating more and more data than ever before. Since the first lunar missions in the 1960s, the data rate from the Deep Space Network has increased more than 10 times. As NASA sets its sights on sending humans to Mars, this demand for higher data volumes will only increase further.

Optical communications is one tool that can help meet this need for higher data volumes by using lasers to enable higher bandwidth communications. Over the next few years, NASA has several missions planned to demonstrate laser communications, which will improve the agency's ability to explore farther into space.

New approach

The network is also looking at new approaches to how it does its work. For most of the DSN's history, for example, each complex was run locally. Now, through a protocol called "Follow the Sun," each complex takes turns running the entire network during the day, then hands over control to the next complex at the end of the day in that region -- essentially, a global relay race that takes place every 24 hours.

The resulting cost savings have been fed back into antenna improvements, and the effort has also strengthened international cooperation among the complexes. "Each site works with the others, not only during handoffs, but also in terms of maintenance and how the antennas are performing on any given day. We have truly become a globally functioning network," Levesque said.

The network has also implemented new ways to manage deep space communications. In the past, for example, if multiple spacecraft orbiting Mars needed to be served simultaneously, the network would have to point one antenna from each spacecraft toward Mars, potentially using all the antennas in a particular building. With a new protocol, the DSN can take multiple signals from a single antenna and split them up in a digital receiver. "We adapted this from commercial telecommunications implementations to benefit our network efficiency," Arnold said.

Another new protocol allows operators to oversee multiple activities simultaneously. Traditionally, each spacecraft activity has had a dedicated operator. Now, DSN has taken an approach that leverages automation, allowing each operator to oversee multiple spacecraft links simultaneously. For the first time, DSN can now fully automate the sequencing and execution of tracking channels, and this work will continue to be enhanced over time.

"The future of DSN will follow the spirit and momentum of the science missions that are flying," Arnold said. "Our responsibility is to make them possible. We do that through communications."