Environmental Satellites: Polar-orbiting Satellite Acquisition Faces Delays; Decisions Needed on Whether and How to Ensure Climate Data Continuity
Released: 2008-06-19T00:00:00

Letter

Background

Since the 1960s, the United States has operated two separate operational polar-orbiting meteorological satellite systems: the Polar-orbiting Operational Environmental Satellite (POES) series— managed by NOAA—and the Defense Meteorological Satellite Program (DMSP)—managed by the Air Force. These satellites obtain environmental data that are processed to provide graphical weather images and specialized weather products—including both terrestrial and space weather. These satellite data are also the predominant input to numerical weather prediction models, which are a primary tool for forecasting weather 3 or more 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 their 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.

NPOESS Overview

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, is considered critical to the United States’ ability to maintain the continuity of data required for weather forecasting and global climate monitoring through the year 2026. To manage this program, DOD, NOAA, and NASA formed the tri-agency Integrated Program Office, located within NOAA.

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; DOD 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 costs of funding NPOESS, while NASA funds specific technology projects and studies. The NPOESS program office is overseen by an Executive Committee, which is made up of the Administrators of NOAA and NASA and the Under Secretary of the Air Force.

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 is to provide satellite development, satellite launch and operation, and ground- based satellite data processing. These deliverables are grouped into four main categories: (1) the space segment, which includes the satellites and sensors; (2) the integrated data processing segment, which is the system for transforming raw data into environmental data records (EDR) and is to be located at four data processing centers; (3) the command, control, and communications segment, which includes the equipment and services needed to support satellite operations; and (4) the launch segment, which includes launch vehicle services.

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, sensor survivability, and environmental data collection activities. The program office considered 4 of the sensors to be critical because they provide data for key weather products; these sensors are in bold in table 1, which describes each of the expected NPOESS instruments.

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 to ensure continuity of climate data with NASA’s Earth Observing System satellites. NPP was to host three of the four critical NPOESS sensors, as well as one other noncritical sensor and to 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, the schedule for launching the satellites was driven by a requirement that the 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 in March 2008, and (3) having the second NPOESS satellite available to back up the final DMSP satellite launch in 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.

NPOESS Experienced Cost Increases, Schedule Delays, and Technical Problems That Led to Decision to Restructure the NPOESS Program

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 the VIIRS sensor and 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 cost growth exceeds certain thresholds. The law requires the Secretary of Defense to notify Congress when a major defense acquisition is expected to overrun its current baseline by 15 percent or more and to certify the current program to Congress when it is expected to overrun its baseline by 25 percent or more. In November 2005, NPOESS exceeded the 25 percent threshold, and DOD was required to certify the program. Certifying a program entails providing 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 2026. This decision approved a cost increase of $4 billion over the prior approved baseline cost and delayed the launch of NPP and the first 2 satellites by roughly 3 to 5 years. The new program also entailed reducing the number of satellites to be produced and launched from 6 to 4, and reducing the number of instruments on the satellites from 13 to 9—consisting of 7 environmental sensors and 2 subsystems. It also entailed using NPOESS satellites in the early morning and afternoon orbits and relying on European satellites for midmorning orbit data. Table 2 summarizes the major program changes made under the Nunn- McCurdy certification decision.

The Nunn-McCurdy certification decision established new milestones for the delivery of key program elements, including launching NPP by January 2010, launching the first NPOESS satellite by January 2013, and launching the second NPOESS satellite by January 2016. These revised milestones deviated from prior plans to have the first NPOESS satellite available to back up the final POES satellite should anything go wrong during that launch.

Delaying the launch of the first NPOESS satellite meant that if the final POES satellite fails on launch, satellite data users would need to rely on the existing constellation of environmental satellites until NPP data becomes available—almost 2 years later. Although NPP was not intended to be an operational asset, NASA agreed to move NPP to a different orbit so that its data would be available in the event of a premature failure of the final POES satellite. If the health of the existing constellation of satellites diminishes—or if NPP data is not available, timely, and reliable—there could be a gap in environmental satellite data.

In order to reduce program complexity, the Nunn-McCurdy certification decision decreased the number of NPOESS sensors from 13 to 9 and reduced the functionality of 4 sensors. Specifically, of the 13 original sensors, 5 sensors remain unchanged (but 2 are on a reduced number of satellites), 3 were replaced with older or less capable sensors, 1 was modified to provide less functionality, and 4 were canceled. The certification decision also made allowances for the reintegration of the cancelled sensors. Specifically, the program was directed to build each NPOESS spacecraft with enough room and power to accommodate the sensors that were removed from the program and to fund the integration and testing of any sensors that are later restored. Agency sponsors external to the program would be responsible for justifying and funding the sensor’s development, while the NPOESS Executive Committee would have the final decision on whether to include the sensor on a specific satellite. Table 3 identifies the changes to the NPOESS instruments.

The changes in NPOESS sensors affected the number and quality of the resulting weather and environmental products, called environmental data records (EDR). 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. As a result, the revised NPOESS system has significantly less capability for providing global climate measures than was originally planned. Specifically, the number of EDRs was decreased from 55 to 39, of which 6 are of a reduced quality. The 39 EDRs that remain include cloud base height, land surface temperature, precipitation type and rate, and sea surface winds. The 16 EDRs that were removed include cloud particle size and distribution, sea surface height, net solar radiation at the top of the atmosphere, and products to depict the electric fields in the space environment. The 6 EDRs that are of a reduced quality include ozone profile, soil moisture, and multiple products depicting energy in the space environment.

Major Restructuring Activities Have Been Completed, but Key Remaining Activities Could Affect Funding and Schedule

The program office has completed major activities associated with restructuring NPOESS, but key supporting activities remain— including obtaining approval of key acquisition documents—and delays in completing these activities could affect the program’s funding and schedule. Restructuring a major acquisition program like NPOESS is a process that involves reassessing and redefining the program’s deliverables, costs, and schedules, and renegotiating the contract. The restructuring process also involves revising important acquisition documents such as the tri-agency memorandum of agreement, the acquisition strategy, the system engineering plan, the integrated master schedule defining what needs to happen by when, and the acquisition program baseline. In April 2007, we reported that the key acquisition documents were over six months late from their original September 2006 due date, and we recommended that the appropriate executives immediately finalize them. This recommendation has not yet been addressed and agency officials subsequently extended the due dates of the documents to September 2007.

During the past year, the program redefined the program’s deliverables, costs, and schedules, and renegotiated the NPOESS contract. To do so, the program developed a new program plan and conducted an integrated baseline review of the entire program, which validated that the new deliverables, costs, and schedules were feasible. It also completed key acquisition documents including the system engineering plan and the integrated master schedule. The program and the prime contractor signed a modified contract in July 2007.

However, key activities remain to be completed, including obtaining executive approval of key acquisition documents. Specifically, even though agency officials were expected to approve key acquisition documents by September 2007, the appropriate executives have not yet signed off on documents including the tri-agency memorandum of agreement or the acquisition strategy report. They have also not signed off on the acquisition program baseline, the fee management plan, the test and evaluation master plan, and the two-orbit program plan (a plan for how to use European satellite data with NPOESS).

Program officials stated that the program has been able to renegotiate the contract and to proceed in developing sensors and systems without these documents being signed because the documents have widespread acceptance within the three agencies. They reported that the delays are largely due to the complexity of obtaining approval from three agencies. For example, program officials reported that an organization within DOD suggested minor changes to the tri-agency memorandum of agreement after months of coordination and after it had already been signed by both the Secretary of Commerce and the Administrator of NASA. Further, after this issue was resolved, a senior official at DOD requested another change to the document. The program office has now made the recommended changes and is re-initiating the coordination process.

More recently, in April 2008, DOD moved the due dates for all of the acquisition documents other than the memorandum of agreement and fee management plan from September 2007 to August 31, 2008. (See appendix I for the history of the due dates and status of each document). In addition, even though DOD has had a role in delaying these documents, the Department has stated it would not release fiscal year 2009 funds to the program if these acquisition documents are not completed by the new due date. Without executive approval of key acquisition documents, the program lacks the underlying commitment necessary to effectively manage a tri-agency program. In addition, given DOD’s newest instructions, any further delays in completing these acquisition documents could affect the program’s funding and schedule.

Program Has Made Progress, but Key Milestones Have Been Delayed and Risks Remain

Over the last year, the NPOESS program has made progress by completing planned development and testing activities on its ground and space segments, but key milestones for delivering the VIIRS sensor and launching NPP have been delayed by about 8 months. Moving forward, risks remain in completing the testing of key sensors and integrating them on the NPP spacecraft, in resolving interagency disagreements on the appropriate level of system security, and in revising estimated costs for satellite operations and support. The program office is aware of these risks and is working to mitigate them, but continued problems could affect the program’s overall schedule and cost. Given the tight time frames for completing key sensors, integrating them on the NPP spacecraft, and getting the ground-based data processing system developed, tested, and deployed, it is important for the NPOESS Integrated Program Office, the Program Executive Office, and the Executive Committee to continue to provide close oversight of milestones and risks.

Ground Segment—Progress Made but Important Work Remains to Be Done

Development of the ground segment—which includes the interface data processing system, the ground stations that are to receive satellite data, and the ground-based command, control, and communications system—is under way and on track. For example, the Interface Data Processing System has been installed at one of the two locations that are to receive NPP data, and the command, control, and communications system passed acceptance testing for use with NPP. However, important work in developing the algorithms that translate satellite data into weather products within the integrated data processing segment remains to be completed. Table 4 describes each of the components of the ground segment and identifies the program-provided risk level and status of each.

Space Segment—Progress Made, but One Sensor Was Delayed and Sensors Continue to Face Risks

Over the past year, the program made progress on the development of the space segment, which includes the sensors and the spacecraft. Five sensors are of critical importance because they are to be launched on the NPP satellite. Initiating work on another sensor, the Microwave Imager Sounder, is also important because this new sensor—which is to replace the canceled Conical-scanned microwave imager/sounder sensor—will need to be developed in time for the second NPOESS satellite launch. Among other activities, the program has successfully completed vibration testing of the flight unit of the Cross-track infrared sounder (CrIS), a major pre-environmental testing review for the VIIRS instrument, integration and risk reduction testing of the flight unit of the Ozone mapper/profiler suite, and thermal testing of the NPP spacecraft with three sensors on board. In addition, the program made decisions on how to proceed with the Microwave imager sounder and recently awarded a contract to a government laboratory for its development.

However, the program experienced problems on VIIRS, including poor workmanship on selected subcomponents and delays in completing key tests. These issues delayed VIIRS delivery to the NPP contractor by 8 months. This late delivery will in turn delay the satellite’s launch from late September 2009 to early June 2010. This delay shortens the time available for incorporating lessons learned from NPP while it is in orbit into future NPOESS missions and could lead to gaps in the continuity of climate and weather data if predecessor satellites fail prematurely. Also, the CrIS sensor experienced a cost overrun and schedule delays as the contractor worked to recover from a structural failure and is currently several weeks behind its schedule due to thermal vacuum testing taking longer than planned. The status and risk level of each of the components of the space segment is described in table 5.

Program Risks Remain; Continued Oversight Is Needed to Prevent Further Cost Increases and Schedule Delays

Moving forward, the program continues to face risks. Over the next 2 years, it will need to complete the development of the key sensors, test them, integrate and test them on the NPP spacecraft, and test these systems with the ground-based data processing systems. In addition, the program faces two other issues that could affect its overall schedule and cost. One is that there continues to be disagreement between NOAA and DOD on the appropriate level of system security. To date, NPOESS has been designed and developed to meet DOD’s standards for a mission essential system, but NOAA officials believe that the system should be built to meet more stringent standards. Implementing more stringent standards could cause rework and retesting, and potentially affect the cost and schedule of the system. Another issue is that program life cycle costs could increase once a better estimate of the cost of operations and support is known. The $12.5 billion estimated life cycle cost for NPOESS includes a rough estimate of $1 billion for operations and support.

The NPOESS program office is working closely with the contractor and subcontractors to resolve these program risks. To address sensor risks, the program office and officials from NASA’s Goddard Space Flight Center commissioned an independent review team to assess the thoroughness and adequacy of practices being used in the assembly, integration, and testing of the VIIRS and CrIS instruments in preparation for the NPP spacecraft. The team found that the contractors for both sensors had sound test programs in place, but noted risks with VIIRS’s schedule and with CrIS’s reliability and performance. The program office adjusted the VIIRS testing schedule and is monitoring the CrIS testing results. In addition, the program office recently instituted biweekly senior-level management meetings to review progress on VIIRS’s development, and program officials noted that both the prime contractor and the program executive office will have senior officials onsite at the contractor’s facility to provide extensive, day-to-day oversight of management activities to assist in resolving issues.

To address the risk posed by changing security requirements late in the system’s development, program officials commissioned a study to determine the effect of more stringent standards on the system. This study was completed in March 2008, but has not yet been released. To address the risk of cost growth due to poor estimates of operations and support costs, DOD’s cost analysis group is currently refining this estimate. Program officials estimated that the program costs could grow by about $1 billion, and expect to finalize revised operations and support costs in July 2008.

The program office is aware of program risks and is working to mitigate them, but these issues could affect the program’s overall schedule and cost. Given the tight time frames for completing key sensors, integrating them on the NPP spacecraft, and getting the ground-based data processing system developed, tested, and deployed, it is important for the NPOESS program office, the Program Executive Office, and the Executive Committee to continue to provide close oversight of milestones and risks.

Agencies Have Undertaken Preliminary Steps to Restore Key Sensors, but Lack Timely Plans to Ensure Long-Term Data Continuity

When the NPOESS restructuring agreement removed four climate and space environment sensors from the program and degraded four others, it led NASA, NOAA, and DOD to reassess their priorities and options for obtaining climate and space environment data. Since the June 2006 restructuring decision, the three agencies have taken preliminary steps to restore the capabilities of selected climate and space weather sensors that were degraded or removed from the NPOESS program by prioritizing the sensors, assessing options for restoring them, and making decisions to restore selected sensors in order to mitigate near-term data gaps. However, the agencies have not yet developed plans to mitigate the loss of these sensors on a long-term basis. Best practices in strategic planning suggest that agencies develop and implement long-term plans to guide their short-term activities. Until such plans are developed, the agencies may lose their windows of opportunity for selecting cost-effective options or they may resort to an ad hoc approach to restoring these sensors. Lacking plans almost 2 years after key sensors were removed from the NPOESS program, the agencies face increased risk of gaps in the continuity of climate and space environment data.

While NPOESS was originally envisioned to provide only weather observations, this mission was later expanded to include long-term continuity for key climate data. Maintaining the continuity of climate and space data over decades is important to identify long- term environmental cycles (such as the 11-year solar cycle and multiyear ocean cycles including the El Niño effect) and their impacts, and to detect trends in climate change and global warming. The Nunn-McCurdy restructuring decision removed four sensors and degraded the functionality of four other sensors that were to provide these data. DOD, NASA, and NOAA are now responsible for determining what to restore, how to restore it, and the means for doing so. This responsibility includes justifying the additional funding needed to develop these sensors within their respective agencies’ investment decision processes. Best practices of leading organizations call for defining a strategic plan to formalize priorities and plans for meeting mission goals. Such a plan would include the agency’s long-term goals for climate and space weather measurements, the short-term activities needed to attain these goals, and the milestones and resources needed to support the planned activities.

NASA, NOAA, and DOD Have Identified Priorities, Assessed Options, and Made Decisions to Restore Selected Sensors

Since the June 2006 restructuring, NASA, NOAA, and DOD have taken preliminary steps to restore sensor capabilities by determining priorities for restoring sensor capabilities, assessing options for obtaining sensor data over time, and making decisions to restore selected sensors. Specifically, in August 2006, the NPOESS Senior User Advisory Group—a group representing NASA, NOAA, and DOD system users—assessed the impact of the canceled or degraded sensors and identified priorities for restoring them. In January 2007, a NOAA and NASA working group on climate sensors prioritized which of the sensors were most important to restore for climate purposes and proposed possible solutions and mitigation efforts. Two other groups— the National Research Council and a NOAA-DOD working group—have also issued reports describing the impact of the loss of climate and space environmental sensors, respectively. Table 6 summarizes the results of these studies.

In addition to prioritizing the sensors, NASA, NOAA, and DOD identified a variety of options for obtaining key sensor data over the next two decades and continue to seek other options. The agencies identified options including adding sensors back to a later NPOESS satellite, adding sensors to another planned satellite, and developing a new satellite to include several of the sensors. Examples of options for several sensors are provided in figure 1. In addition, in December 2007, NOAA released a request for information to determine whether commercial providers could include selected environmental sensors on their satellites.

In addition to prioritizing sensors and identifying options, over the last year, NASA, NOAA, and DOD have taken steps to restore three sensors on a near-term basis. Specifically, in April 2007, the NPOESS Executive Committee decided to restore the limb component of the Ozone mapper/profiler suite to the NPP satellite; in January 2008, to add the Clouds and the earth’s radiant energy sensor to NPP; and in May 2008 to add the Total solar irradiance sensor to the first NPOESS satellite. These decisions are expected to provide continuity for these sensors through approximately 2015. Table 7 shows the latest planned configuration of NPOESS satellites. NASA officials noted that they also took steps to mitigate a potential gap in total solar irradiance data by proposing to fund an additional 4 years of the SORCE mission (from 2008 to 2012).

Agencies Lack Plans to Ensure Long-Term Data Continuity

While NASA, NOAA, and DOD have taken preliminary steps to address the climate and space sensors that were removed from the NPOESS program almost 2 years ago, they do not yet have plans for restoring climate and space environment data on a long-term basis. Specifically, there are as yet no firm plans for obtaining most of this data after 2015. The Office of Science and Technology Policy, an organization within the Executive Office of the President, is currently working with NASA, NOAA, and DOD to sort through the costs and benefits of the various options and to develop plans. However, this effort has been under way for almost 2 years and officials could not estimate when such plans would be completed.

Delays in developing a comprehensive strategy for ensuring climate and space data continuity may result in the loss of selected options. For example, NASA and NOAA estimated that they would need to make a decision on whether to build another satellite to obtain ocean altimeter data in 2008. Also, the NPOESS program office estimated that if any sensors are to be restored to an NPOESS satellite, it would need a decision about 6 years in advance of the planned satellite launch. Specifically, for a sensor to be included on the second NPOESS satellite, the sponsoring agency would need to commit to do so by January 2010.

Without a timely decision on a plan for restoring satellite data on a long-term basis, NASA, NOAA, and DOD risk losing their windows of opportunity on selected options and restoring sensors in an ad hoc manner. Ultimately, the agencies risk a break in the continuity of climate and space environment data. As national and international concerns about climate change and global warming grow, these data are more important than ever to try to understand long-term climate trends and impacts.

GAO Made Recommendations To Ensure That Future Climate Needs are Addressed and to Complete Restructuring Activities

Because of the importance of effectively managing the NPOESS program to ensure that there are no gaps in the continuity of critical weather, environmental, and climate observations, in our accompanying report we made recommendations to the Secretaries of Commerce and Defense and to the Administrator of NASA to establish plans on whether and how to restore the climate and space sensors removed from the NPOESS program by June 2009, in cases where the sensors are warranted and justified. In their comments on the report, all three agencies concurred with our recommendations. In addition, both the Department of Commerce and NASA reiterated that they are working with their partner agencies to finalize plans for restoring sensors.

In addition, we also reemphasized a recommendation made in our prior report that the appropriate NASA, NOAA, and DOD executives immediately finalize key acquisition documents. All three agencies also concurred with this recommendation. Further, Commerce noted that DOD and NASA executives need to weigh in to resolve issues at, or immediately below, their levels in order to ensure prompt completion of the key acquisition documents. NASA noted that difficulties in gaining consensus across all three NPOESS agencies have delayed the signature of key acquisition documents, and reported that they are committed to moving these documents through the signature cycle once all of the issues and concerns are resolved.

In summary, over the past year, program officials have completed major activities associated with restructuring the NPOESS program and have made progress in developing and testing sensors, ground systems, and the NPP spacecraft. However, multiple risks remain. Agency executives have still not signed off on key acquisition documents that were originally to be completed in September 2006, and now DOD is threatening to withhold funding if the documents are not completed by August 2008—even though DOD has contributed to the delays in completing these documents. Also, one critical sensor has experienced technical problems and schedule delays that have led program officials to delay the NPP launch date by about 8 months. Any delay in the NPP launch date shortens the time available for incorporating lessons learned from NPP onto future NPOESS missions and could also lead to gaps in critical climate and weather data. In addition, risks to the program remain in resolving interagency disagreements on the appropriate level of system security and in revising estimated costs for satellite operations and support. The program office is aware of these risks and is working to mitigate them, but continued problems could affect the program’s overall schedule and cost.

When selected climate and space weather sensors were removed from the NPOESS program during its restructuring, NASA, NOAA, and DOD became responsible for determining what environmental data to restore and how to restore them. This responsibility includes justifying the additional funding needed to develop these sensors within their respective agency’s investment decision processes. In the 2 years since the restructuring, the agencies have identified their priorities and assessed their options for restoring sensor capabilities. In addition, the agencies made decisions to restore two sensors to the NPP satellite and one to the first NPOESS satellite in order to mitigate near-term data gaps. However, the agencies lack plans for restoring sensor capabilities on a long-term basis. Without a timely decision on a long-term plan for restoring satellite data, the agencies risk a break in the continuity of climate and space environment data. With the increased concern about climate change and global warming, these data are more important than ever to try to understand long-term climate trends and impacts.

Mr. Chairman, this concludes my statement. I would be happy to answer any questions that you or members of the committee may have at this time.

If you have any questions on matters discussed in this testimony, please cont act me at (202) 512-9286 or by e-mail at pownerd@gao.gov. Other key contributors to this testimony include Colleen Phillips (Assistant Director), Kate Agatone, and Kathleen S. Lovett.

Appendix I: Status of Key Acquisition Documents

Table 1 identifies the key NPOESS acquisition documents as well as their original and revised due dates. Original due dates were specified in the June 2006 restructuring decision memo. The revised due dates were specified in an addendum to that memo, dated June 2007, and then revised again in another addendum, dated April 2008. Documents that are in bold are overdue.