OMAHA, Neb. — A problem with a key instrument and ongoing ground systems issues led NASA and the National Oceanic and Atmospheric Administration earlier this month to delay the launch of the first next-generation polar-orbiting weather satellite by at least two months.

NOAA announced Aug. 5 that it was delaying the launch of the Joint Polar Satellite System (JPSS) 1 spacecraft from January to no earlier than March 2017. NOAA said that decision was based on “recent tests of the flight and ground systems,” but did not elaborate. At the time of the announcement, companies involved in the JPSS program referred questions about the delay to NOAA.

Preston Burch, the JPSS program manager at NASA, which serves as the acquisition agent for the NOAA-funded program, said Aug. 26 that one reason for the delay was because of a problem with the Advanced Technology Microwave Sounder (ATMS), one of the spacecraft’s instruments. ATMS collects microwave emissions from the Earth’s atmosphere and surface to provide temperature and moisture data.

Burch said that, during spacecraft testing in July, technicians discovered a problem with one of the instrument’s 22 channels. “Further testing and evaluation led to a decision to remove ATMS from the observatory and return it to Northrop Grumman” for further testing and repairs, he said. ATMS is provided by Northrop Grumman Electronic Systems of Azusa, California.

While repairs of the ATMS instrument are in progress, testing of the overall JPSS-1 is continuing with an engineering model of the instrument temporarily installed on the spacecraft. That, Burch said, is intended to minimize launch delays.

A separate issue contributing to the delay is work on the JPSS ground system, which has been undergoing extensive tests. “A higher than expected number of problem reports with the ground system has led to unplanned remedial work, which has affected the ground test and verification program and related mission operations preparations,” Burch said.

Those issues led NASA and NOAA to delay the JPSS-1 launch, which had been scheduled for Jan. 20 on a United Launch Alliance Delta 2 from Vandenberg Air Force Base in California. That launch is now scheduled for no earlier than March 16. “NOAA and NASA are currently evaluating progress on the ATMS troubleshooting and ground system test and verification to assess the level of risk associated with a commitment to a March 2017 launch date,” Burch said.

The announcement of the delay earlier this month came after a House Science Committee hearing in July where the U.S. Government Accountability Office raised concerns about JPSS-1’s launch readiness. David Powner, director of information technology management issues at the GAO, said at the July 7 hearing that the program had missed interim milestones involving the spacecraft itself, one of its instruments and the ground systems, although the program overall remained on track at that time.

Delays in the launch of JPSS-1 raise concerns about potential data gaps that could lessen the accuracy of weather forecasts. The ATMS instrument on the Suomi National Polar-orbiting Partnership spacecraft is in danger of failing for reasons unrelated to the issue with the ATMS developed for JPSS-1.

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...