On a remote military base in the desert, the United States government is communicating with outer space.
It’s happening deep in California’s Mojave Desert, tucked well out of sight of bleary-eyed Los Angelinos taking I-15 home after a weekend in Las Vegas, the hikers sweating in Death Valley, the freight trains rattling through Barstow.
None of this is a secret. It’s all taking place on a section of Ft. Irwin, and if you make arrangements in advance you can even visit—though the friendly soldiers with the large sidearms will need to see your photo ID before you enter the base.
The place really is remote. As the locals will warn you, the stark, arid hills and dry washes are home to scorpions and rattlers, along with wanderers that are easier to spot, like the herds of wild burros whose ancestors worked in the old mining camps. And don’t drink the water.
The isolation serves a purpose. It’s all about finding a quiet place, quiet enough to hear the sky. These ridges make a home relatively free of radio interference for NASA’s Goldstone Deep Space Communications Complex, part of the planet-wide Deep Space Network (DSN). This spot is one of only a handful of places on Earth where we can talk to the spacecraft that have flown beyond low Earth orbit—often way beyond. Goldstone and its counterpart sites in Spain and Australia are online 24 hours, in daily contact with missions at Mars, Saturn and even the dark reaches beyond the edge of the Solar System. (See some of the missions that Goldstone tracks, and learn more about them.)
The antennas at Goldstone receive the signals from these spacecraft, uplink commands to them, and help them navigate among the planets. They even take science observations of their own from the ground by, for example, blasting distant asteroids with bursts of radar in order to image their shapes. The teams at Goldstone then pass the data on to NASA’s Jet Propulsion Laboratory, the European Space Agency, or wherever the people who fly the missions are working.
All of this is even harder than it sounds. Consider this: in order to conserve precious weight, the communication systems on interplanetary probes transmit signals at very low power, typically around 20 watts. This is roughly the amount of power it takes to light a refrigerator light bulb. The farther away from Earth that a spacecraft travels, the weaker its signal. And these ships are at Mars, the asteroid belt, even speeding toward the cold, dark orbit of Pluto. When it reaches a DSN antenna the transmission can be one billionth of one billionth of one watt, a billion times weaker than the power of a wristwatch battery.
To listen to these whispers, engineers have created hardware that can take its rightful place among the most amazing devices ever created. The antennas at Goldstone reach several stories into the sky and their dishes range in size from 26 meters to 70 meters across. But they are a far cry from static pieces of metal. Despite their massive size, they are complex and precision-engineered machines with the ability to point at and lock onto a patch of sky no bigger than what you would see looking through a straw. Shielded underground beneath each dish is a maze of circuitry and machinery humming so loudly it’s difficult to hold a conversation, including fantastically sensitive low-noise amplifiers that are cryogenically cooled with liquid helium to near absolute zero.
The information received is transferred via land lines and satellites to the Deep Space Operations Control Center at JPL, where the raw data is processed into usable products, like pictures of a Martian landscape or radar maps of lakes on Titan.
In October, I had the privilege of joining other space bloggers at a social media event hosted by NASA at Goldstone. We were treated to a behind-the-scenes tour of the complex, and heard first-hand from the teams that run it, agency brass responsible for communication in space, and even an engineer from one of the deep space missions now underway.
- We visited a signal processing center reminiscent of an iconic mission control center, only the flights being tracked here were all being carried out by robots. We saw an engineer sitting at a console with a bank of large monitors, poring over a stream of numbers—which may not sound exciting until you realize that she was receiving data at that moment from a rover on the surface of Mars. Several other missions across the Solar System were transmitting at the same moment. We were there at the interplanetary switchboard.
- We heard from NASA officials who outlined future plans for the Deep Space Network, including the ability to use optical signals and other technology that will someday allow for live video from other planets, and delay-tolerant networking to extend Internet-like networks to the moon, Mars and beyond. An early test of these new systems will be included on a mission next year.
- Goldstone engineers walked us through some of the staggering technical challenges of building and maintaining antennas the size of buildings. To get the whole story of how one antenna underwent a high-pressure repair, see this video or check out National Geographic’s The World’s Toughest Fixes season 4, “Deep Space Antenna”.
- My favorite part was hearing Mars Curiosity rover flight systems engineer Ann Devereaux regale us with the tale of the thrilling landing we all saw in August. Here’s the thing: it wasn’t luck; it was engineering. In her presentation, she explained how the rover calls home using the radios she helped design.
Thanks to videographer and fellow NASA Socialista Jim Greenleaf, you can see many of the day’s events.
Following are some more pictures from Goldstone, and ways to find out more.
You may also be interested to know what it was like to witness the launch of one of these deep space missions.
Places to Find Out More About Goldstone & the Deep Space Network
NASA – NetworKing game
Flickr – More pictures
National Geographic – The World’s Toughest Fixes – See season 4, “Deep Space Antenna”
NASA – Some footage from Goldstone and interviews with its staff, some of which were used in the National Geographic special