The U.S. government’s effort to develop a new generation of civil-military weather satellites is facing financial and technical problems so severe that a complete overhaul of the program may be required, according to U.S. government officials closely following the troubled program.

The National Polar-orbiting Operational Environmental Satellite System (NPOESS), a six-satellite program managed jointly by the U.S. Air Force, National Oceanic and Atmospheric Administration (NOAA) and NASA, is encountering serious development setbacks, primarily involving its suite of advanced sensors. These issues, which already have driven the program’s projected price tag up by $1 billion, to $8 billion, now threaten to push the cost up by another $1 billion or more, sources say.

A planned 2010 launch of the first NPOESS satellite, dubbed C1, is no longer considered realistic, and a delay of up to four years could be unavoidable if no additional money beyond what already has been budgeted is found for the program, according to government officials and documents obtained by Space News.

Consideration also has been given in recent months to options as drastic as canceling NPOESS C1, eliminating certain instruments and capabilities from the first two satellites, and scrapping a NASA-led precursor mission intended to demonstrate key NPOESS sensors, documents show. These options would free up hundreds of millions of dollars to help minimize — but not eliminate — an NPOESS launch delay.

At least a half-dozen other options in addition to these have been put forward by the NPOESS Integrated Program Office since it learned from the project’s prime contractor, El Segundo, Calif.-based Northrop Grumman Space Technology, in late March that it could not deliver the satellites on cost or on schedule.

As recently as mid-August, some of the options had been dropped and NPOESS program officials were proposing a middle course that would entail delaying the launch of the first NPOESS satellite by 10 months and leaving off one of its key instruments, officials said. This option still would require at least $800 million in additional funding through the end of the decade, including about $60 million in 2006, they said. The Air Force and NOAA, which are providing the bulk of the NPOESS funding, requested a combined $645 million for the program next year.

NPOESS program officials, according to documents and government sources , had been expecting senior officials with the agencies participating in the program to select one of the options by the end of August and then take it forward to the White House Office of Management and Budget for approval. But that did not happen.

U.S. government officials involved in the NPOESS discussions said there is virtually no chance of finding significant additional 2006 money for the program this late in the annual budget process, making some of the proposed options moot. These sources also said there is a general lack of confidence in the NPOESS program office’s numbers. For these reasons, the officials said, the NPOESS participating agencies are unlikely to select any of the options offered by the program office until the results are in from at least two independent reviews of the program ordered this summer. Those reviews, led by U.S. Defense Department teams, are expected to be completed by the end of the year, with preliminary results available as soon as October.

The U.S. Government Accountability Office, the investigative arm of Congress, also has launched an NPOESS review, its third since 2003. Last September, the watchdog agency projected that cost of completing the multi-satellite system would grow to $8.1 billion, an increase of $1.2 billion over previous estimates. Government sources said the situation has only grown worse since then.

NOAA spokesman John Leslie said Sept. 9 that officials in the NPOESS program office declined to be interviewed for this story. Leslie said his agency is working closely with the Pentagon and NASA to resolve the cost and schedule problems associated with the NPOESS sensors and to review options for the program’s future.

The NPOESS program manager, John Cunningham, announced Aug. 18 that he would be resigning his post and leaving government service by mid-September. Leslie said previously that the agencies are “working aggressively” to find Cunningham’s replacement.

Northrop Grumman spokeswoman Sally Koris acknowledged Sept. 9 that three NPOESS sensor development efforts have encountered significant difficulties. Work on those instruments already was well under way when Northrop Grumman bested Lockheed Martin Space Systems of Sunnyvale, Calif., to win the NPOESS prime contract in 2002, she said .

Government officials have identified the Visible Infrared Radiometer Suite, being built by a unit of Raytheon Co. in Santa Barbara, Calif., as the main culprit behind the NPOESS cost growth. The instrument is intended to provide imagery, sea-surface temperature readings, and ocean color measurements. Sabrina Steele, a Raytheon spokeswoman, deferred to Northrop Grumman for comment.

Koris said two other instruments — the Ozone Mapping and Profiler Suite and the Conical Microwave Imager/Sounder — also are encountering development problems . The ozone mapping suite is being built by Boulder, Colo.-based Ball Aerospace and Technologies Corp., while the Conical Microwave Imager/Sounder, is being built by Boeing Satellite Development Center of El Segundo, Calif. The latter sensor is intended to track atmospheric temperature and humidity, cloud cover and ocean-surface wind.

Sarah Hoyt, a spokeswoman for Ball, did not dispute Northrop Grumman’s characterization of the problem and did not comment further. Boeing spokesman Eric Warren deferred to Northrop Grumman.

Koris said the government added reserve funding to the NPOESS program in recent years to head off unforeseen problems quickly without having to go through a lengthy congressional reprogramming process, but that money has been exhausted . That funding included $10 million in 2003, $27 million in 2004, and $18 million in 2005, according to a government source.

“As in any development there are a variety of causes for design difficulties and program delays,” Koris said in a written statement. “On this program, they can be broadly categorized as design errors, fabrication process flaws, and assembly and test process errors related to the sensors.”

Some of the sensor problems, she said, “were the result of systemic subcontractor process issues that required (and continue to require) broad-reaching Northrop Grumman and government intervention for proper resolution.”

The NPOESS program was intended to save money by merging separate polar-orbiting weather satellite systems operated by NOAA and the Air Force. NASA, a junior partner in the program, is counting on the new system for environmental measurements important to researchers.

Brian Berger is editor in chief of and the SpaceNews magazine. He joined in 1998, spending his first decade with the publication covering NASA. His reporting on the 2003 Space Shuttle Columbia accident was...