Space Situational Awareness:

Status of Efforts and Planned Budgets

GAO-16-6R: Published: Oct 8, 2015. Publicly Released: Oct 8, 2015.

Additional Materials:


Cristina T. Chaplain
(202) 512-4841


Office of Public Affairs
(202) 512-4800

What GAO Found

Space systems provide critical capabilities essential for government and commercial operations. These systems are increasingly vulnerable to a variety of intentional and unintentional threats. The government relies primarily on the Department of Defense (DOD) and the Intelligence Community to provide Space Situational Awareness (SSA)—the current and predictive knowledge and characterization of space objects and the operational environment upon which space operations depend—to provide critical data for planning, operating, and protecting space assets and to inform government and military operations.

According to DOD, a potential of 375 sensors and systems—satellites, ground-based radars, and optical telescopes—are available to contribute to SSA across the government and commercial sectors. Currently, the primary sensors used are a core group of 8 dedicated and 18 multiple mission sensors. While DOD provides most of these sensors and systems, other entities—National Aeronautics and Space Administration (NASA), National Oceanic and Atmospheric Administration (NOAA), intelligence community, and commercial companies—also provide data used for SSA. For much of the core group of sensors, DOD is leveraging assets by using sensors that perform other missions as their primary functions, such as sensors used for missile defense and missile warning. U.S. Strategic Command’s Joint Space Operations Center (JSpOC) is responsible for analyzing the data provided by the sensors and processing it into useable SSA information.

To support and sustain its SSA efforts over the next 5 years and to meet the expanded mission focus of SSA, DOD plans to relocate sensor systems; develop, field, and upgrade several additional sensors and systems; and develop new technologies. For example, the Air Force’s Space Fence program is developing one or more ground-based radars to track space objects that are smaller than those identified by current sensors, and the JSpOC Mission System program is developing and fielding a new command and control system designed to maintain the catalog of space object information and provide new analytical capabilities, such as providing real-time alerts of hostile actions toward U.S. sensors.

Based on data reported by the agencies, the government’s planned budget for SSA core efforts—DOD, NASA, and NOAA operations of sensors, upgrades, and new developments—averages about $1.0 billion per year for fiscal years 2015 through 2020. Table 1 summarizes the budget for SSA core efforts over the next several years.

Table 1: Budget for Space Situational Awareness Core Efforts—Fiscal Years 2015 to 2020                     (in millions of then-year dollars)








Operations and Payroll







New Sensors and Systems







Upgrades to Sensors and Systems














Note: aValues may not add to totals because of rounding.
Source: DOD, NASA, and NOAA data; GAO presentation.

The budget for SSA operations and payroll averages about 63 percent of the core budget during fiscal years 2015 through 2020. In addition, the government is planning to invest about $1.8 billion in new sensors and systems over the next few fiscal years. Compiling a more complete SSA budget beyond the core efforts is challenging because the SSA mission involves assets from multiple agencies and organizations, and a comprehensive budget is not maintained. In addition, since SSA is not the primary mission for most of the sensors that perform this mission, their SSA efforts are not tracked because these sensors would continue to operate even if the SSA mission did not exist. For example, the Missile Defense Agency has not determined what percentage of its budget for operating the missile defense sensors, which averages about $538 million per year over the next several years, would be allocated to the SSA mission.

Why GAO Did This Study

As space has become more congested and contested, the potential for intentional and unintentional threats to space assets has increased, according to DOD. In response, the SSA mission focus has expanded from awareness of the location and movement of space objects to also include assessments of their capabilities and intent to provide battlespace awareness for protecting U.S. and allies’ people and assets.

In a report accompanying a bill for the National Defense Authorization Act for Fiscal Year 2015, the Senate Armed Services Committee included a provision for GAO to estimate the cost of SSA efforts over the next 5 fiscal years. This report includes information we provided in a briefing to the committee, updated to reflect current data on SSA workloads and to incorporate additional agency technical comments. This report addresses the following: (1) What are the government’s current and planned SSA-related research and development, procurement, and operations efforts? (2)  What is the planned budget for these efforts for fiscal years 2015 through 2020?

To determine the governments’ current and planned SSA-related efforts and compile related budgets, we obtained and reviewed relevant program documentation, such as program budget requests and status briefings, and discussed the efforts with officials at DOD, NASA, and NOAA.

What GAO Recommends

GAO is not making any recommendations in this report.

For more information, contact Cristina T. Chaplain at 202-512-4841 or

Oct 19, 2017

Oct 4, 2017

Aug 9, 2017

Jun 9, 2017

May 16, 2017

Apr 27, 2017

Mar 23, 2017

Feb 16, 2017

Dec 7, 2016

Looking for more? Browse all our products here