U.S. Earth-Sensing Satellites Left Out In the Cold
Government programs are giving weather prediction and climate monitoring shorter shrift
PHOTO: john macneill
Uncertainty clouds the future of QuikSCAT--a vital, but elderly, weather data satellite.
When Hurricane Katrina crashed into New Orleans in August 2005, the floodwaters triggered a cascade of infrastructure failures, resulting in many hundreds of fatalities. How much worse it would have been, however, if the city had not been evacuated at all. The decision to evacuate was based primarily on observations made from a family of satellites that feed data to the National Weather Service’s supercomputers.
”The satellite systems are an enormous scientific powerhouse that saved we don’t know how many people,” says Berrien Moore III, the director of the Institute for the Study of Earth, Oceans and Space at the University of New Hampshire, Durham.
The degree of precision needed to forecast hurricanes, and the future accuracy of climate modeling as well, may be in danger if recent trends in Earth-observing satellite programs persist, says a survey report published in January by the U.S. National Academy of Sciences. According to the report, ”Earth Science and Applications From Space: National Imperatives for the Next Decade and Beyond,” the number of instruments now collecting environmental data aboard American satellites will likely decrease by 40 percent within the next three years, if current trends continue. Few replacements are in the works at NASA and the National Oceanic and Atmospheric Administration (NOAA), in Washington, D.C., the agencies that conduct the bulk of Earth science research from space.
William Gail, a member of the panel that produced the report, puts its central message bluntly: ”There’s a train wreck coming.”
Hanging in the balance is the continuity of climate data records, not to mention the measurements needed to predict natural disasters and monitor other aspects of ecosystem health, says Gail, director of strategic development for Microsoft Virtual Earth, in Boulder, Colo.
Moore, who cochaired the academy survey, agrees. Referring to Katrina, he notes that ”the combination of satellite observations, mathematical models, and measurements from aircraft nailed a class-five hurricane going into a major American city three days in advance. I just ask you, imagine a world where [all of] those three things are not there.”
The survey, unprecedented in Earth sciences and intended to provide a road map for the field’s next decade, finds that the condition of U.S. Earth-observing satellites has significantly worsened since 2005, when the survey’s panel wrote in an interim report that the satellite system was ”at risk of collapse.” NASA’s budget for Earth science applications has dropped about 30 percent since 2000, from US $2 billion to $1.5 billion in 2006. This decline, together with demands of the space shuttle program, the Hubble Space Telescope, and the International Space Station, has forced NASA to significantly scale back or cancel its climate- and weather-forecasting plans.
NOAA, whose budget has grown slightly, has also taken on more obligations, resulting in no net gain for its Earth-observing capabilities. The survey strongly urges NASA to restore its Earth sciences budget to the $2 billion level by 2010 and to modestly bolster NOAA’s budget for climate applications.
White House officials, however, propose just slight growth for NASA’s Earth-related satellite programs in the next two years, leaving some projects grounded. After that, there are to be steeper decreases--which has prompted a certain amount of panicked e-mail correspondence among Earth scientists.
Meanwhile, the administration continues to pressure NASA to preserve its dominance in space flight with missions to Mars. ”I’m quite excited by the notion of the moon and Mars, but it doesn’t have to be done today,” says Eric Barron, the dean of the Jackson School of Geosciences at the University of Texas at Austin.
The foundation for U.S. Earth-sensing programs dates back to the 1999 launch of NASA’s first major environmental mission, the Earth Observing System (EOS). According to NASA’s original marching orders, consecutive sets of satellites would, over the course of 15 years, replace their decaying predecessors. But as NASA’s Earth science budget was squeezed, the later EOS missions never materialized. As a result, the burden of climate-measuring instruments was heaved onto the shoulders of a separate mission, primarily under the auspices of NOAA.
That mission, known as NPOESS, for National Polar-orbiting Operational Environmental Satellite System, suffered its own set of traumas. Its progenitors were two distinct but overlapping polar-orbiting satellite programs--one run by the Department of Defense, one by NOAA--which were folded into one to trim costs. The NPOESS platforms were already stuffed with instruments, and the added NASA climate-monitoring instruments turned it into a bloated behemoth of a space mission.
NPOESS soon went careening over budget. First, NOAA slashed some instruments. Then, prodded by a congressionally mandated review, the mission was scaled back entirely to its original reason for being: to acquire data purely for short-term weather forecasting. Virtually all climate sensors--namely, the ones inherited from the canceled EOS program--were dropped [see ”Troubled Weather Satellite Program,” IEEE Spectrum, News, June 2006].
Despite the natural relationship between weather and climate, NOAA’s financial problems have made it an unreliable sponsor. The bulk of climate duties, therefore, have defaulted right back to NASA. But NASA never drafted a new plan for Earth observations after it stopped pursuing the EOS program, according to Anthony Janetos, who directs the Joint Global Change Research Institute, in College Park, Md., a unit of the Pacific Northwest National Laboratory, Richland, Wash. Absence of a new plan, he says, has led to a neglect of Earth science research needs. ”The inevitable technological fact is that the systems you have in orbit will degrade and age,” Janetos says.
Taking a whack at this chronic bureaucratic tangle, the decadal report suggests staggering 17 missions of different sizes during the next 10 years--a departure from the existing model of infrequent launches of very large, expensive platforms laden with instruments. The new set of proposed instruments would measure, among other things, water vapor, solar radiation, sea surface winds, cloud activity, and land cover. In order to start with proven technologies, the proposed near-term missions build on canceled NASA projects that were partially or fully developed and then abandoned for budgetary reasons.
Some of the instruments the survey proposes replacing are practically antique--for example, the QuikSCAT mission has an active scatterometer, which measures ocean surface winds and has directly contributed to short-term weather forecasting, hurricane prediction, and understanding the conditions of El Niño, which can improve crop yields [see photo, ”Lone Ranger”].
The QuikSCAT mission is so far beyond its expected lifetime that it could fail tomorrow and no one would be surprised, says Arthur Charo, a senior program officer of the National Research Council’s Space Studies Board, who handled the report. Its eventual replacement will likely be a cheaper, less technically risky instrument--a passive microwave sensor that operates worse in slow wind speeds and in rain conditions. The new instrument, which has a shorter antenna, will provide less accurate El Niño predictions and weather forecasts in coastal areas. ”With a lot of these things, we’re going to take a huge step backward, with fewer observations at a time when the entire international community is clamoring for more information about this planet,” says the University of Texas’s Barron.
Following the recently released fourth report of the Intergovernmental Panel on Climate Change, Geneva, which stated that climate change was ”unequivocal” and ”very likely” due to human activities, the imperative to bolster political decision-making with the most complete and reliable climate models possible has only grown. ”To me, it should be a no-brainer, given the reasonableness of the cost and the importance of what’s going on on this planet,” says Richard Anthes, the president of the University Corporation for Atmospheric Research and a cochair of the survey report. ”I’m confident this program would save hundreds, perhaps thousands, of lives and actually pay back in terms of savings to the economy.”