By Sean McClinton
Sometimes in life in order to know where you are headed, it’s useful to think about where you’ve come from. October is an important month in the history of space exploration. On October 4, 1957, Sputnik became the first human-made satellite to orbit the Earth, catching many around the world by surprise. Sputnik was also the first opportunity for individuals and organizations around the world to listen to signals sent from space to the Earth. Ever since that moment, ground stations have been essential to generating value in space. Without a ground station, there is no way to communicate with satellites and get the data down to the Earth in way that is usable. While Sputnik and the American Vanguard project were done under the guise of science for the International Geophysical Year (IGY), the militaries of both countries were deeply involved. The US Air Force, Navy, and Army have all been a key players in the development of infrastructure for space exploration like the ground segment, and remain so today. How did we get to where we are today in the ground segment? Let’s take a look at where we’ve come from.
After World War II, technology relevant to space exploration began to advance rapidly as teams from Germany were brought to the United States and the Soviet Union to begin work on their respective country’s rocket programs. In 1955, the United States began preparing to launch its first satellite for the IGY under Project Vanguard, run by the US Naval Research Laboratory. In May 1956, The US Department of the Navy was granted a permit to use 23 acres from the Army’s Diamond Ordnance Fuze Laboratory Test Area (originally called Blossom Point Proving Ground). The location was originally chosen due to its lack of noise and electronic interference, two key qualities for a ground station. By July of 1956, the first station went into operation and was soon being used as the headquarters for training and testing of the first satellite tracking system. The system was named Minimum Trackable Satellite or “Minitrack” and comprised an array of 14 stations that included Blossom Point.
What the United States didn’t know at the time during the build out of the Minitrack was that the Soviet Union was very far along with its own plans to launch a satellite into space. On October 4, 1957, the Soviet Union launched Sputnik I, the world’s first artificial, Earth-orbiting satellite. Shortly after launch, Minitrack receivers were modified to be able to track Sputnik, which made the US Naval Research Laboratory the first to demonstrate the feasibility of a radio detection and tracking system for satellites. Vanguard I, the United States first satellite, was also tracked by the station beginning in March of 1958. Of note, Vanguard I is now the oldest satellite still orbiting the Earth today. Today, Blossom Point is a robust satellite tracking facility with 11 antennas on a 42 acre campus that is in continuous operation 24 hours a day, 7 days a week.
The US Army concurrently developed its own ground station network in the late 1950s. In 1956, the U.S. government awarded Lockheed a contract for development of the country’s first reconnaissance satellite, which eventually carried the top secret name “Corona.” Corona was originally to be launched from Cape Canaveral, Florida, and would be supported by satellite tracking facilities around the world. Some of those stations were already in place on Pacific islands to support missile tests. By 1958, the Air Force’s Ballistic Missile Division (renamed from the Western Development Division) determined that additional tracking stations were required and added Vandenberg Air Force Base and Point Mugu, California; Ka’ena Point, Hawaii; and Kodiak, Alaska, to the network. Antenna networks are more common today by both government and commercial operators, but back then were just getting started. The expansion and modernization of the satellite tracking stations continued after the Corona launch as the United States began developing communications and weather satellite systems. By June 1962, the Air Force’s network was able to support the tracking of multiple satellites. Network operators supported as many as 10 programs, including their primary mission, Corona.
The developments by the US Air Force, Navy, and Army in the area of ground stations and commercial partnerships have allowed both commercial and government operators to use that technology and develop new capabilities. The US Air Force in particular has set up mechanisms such as the Air Force Research Lab (AFRL) to help advance technology in the ground segment in partnership with industry. With all of the advancement in space exploration, space has become even more contested. This new reality has brought about the establishment of the US Space Force. This means the US military and civilian agencies (e.g. NASA, NOAA) will continue to play a large role in advancing peace, security, and technology in space. On the commercial and government side of the ground segment, we’re seeing incredible innovation in such areas as optical communications, LEO tracking antennas, higher frequencies and data rates (S/X, Ka), software defined ground stations including software defined radios (SDRs), and RF over IP. All of these advances and partnerships have built on what was accomplished in the early days of space exploration. The future of the ground segment points towards increased security, greater flexibility, increased performance and lower costs through innovation, partnerships and development. A very exciting future in space will continue to be made possible by advancements we make on the ground.