Team Members Visit the DSN
Large antennas in the desert were used during Deep Impact mission
August 15, 2005 - David Acton
While I was in Southern California supporting the "Encounter" of the Deep Impact spacecraft with comet Tempel 1 in early July 2005, I had the opportunity to visit the Goldstone Deep Space Communications Complex about a hundred miles northeast of Los Angeles in the Mojave Desert. Everything had gone well with the spacecraft activities on July 3rd and 4th so by later that week it was okay for me and some colleagues to take a day off and do some sightseeing. One of our JPL contacts arranged a flight to Goldstone and a private tour for our group.
The Goldstone complex is one of three such facilities around the globe which support NASA's Deep Space Network (DSN). The DSN provides communication with robotic spacecraft exploring the solar system and beyond. The huge antennas of the DSN are the link to these distant voyagers, controlling their movements and returning scientific data to Earth. To compensate for the Earth's rotation and allow 24-hour communication with remote spacecraft, the complexes are located about 120 degrees apart around the globe - in Goldstone, California; Madrid, Spain; and Canberra, Australia. The Goldstone complex occupies a 52 square-mile area, throughout which are scattered about 15 different antennas, ranging in size from 9 meters (29.5 ft) across to a mammoth 70 meters (230 ft).
Early the morning of July 7 the group of us met at Burbank airport for our flight. Being part of the Deep Impact team, we were able to fly to the Goldstone complex on the NASA-7 aircraft, a small plane used to shuttle personnel between NASA facilities. Including myself (a systems engineer from Ball Aerospace), the group consisted of David Holshouser - a software engineer from Ball Aerospace, Lew Kendall - an attitude control engineer from Ball Aerospace, Stef McLaughlin - a science team member from the University of Maryland, Jay Melosh - a science team member and geophysicist from the University of Arizona, and Garrett Elliott - an intern from Ohio State University working with the data processing team at Cornell University.
We took off at 6:45 AM in order not to compete with the commercial flights for the Burbank runway. The 30 minute flight to Goldstone was very scenic, traversing the San Gabriel Mountains, before landing on a small runway on the south side of Goldstone Dry Lake. We were shuttled to the main office buildings where we met our tour guides Marie Massey and Karla Warner, received an introductory presentation to the facility, and saw the museum.
Over the next six hours we were driven all around the complex seeing different antennas and facilities. We saw the 34-m antenna at the DSS-13 "Venus" site, and were able to see the complex RF and electrical equipment inside (below) the antenna. At this site we also talked to an RF engineer at the High-Power Transmitter facility. He is testing a 250,000 watt transmitter which will be used later on one of the other antennas. (That kind of power could certainly fry some bacon.) We saw the DSS-27 "Gemini" site and the DSS-24, -25, -26 cluster of 34-m antennas, all of which were used during the Deep Impact mission to talk to our spacecraft. It was interesting to compare the newer RF setup inside the DSS-24 antenna to the older setup we'd seen in DSS-13.
During lunch we saw DSS-12 at the "Echo" site. This 34-m dish, also referred to as the Goldstone Apple Valley Radio Telescope (GAVRT) is used remotely by K-12 students to teach them radio astronomy and how to collect real data for science applications. After lunch we saw the DSS-15 "Uranus" site and then proceeded to the "Mars" site to see the Signal Processing Center (SPC) and the giant 70-m DSS-14 antenna. The SPC is the focal point for all data handled at the Goldstone complex, and provides remote operation of all the antennas. The DSS-14 dish is the largest of the Goldstone antennas. It was originally designed to support the Mariner and Voyager missions to Mars, and is used today for high data-rate "passes" for numerous missions. This antenna was the one receiving the primary science images from Deep Impact when the Impactor hit the comet a few days earlier. We climbed up several levels on the antenna to see some of the inner workings. It is a fascinating piece of machinery.
We met back at the runway at about 2:30 PM for our return flight, which unfortunately was a bit choppy due to the afternoon thermals. We had great pilots though, who delivered us safely back to Burbank in time to beat a bit of the LA traffic. Overall, the trip was an excellent opportunity to see some of the remarkable equipment that makes deep space missions like ours possible.
Thanks to Al Nakata, our JPL representative who arranged the visit for us, and to Marie Massey and Karla Warner for providing us an extremely interesting and in-depth tour.