NASA may be best known for its moon landings, spectacular rocket launches, and stunning images of distant stars and galaxies. But it has also developed some of the most powerful tools we have for understanding our own planet, its climate, and its environment.
In its 54 years of existence, NASA has launched more than 60 Earth-observation missions, many of these capable of providing insights about our own planet that could not be gained from its surface.
The Aerospace Industries Association (AIA) today released a report that lays out the many practical benefits of space programs in the face of the approaching “fiscal cliff,” which threatens an 8.2 percent funding cut for NASA.
In the light of increasing urgency around climate change, NASA scientists are offering more insights than ever into global weather patterns and the environment—and may just help to turn the tide on global warming.
Predicting extreme weather
When Hurricane Sandy struck the East Coast in October, it didn’t follow the U-shaped path most hurricanes take back out into the Atlantic. Instead, it turned west around Cape Hatteras.
“Hurricanes don’t normally do that,” said Gary Lagerloef, president of Seattle-based nonprofit Earth & Space Research. “But the forecasters were able to predict that.”
Earth-observing missions don’t just track environmental conditions day to day—the Aquarius/Satélite de Aplicaciones Científicas (SAC-D) satellite mission, led by Lagerloef, is one of many efforts to seek long-term insights. The mission is a collaboration between NASA and Argentina’s space agency.
In 2011, Aquarius was able to create the most accurate global salinity map ever made. The map offers insight into changing global temperatures, which appear to be causing more evaporation in drier areas like the North Atlantic, where it leaves behind a higher concentration of salt, and more precipitation in wetter areas like the North Pacific, Lagerloef explained.
Salinity maps like Aquarius’s may soon help forecasters predict the behavior of storms. When hurricanes pass over areas of water with lower concentrations of salt, they can become more intense. Intensity can be more accurately predicted now that scientists better know where those freshwater areas are.
Satellites have been predicting severe weather for decades. Since the 1980s, the Famine Early Warning Systems Network has been tracking weather conditions that can lead to crop failure, and gives drought-stricken regions—especially those in Africa—time to prepare before a famine arrives. Polar Operational Environment Satellites were able to predict a rash of tornadoes in the Southeastern U.S. in April 2011.
Cutting emissions with the help of GPS
After the Air Force’s Global Positioning System became fully operational in 1994, the satellite signal was made available for public use, and within a decade had become invaluable in the ranks of perpetually lost drivers.
Today, companies like John Deere are selling GPS systems that help farms cut their use of fuel, natural gas, insecticide, and herbicide. This technology pinpoints and automates seeding and fertilizing to cut down on mistakes, while also coordinating with weather forecasts to reduce chemical run-off. GPS-based guidance systems can save a 1,000-acre corn farm about $13,000 a year, helping farmers recoup their investment in two to three years, the USDA Natural Resources Conservation Service estimates.
Similar gains in efficiency could be extended to air travel. The Federal Aviation Association’s Next Generation Air Transportation System (NextGen) would convert aviation traffic’s radar-based system to GPS at an estimated cost of $29 to $42 billion, the AIA reported in 2010.
That's a lot of money. But NextGen could reduce fuel consumption and greenhouse gas emissions anywhere from 6 to 15 percent, a representative of the Air Transport Association of America told the House Transportation and Infrastructure Committee in 2011. According to the AIA, a 12 percent reduction in airplane-related emissions would be equivalent to taking 2.2 million cars off the road for a year.
A better view of melting glaciers
The most comprehensive study of global ice sheet losses to date, published in the journal Science on Thursday, has yielded some disturbing numbers: Ice sheets in Greenland and Antarctica are losing ice at more than three times the annual rate seen in the 1990s. Melting ice from these areas alone has contributed to a sea level rise of 0.44 inches since 1992, an international team of 47 researchers from NASA and the European Space Agency concluded.
Observations from 10 satellite missions were combined to arrive at this conclusion.
“When you’re trying to get a sense of the earth’s climate, you need to assess the whole planet at once, and the only way you can do that is with satellites,” explained Tom Wagner, cryosphere program scientist at NASA.
Moreover, just one type of data isn’t enough to tell the whole story. This proved to be the case when, this summer, NASA’s Jet Propulsion Laboratory combined radar data from the Indian Space Research Organisation’s Oceansat-2 satellite with surface temperature information from its own Terra and Aqua satellites. Scientists then discovered that 97 percent of the ice sheet surface in Greenland had melted by mid-July. Normally, only about half of the ice sheet’s surface melts.
Another of NASA’s international collaborations, Gravity Recovery and Climate Experiment (GRACE), utilizes a pair of satellites to measure the Earth’s gravitational field.
“GRACE has shown that we’re losing tremendous amounts of mass from all around Greenland and all around Antarctica,” Wagner said.
Adapting rocket science to cut emissions
Every time the Space Shuttle launched, its main engine heated from -435 degrees Fahrenheit to more than 6,000 degrees within seconds. So it’s not surprising that the engineers at California-based Pratt & Whitney Rocketdyne (PWR), who designed that engine, came away from the project with a unique set of skills.
“They have special expertise on energy loss and on thermodynamic issues,” explained Dan Hendrickson, director, space systems, at the AIA.
Now the company is applying those skills to projects here on Earth. A compact gasifier the company is developing for power plants could reduce water consumption 30 percent and CO2 emissions 10 percent by converting coal, biomass, and petcoke into syngas, a combination of carbon monoxide and hydrogen that can be used to produce fuels, electricity or chemicals.
“When you look at the global demand for coal gasification, particularly in developing countries, these are game-changing numbers,” John Vilja of PWR told a House Committee in July.
Another PWR innovation is its system of storing solar heat in molten salt, an approach it first proved successful in the 1990s. Receivers on molten salt power towers have shown to be 88 percent efficient, while molten salt stores energy long enough to continue producing energy for hours after the sun goes down. PWR is collaborating with SolarReserve, LLC, to construct the Crescent Dunes Solar Energy Project in Nevada, expected to power up to 75,000 homes at peak times of day. Such innovations could provide an answer to solar power’s rainy-day conundrum.
Inspiring the next generation of scientists and engineers
Scientists, engineers, and mathematicians will design the renewable energy systems of the future. Many of them will be inspired by the space program.
An AIA graph compares NASA budgetary trends with the number of doctoral degrees granted per year in science, technology, engineering and mathematics (STEM) from a 1993 National Science Foundation report. Fluctuations in science enrollment move in sync with NASA budget fluctuations, although they lag four to six years behind.
Today, with the number of U.S. STEM graduates falling far behind other countries, Hendrickson, who has a degree in aeronautical engineering, thinks the answer is inspiration.
“I was a kid that lived in the Midwest—had no connection to space, had no connection to NASA,” he said. Then, he saw footage of the Apollo 11 mission. “I saw what was possible, and that totally shifts your paradigm of thinking.”
As an adult, the full picture of the space program has come into focus for Hendrickson.
“You come for the human space flight, you stay for the space science,” he said, “because you realize space science is really answering questions that we’ve dreamed about for thousands of years.”