SAN FRANCISCO — U.S. government officials differ on the likelihood that the United States will suffer a gap in weather satellite coverage in the coming years but agree that an outage would have extremely serious implications for the nation’s weather forecasts.

David Powner, director of information technology management issues for the U.S. Government Accountability Office (GAO), predicted a significant gap between the end of operations for the Suomi National Polar-orbiting Partnership spacecraft and the beginning of operations for its successor, the Joint Polar Satellite System (JPSS)-1. 

“We are predicting a 17-month gap,” Powner told members of the House Science subcommittees on oversight and environment during a joint hearing Sept. 19. “No gap at all is highly unlikely.”

In contrast, Mary Kicza, assistant administrator for satellite and information services at the U.S. National Oceanic and Atmospheric Administration (NOAA), said there is a 50 percent chance the country will experience a gap in polar satellite coverage. NOAA and NASA are making significant progress in keeping JPSS-1 on schedule, including completing assembly of all JPSS-1 instruments. That, coupled with the current health of Suomi, is strengthening her confidence that the country will be able to avoid a gap altogether, Kicza told lawmakers.

“We now have two years of successful operations of Suomi on orbit,” Kicza said. “The issues that we would have expected to see that are referred to as infant mortality issues — early issues that will manifest themselves and present themselves as problems — have not been seen. If Suomi continues to perform as expected we can significantly reduce our projected risk of a gap on orbit.”

JPSS-1 is scheduled to launch in March 2017. In its 2014 budget plan submitted to Congress in April, the administration of U.S. President Barack Obama recommended refocusing the JPSS program on its weather forecasting mission and giving NASA responsibility for three climate sensors previously expected to fly on that spacecraft: the Clouds and Earth Radiant Energy System, the Ozone Mapping and Profiler Suite-Limb, and the Total Solar Irradiance Sensor. 

While Kicza said the revised plan strengthened the JPSS program and enabled NOAA to accelerate the schedule for the JPSS-2 spacecraft, Powner warned lawmakers of uncertainties associated with the decision to move the climate sensors off JPSS-1. Specifically, Powner questioned which satellites ultimately would host the climate sensors and whether steps taken to refocus JPSS would prevent the program’s life-cycle costs from rising above $11.3 billion. 

Powner also pointed out weaknesses in NOAA’s plans to address potential coverage gaps for both polar- and geostationary-orbiting weather satellites. “We take gaps very seriously so we need to have robust backup plans,” he said.

NASA and NOAA have been working together on plans to mitigate the impact of gaps, Kicza told lawmakers. For example, agency officials are exploring ways to make better use of microwave sensor data obtained by the Pentagon’s Defense Meteorological Satellite Program; use solar radiance data obtained in cloudy regions; extend operations of U.S. and European polar-orbiting satellites; and take advantage of commercial data sources. 

“Radio occultation in particular is one data source of interest,” Kicza said. At least two U.S. companies, PlanetIQ and GeoOptics, are planning satellite constellations to collect radio occultation data, which can be used to measure atmospheric humidity and temperature.

Lawmakers encouraged NOAA to explore commercial data sources rather than relying on Chinese weather satellites, a reference to a report prepared for NOAA in February by Riverside Technology of Fort Collins, Colo. That report, “JPSS Gap Mitigation Analysis of Alternatives,” noted that China’s Feng Yun-3C and -3D satellites are scheduled to launch in 2013 and 2014 into orbits similar to that of JPSS-1. In looking at various options to obtain weather data from various sources, the Riverside team called collaboration with the Chinese “a silver bullet.”

“I have grave concerns about incorporating data into U.S. systems from a country well-known for its persistent and malicious cyber attacks against our nation,” said Rep. Paul Broun (R-Ga.), chairman of the House Science oversight subcommittee. “Using Chinese data as a silver bullet is absolutely not appropriate. I hope you will look to other data sources and put in place policies that look to commercial sources for backfilling all these gaps.”

Kicza acknowledged that “security concerns exist with the use of Chinese data” but added that in the event of a gap, many U.S. government agencies, including those charged with maintaining national security, would be involved in any decision to use Chinese satellite data. 

While much of the hearing focused on the potential gap in polar satellite coverage, witnesses and lawmakers also aired concerns about NOAA’s Geostationary Operational Environmental Satellite (GOES) fleet, which features two operational satellites — one covering each U.S. coast — and one on-orbit spare. The oldest satellite in NOAA’s current geostationary fleet, GOES-13, is expected to cease operations in 2015, according to GAO. At that time, NOAA will only have two satellites in orbit and be without an on-orbit spare for a period “just short of two years,” Powner said. Currently, NOAA plans to launch the GOES-R satellite in early 2016 and spend approximately six months validating the spacecraft on-orbit before relying on it for weather data, he added. 

Further delays in the GOES-R launch schedule would exacerbate the problem and leave NOAA with a single geostationary weather satellite in orbit. To prevent that from occurring, GAO recommended that NOAA modify the sequence of activities planned in the GOES-R program and thoroughly assess the risk of delays in the schedule for completion of ground systems and spacecraft.

In conjunction with the hearing, GAO issued three reports on the weather satellite programs. One of those, dubbed “Focused Attention Needed to Improve Mitigation Strategies for Satellite Coverage Gaps” and published Sept. 19, GAO calls on NOAA to take further steps to address possible gaps in coverage. 

“The agency does not yet have comprehensive contingency plans that identify specific actions with defined timelines, and triggers,” the report said. “Until NOAA establishes comprehensive contingency plans that addresses these shortfalls, its plans for mitigating potential gaps may not be effective in avoiding significant impacts to its weather mission.”

The other two reports delved more deeply into NOAA’s geostationary- and polar-orbiting weather satellite programs.

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She is...