The U.S. government’s NASA-led climate-change research effort faces uncertainty at best, collapse at worst, in the wake of the restructuring of the nation’s civil-military weather satellite program, scientists said.

Several key research sensors have been dropped from the National Polar-orbiting Operational Environmental Satellite System (NPOESS) in order to bring its soaring costs under control. In addition, a NASA-funded satellite that was to bridge the measurement gap between the agency’s Earth Observing System and NPOESS has been delayed from 2005 to 2009.

“We have been assuming NPOESS would be a key foundation upon which to build,” said Richard Anthes, president of the Boulder, Colo.-based University Corporation for Atmospheric Research and co-chairman of the National Academy of Sciences’ Earth science decadal survey committee. “Obviously it’s not the foundation we thought it would be.”

NASA pinned its long-term climate-change research strategy on NPOESS several years ago, when it became clear that projected federal budgets would not support the agency’s earlier plan to build and launch dedicated satellites to carry out the measurements, some of which date back to the 1970s. NPOESS is a joint effort of the U.S. Air Force and the National Oceanic and Atmospheric Administration (NOAA), with NASA as a junior partner.

The Pentagon announced its restructured NPOESS program plan, which pares back the number of satellites, delays the demonstration mission and drops seven secondary sensors, June 5. The Pentagon’s Cost Analysis Improvement Group estimates that dropping those sensors will save about $860 million, according to Maj. Regina Winchester, an Air Force spokeswoman.

Testifying before the House Science Committee June 8, NOAA Administrator Conrad Lautenbacher said “difficult choices and tradeoffs” had to be made in dropping the secondary sensors. He also said, however, that that the NPOESS satellite platform will retain the capacity to host the sensors should funding to build them become available.

Meanwhile, Lautenbacher said, NASA has alternatives for some of the sensors that have been displaced.

Testifying at the same hearing, NASA Administrator Mike Griffin agreed that the restructuring does not pose an immediate threat to climate research. “We’re not looking at a problem immediately,” he said. “We’re looking at problems that would occur out in the 2010, 2011 — that timeframe or later.”

NASA’s will develop a new long-term research plan based in part on the results of the National Academy of Sciences’ decadal survey on Earth science, Griffin said.

“Right now … we don’t have a plan,” Griffin said. “Any instruments that would need to be developed, any missions that would need to be developed to lessen these impacts or impacts on our international partners would require money not presently in the budget.”

The results of the decadal survey, begun in 2003, are due in October, but Anthes said the NPOESS restructuring “throws a wrench” in that schedule.

“It’s going to be hard to even hold our own in terms of capabilities to do weather forecasting and monitoring and observing the climate. It’s really a severe blow to the plans,” Anthes continued. “This is a serious problem when you see what we’ve lost. This is not just a small degradation. It’s a huge loss of the expected capability combined with a delay of what’s left.”

“It makes you wonder if it’s even worth going forward with NPOESS in its reduced form,” Anthes said.

James Hansen, a climate researcher and director of the NASA Goddard Institute for Space Studies in New York, said it was a mistake to try and incorporate research into the NPOESS mission.

“The attempt to put climate measurements onto the weather satellites was a terrible idea right from the beginning ‑‑‑‑ a bureaucratic solution that was doomed to fail eventually,” Hansen said. “Thank goodness the thing has collapsed under its own weight early on. Good riddance to a bad bureaucratic idea.”

Anthes added that in the interim report of the Earth science decadal survey, “we said that our Earth-observing system was at risk of collapse, and that is before we knew what was happening with NPOESS. The collapse is now happening before our eyes. We can only hope that this is the bottom and over the next few years we will start climbing back out.”

The sensors dropped from the NPOESS satellites are:

– Aerosol Polarimetry Sensor

– Total Solar Irradiance Sensor

– A portion of the Ozone Mapping and Profile Suite.

– Earth Radiation Budget Suite

– Altimeter

– Survivability Sensor

– Full Space Environment Sensors

Michael King, Earth Observing System senior project scientist at NASA’s Goddard Space Flight Center, Greenbelt, Md., is part of a NOAA-led group that has been asked to report to the White House Office of Science and Technology Policy before the end of June on how the restructured NPOESS program will impact data collection on 15 different climate variables.

“It’s fair to assume that some of the variables are not affected at all because those sensors or orbits are not affected, so the capability exists,” King said. “For others, there are still some question marks over implementation. There may be an impact, or there may not.”

King said the restructuring does threaten an Earth radiation budget database that extends back to 1978, when NASA satellites first began measuring how much solar energy is radiated back into space.

While one such instrument that NASA already has paid for will be flown on the first NPOESS satellite, the follow-on instrument that was supposed to fly on the third NPOESS satellite has been deleted. King said NASA currently has no plan for how to continue the Earth radiation budget measurement beyond the life of the first NPOESS satellite.

King said not all the deletions are necessarily bad news for climate researchers. “One example is [the study of] sea level variability with radar altimetry,” he said. “We’ve got a data record going back to 1991 or 1992 of global sea level and its variability and rise via Topex-Poseidon and Jason-1″ The deletion of the altimeter from NPOESS, he said, is ” not a bad thing because it was the wrong orbit for an altimeter anyway.”

Researchers will continue to have access to aerosol data, which can help monitor greenhouse gases , from a similar sensor that will be used on NASA’s Glory mission, Lautenbacher said. A plan is under discussion to find a new method of gathering that data after Glory reaches the end of its five- to 10-year life, he said. Glory is slated to launch in December 2008.

There is no plan yet to replace the Total Solar Irradiance Sensor, Lautenbacher said. However, one option could be using NASA’s Solar Radiation and Climate Experiment, he said.

Comments: jsinger@space.com , bberger@space.com