Contrails, the lines of clouds left by high-flying aircraft as they cut through air, are found to be trapping heat in the atmosphere.<\/p>\n
Working with Boeing, United Airlines, and other industry, government, and international partners, NASA researchers are collecting data to see how new, greener aviation fuels can help reduce the problem.<\/p>\n
NASA’s contrail research through Boeing’s ecoDemonstrator program is a multi-year effort to analyze replacing conventional aviation fuel with sustainable aviation fuel and its effects on condensation trail formation.<\/p>\n
A Boeing 737-10 ecoDemonstrator Explorer aircraft has conducted test flights over American skies switching between tanks filled either with sustainable aviation fuel or conventional fuel. It was followed by NASA’s DC-8 aircraft, measuring emissions and contrail ice formation from each type of fuel. This data will help determine whether sustainable aviation fuels help reduce the formation of contrails, according to NASA.<\/p>\n
The ecoDemonstrator Explorer aircraft is the largest flying science laboratory in the world.<\/p>\n
“Contrails are believed to be a major source of pollution,” said Rich Moore, a research physical scientist in NASA’s Langley Aerosol Research Group Experiment. Moore was among the researchers who flew aboard the DC-8. “With this mission, we’re looking not so much at correcting contrails, but at preventing them.”<\/p>\n
In addition to the DC-8, which is based at NASA’s Armstrong Flight Research Center in Edwards, California, the U.S. space agency contributed other critical capabilities, including a mobile laboratory for ground testing. Other collaborators for the ecoDemonstrator flights include General Electric Aerospace, the German Aerospace Center, National Research Council Canada, and the Federal Aviation Administration.<\/p>\n
The results of the research will be published within a year, NASA says.<\/p>\n
Contrail clouds form when aircraft operate in the cold temperatures at high altitudes and water vapor in engine exhaust condenses and freezes. Made up of ice particles, contrail clouds can have both a cooling and warming effect based on ambient conditions, timing, and persistence – but scientists estimate that their warming effect is greater on a global scale.<\/p>\n
Over the past decade, NASA-funded research has shown that sustainable aviation fuels have significant benefits for reducing engine particle emissions that can influence local air quality near airports and contribute to the formation of contrails.<\/p>\n
Efforts to develop and evaluate sustainable aviation fuels focus on delivering the performance of conventional jet fuel without releasing new carbon dioxide into the environment. These fuels can be derived from sustainable sources such as feedstocks and waste resources. <\/p>\n