For several years, some have expressed concern about the possibility of a "data gap," which could occur if the newest POES satellite, launched in 2011, fails before its successor is launched and operational sometime in 2017. The Government Accountability Office (GAO) has reported that a polar-orbiting weather satellite data gap would result in less accurate and timely weather forecasts and warnings of extreme weather events, which could endanger lives, property, and critical infrastructure. In its FY2016 budget justification, NOAA released a new strategy called Polar Follow On (PFO) that would fund two JPSS satellites that would launch in FY2026 and FY2031, as well as other contingency options to mitigate the consequences of a data gap (in the JPSS program, one satellite is currently in orbit and two satellites are under construction and scheduled to launch in FY2017 and FY2022). NOAA requested $380 million as initial funding for PFO in FY2016. House appropriators did not provide any funding for PFO in the House FY2016 appropriations bill for Commerce, Justice, Science, and Related Agencies ( H.R. 2578 ), and Senate appropriators provided $135 million for FY2016 in their bill. The Consolidated Appropriations Act, 2016 ( P.L. 114-113 ), however, provided $370 million for PFO in FY2016. The Data Gap

The Suomi-NPP satellite operates in the afternoon orbit, providing full global coverage twice a day. The likelihood and duration of a data gap are subject to considerable uncertainty. In written testimony delivered to the Subcommittees on Environment and Oversight of the House Committee on Science, Space, and Technology on December 10, 2015, the NOAA witness stated that "NOAA's annual lifetime analysis report indicates a high probability (greater than 80 percent) that the expected lifetime of Suomi-NPP will extend beyond JPSS-1 launch and commissioning." If Suomi-NPP operated through JPSS-1 launch and commissioning, then no data gap would occur, assuming JPSS-1 was fully operational. However, we reported that several factors could cause a gap to occur sooner and last longer—potentially up to several years. These terms have specific meanings in the report: "the IRT believes that the definition of a robust program is that two failures must occur before a gap is created and an option must be available to return to a 'two failure' condition if a failure occurs." Conversely, a fragile program is "one spacecraft away from catastrophe." NOAA testified in front of the House Committee on Science, Space, and Technology on December 10, 2015, that the PFO plan would achieve a resilient and fault-tolerant position by 2023 (implying robustness) and would secure that position through 2038. Outlook

Funding the PFO at $370 million in FY2016 appears to reflect congressional support of the PFO strategy for NOAA's polar-orbiting weather satellite program. However, Congress likely will continue close scrutiny of the program and oversight of cost and scheduling changes, given the history of NPOESS and JPSS since the mid-1990s. In addition to efficient and effective management, the PFO program's success likely will also hinge on Congress appropriating funding to meet program needs without disrupting the cadence of the procurement, construction, launch, and on-orbit checkout schedule. If Congress continues to support and fund PFO and if NOAA implements the program as planned, then the polar-orbiting weather satellite system could achieve robustness by 2023. Given that the rubric of robustness and fragility threads through the PFO proposal and in congressional report language accompanying appropriations legislation, congressional oversight of the many factors determining robustness versus fragility likely will be a priority for many years.
Concerns have been raised in Congress about the possibility of a "data gap" in the polar-orbiting weather satellite coverage. A near-term data gap could occur if the currently operating polar-orbiting weather satellite, the Suomi National Polar-orbiting Partnership (Suomi-NPP), fails before its successor, the first Joint Polar Satellite System (JPSS-1), is launched and operational sometime in 2017. The Government Accountability Office (GAO) has reported that a polar-orbiting weather satellite data gap would result in less accurate and timely weather forecasts and warnings of extreme weather events, which could endanger lives, property, and critical infrastructure.
The likelihood and duration of a data gap are subject to considerable uncertainty. In testimony provided to the Subcommittees on Environment and Oversight of the House Committee on Science, Space, and Technology on December 10, 2015, the National Oceanic and Atmospheric Administration (NOAA) indicated a high probability (greater than 80%) that the expected lifetime of Suomi-NPP will extend beyond the JPSS-1 launch and commissioning. If Suomi-NPP continues to function until JPSS-1 is fully operational, then no data gap would occur. At the same hearing, the witness for GAO stated that several factors could cause a gap to occur sooner and last longer—potentially up to several years.
NOAA released a new strategy called Polar Follow On (PFO) that would fund the third and fourth JPSS satellites and other contingency options to mitigate the consequences of a data gap. The PFO is NOAA's strategy to transition the current JPSS polar-orbiting weather satellite program from its current "fragile" state to a "robust" state. An independent review team (IRT) for NOAA defined a robust program as one in which two failures must occur before a gap is created and in which an option must be available to quickly return to a two-failure condition if a failure occurs. Conversely, the IRT defines a fragile program as one spacecraft away from catastrophe. NOAA argues that the PFO plan would achieve a resilient and fault-tolerant position by 2023 (implying robustness) and would secure that position through 2038.
NOAA requested $380 million as initial funding for PFO in FY2016. House appropriators did not provide any funding for PFO in H.R. 2578, the House FY2016 appropriations bill for Commerce, Justice, Science, and Related Agencies, and Senate appropriators provided $135 million for PFO in their bill. The Consolidated Appropriations Act, 2016 (P.L. 114-113), however, provides $370 million for PFO in FY2016.
The decision to fund the PFO at $370 million in FY2016 appears to reflect congressional support of the PFO strategy for NOAA's polar-orbiting weather satellite program. However, Congress likely will continue close scrutiny of the program and oversight of cost and scheduling changes, given the program's delays and cost growth since the mid-1990s. In addition to efficient and effective management, the PFO program's success may also hinge on Congress appropriating continued funding to meet program needs without disrupting the cadence of the procurement, construction, launch, and on-orbit checkout schedule. Congressional oversight of the many factors determining robustness versus fragility likely will be a priority for many years. Without robustness, the threat of a polar-orbiting weather satellite data gap would remain.