WASHINGTON — The U.S. commerce secretary says current weather satellite development programs are on track but nonetheless she continues to worry about a future gap in coverage.

In hearings before House and Senate panels April 9 and April 10, respectively, Commerce Secretary Penny Pritzker repeatedly said the National Oceanic and Atmospheric Administration’s weather satellite programs were “on schedule and on budget.”

NOAA, which manages and procures U.S. civil weather satellite systems, is part of the Commerce Department. The agency operates geostationary-orbiting satellites for continental coverage and a polar-orbiting craft for global coverage. Budget difficulties and delays to the systems currently under development have led to concerns about gaps in coverage, primarily from polar orbit.

“The potential for a gap is still too high,” Pritzker told the Senate Appropriations commerce, justice, science and related agencies subcommittee.

Both House and Senate leaders cited an independent assessment that said NOAA is making progress on the Geostationary Operational Environmental Satellite (GOES)-R and Joint Polar Satellite System (JPSS) programs. But that assessment, along with others by the Commerce Department’s inspector general and the Government Accountability Office, identified program risks including the possibility of a gap in JPSS coverage.

As recently as September, Mary Kicza, NOAA’s assistant administrator for satellite and information services, said there is a 50 percent chance the country will experience a gap in polar satellite coverage.

Pritzker said one way to reduce those odds is to keep the JPSS-1 satellite on schedule for a launch in 2017. She also appeared to lend credibility to the idea of accelerating  the launch date for JPSS-2, which is not yet under contract but is nonetheless tentatively slated for a 2021 liftoff.

“What we’re trying to do now is move the JPSS-2 so there’s greater overlap with the JPSS-1 program,” Pritzker said during the Senate hearing. “To do that, we need to have the procurement of the instruments, the bus, the ground system and the launch.”

According to documents accompanying its 2015 budget request, NOAA has ruled out the possibility of launching JPSS-1 early, but left the door open for moving up the launch date for JPSS-2. Starting work on JPSS-2 instruments now “may enable options to accelerate JPSS-2 schedules and reduce risk of a data gap between JPSS-1 and JPSS-2,” NOAA said.

NOAA has said it is considering other “potential gap mitigation missions” within the JPSS program but did not provide details.

The agency’s 2015 budget request includes a $165 million increase to buy spare JPSS instruments, which Pritzker called the most important step in building any kind of gap-filler program. NOAA recently announced its intent to procure additional JPSS instruments, including two spare sensors, from the incumbent contractors.

But during questions, lawmakers said they still had concerns about NOAA’s satellite program.

“While Commerce’s budget shows continued reforms to NOAA’s satellite programs in response to critical reviews from this Committee and expert outside analysts, I remain concerned about the stability of these important satellite programs,” Sen. Barbara Mikulski (D-Md.), who chairs the full Senate Appropriations Committee as well as the commerce, justice, science subcommittee, said in written testimony.

Meanwhile, Sen. Richard Shelby (R-Ala.), the ranking member of the full committee and subcommittee, questioned the need for one of NOAA’s secondary satellite projects, the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC)-2. That project, being pursued jointly with Taiwan, consists of 12 small satellites that would measure atmospheric conditions based on GPS signal distortion, or occultation.

Shelby told Pritzker he viewed the JPSS and GOES-R as must-haves, and the COSMIC-2 satellites as “nice-to-haves.”

Mike Gruss covers military space issues, including the U.S. Air Force and Missile Defense Agency, for SpaceNews. He is a graduate of Miami University in Oxford, Ohio.