SCaN (Space Communications and Navigation)
SCaN (Space Communications and Navigation) — the 'ground' infrastructure of NASA
Space Communications and Navigation (SCaN) serves as the Program Office for all of NASA's space communications activities. SCaN manages and directs the ground-based facilities and services provided by the Deep Space Network (DSN), Near Earth Network (NEN) and Space Network (SN), and the SN's space segment, the Tracking and Data Relay Satellites (TDRS).
Space Communications and Navigation: Exploration Enabled, Then and Now 1)
Fifty years ago, NASA captured the world's imagination and inspired generations with the Apollo 11 Moon landing. Back then, NASA's communications networks were crucial to mission success. Today, they provide critical service as America moves forward to the Moon in 2024.
NASA's SCaN (Space Communications and Navigation) Program manages and directs the three prime NASA space communications networks, namely DSN (Deep Space Network), NEN (Near Earth Network) and SN (Space Network), into a global communications infrastructure for space exploration. SCAN was established in 2006, it was previously known as the Space Communications & Data Systems (SCDS) Program.
The agency's new lunar exploration program is called Artemis. NASA's SLS (Space Launch System) rocket will send astronauts aboard the Orion spacecraft to the Gateway in lunar orbit. Crew will take expeditions to the surface of the Moon in a human landing system, go back to the Gateway and return to Earth aboard Orion.
SCaN will support Artemis missions each step of the way. We're modernizing technologies like optical communications to ensure better data rates and improve astronaut communications at the Moon, and ultimately, Mars.
Today, SCaN supports over 100 NASA and non-NASA missions. Some missions look down at the Earth and observe changes; others observe the Sun's influence on the Earth; some study the Moon and the planets, while others study the origins of the universe.
Apollo 11: Seeing is Believing: On July 20, 1969, NASA astronauts Neil Armstrong and Buzz Aldrin, with Michael Collins orbiting above, became the first humans to land on another world, our Moon.
Affixed to the inside of the Eagle lander's door was a small, unconventional TV camera. The extraordinary images it captured showed Armstrong and Aldrin amid the "magnificent desolation" of the lunar surface.
Getting this incredible video to hundreds of millions of people back on Earth, gathered around countless television sets in rural homes, on city streets, and in remote villages around the globe, was up to the flexibility and resourcefulness of NASA's Manned Space Flight Network (MSFN) and DSN.
During lunar landing and liftoff, NASA "dishes" in Madrid, Spain, would provide tracking support for Apollo 11. But, at the time of the moonwalk, Madrid was facing away from the Moon and, thus, couldn't "see" it. So, the job of getting those first historic pictures down to the world fell to tracking stations in Australia and here in the United States.
When Armstrong finally started descending the Lunar Module ladder three hours after the Eagle had landed at Tranquility Base, a 64-meter antenna in Goldstone, California received the first downlink, and two-way communication from the surface of the Moon.
However, by the time Armstrong reached the foot of the ladder, Mission Control in Houston, Texas switched the transmission to Honeysuckle Creek's 26-meter antenna located outside of Canberra, Australia. The improvement in picture quality was extraordinary.
But, responsibility for voice communications remained at Goldstone.
These iconic words in history, "That's one small step for (a) man, one giant leap for mankind" ended their 240,000-mile journey to Earth at one location, while the pictures of Neil Armstrong speaking them came to be seen through another.
After almost nine minutes into the broadcast, a 64-meter dish at Parkes Observatory located in Parkes, New South Wales, Australia provided an even better picture. Television transmission would continue through July 23, 1969.
Behind these tracking stations were real people spending countless hours to make human exploration on the Moon possible.
"People everywhere appreciate the fact that the U.S. was willing to share its program so effectively with them by means of modern communications. People of many countries have told me personally that they certainly appreciate not only our technology but also our intebuild a better world through our space experiences. To those of you out there on the network who made all of the electrons go to the right places, at the right time — and not only during Apollo 11.... I would like to say, ‘Thank you.'" - Neil Armstrong to tracking network personnel, March 18, 1972.
Figure 1: This video commemorates the technological innovations that made possible the first live TV broadcast from the moon by the Apollo 11 crew on July 20, 1969 (video credit: NASA)
This video was aired when NASA Television was honored with a Primetime Emmy Award by the Academy of Television Arts & Sciences. The 2009 Philo T. Farnsworth Award recognizes the agency for engineering excellence and commemorates the 40th anniversary of the technological innovations that made possible the first live TV broadcast from the moon by the Apollo 11 crew on July 20, 1969.
The SCaN Networks
SCaN: The SCaN networks—comprised of the Near Earth Network (NEN), the Space Network (SN), and the DSN—provide communications and navigation services over the full operational life cycle of a mission from launch to end of life and/or deorbit. While missions may have a desire to use specific resources in accordance with NPD 8074.1 Management and Utilization of NASA's Space Communication and Navigation Infrastructure, the SCaN network swill make the final decision on the provision of its assets.
DSN: The DSN, consisting of ground stations utilizing 34- and 70-meter antennas, is focused on providing support to missions operating beyond Geosynchronous Earth Orbit (GEO). Historically, the DSN has supported High Earth Orbit (HEO), Lunar, Lagrangian, and planetary missions. The DSN operations are the responsibility of the Jet Propulsion Laboratory (JPL) in Pasadena, California.
NEN: The NEN, consisting primarily of a combination of NASA, partner, and commercial ground stations with antennas up to 18 meters in diameter, is focused on supporting launch and operational activities in the Low Earth Orbit (LEO) range as well as GEO, Lunar, and Earth-Sun Lagrange points. Most NEN antennas slew very quickly, enabling the NEN to track Launch vehicles during ascent and high-speed low altitude missions with brief visibility windows. The NEN operations are the responsibility of Goddard Space Flight Center (GSFC) in Greenbelt, Maryland.
SN: The SN, consisting of a constellation of relay satellites in GEO pointing towards the Earth and the ground segment that operates the constellation, enables continuous communications services to missions operating in Medium Earth Orbit (MEO) and below with support provided to Highly Elliptical Orbit (HEO) when the orbit brings the spacecraft within range. The SN has continuous visibility to missions from Launch through LEO operations. NASA's SN is the responsibility of the GSFC.
Ground Stations (DSN Complexes)
Each of NASA's three DSN (Deep Space Network) sites has multiple large antennas and is designed to enable continuous radio communication between several spacecraft and Earth. All three complexes consist of at least four antenna stations, each equipped with large, parabolic dish antennas and ultra-sensitive receiving systems capable of detecting incredibly faint radio signals from distant spacecraft. 3)
The DSN's large antennas are focusing mechanisms that concentrate power when receiving data and when transmitting commands. The antennas must point very accurately towards the spacecraft, because an antenna can "see" only a tiny portion of the sky – not unlike looking at the sky through a soda straw.
To hear the spacecraft's faint signal, the antennas are equipped with amplifiers, but there are two problems. First, the signal becomes degraded by background radio noise, or static, emitted naturally by nearly all objects in the universe, including the sun and earth. The background noise gets amplified along with the signal. Second, the powerful electronic equipment amplifying the signal adds noise of its own. The DSN uses highly sophisticated technology, including cooling the amplifiers to a few degrees above absolute zero, and special techniques to encode signals so the receiving system can distinguish the signal from the unwanted noise.
Antenna stations are remotely operated from a signal processing center at each complex. The centers house electronic systems that point and control the antennas, receive and process data, transmit commands and generate spacecraft navigation data.
Once the data is processed at the complexes, it is transmitted to NASA's JPL (Jet Propulsion Laboratory) for further processing and distribution to science teams over a ground communications network.
The Australian complex is located 40 kilometers (25 miles) southwest of Canberra near the Tidbinbilla Nature Reserve. The Spanish complex is located 60 kilometers (37 miles) west of Madrid at Robledo de Chavela. The Goldstone complex is located on the U.S. Army's Fort Irwin Military Reservation, approximately 72 kilometers (45 miles) northeast of the desert city of Barstow, California. Each complex is situated in semi-mountainous, bowl-shaped terrains to shield against external radio frequency interference.
Figure 3: NASA has robotic explorers all over our solar system – and beyond! How do we communicate with these faraway spacecraft? With the big antennas of the Deep Space Network, or DSN! The DSN has three antenna complexes evenly spaced around the world in the United States, Spain, and Australia. Watch this virtual tour of each complex to learn more about each one! (video credit: NASA)
Status of the SCaN Project
• June 8, 2022: The NASA podcast explores a variety of space communications and navigation topics, and the upcoming fifth season will focus on the JPL-managed Deep Space Network. 4)
- NASA's "The Invisible Network" podcast returns on June 9 for a six-episode season about NASA's Deep Space Network. Managed by the Jet Propulsion Laboratory in Southern California, the Deep Space Network provides critical communications links to flagship NASA missions at Mars, the outer planets, and even in interstellar space.
- "The Invisible Network" first debuted in 2018 with a six-episode season covering a variety of topics related to NASA's Space Communications and Navigation (SCaN) program office. Since then, the podcast's 22 episodes have covered burgeoning commercialization efforts, laser communications technologies, NASA's Artemis Moon missions, and so much more.
- The technologies that allow NASA to talk to and navigate spacecraft are often overlooked – perhaps because they work so well. Join us as we shine a light on the invisible networks that power space science and exploration.
- From long-form interviews with astronauts and engineers to stories that take you on a tour of the galaxy, NASA's audio offerings let you experience the thrill of space exploration without ever leaving Earth. Discover all of NASA's podcasts at: nasa.gov/podcasts.
• March 16, 2022: Part of an ongoing project to grow the capacity of the Deep Space Network, which acts as a kind of interplanetary switchboard, the new antenna is the network's 14th. 5)
- There's a powerful new member of NASA's family of giant antennas that enable engineers and scientists on Earth to communicate with the growing number of spacecraft exploring our solar system.
- Called Deep Space Station 53, or DSS-53, the 111-foot (34-meter) antenna is part of NASA's Deep Space Network (DSN). It's now operational at the network's facility outside Madrid, one of three such ground stations around the globe. The Madrid station is managed on NASA's behalf by Spain's Instituto Nacional de Técnica Aeroespacial (National Institute of Aerospace Technology). To mark the antenna's debut, King Felipe VI of Spain attended the March 16 inauguration ceremony alongside NASA officials and dignitaries from Spain and the U.S.
- "NASA is honored and humbled to have the king acknowledge this important milestone by joining us at the Madrid station. His inauguration of the Deep Space Station 53 antenna highlights the critical and historical collaboration between the Kingdom of Spain and the United States that, through the Deep Space Network, will continue to enable humankind's exploration of the heavens for many years to come," said Badri A. Younes, deputy associate administrator for Space Communications and Navigation (SCaN) at NASA Headquarters in Washington.
- Managed by NASA's Jet Propulsion Laboratory in Southern California for SCaN, the DSN allows missions to track, send commands to, and receive scientific data from faraway spacecraft. Now with 14 operational antennas, the network supports about 40 missions and is expected to support another 40 that will launch in the coming years.
Growing the Network
- With so many missions to support currently and in the future, NASA began a project to expand the DSN more than a decade ago. DSS-53 is the fourth among six new beam waveguide antennas that the agency is adding to the network. When the project is complete, each ground station – Madrid, along with one in Canberra, Australia, and the Goldstone facility near Barstow, California – will have a total of four such antennas. The DSN's three ground stations are spaced almost evenly around the globe so the network never loses sight of missions as Earth turns.
Figure 8: Construction of NASA's DSS-53 antenna at the Deep Space Network's Madrid complex is shown from November 2018 to March 2020. A nearly two-year commissioning process followed – including installation of electronics and testing – before the antenna became operational in late February 2022 (image credit: NASA/JPL-Caltech)
- Together, the new antennas are capable of backing up each site's 230-foot (70-meter) antenna. They also mean increased capacity to receive information on Earth – like images of the mysterious asteroid Psyche that the mission of the same name will acquire, or data from the forthcoming Europa Clipper mission revealing whether Jupiter's icy moon has the capability to support life as we know it.
- "This new antenna adds about 8% more capacity to the network. What it's going to mean is 8% more science, and that's really significant," said JPL's Bradford Arnold, the DSN project manager.
- DSS-53 will act as a "workhorse" antenna capable of communicating on the frequencies most commonly used by NASA spacecraft. Its construction began in 2016. A complicated two-year commissioning period included a weekslong process when engineers and technicians adjusted each of the dish's some 300 reflector panels, often as little as a quarter-turn of a screw, to optimize performance.
- The new antenna follows DSS-56 coming online in Spain in early 2021, making the Madrid facility the first to have completed its build-out as part of NASA's antenna-enhancement effort. The fifth new antenna in the effort, DSS-23, is expected to go online at Goldstone in 2025. The sixth antenna will be at the Canberra facility.
- The forerunner to the Deep Space Network was established in 1958 when JPL was contracted by the U.S. Army to deploy portable radio tracking stations in California, Nigeria, and Singapore to receive telemetry of the first successful U.S. satellite, Explorer 1. Shortly after JPL was transferred to NASA later that year, the newly formed U.S. civilian space program established the Deep Space Network to communicate with all deep space missions. It has been in continuous operation since 1963 and remains the backbone of deep space communications for NASA and international missions, supporting historic events such as the Apollo Moon landings and checking in on our interstellar explorers, Voyager 1 and 2.
• January 27, 2021: Microsoft is working with the Jet Propulsion Laboratory to speed up the process for scheduling communications with distant spacecraft through NASA's Deep Space Network (DSN). 6)
- Scheduling communications for spacecraft that rely on the Deep Space Network is becoming increasingly difficult. JPL receives several hundred weekly requests to relay mission-related communications.
- Missions like Mars 2020 Perseverance Rover and the James Webb Space Telescope relay higher-fidelity data than older spacecraft, increasing the load on the Deep Space Network. Artemis lunar missions are expected to further tax the Deep Space Network.
- For help solving its scheduling problem, JPL is working with Azure Quantum, a Microsoft Azure service designed for quantum computing programs and solving complex, multivariate problems.
- The Microsoft Quantum team worked with JPL to begin developing solutions for the scheduling problem. The initial solutions has limited features. The eventual goal is to develop a solution that incorporates extensive requirements.
- When Microsoft began working with JPL the tech giant noted that it sometimes took JPL more than two hours to produce a weekly schedule. With the aid of Azure Quantum optimization algorithms, schedules can be produced in minutes.
- "Schedules that are produced in minutes rather than hours not only allow JPL to create many candidate schedules, but also allow the organization to be more agile as missions and demands increase," according to a Jan. 26 Microsoft news release.
- The Deep Space Network, NASA's global array of giant radio antennas operated by JPL, relays communications for missions beyond Earth orbit. Deep Space Network antennas are located in Goldstone, California, Canberra, Australia, and Madrid.
• July 27, 2021: The ability to transmit and receive data is crucial in space exploration. Spacecraft need robust networking capabilities to send data – including large files like photos and videos - captured by onboard instruments to Earth as well as simultaneously receiving commands from control centers. NASA has made significant strides to improve the agency's space communications capabilities while simultaneously maintaining ongoing operations and service to a large number of missions. 7)
- The Space Network Ground Segment Sustainment (SGSS) project implemented critical upgrades to NASA's space communications infrastructure by modernizing Tracking and Data Relay Satellite (TDRS) ground terminals and improving many system capabilities. Orbiting 22,300 miles above Earth, multiple TDRS provide communication links between orbiting satellites, such as the Hubble Space Telescope and the International Space Station, and ground-based control centers. TDRS allow missions to be in nearly constant contact with their control and data centers on Earth.
- In April 2021, the SGSS team finished initial upgrades to systems at the Second TDRS System Ground Terminal (STGT) and the White Sands Ground Terminal (WSGT) sites, located at NASA's White Sands Complex in Las Cruces, New Mexico.
- These upgrades included installing new equipment to support TDRS communication antennas at the STGT and WSGT locations. Approximately 40 racks of electronic and computing equipment were installed in each of the two locations, reflecting more than an approximately 80 percent reduction in the number of racks needed to support TDRS operations as compared to the old equipment. Additionally, the team upgraded several ground antennas, including one main mission antenna, four test antennas, and one backup communications antenna that can be used if any of the mission antennas become unavailable.
- The improvements allow more data to flow through the system, create additional data transfer modes, and increase antenna reliability. These features are designed to ensure the uninterrupted flow of data, enabling future discoveries.
- "Upgrading the existing ground system has modernized the electronics and uses more commercially available products. This should help reduce the cost of maintaining systems like TDRS, and helps make extensibility, flexibility, and scalability more straightforward," said Tom Gitlin, the deputy project manager, technical for SGSS. "SGSS is still compatible with the old system, but will provide new functions, higher data rates, and support more modern data coding schemes."
- The SGSS project converted a WSGT legacy antenna to support two radio frequency bands for communication to and from a TDRS. This newly modified antenna can transmit using Ku-band — used for communications with the TDRS for normal operations, and at S-band — used when storing a TDRS on orbit or when the Ku-band is unavailable for any reason. Prior to this upgrade, the antenna only supported the Ku-band frequency. With the SGSS system operational, this antenna can easily switch between the two bands when needed, ensuring TDRS communications services are not interrupted and minimizing the need to switch antenna assets.
- NASA has never performed an upgrade of this magnitude while simultaneously maintaining operations. Much of the existing ground terminal technology uses analog signaling that suffers degradation as it travels through the ground terminal. The SGSS system converts signal transport paths to digital form, which does not suffer losses or signal degradation. SGSS digitizes signals immediately at the ground station antenna.
- "This is the first major upgrade of a full ground station while the legacy equipment was still in use," said Richard Von Wolff, deployment, transition, and operations manager for SGSS.
- Working on-site at White Sands, Von Wolff took charge of getting the equipment ready for deployment and ensured there was a seamless transition of operations. In addition to performing those tasks in tandem with the equipment turnover, he made sure operations training and documentation would be ready so that once the upgrades are complete, the SGSS system can be transferred to NASA's Advanced Communications Capabilities for Exploration and Science Systems (ACCESS) project. ACCESS has assumed responsibility for the system and is conducting additional tests and modifications as necessary.
- These upgrades are the third generation of improvements at the site and take White Sands into the digital era, enabling lower TDRS system maintenance costs, and providing higher data rates with minimal disruptions. The new infrastructure will support the next generation of satellites, allowing NASA to discover more about our planet, the solar system, and beyond.
- NASA's Goddard Space Flight Center in Greenbelt, Maryland manages the operations and maintenance of the TDRS fleet, its ground terminals, and the SGSS project on behalf of NASA's Space Communications and Navigation (SCaN) program, part of the agency's Human Exploration and Operations Mission Directorate. SCaN is responsible for the SGSS project and the Near Space Network. For more information about the SCaN program, visit: https://www.nasa.gov/scan.
• July 10, 2021: A growing number of spacecraft missions, as well as NASA's Artemis program, are putting new pressures on the agency's Deep Space Network of antennas that communicate with them. 8)
- In a July 7 presentation to the steering committee of the planetary science decadal survey, Brad Arnold, manager of the Deep Space Network (DSN) at the Jet Propulsion Laboratory, says that even with upgrades to the radio antennas at sites in Australia, California and Spain, the system can't keep up with growing demand from missions.
- "We're trying to add capacity and more antennas, but we can't keep up with the demand that's currently out there, so missions should expect to be getting less availability," he said.
- The DSN is used for communications with missions beyond Earth orbit. Arnold says the network relies on projections of demand from current and proposed missions, then runs "loading studies," or simulations to see how the various antennas can accommodate them.
- Missions typically ask for about 20% more data than they actually get. "At this point, nobody is complaining about that. That's sort of the game: you ask for 20% high and you end up with what you need," he said. However, over the next decade that 20% difference between what missions ask and what the DSN can provide will grow. "Instead of being 20% short, we're going to be about 40% short."
- Those missions in critical phases, such as launches, orbital insertions and landings, will be prioritized so they get the communications they need. "Outside of that, you will get a little less," he said.
- Another factor will be demands on the DSN from Artemis missions to the moon. "This is the gorilla in the room," he said. "When they need telecom and hot backups and priority 24/7, they're going to get it. That ultimately will affect our ability to service the rest of the missions."
- The proximity of the moon would appear to allow the DSN to use smaller dishes, saving larger ones, 34 and 70 meters across, for more distant missions. "Obviously at lunar distances we don't need a 34-meter" dish, he said. However, he added they may be cases where larger dishes may be required to provide sufficient margin for some receivers.
- Arnold said the DSN is looking at several approaches to increase capacity on the network. One is to push missions to move from X-band to higher Ka-band frequencies. "X-band is becoming congested and the spectrum for data is limited. We really need to start pushing up to Ka-band," he said, along with studies of optical communications that could provide even higher bandwidth.
- X-band, he added, will be around "for the next couple decades" for current missions and those in development. "My point is, we really need to collectively as a group, as we move to the future, think about getting off X-band."
- While NASA is exploring commercialization options for communications with spacecraft in Earth orbit, Arnold says that is not an option for the DSN. "The return on investment is not clear right now for a commercial enterprise," he said. "We're quite a long ways off from that actually happening."
• June 10, 2021: In the early days of cellphone use, each user was limited to their chosen provider's network and service capabilities. Restricting customers to service within one network led to high prices for out-of-network calls and limited value for customers. Cellphone providers long ago adopted roaming, allowing devices to jump from network to network without interrupting service and increasing competition across the industry and value to consumers. 9)
- Roaming isn't available in space, so network access is an issue as satellites and spacecraft orbit the Earth. This will soon change as NASA develops a new Wideband Ka-band communications terminal, which is a transceiver that operates over government and commercial Ka-band spectrum allocations (17.7 GHz – 31 GHz). This roaming function will give spacecraft the ability to seamlessly connect to various communications networks and allow for multi-access points of services, lower latency, and lower costs.
- "This is a first for a Ka-band user terminal," said Nang Pham, Wideband Project Manager at NASA's Glenn Research Center in Cleveland. "The versatile capabilities demonstrated by the terminal bring us a step closer to space communications interoperability for future NASA near-Earth missions."
- The new terminal will support NASA's plans to rely exclusively on commercial providers for near-Earth space communications and navigation operations by the mid-2030s and further foster an affordable and robust space commercialization path in the United States.
- For almost 40 years, NASA has relied on its Tracking and Data Relay Satellites (TDRS) system to provide near-constant communication links between the ground and satellites in low-Earth orbit, but the infrastructure was not originally designed for interoperability between networks.
- This new Wideband Ka-band terminal prototype will allow satellites to connect with multiple space relay networks, including TDRS, enabling NASA's transition from government to commercial space communications services.
- "This terminal will allow missions to reduce risk and costs by offering competitive choices for where they get their commercial satellite service," said Marie Piasecki, Wideband Project Principal Investigator at Glenn. "A high Technology Readiness Level terminal capable of operating on a wide assortment of networks truly takes advantage of commercial investments in space."
- NASA recently concluded a month of trailblazing tests that successfully demonstrated communications over-the-air with the Wideband Ka terminal prototype for the very first time. A groundbreaking roaming experiment was the highlight of testing, where services switched in real-time between NASA's TDRS system and Inmarsat's Global Xpress Satellite.
- This successful demonstration provides proof of initial roaming capabilities and confidence that commercial services can one day support future space users. The Wideband Ka-band terminal prototype is at a sufficiently high technology readiness level that the next technology transitional phase will be to demonstrate in a space environment.
- The Wideband terminal prototype will now undergo additional ground testing and demonstrations with various commercial service providers. NASA's SCaN (Space Communications and Navigation) program is planning a flight demonstration, currently targeted for 2025, to evaluate in-orbit roaming capabilities across multiple government and commercial networks.
• May 12, 2021: NARRATOR: NASA has long relied on commercial industry for critical space communications and navigation services and support. Government-owned, contractor-operated infrastructure was fundamental to the success of the agency's earliest missions. Commercial partnerships have provided NASA with the workforce needed to operate a global network of ground stations, to upgrade and maintain their antennas, and to build the telecommunications satellites that support missions like the International Space Station. 10)
- Today, in a paradigm shift that seeks to help nurture the U.S. space economy, NASA's SCaN (Space Communications and Navigation) program is embracing commercialization even further.
- NASA plans to rely primarily on industry-provided communications services for missions close to Earth by 2030. Rather than using government-owned relay satellites and ground stations, SCaN will work with private industry to furnish missions with comprehensive, commercial network services. In order to make this bold objective a reality, NASA is fostering new entrants into the space communications marketplace.
- I'm Danny Baird. This is the Invisible Network.
- SCaN started as a formal headquarters program in 2006. You know, commercialization has been part of our overall ... architecture — how we provide services to users — since the beginning ... Our most recent decision ... is that we think — measuring the market and where people's technical capabilities are — that we don't need to go build out necessarily NASA-owned and -operated capacity in the future. There's enough vendors, they have enough operational history, that we can start to rely on them for the vast majority, if not 100%, of our comm and nav services in the near-Earth domain.
- Greg Heckler serves as the engineering manager for the Network Services Division of SCaN at NASA Headquarters in Washington. He's been working on SCaN's commercialization efforts for a while now, focusing on near-space, a region that extends from LEO (Low-Earth Orbit), out to geosynchronous orbit, some 22,000 miles in altitude, roughly 1/10 the distance to the Moon.
- It's in alignment with NASA's overall strategy, right? We want to try to encourage what we're calling a LEO commercial space environment. We can't do it all ourselves, right? We don't have enough dollars to do that. But we're trying to make key investments. Drive dollars into key places to allow this larger ecosystem to evolve.
- The near-space region is filled with user missions in a variety of disciplines ranging from Earth science to astrophysics. The International Space Station flies in low-Earth orbit, about 250 miles above Earth. Deep space missions must ascend through the region before their long journeys to destinations like Mars, the asteroid belt, or the outer planets. In the future, what can these missions expect from a commercial communications paradigm?
- I think they will have access to more capacity — more capability — and in a cheaper way than we could provide ourselves, right? ... There's enough demand outside of NASA — other government agencies, international space agencies, and even ... commercial space entities themselves — that we're no longer going to be the anchor tenant, or even a driving customer.
- ... By going in and bringing those commercial vendors out there into our ecosystem — and offering those to our users — they have access to a lot more capacity. This helps mission design, right?
- The benefits aren't just for missions. There's the obvious benefit to the commercial companies developing new capabilities — some of which could be used by consumers — but there's also enormous benefit to the agency. It frees up resources.
- Significantly for NASA, that means we don't have to carry… operations and maintenance costs from here — basically — forever into the future. And so to us, it makes a lot of sense. The economics are pushing us in this direction. The technical capability of the vendors are pushing in this direction. There'll be some risk. We'll see vendors come and go, but we have means of addressing those risks while still meeting our obligations to our users.
- As the commercial marketplace matures, what is NASA's role in space communications? Largely, it remains the same. It's a role the agency has played for decades.
- We need to be there to drive the market, right? We need to represent the agency on not only what our users do today, but what they want in five and 10 and 15 years down the road ... We do that inside the agency. And we use that to plan how we evolve our network architecture ... The other thing we can do is around interoperability and standards ... We want to be a champion of emerging commercially defined standards, that we hope we can get enough of these entities together to agree to.
- NASA historically ... our position has been not to do explicitly what the industry can do, right? We're there to do the new things, the things where it takes government investment to make something happen ... So by reducing our focus on operations and maintenance of government systems over time and potentially ... realizing some cost efficiencies, then we can focus on the things that ... really excite us ... So we really need to be focused on supporting the agency's goals and endeavors in those places where it's not a realistic expectation to stand up a commercial market.
- Now the question remains: How will SCaN help nurture commercial industry to create this competitive environment? What steps is NASA taking to foster this new marketplace? Two NASA centers with over a century of combined space communications experience are leading the effort.
- At NASA's Glenn Research Center in Cleveland, the SCaN community has long endeavored to advance communications technology, researching innovations like cognitive radios, artificial intelligence, and quantum networking. For the commercialization effort:
- We're working on the SATCOM piece — so the satellite communications.
- Eli Naffah serves as the project manager for Glenn's CSP (Communications Services Project).
- CSP is a new project in formulation to explore the feasibility of commercial SATCOM services for NASA missions ... NASA has embarked on, really kind of an evolution ... to take operations and, and the things that we used to do in low-Earth orbit routinely and start turning that over to the commercial sector ...
- If you look at the evolution of the industry in low-Earth orbit, the first thing that NASA embarked on was the Commercial Cargo or the Commercial Orbital Transportation System, which is now you know, a true market. You can see the success that we've had with Commercial Cargo going to space station, and then the next step was a Commercial Crew Program ... And so the evolution also is now stretching to communications and navigation.
- SATCOM satellites provide space relay services, acting as a conduit for data. They're essentially an intermediary between ground stations and spacecraft. Space relays can provide more coverage than a single ground station. A collection of them can provide near-continuous communications to LEO satellites. These types of services are critical to flagship missions like the space station or the Hubble Space Telescope.
- So, the idea is to eventually prove the feasibility of commercial SATCOM services ... to create a market where we can be one of many buyers of those types of services, and then eventually divest ourselves of the infrastructure that we currently have, at least in the near-Earth regime.
- NASA's current SATCOM system is called the TDRS (Tracking and Data Relay Satellite) constellation. The last in the third generation of these satellites, TDRS-13, launched in 2017, replenishing the fleet. The constellation will continue to support users for many years to come, but NASA has no plans to build any more TDRS satellites of its own.
- When that system was initially developed, there was only a handful of satellites that were commercial that were flying at that time.
- That's Thomas Kacpura. He serves as deputy project manager of the Communications Services Project.
- And that work was done back in the 80s. And actually, some of the development work was really done in the 1970s. And so, you had a handful of satellites back then. Now… there's literally thousands of commercial satellites that are up there. And every day, there's more that are being added to it ...
- And ultimately, I think that.. rather than buying a satellite – now we can go out and actually buy and specify a service. And that's what part of the work that we're trying to take a look at. It's trying to figure out, what are those next steps?
- How can NASA motivate commercial industry to develop the capabilities SCaN needs? What model will they follow. Once again, Eli Naffah:
- So, when you look at what Commercial Orbital Transportation System did, they essentially became investors in… a capability. And so that's what we're intending to do. We're kind of following the model that they set of really not setting specific requirements, but laying out goals and what we're interested in buying in the future ....
- There's no real technology development that's required here. Industry is pretty mature .... Typically, industry right now is serving terrestrial markets. So, they have a lot of infrastructure for providing a comm and nav solutions for terrestrial users ... on the ground, in the air, or at sea. And so, the question is, can they provide those same capabilities or similar capabilities to a spacecraft?
- The answer, they think, is a resounding, "Yes." The commercial aerospace industry has evolved so much over the decades since NASA launched the first TDRS satellite. Further, the benefits of embracing industry-developed capabilities are too good to pass up.
- So, it's not just driving the cost down for us, and divesting ourselves of the infrastructure and having to maintain that but it's also about improving performance and capability eventually ... The ultimate goal is to have ... an internet in the sky .... When cell phones first came out ... you didn't want to roam ... If you left your network, you were going to get hit with a big bill.
- And then, industry finally figured out that if they built in interoperability into their networks — so that a cell phone could easily switch from one network to another depending on the location — that it would increase the use of cell phones overall and increase their market share. And so, they decided to develop commercial interoperability standards.
- So, I think ultimately, that's where we would like to be in space. Is to be able to have the flexibility to roam in space between networks, depending on what would be available.
- At NASA's Goddard Space Flight Center in Greenbelt, Maryland, communications engineers are working with commercial enterprise to develop industry capabilities that could supplement Goddard-managed infrastructure like TDRS and their collection of direct-to-Earth ground stations.
- LaNetra Tate serves as the deputy program manager for execution of the Exploration and Space Communications (ESC) projects division, which provides communications services to many NASA missions. LaNetra also serves as the acting chief of the CIS (Commercialization, Innovation, and Synergies) office.
- SCaN has seen that the market is ready and mature to be at the forefront of providing communications and navigation services to users and to customers. And I think we see this as an alliance between industry and government, with industry leading and NASA really serving as — I like to say — a cornerstone to drive standardization and interoperability ... Goddard has a long history in space communications and navigation and, you know, there's a team that is both strategic and tactical — and really, really poised to support this commercialization effort in partnership with SCaN.
- Goddard and ESC are meeting SCaN's commercialization goals through their newly established Near Space Network enterprise. This enterprise subsumed a collection of projects that previously provided communications services into three new efforts.
- CIS garners new entrants into the space communications marketplace. The NSN (Near Space Network) project provides services from the marketplace and helps user missions to develop their communications architectures. The ACCESS (Advanced Communications Capabilities for Exploration and Science Systems) project supplies the marketplace with services from NASA's portfolio of government-owned, contractor-operated infrastructure like TDRS and ground stations worldwide.
- CIS, the Near Space Network project, and ACCESS will really change the landscape of how we provide communications services... I'm just so excited to be a part of such a great team that we are actively working to define ... the next 60 years.
- And how is CIS defining the next 60 years in the near-term?
- We have developed a series of industry engagement activities that really bring about awareness to the to the potential providers of how they can join or be a part of the Near Space Network.
- We have sessions like the OneLink session, which is a one-hour briefing for industry to hear from us. Then we have another session called ... the UpLink session. And that's a one-hour one-on-one session, where industry can talk about their capabilities directly with our subject matter experts within the Near Space Network. Then we have these really engaging activities called the BEAM session, which is really bridging potential providers with users... And another type of activity that we're looking at is called an Amplifier ... So, the Amplifier session is a one-day workshop, where we ... work and we engage with small startups or entrepreneurs ... One that is probably very exciting ... is we call Ignite the Flight, and this is a pitch competition. It's going to run twice a year, and it's really our way of looking for disruptive future comm and nav capabilities.
- Those are just a few things that we're doing on the industry side. And then we'll we're also planning of how we proactively engage on the mission side.
- But what does LaNetra think these markets will look like? She echoed many of the sentiments of her colleagues at Glenn Research Center and NASA Headquarters:
- I think the marketplace looks like an environment that sees partnerships ... really with a shared vision, and an opportunity to promote cost effective solutions. I see a marketplace that has a common set of standards ... I think another area is a firm commitment on how we approach ... IT security ... As we move into more cloud services — we move more into colocation of RF equipment and sharing of equipment — you know, there has to be an assessment of security protocols and resiliency.
- NASA can't do it by it by ourselves, and industry can't do it by themselves. But a shared collaboration and a shared vision of being able to identify challenges, overcome the challenges ... and I think that's how I see the future marketplace.
- Establishing this future marketplace takes all of the agency's communications and navigation community working together toward SCaN's shared vision.
- I think the combination between SCaN, and Goddard, and JPL, and Glenn Research Center really offers a great collaboration of NASA as a whole, really working with industry as a whole to really define the next 60 years of communications and navigation services.
- It's hard to express the immense importance of these commercialization activities. While the Commercial Crew Program has garnered a lot of interest from the public, SCaN's game-changing efforts to establish a commercial marketplace are mostly celebrated by those directly involved. As the name of this podcast reminds us, mission-enabling infrastructure is often "invisible," unnoticed because it works so well.
- Touchdown confirmed. Perseverance safely on the surface of Mars, ready to begin seeking the signs of past life.
- Recently, I watched the Perseverance Rover touch down on the surface of Mars. Mission updates from NASA's Jet Propulsion Laboratory in Southern California excited millions around the world. They tuned in to see and hear the strange sights and sounds of the Red Planet.
- Behind the scenes, communications and navigation professionals enabled Perseverance's gentle touchdown on the Martian surface and the transmission of these incredible pieces of media.
- SCaN is a key part of every mission, but it's not well known in the agency. We're an enabling organization ... We don't get the tweets and the YouTube views like Perseverance ... but that video — that video that we all watched the other day — ... We would not [have] been able to deliver those images back to the Earth without SCaN, and communications and navigation capabilities, and capacity we give to the agency.
- This commercialization-focused season of "The Invisible Network" debuted in May of 2021. Our next season will focus on the Laser Communications Relay Demonstration and debut after the launch of the mission later this year.
- The podcast is produced by the SCaN (Space Communications and Navigation) program out of Goddard Space Flight Center in Greenbelt, Maryland. Episodes were written and recorded by me, Danny Baird, with editorial support from Katherine Schauer. Our public affairs officers are Lora Bleacher of Goddard's Office of Communications and Kathryn Hambleton of the Human Exploration and Operations Mission Directorate.
- Special thanks to Barbara Adde, SCaN Policy and Strategic Communications director, Rob Garner, Goddard Web Team lead, and all those who have leant their time, talent and expertise to making "The Invisible Network" a reality. Be sure to rate, review, and follow the show wherever you get your podcasts. For transcripts of the episodes, visit NASA.gov/invisible. To learn more about the vital role that space communications plays in NASA's mission, visit NASA.gov/SCaN. And for more NASA podcast offerings, visit NASA.gov/podcasts.
- The network of antennas and dishes relays messages from missions such as Voyager 1 and the Deep Space Climate Observatory (DSCOVR). Voyager 1 launched in 1977 and is still sending signals back from interstellar space, some 22 billion km (14 billion miles) away. DSCOVR takes full-disc images of Earth from 1.6 million kilometers (1 million miles) away.
Figure 14: NASA has robotic explorers all over our solar system – and beyond! How do we communicate with these faraway spacecraft? With the big antennas of the DSN (Deep Space Network)! The DSN has three antenna complexes evenly spaced around the world in the United States, Spain, and Australia. Watch this virtual tour of each complex to learn more about each one! (video credit: NASA)
- The most powerful antenna at the Madrid facility is Deep Space Station 63. With a diameter of 70 meters (230 feet), it receives signals from missions as far away as interstellar space. In January 2021, engineers completed the installation of Deep Space Station 56, a versatile 34-meter (112-foot) antenna that is capable of communicating at multiple frequencies and with multiple spacecraft. Existing antennas are limited in the frequency bands they can receive and transmit, often restricting them to communicating only with specific spacecraft.
- In addition to tracking and communicating with distant spacecraft, scientists make use of data from the DSN to study Earth's shape and gravity field, a discipline known as very-long-baseline interferometry (VLBI) to track small changes in Earth's crust such as the movement of tectonic plates.
• January 22, 2021: A powerful new antenna has been added to the NASA Space Communications and Navigation's Deep Space Network (DSN), which connects us to the space robots exploring our solar system. Called Deep Space Station 56, or DSS-56, the dish is now online and ready to communicate with a variety of missions, including NASA's Perseverance rover when it lands on the Red Planet next month. 12)
DSN radio antennas communicate with spacecraft throughout the solar system. Previous antennas have been limited in the frequency bands they can receive and transmit, often being restricted to communicating only with specific spacecraft. DSS-56 is the first to use the DSN's full range of communication frequencies. This means DSS-56 is an "all-in-one" antenna that can communicate with all the missions that the DSN supports and can be used as a backup for any of the Madrid complex's other antennas.
With the addition of DSS-56 and other 34-meter antennas to all three DSN complexes, the network is preparing to play a critical role in ensuring communication and navigation support for upcoming Moon and Mars missions and the crewed Artemis missions.
The Deep Space Network is managed by NASA's Jet Propulsion Laboratory for the agency's Human Exploration and Operations' Space Communication and Navigation program.
The new 34-meter-wide dish has been under construction at the Madrid Deep Space Communications Complex in Spain since 2017. Existing antennas are limited in the frequency bands they can receive and transmit, often restricting them to communicating only with specific spacecraft. DSS-56 is the first to use the Deep Space Network's full range of communication frequencies as soon as it went online. This means DSS-56 is an "all-in-one" antenna that can communicate with all the missions that the DSN supports and can be used as a backup for any of the Madrid complex's other antennas.
"DSS-56 offers the Deep Space Network additional real-time flexibility and reliability," said Badri Younes, deputy associate administrator and program manager of NASA's Space Communications and Navigation (SCaN). "This new asset symbolizes and underscores our ongoing support for more than 30 deep space missions who count on our services to enable their success."
"The Deep Space Network is vital to so much of what we do – and to what we plan to do – throughout the solar system. 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," said Thomas Zurbuchen, associate administrator of the Science Mission Directorate at NASA's headquarters in Washington. "This latest antenna was built as an international partnership and will ultimately benefit all of humanity as we continue to explore deep space."
With DSS-56's increased flexibility came a more complex start-up phase, which included testing and calibration of a larger suite of systems, before the antenna could go online. On Friday, Jan. 22, the international partners who oversaw the antenna's construction attended a virtual ribbon-cutting event to officially mark the occasion – an event that had been delayed due to historic snowfall blanketing much of Spain.
"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 NASA's Jet Propulsion Laboratory in Southern California. "Even though pandemic restrictions and the recent weather conditions in Spain have been significant challenges, the staff in Madrid persevered, and I am proud to welcome DSS-56 to the global DSN family."
More About the Deep Space Network
In addition to Spain, the Deep Space Network has ground stations in California (Goldstone) and Australia (Canberra). This configuration allows mission controllers to communicate with spacecraft throughout the solar system at all times during Earth's rotation.
The forerunner to the DSN was established in January 1958 when JPL was contracted by the U.S. Army to deploy portable radio tracking stations in California, Nigeria, and Singapore to receive telemetry of the first successful U.S. satellite, Explorer 1. Shortly after JPL was transferred to NASA on Dec. 3, 1958, the newly-formed U.S. civilian space program established the Deep Space Network to communicate with all deep space missions. It has been in continuous operation since 1963 and remains the backbone of deep space communications for NASA and international missions, supporting historic events such as the Apollo Moon landings and checking in on our interstellar explorers, Voyager 1 and 2.
The Deep Space Network is managed by JPL for SCaN, which is located at NASA's headquarters within the Human Exploration and Operations Mission Directorate. The Madrid station is managed on NASA's behalf by Spain's national research organization, Instituto Nacional de Técnica Aeroespacial (National Institute of Aerospace Technology).
• March 4, 2020: Starting in early March, NASA's Voyager 2 will quietly coast through interstellar space without receiving commands from Earth. That's because the Voyager's primary means of communication, the Deep Space Network's 70-meter-wide radio antenna in Canberra, Australia, will be undergoing critical upgrades for about 11 months. During this time, the Voyager team will still be able to receive science data from Voyager 2 on its mission to explore the outermost edge of the Sun's domain and beyond. 13)
About the size of a 20-story office building, the dish has been in service for 48 years. Some parts of the 70-meter antenna, including the transmitters that send commands to various spacecraft, are 40 years old and increasingly unreliable. The Deep Space Network (DSN) upgrades are planned to start now that Voyager 2 has returned to normal operations, after accidentally overdrawing its power supply and automatically turning off its science instruments in January.
The network operates 24 hours a day, 365 days a year and is spread over three sites around the world, in California, Spain and Australia. This allows navigators to communicate with spacecraft at the Moon and beyond at all times during Earth's rotation. Voyager 2, which launched in 1977, is currently more than 11 billion miles (17 billion kilometers) from Earth. It is flying in a downward direction relative to Earth's orbital plane, where it can be seen only from the southern hemisphere and thus can communicate only with the Australian site.
Moreover, a special S-band transmitter is required to send commands to Voyager 2 - one both powerful enough to reach interstellar space and on a frequency that can communicate with Voyager's dated technology. The Canberra 70-meter antenna (called "DSS43") is the only such antenna in the southern hemisphere. As the equipment in the antenna ages, the risk of unplanned outages will increase, which adds more risk to the Voyager mission. The planned upgrades will not only reduce that risk, but will also add state-of-the art technology upgrades that will benefit future missions.
"Obviously, the 11 months of repairs puts more constraints on the other DSN sites," said Jeff Berner, Deep Space Network's chief engineer. "But the advantage is that when we come back, the Canberra antenna will be much more reliable."
The repairs will benefit far more than Voyager 2, including future missions like the Mars 2020 rover and Moon to Mars exploration efforts. The network will play a critical role in ensuring communication and navigation support for both the precursor Moon and Mars missions and the crewed Artemis missions. "The maintenance is needed to support the missions that NASA is developing and launching in the future, as well as supporting the missions that are operating right now," said Suzanne Dodd, Voyager project manager and JPL Director for the Interplanetary Network.
The three Canberra 34-meter antennas can be configured to listen to Voyager 2's signal; they just won't be able to transmit commands. In the meantime, said Dodd, the Voyager team will put the spacecraft into a quiescent state, which will still allow it to send back science data during the 11-month downtime.
"We put the spacecraft back into a state where it will be just fine, assuming that everything goes normally with it during the time that the antenna is down," said Dodd. "If things don't go normally - which is always a possibility, especially with an aging spacecraft - then the onboard fault protection that's there can handle the situation."
Berner says the work on the 70-meter antenna is like bringing an old car into the shop: There's never a good time to do it, but it will make the car much more dependable if you do.
The work on the Canberra DSN station is expected to be completed by January 2021. The DSN is managed by NASA's Jet Propulsion Laboratory for the agency's Human Exploration and Operations' Space Communication and Navigation program.
• October 1, 2014: NASA's newest Deep Space Network antenna, Deep Space Station 35 (DSS-35) in Canberra, Australia is now operational. DSS-35 is the first in a series of 34 meter Beam Waveguide (BWG) antennas to be built as part of the Deep Space Network Aperture Enhancement Project (DAEP). The ribbon-cutting ceremony will take place sometime in early 2015. 14)
The BWG antenna is different than its predecessors because the antenna allows for multiple frequencies to be transmitted and received by the turning of the mirror in the pedestal room below the antenna. The antenna is much easier to maintain and signals can be translated on the spot to information that we can understand.
The Deep Space Network (DSN), which turned 50 on December 24, 2013, provides communication and tracking services to about 35 NASA and non-NASA missions beyond geosynchronous orbit (GEO). The DSN consists of three ground stations located approximately 120 degrees apart on Earth. This is to ensure that any satellite in deep space is able to communicate with at least one station at all times. The stations are located in Goldstone, California; Madrid, Spain; and Canberra, Australia.
CSIRO (Commonwealth Scientific and Industrial Research Organisation) performs the day-to-day operations at the Canberra Deep Space Communications Complex. NASA's Space Communication and Navigation (SCaN) Office has assigned operations and maintenance to the Jet Propulsion Laboratory (JPL).
• October 1, 2014: The Deep Space Network (DSN) consists of three complexes located approximately 120 degrees apart on Earth. The three complexes located in Goldstone, California; Madrid, Spain; and Canberra, Australia currently have a 70 meter antenna, one 34 meter High Efficiency (HEF) antenna and one or more 34 meter Beam Wave Guide (BWG) antennas. 15)
The 70 meter antennas were originally built as 64 meter antennas in the late 1960's to capture signals from the satellites exploring Venus and Mars. The antennas were upgraded to 70 meters in the mid 1980's when Voyager missions were exploring Uranus and Neptune.
The 34 meter High Efficiency (HEF) antennas were built in the 1980's and were the first to support X-band uplink, which was needed for missions exploring the outer planets. The 34 meter Beam Wave Guide (BWG) antennas, the newest of the group, were built in the 1990's. The BWG antenna routes energy between the reflector at the top of the dish and the pedestal room below ground. This allows for multiple feeds and amplifiers at multiple frequencies to be illuminated selectively by a single mirror and remove sensitive electronics from the tipping structure.
Starting in 2002, multiple studies were conducted to determine the most cost effective and technically feasible solution for retiring the 70 meter antennas. These antennas were built over 40 years ago and have begun showing their age. Parts have become difficult to find and maintenance costs are high and continue to increase. These antennas present both physical and technological limitations to potential upgrades needed to support future mission needs.
The Space Communications and Navigation (SCaN) office decided to decommission the 70 meter antennas and replace them with arrays of four 34 meter antennas by 2025. An array of four antennas is easier to maintain and can provide the same/better performance as the 70 meter antenna. The array would consist of four antennas for the receiver function and one 34 meter antenna equipped with an 80 kW for the transmitter function. This plan is called the Deep Space Network (DSN) Aperture Enhancement Project (DAEP).
The first step in the DAEP is to have in three more 34 meter BWG antennas built in Canberra, Australia by 2018. Groundbreaking occurred in February 2010 with US and Australian government officials present.
By 2025, the 70 meter antennas at all three locations will be decommissioned for communications and replaced with the 34 meter BWG antennas arrays. All systems will be upgraded to have X-band uplink capabilities and both X- and Ka-band downlink capabilities.
1) Megan Wallace, "Space Communications and Navigation: Exploration Enabled, Then and Now," NASA, 1 July 2019, URL: https://www.nasa.gov/directorates/heo/scan/apollo50
2) "Space Communications and Navigation (SCaN)Mission Operations and Communications Services(MOCS)," NASA HQ, SCaN-MOCS-0001, Revision 2, March 15, 2019, URL: https://explorers.larc.nasa.gov/HPMIDEX/pdf_files/08a_SCaN-MOCS-0001_Rev%202_final.pdf
3) "DSN Complexes," NASA, 30 March 2020, URL: https://www.nasa.gov/directorates/heo/scan/services/networks/deep_space_network/complexes
4) Danny Baird, "Season Five of ‘The Invisible Network' Explores the Deep Space Network," NASA/JPL News Release: 2022-082, 8 June 2022, URL: https://www.jpl.nasa.gov/news/season-five-of-the-invisible-network-explores-the-deep-space-network?utm_source=iContact&utm_medium=email&utm_campaign=nasajpl&utm_content=media-dsn20220608
5) "NASA Adds Giant New Dish to Communicate With Deep Space Missions," NASA/JPL News, 16 March 2022, URL: https://www.jpl.nasa.gov/news/nasa-adds-giant-new-dish-to-communicate-with-deep-space-missions?utm_source=iContact&utm_medium=email&utm_campaign=nasajpl&utm_content=dsn20220316-1
6) Debra Werner, Microsoft helps JPL with Deep Space Network scheduling," SpaceNews, 27 January, 2022, URL: https://spacenews.com/microsoft-jpl-dsn-scheduling/
7) Kendall Murphy, "Upgrades to NASA's Space Communications Infrastructure Pave the Way to Higher Data Rates," NASA Feature, 27 July 2021, URL: https://www.nasa.gov/feature/goddard/2021/upgrades-to-nasa-s-space-communications-infrastructure-pave-the-way-to-higher-data-rates
8) Jeff Foust, "Increasing demands putting pressure on Deep Space Network," SpaceNews, 10 July 2021, URL: https://spacenews.com/increasing-demands-putting-pressure-on-deep-space-network/
9) Molly Kearns, Kelly Sands, "Roaming! NASA's Space Communications User Terminal," NASA Feature, 10 June 2021, URL: https://www.nasa.gov/feature/glenn/2021/roaming-nasa-space-communications-user-terminal
10) Danny Baird, "'The Invisible Network' Podcast - Episode 16: Commercialization | Marketplace," NASA Space Communications, 12 May 2021, URL: https://www.nasa.gov/mediacast/goddard/2021/the-invisible-network-podcast-episode-15-commercialization-marketplace
11) "A Line from Spain to Deep Space," NASA Earth Observatory, Image of the Day for 30 March 2021, URL: https://earthobservatory.nasa.gov/images/148111/a-line-from-spain-to-deep-space?src=eoa-iotd
12) "NASA's Deep Space Network Welcomes a New Dish to the Family," NASA/JPL, 22 January 2021, URL: https://www.jpl.nasa.gov/news/nasas-deep-space-network-welcomes-a-new-dish-to-the-family/?utm_source=iContact&utm_medium=email&utm_campaign=nasajpl&utm_content=weekly20210122-3
13) "NASA's Deep Space Antenna Upgrades to Affect Voyager Communications," NASA/JPL News, 4 March 2020, URL: https://www.jpl.nasa.gov/news/nasas-deep-space-antenna-upgrades-to-affect-voyager-communications/
14) "New Deep Space Network Antenna is Operational," NASA, 1 October 2014, URL: https://www.nasa.gov/directorates/heo/scan/news_dsn_dss35_operational.html
15) "Deep Space Network Aperture Enhancement Project (DAEP)," NASA, 1 October 2014, URL: https://web.archive.org/web/20200208015011/https://www.nasa.gov/directorates/heo/scan/services/networks/txt_daep.html
The information compiled and edited in this article was provided by Herbert J. Kramer from his documentation of: "Observation of the Earth and Its Environment: Survey of Missions and Sensors" (Springer Verlag) as well as many other sources after the publication of the 4th edition in 2002. Comments and corrections to this article are always welcome for further updates (firstname.lastname@example.org).