Radio - Blog Posts
Around the World in Seven Ground Stations
Happy Birthday, Jules Verne!
Considered by many to be the father of science fiction, French novelist Jules Verne takes his readers on a “From the Earth to the Moon,” “Twenty Thousand Leagues Under the Sea” and “Around the World in Eighty Days.” In his honor, let’s take our own journey around the world, exploring seven far-flung ground stations and the communications networks they support. These ground stations downlink data from science and exploration missions, maintaining the critical link from space to ground.
Our Deep Space Network supports far-out missions like Voyager 1, a spacecraft that's now over 13 billion miles from Earth. To communicate that far, the Network uses antennas as large as 230 feet in diameter. The network has ground stations in Pasadena, California; Madrid, Spain; and this one in Canberra, Australia. The ground stations are strategically placed for maximum coverage of the night sky, ensuring that deep space missions can communicate their data back to Earth. Check out that lizard!
Our Space Network uses relay satellites in conjunction with ground stations to provide continuous communications coverage for satellites in low-Earth orbit like the International Space Station, enabling 24/7 connection with astronauts onboard. Spacecraft using the Space Network beam their data to the constellation of Tracking and Data Relay Satellites, which forward that data to the ground. This is a photo of a Space Network ground station in Guam, a U.S. territory. The spherical structures around the antennas are called “radomes” and protect the antennas from the tropical storms!
Optical communications uses lasers to provide missions with higher data rates than radio communications. Optical terminals also offer missions reduced size, weight and power requirements over comparable radio antennas. A smaller system leaves more room for science instruments, a weight reduction can mean a less expensive launch and reduced power allows batteries to last longer. This ground station in Haleakalā, Hawaii, will relay data to California through a groundbreaking optical communications satellite, the Laser Communications Relay Demonstration. The demonstration will show the power and promise of optical communications to support the next generation of science missions.
Antarctica may seem like an odd place for radio antennas, but McMurdo Ground Station is vitally important to our networks. In 2017, we used the McMurdo ground station to demonstrate a new technology called Disruption Tolerant Networking (DTN), sending a selfie from McMurdo to the space station through numerous DTN nodes. DTN protocols allow data to be stored at points along its route that do not have an open connection to the next intermediary, preventing data loss and improving data returns.
This Near Earth Network ground station in Santiago, Chile, might not be our only South American ground station for long. The Near Earth Network is considering Punta Arenas, Chile, as a possible location for Ka-band antennas, which would provide missions with higher data rates. The Near Earth Network is also experimenting with Ka-band arraying, which uses multiple smaller antennas to provide the same capabilities of a larger, Ka-band antenna. Ka-band services will greatly increase the amount of science data we can gather!
If the space station ever has communications trouble, we could communicate with our astronauts through emergency very high frequency (VHF) communications ground stations like this one in Wallops Island, Virginia. VHF offers voice-only, contingency communications for the station and the Soyuz spacecraft, which ferries astronauts to and from the station. We maintain two VHF stations strategically placed to maximize contact with the space station as it orbits above North America. International partners operate VHF stations that provide contacts as the station orbits above Asia and Europe. NASA’s segment of the VHF network recently underwent critical upgrades that improve the reliability and durability of the system.
This beautiful photo captures Near Earth Network antennas in Svalbard, Norway, beneath the glow of the Northern lights, a phenomenon that occurs when charged particles from the Sun interact with various gasses in Earth’s atmosphere. If one were to visit Iceland, one could see these same lights above Snæfellsjökull volcano, featured in Jules Verne’s “A Journey to the Center of the Earth” as the imaginary entrance to a subterranean world.
A lot has changed in the nearly two centuries since Jules Verne was born. Verne’s 1865 novel “From the Earth to the Moon” and its 1870 sequel “Around the Moon” imagine a giant cannon capable of launching three men into lunar orbit. These imaginary astronauts used opera glasses to survey the lunar surface before returning safely to Earth.
Such a story may seem ridiculous in an age where humanity has occupied space for decades and satellites explore distant worlds with increasing regularity, but Verne’s dreams of spaceflight were novel – if not revolutionary – at the time. This change in worldview reflects humanity’s inexorable technological progress and our mission at NASA to turn science fiction into science fact.
As the next generation of exploration commences, our ever-evolving communications capabilities rise to meet the demands of missions that dreamers like Verne could hardly imagine.
The seven ground stations featured here were just a taste of our communications infrastructure. To learn more about space communications, visit: https://www.nasa.gov/SCaN
Optical Communications: Explore Lasers in Space
When we return to the Moon, much will seem unchanged since humans first arrived in 1969. The flags placed by Apollo astronauts will be untouched by any breeze. The footprints left by man’s “small step” on its surface will still be visible across the Moon’s dusty landscape.
Our next generation of lunar explorers will require pioneering innovation alongside proven communications technologies. We’re developing groundbreaking technologies to help these astronauts fulfill their missions.
In space communications networks, lasers will supplement traditional radio communications, providing an advancement these explorers require. The technology, called optical communications, has been in development by our engineers over decades.
Optical communications, in infrared, has a higher frequency than radio, allowing more data to be encoded into each transmission. Optical communications systems also have reduced size, weight and power requirements. A smaller system leaves more room for science instruments; a weight reduction can mean a less expensive launch, and reduced power allows batteries to last longer.
On the path through this “Decade of Light,” where laser joins radio to enable mission success, we must test and demonstrate a number of optical communications innovations.
The Laser Communications Relay Demonstration (LCRD) mission will send data between ground stations in Hawaii and California through a spacecraft in an orbit stationary relative to Earth’s rotation. The demo will be an important first step in developing next-generation Earth-relay satellites that can support instruments generating too much data for today’s networks to handle.
The Integrated LCRD Low-Earth Orbit User Modem and Amplifier-Terminal will provide the International Space Station with a fully operational optical communications system. It will communicate data from the space station to the ground through LCRD. The mission applies technologies from previous optical communications missions for practical use in human spaceflight.
In deep space, we’re working to prove laser technologies with our Deep Space Optical Communications mission. A laser’s wavelength is smaller than radio, leaving less margin for error in pointing back at Earth from very, very far away. Additionally, as the time it takes for data to reach Earth increases, satellites need to point ahead to make sure the beam reaches the right spot at the right time. The Deep Space Optical Communications mission will ensure that our communications engineers can meet those challenges head-on.
An integral part of our journey back to the Moon will be our Orion spacecraft. It looks remarkably similar to the Apollo capsule, yet it hosts cutting-edge technologies. NASA’s Laser Enhanced Mission Communications Navigation and Operational Services (LEMNOS) will provide Orion with data rates as much as 100 times higher than current systems.
LEMNOS’s optical terminal, the Orion EM-2 Optical Communications System, will enable live, 4K ultra-high-definition video from the Moon. By comparison, early Apollo cameras filmed only 10 frames per second in grainy black-and-white. Optical communications will provide a “giant leap” in communications technology, joining radio for NASA’s return to the Moon and the journey beyond.
NASA’s Space Communications and Navigation program office provides strategic oversight to optical communications research. At NASA’s Goddard Space Flight Center in Greenbelt, Maryland, the Exploration and Space Communications projects division is guiding a number of optical communications technologies from infancy to fruition. If you’re ever near Goddard, stop by our visitor center to check out our new optical communications exhibit. For more information, visit nasa.gov/SCaN and esc.gsfc.nasa.gov.
Spooky Sounds from Across the Solar System
Soaring to the depths of our universe, gallant spacecraft roam the cosmos, snapping images of celestial wonders. Some spacecraft have instruments capable of capturing radio emissions. When scientists convert these to sound waves, the results are eerie to hear.
In time for Halloween, we've put together a compilation of elusive "sounds" of howling planets and whistling helium that is sure to make your skin crawl.
Listen to a few here and visit our Soundcloud for more spooky sounds.
Cassini Ring Crossing
This eerie audio represents data collected by our Cassini spacecraft, as it crossed through the gap between Saturn and its rings on April 26, 2017, during the first dive of the mission's Grand Finale. The instrument is able to record ring particles striking the spacecraft in its data. In the data from this dive, there is virtually no detectable peak in pops and cracks that represent ring particles striking the spacecraft. The lack of discernible pops and cracks indicates the region is largely free of small particles.
Voyager Tsunami Waves in Interstellar Space
Listen to this howling audio from our Voyager 1 spacecraft. Voyager 1 has experienced three "tsunami waves" in interstellar space. This kind of wave occurs as a result of a coronal mass ejection erupting from the Sun. The most recent tsunami wave that Voyager experienced began in February 2014, and may still be going. Listen to how these waves cause surrounding ionized matter to ring like a bell.
Voyager Sounds of Interstellar Space
Our Voyager 1 spacecraft captured these high-pitched, spooky sounds of interstellar space from October to November 2012 and April to May 2013.
The soundtrack reproduces the amplitude and frequency of the plasma waves as "heard" by Voyager 1. The waves detected by the instrument antennas can be simply amplified and played through a speaker. These frequencies are within the range heard by human ears.
When scientists extrapolated this line even further back in time (not shown), they deduced that Voyager 1 first encountered interstellar plasma in August 2012.
Plasma Sounds at Jupiter
Ominous sounds of plasma! Our Juno spacecraft has observed plasma wave signals from Jupiter’s ionosphere. The results in this video show an increasing plasma density as Juno descended into Jupiter’s ionosphere during its close pass by Jupiter on February 2, 2017.
Roar of Jupiter
Juno's Waves instrument recorded this supernatural sounding encounter with the bow shock over the course of about two hours on June 24, 2016. "Bow shock" is where the supersonic solar wind is heated and slowed by Jupiter's magnetosphere. It is analogous to a sonic boom on Earth. The next day, June 25, 2016, the Waves instrument witnessed the crossing of the magnetopause. "Trapped continuum radiation" refers to waves trapped in a low-density cavity in Jupiter's magnetosphere.
Visit the NASA Soundcloud for more spooky space sounds: https://soundcloud.com/nasa/sets/spookyspacesounds
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.