WASHINGTON — The fiscal year 2018 budget request for the National Oceanic and Atmospheric Administration offers full funding for ongoing major weather satellite programs while deferring work on future efforts.

The NOAA request, released May 23 with the rest of the administration’s budget proposal, would provide nearly $1.58 billion for NOAA satellite procurement activities, down from the nearly $1.98 billion those programs received in the fiscal year 2017 omnibus spending bill passed in early May.

NOAA’s two major satellite programs would remain on track in the budget request. The Geostationary Operational Environmental Satellite R (GOES-R) program, developing a new generation of geostationary weather satellites, would get $518.5 million in the 2018 request. That is down more than $230 million from what the program received in 2017, but identical to the projected 2018 funding level in NOAA’s 2017 budget request.

The decline represents changes in the program reflecting the completion and launch of the first GOES-R satellite, GOES-16, in November 2016. On May 25, NOAA announced that GOES-16 will be placed into operation this November at the GOES-East orbital location of 75 degrees west.

“GOES-16 will be placed in the east position where it can observe the entire continental U.S., and monitor areas most vulnerable to tornadoes, floods, land-falling tropical storms, hurricanes and other severe storms,” Stephen Volz, director of NOAA’s Satellite and Information Service, said in a statement about the decision to place GOES-16 in the eastern orbital slot.

The second satellite in the GOES-R series, GOES-S, is nearing completion and is scheduled for launch in the spring of 2018, and will be located at the GOES-West orbital slot at 137 degrees west. Two additional satellites, GOES-T and GOES-U, are planned for launch in 2020 and 2024, respectively.

NOAA’s other major weather satellite program, the Joint Polar Satellite System (JPSS), would receive $775.8 million in the request, $11 million less than in 2017 but $30 million more than what last year’s budget request projected for 2018. The first JPSS satellite, JPSS-1, is scheduled for launch in September, with JPSS-2 under development for launch in 2021.

Plans for future JPSS satellites, though, would be reviewed if the administration’s budget request is enacted. JPSS-3 and -4 are included in a separate program called Polar Follow-On, which received $328.9 million in 2017. Last year’s budget request anticipated spending $586 million on Polar Follow-On in 2018, but the new budget request seeks only $180 million for the program for 2018.

The reduction is linked to plans to revisit the schedule of launching JPSS-3 and -4 suggested in the administration’s budget blueprint document issued in March. “NOAA will work to improve its constellation strategy for polar weather satellite continuity while seeking cost efficiencies, managing system technical risks, and leveraging partnerships,” the agency’s 2018 budget document states.

Previous plans called for building JPSS-3 and -4 by the mid-2020s, to be launched between 2026 and 2031 depending on the health of the earlier JPSS satellites. Instead, “NOAA will also identify new launch dates for JPSS-3 and JPSS-4 consistent with the revised budget profile” during fiscal year 2018, the agency’s budget documents state. The budget also doesn’t include projections for future funding beyond 2018 for the program because of the uncertain launch dates for those missions.

Stretching out the schedules for the later JPSS satellites can provide near-term savings, but raise the risk of a later gap in service. “Our challenge on that one is going to be what does that mean for the risk posture for the observing system,” Volz said in a May 3 presentation to the Space Studies Board of the National Academies here. “We have to quantify the risk of that implementation plan and see if there are ways to mitigate that risk in different ways.”

A similar concern, although on a smaller scale, exists for the Space Weather Follow-On program. That program, which seeks to develop spacecraft for launch in the 2020s to replace the existing DSCOVR and SOHO spacecraft that provide warnings of solar storms, received $5 million in 2017, double the original request.

However, the 2018 budget proposal provides just $500,000 for the program, even though the 2017 request had projected spending more than $53 million on the program in 2018 as development of the new spacecraft ramped up. The 2018 request effectively shifts the funding profile of the overall program by a year.

NOAA’s budget proposal suggests the agency will examine alternative ways of carrying out the space weather mission using the limited funding available. “Base funds are being used to begin formulation studies that will determine the best possible architecture and way forward” for the program, the NOAA budget document states, including “potential opportunities for incorporating commercial abilities.”

The budget request makes no major changes to some smaller NOAA programs. A commercial weather data pilot program would receive $3 million in 2018, compared to $5 million in 2017 and $3 million in 2016. NOAA recently completed a first set of data purchase contracts with GeoOptics and Spire, funded using the 2016 appropriations, and is in planning for a new request for proposals for 2017.

The administration is proposing $1.2 million for NOAA’s Commercial Remote Sensing Regulatory Affairs office, which licenses commercial imaging satellites, the same amount as it received in 2017. NOAA’s Office of Space Commerce would also get $1.2 million, up from $800,000 in 2017, to support the commercial weather data program.