government is making steady progress on a troubled effort to develop a new generation of weather satellites to serve both military and civil users, according to the official overseeing the effort.
Dan Stockton, program executive officer for the National Polar-orbiting Operational Environmental Satellite System (NPOESS), said he does not see issues at this point that would interfere with the planned first NPOESS launch in 2013, or the launch of a demonstration platform scheduled for 2010.
The NPOESS satellites are being built by Northrop Grumman Space Technology of Redondo Beach, Calif., on behalf of the U.S. Air Force and National Oceanic and Atmospheric Administration, who are jointly funding the multibillion-dollar effort.
NASA is a junior partner in the tri-agency program office, and is overseeing the demonstration satellite, known as the NPOESS Preparatory Project, which features several key NPOESS instruments. The NPOESS Preparatory Project satellite platform is being built by Ball Aerospace and Technologies Corp. of
The NPOESS team is in the midst of testing instruments that will fly first on the NPOESS Preparatory Project. The Visible/Infrared Imaging Radiometer Suite (VIIRS) began testing in June to examine potential issues with electromagnetic interference, and results have been good thus far, said in a July 10 interview.
This testing is intended to examine potential interference across circuits in the sensor. The VIIRS effort previously ran into issues with optical interference, leading to a decision last fall to launch the sensor with some degradation in performance for the NPOESS Preparatory Project mission while correcting the problem with a new filter for the NPOESS satellites.
Next on the agenda for VIIRS, which will monitor cloud formations and other atmospheric and ocean-surface phenomena, will be vibration and thermal vacuum chamber testing, said.
Developmental problems with VIIRS, being built by Raytheon Space and Airborne Systems of El Segundo, Calif., have been blamed for much of the difficulty thus far with the NPOESS effort. Massive cost growth forced a restructuring of the program in 2006 that reduced the number and capability of the satellites.
Rep. Nicholas Lampson (D- Texas), chairman of the House Science and Technology energy and environment subcommittee, expressed concern during a June 19 hearing that a recent manufacturing error on the first VIIRS instrument could require its complete disassembly and delay the NPOESS Preparatory Project launch.
However, said that the issue was limited to external hardware that since has been replaced without significant disruption to work on the instrument.
The other NPOESS Preparatory Project sensors undergoing testing are performing well, said. The Ozone Mapping and Profiler Suite, which will map atmospheric ozone, is in the middle of thermal vacuum testing, while the Cross-track Infrared Sounder, designed to collect atmospheric temperature and moisture profiles, is nearing the end of thermal vacuum testing, he said.
Those two instruments are slated to be delivered to Ball Aerospace in late summer or early fall, said.
also expressed confidence that the NPOESS team would meet an August deadline for completion of certain program documentation.
According to a U.S. Government Accountability Office report released in June, Pentagon acquisition chief John Young threatened to withhold military funding for NPOESS if the program office missed the deadline.
An administration source characterized the deadline as a matter of Young wanting to ensure that the documentation was completed rather than any faltering in support for NPOESS.
said the documents are intended to officially recognize organizational changes made to the program in recent years, including the creation of his post of program executive officer and fee structure changes. Both changes were part of the 2006 NPOESS restructuring.