Since the 1960s, the United States has operated two separate operational polar-orbiting meteorological satellite systems: the Polar-orbiting Operational Environmental Satellite (POES) series, which is managed by NOAA, and the Defense Meteorological Satellite Program (DMSP), which is managed by the Air Force. These satellites obtain environmental data that are processed to provide graphical weather images and specialized weather products. These satellite data are also the predominant input to numerical weather prediction models, which are a primary tool for forecasting weather days in advance—including forecasting the path and intensity of hurricanes. The weather products and models are used to predict the potential impact of severe weather so that communities and emergency managers can help prevent and mitigate its effects. Polar satellites also provide data used to monitor environmental phenomena, such as ozone depletion and drought conditions, as well as data sets that are used by researchers for a variety of studies such as climate monitoring. Unlike geostationary satellites, which maintain a fixed position relative to the earth, polar-orbiting satellites constantly circle the earth in an almost north-south orbit, providing global coverage of conditions that affect the weather and climate. Each satellite makes about 14 orbits a day. As the earth rotates beneath it, each satellite views the entire earth’s surface twice a day. Currently, there is one operational POES satellite and two operational DMSP satellites that are positioned so that they cross the equator in the early morning, midmorning, and early afternoon. In addition, the government is also relying on a European satellite, called the Meteorological Operational (MetOp) satellite. Together, they ensure that, for any region of the earth, the data provided to users are generally no more than 6 hours old. Besides the four operational satellites, six older satellites are in orbit that still collect some data and are available to provide limited backup to the operational satellites should they degrade or fail. The last POES satellite was launched in February 2009 and declared operational in early June 2009. The Air Force plans to launch its two remaining DMSP satellites as needed. Figure 1 illustrates the current ustrates the current operational polar satellite configuration. operational polar satellite configuration. Polar satellites gather a broad range of data that are transformed into a variety of products. Satellite sensors observe different bands of radiation wavelengths, called channels, which are used for remotely determining information about the earth’s atmosphere, land surface, oceans, and the space environment. When first received, satellite data are considered raw data. To make them usable, processing centers format the data so that they are time-sequenced and include earth location and calibration information. After formatting, these data are called raw data records. The centers further process these raw data records into channel-specific data sets, called sensor data records and temperature data records. These data records are then used to derive weather and climate products called environmental data records. These environmental data records include a wide range of atmospheric products detailing cloud coverage, temperature, humidity, and ozone distribution; land surface products showing snow cover, vegetation, and land use; ocean products depicting sea surface temperatures, sea ice, and wave height; and characterizations of the space environment. Combinations of these data records (raw, sensor, temperature, and environmental data records) are also used to derive more sophisticated products, including outputs from numerical weather models and assessments of climate trends. Figure 2 is a simplified depiction of the various stages of satellite data processing, and figure 3 depicts examples of two different weather products. With the expectation that combining the POES and DMSP programs would reduce duplication and result in sizable cost savings, a May 1994 Presidential Decision Directive required NOAA and DOD to converge the two satellite programs into a single satellite program capable of satisfying both civilian and military requirements. The converged program, NPOESS, was considered critical to the nation’s ability to maintain the continuity of data required for weather forecasting and global climate monitoring. To manage this program, DOD, NOAA, and NASA formed a tri-agency Integrated Program Office. Within the program office, each agency has the lead on certain activities: NOAA has overall program management responsibility for the converged system and for satellite operations; the Air Force has the lead on the acquisition; and NASA has primary responsibility for facilitating the development and incorporation of new technologies into the converged system. NOAA and DOD share the cost of funding NPOESS, while NASA funds specific technology projects and studies. In addition, an Executive Committee—made up of the administrators of NOAA and NASA and the Under Secretary of Defense for Acquisition, Technology, and Logistics—is responsible for providing policy guidance, ensuring agency support and funding, and exercising oversight authority. Figure 4 depicts the organizations that make up the NPOESS program office and lists their responsibilities. NPOESS is a major system acquisition that was originally estimated to cost about $6.5 billion over the 24-year life of the program from its inception in 1995 through 2018. The program includes satellite development, satellite launch and operation, and ground-based satellite data processing. When the NPOESS engineering, manufacturing, and development contract was awarded in August 2002, the cost estimate was adjusted to $7 billion. Acquisition plans called for the procurement and launch of six satellites over the life of the program, as well as the integration of 13 instruments— consisting of 10 environmental sensors and 3 subsystems. Together, the sensors were to receive and transmit data on atmospheric, cloud cover, environmental, climatic, oceanographic, and solar-geophysical observations. The subsystems were to support non-environmental search and rescue efforts, system survivability, and environmental data collection activities. In addition, a demonstration satellite, called the NPOESS Preparatory Project (NPP), was planned to be launched several years before the first NPOESS satellite in order to reduce the risk associated with launching new sensor technologies and ensure continuity of climate data with NASA’s Earth Observing System satellites. NPP is a joint mission between the NPOESS program office and NASA. NPP was to host four NPOESS sensors and provide the program office and the processing centers an early opportunity to work with the sensors, ground control, and data processing systems. When the NPOESS development contract was awarded in 2002, the schedule for launching the satellites was driven by a requirement that the NPOESS satellites be available to back up the final POES and DMSP satellites should anything go wrong during the planned launches of these satellites. Early program milestones included (1) launching NPP by May 2006, (2) having the first NPOESS satellite available to back up the final POES satellite launch then planned for March 2008, and (3) having the second NPOESS satellite available to back up the final DMSP satellite launch then planned for October 2009. If the NPOESS satellites were not needed to back up the final predecessor satellites, their anticipated launch dates would have been April 2009 and June 2011, respectively. Over several years, we reported that NPOESS had experienced continued cost increases, schedule delays, and serious technical problems. By November 2005, we estimated that the cost of the program had grown from $7 billion to over $10 billion. In addition, the program was experiencing major technical problems with a critical imaging sensor that were expected to delay the launch date of the first satellite by almost 2 years. These issues ultimately required difficult decisions to be made about the program’s direction and capabilities. The Nunn-McCurdy law requires DOD to take specific actions when a major defense acquisition program’s cost growth exceeds certain thresholds. Where applicable, the law requires the Secretary of Defense to certify the program to Congress when it is expected to overrun its current baseline by 25 percent or more. In November 2005, NPOESS breached the 25 percent threshold, and DOD was required to certify the program for it to continue. The requirements for certifying a program, as relevant here, involved a determination that (1) the program is essential to national security, (2) there are no alternatives to the program that will provide equal or greater military capability at less cost, (3) the new estimates of the program’s cost are reasonable, and (4) the management structure for the program is adequate to manage and control costs. DOD established tri- agency teams—made up of DOD, NOAA, and NASA experts—to work on each of the four elements of the certification process. In June 2006, DOD (with the agreement of both of its partner agencies) certified a restructured NPOESS program, estimated to cost $12.5 billion through 2024—an increase of $4 billion more than the prior life-cycle cost estimate. This restructuring decision delayed the launch of NPP and the first two satellites (called C1 and C2) by roughly 3 to 5 years—a deviation from the requirement to have NPOESS satellites available to back up the final POES and DMSP satellites should anything go wrong during those launches. The restructured program also reduced the number of satellites to be produced by relying on European satellites for the midmorning orbit and planning to use NPOESS satellites in the early-morning and afternoon orbits. In addition, in order to reduce program complexity, the Nunn- McCurdy certification decision decreased the number of NPOESS instruments from 13 to 9 and reduced the functionality of 4 sensors. Table 1 summarizes the major program changes made by the Nunn-McCurdy certification decision and table 2 describes the sensors that were planned for NPP and NPOESS after the Nunn-McCurdy certification. The changes in NPOESS sensors affected the number and quality of the resulting weather and environmental products. In selecting sensors for the restructured program during the Nunn-McCurdy process, decision makers placed the highest priority on continuing current operational weather capabilities and a lower priority on obtaining selected environmental and climate measuring capabilities.