"If we could forecast where and when" virus-infected insects would swarm, crews "could adjust their control operations to reduce mosquito abundance and have things in place" before people fall ill, he says.
Endemic to the western USA, especially the Four Corners region of the Southwest (the meeting point of Utah, Colorado, Arizona, and New Mexico), bubonic plague spread by rats and their fleas sickens 10 to 20 people a year.
Because rats tend to breed in canyons, NASA combines topographical data with predictions of rodent food supply and migration patterns to predict the location of outbreaks. It shares the information with the CDC. Early warning is crucial, because the plague's flulike symptoms can lead to misdiagnoses that could prove fatal if antibiotics aren't administered promptly.
NASA satellites also can help distinguish between a naturally caused outbreak and one that might result from bioterrorism.
When an outbreak of Rift Valley Fever killed more than 120 people in Saudi Arabia and Yemen in 2000, U.S. military commanders worried it might have been caused by the release of the fever-causing virus by a terrorist cell.
Using rainfall data from NASA's Tropical Rainfall Measuring Mission satellite and vegetation measurements from the Terra and Aqua satellites, scientists discovered "the heaviest rainfall in that area than they'd had in 30 years." The rain boosted the mosquito population, so "with extremely high likelihood, we determined it was naturally caused," Haynes says.
NASA plans seven more global climate science satellites by 2013, which should expand the number of infectious diseases it can monitor.
One candidate is avian flu, which is spread by waterfowl. The U.S. Agency for International Development already finances programs to tag migratory birds with GPS satellite transmitters to monitor their movement and match their paths with disease outbreaks.
"It's up to us at NASA to use our research ability to determine if there are any environmental observations (that can shed light on) the transmission of this disease," Haynes says.