Report: The Spectrum Needs of US Space-Based Operations: An Inventory of Current and Projected Uses (NTIA 2021)

Future uses…

Source: NTIA


The United States is a global leader in the development and deployment of advanced, space-based technologies. Yet there is relatively little public awareness of the scope and scale or the economic benefits of these space-based technologies and even less recognition of the core public resource needed to operate and support them: radio-frequency spectrum.

This report aims to provide basic information that will help increase public understanding of the scope and value of these space-based operations and the importance of their access to spectrum. It describes the wide range of government and commercial space-based operations and the value they provide to the economy and our quality of life, both here in the United States and globally. The report also contains detailed information about the specific frequencies used by these systems- a hopefully useful tool for policymakers and others going forward.

Every day, Americans use and depend on space-based technologies, whether they know it or not. Take the Global Positioning System (GPS), a U.S.-government satellite system, which is well known for the navigation services it provides to users of mobile phones and other devices. What is less well known, however, is the positioning, navigation, and timing applications GPS provides, such as synchronization of computer and financial networks and for satellite orbit maneuvers and orbit determination. Other important space-based technologies provide the data and images used to make accurate weather forecasts and the video we see of breaking news and live sports events. The progress we have made in predicting weather several days in advance including real-time information on the path of hurricanes and tornados- is attributable in large part to advances in data from weather satellites. Similarly, our ability to see video from around the globe, whether on television or the Internet, depends to some extent on the ability of commercial satellites to transmit live images. For people in rural or remote areas, multichannel television and Internet access through satellite may be the only option available. The same is true for information about impending natural hazards and long-term monitoring of the climate, soil moisture, weather, precipitation, and pollination each critically important concerns for the global community.

Less visible to most of us but perhaps more vital for our security and prosperity are the space-based technologies that drive our national security, public safety, space and earth exploration, and scientific infrastructures. Our military depends on space-based assets for planning, readiness, and tactical operations. The same goes for public safety entities at the national level, including the Department of Homeland Security (DHS), Federal Emergency Management Agency (FEMA), and the Forest Service, and at the state and local level, including government users, private agencies, and individual users. Air traffic control and the Emergency Alert System each depend on space-based systems.

Space-based systems and their services provide enormous economic benefits. Government services like GPS, weather forecasting, and air traffic control add hundreds of billions of dollars or more in productivity, efficiency, and safety, while improvements in national defense and science are incalculable. Communications enabled by space are equally valuable, particularly in rural areas and during emergencies.

Altogether, the space sector provides hundreds of thousands of high-paying jobs and the kind of innovation that must continue to characterize the American economy if we are to protect ourselves and stay at the forefront of the global economy. A recent review by the Department of Commerce’s Bureau of Economic Analvsis (BEA) found the U.S. space economy added $108.9 billion value to the current-dollar GDP (0.5 percent of total U.S. current-dollar GDP). The BEA estimate included wages, salaries, and employer contributions to pensions and insurance, supporting more than 365,000 private sector jobs.

Space-based operations depend on access to spectrum for communications or observations or both. Access to space itself- -whether orbiting the Earth or travelling to the Moon and beyond- depends on the availability of spectrum. Spectrum is critical for rocket launches, to operate and communicate with Earth after launch, and to observe the Earth itself.

That access to spectrum is uniquely vulnerable to interference from other spectrum users, particularly when compared with ground-based systems that use spectrum. For ground-based operations, the distance between where a signal is transmitted and where it is received typically is measured in feet, miles, or tens of miles. In space-based operations, those distances are typically hundreds or thousands of miles and, for space exploration, millions of miles. As a result, the signals are relatively weak by the time they reach their destination.

Additionally, some space-based operations, such as weather satellites and radio astronomy observatories, require a particularly quiet environment because they rely on receiving weak distant signals that cannot be boosted, for example from oxygen or water vapor molecules on Earth or from distant stars light years away.

In recent years, as many of these space-based operations have had to compete with each other and with the legitimate and rapidly growing demand for spectrum by other wireless users, there have been increasing concerns regarding the potential for interference to space operations. Those concerns have involved key space assets like GPS, weather satellites, radio astronomy, commercial operators, mobile networks, Wi-Fi, fixed microwave, and high-altitude platforms. To some extent, these kinds of concerns are inevitable as the demand for spectrum increases. Over time, technological innovation may help to increase the opportunities for spectrum sharing, but these laws of physics will always present challenges.

A full appreciation for the value of space-based systems and their spectrum needs will enable policymakers to weigh necessary trade-offs.

Print Friendly, PDF & Email