WASHINGTON U.S. Senate appropriators on Sept. 16 passed a defense spending bill that would put the brakes on the Defense Department’s plans to begin development of a new weather satellite constellation in 2011.

The Senate Appropriations Committee’s version of the 2011 Defense Appropriations Bill also added $44 million to the Pentagon’s $94 million request for the Operationally Responsive Space Office to fund responsive space launch capabilities.

The Pentagon has spent the last few months conceiving a new weather satellite program after the White House in February dismantled the military-civilian National Polar-orbiting Operational Environmental Satellite System (NPOESS) effort. Plans for the new Defense Weather Satellite System (DWSS) were approved in August by the Pentagon’s acquisition chief. A new civil weather satellite system is being developed by NASA and the National Oceanic and Atmospheric Administration (NOAA).

The Senate Appropriations Committee provided only $50 million of the $325.5 million requested by the Air Force for the DWSS program; the bill must still be passed by the full Senate and reconciled with a House version of the bill that has yet to be drafted. With two weeks remaining before the beginning of the new fiscal year, Congress has yet to vote on any of its 12 spending bills for 2011.

As currently planned, the DWSS satellites will feature two instrument packages originally planned for NPOESS: the Visible Infrared Imager Radiometer Suite and the Space Environmental Monitoring sensor. The system will also carry a to-be-determined microwave sensor.

Northrop Grumman Aerospace Systems of Redondo Beach, Calif., was the prime contractor for NPOESS, responsible for developing the satellite platform and managing instrument subcontractors and overall system integration. The company is now expected to provide satellite platforms for the first two DWSS spacecraft, but whether they will feature the NPOESS design has yet to be determined.

The Senate committee is concerned that the total cost to complete both the military and civil weather satellite constellations will exceed $20 billion, including the roughly $5 billion that was spent on NPOESS. The Pentagon estimates its program will cost nearly $6 billion, and the civil system is expected to cost another $9.4 billion, according to language in the report accompanying the bill.

Because the Air Force still has two legacy Defense Meteorological Satellite Program spacecraft that have yet to launch, the committee declined to fund development of new DWSS constellation. It provided $50 million for continued development of military weather satellite sensors.

“While the committee understands the importance of these satellites and their missions, the committee believes there must be a more cost-effective way for [the Defense Department] to utilize  NOAA’s investment,” the committee wrote. “It is premature at this time for the [Defense Department] to set up a large program office and begin to build DWSS.”

Meanwhile, the new civil weather satellite program, dubbed the Joint Polar Satellite System, has received more support from Congress. The Senate Appropriations Committee on July 22 passed its version of the 2011 Commerce, Justice and Science Appropriations Bill, which provided the full $1.06 billion requested for the satellite program by NOAA. The House version of the bill has not yet made it out of committee.

NASA is developing the Joint Polar Satellite System on behalf of NOAA and plans to launch the first satellite in 2014. NASA in September awarded an $82.4 million contract to Ball Aerospace & Technologies Corp. of Boulder, Colo., to build the Ozone Mapping and Profiling Suite for the first satellite. The agency also intends to issue a $214 million sole-source contract to Ball to provide the satellite’s platform, according to an Aug. 23 posting on the Federal Business Opportunities website.