NASA ‘flying lab’ takes to European skies for experiments with German research plane
RAMSTEIN AIR BASE, Germany — The flight line here is hosting two aircraft typically not seen in these parts.
NASA’s DC-8 “flying laboratory,” an aircraft based near Edwards Air Force Base, Calif., and decked out with various sensors and intake valves, is in Germany this month to conduct joint research with the German Aerospace Center and its Airbus A320 research aircraft.
The agencies are conducting flights in tandem through the skies over Europe to see how traditional jet fuel blended with alternative fuels changes the physical characteristics of contrails — short for condensation trails — and their effect on the environment.
The current effort is the latest in a series of research projects during the past few years, some in the United States and some in Germany, using different aircraft and other sampling techniques to measure the effect of alternative fuels on emissions.
On Wednesday, the two planes took off one after the other into rainy skies. The NASA plane trailed the A320 by several minutes, carrying on board researchers and an assortment of instruments to sample and analyze gases and particles within the lead aircraft’s wake.
“We know that CO2 (carbon dioxide) emissions from aircraft are a problem,” said Bruce Anderson, a senior research scientist at the NASA Langley Research Center in Hampton, Va. “The contrails that form from aircraft create cloudiness over large regions, and as air travel increases, that’s going to be more and more cloudiness.”
Contrails — or the ice clouds that form in the exhaust of aircraft flying at higher altitudes where the temperatures are colder — can trap heat and make the surface of the earth warmer at night, Anderson said. “This research will hopefully tell us ways that we can reduce that effect.”
So far, the teams have flown three joint flights. At least three more are planned.
The government shutdown temporarily grounded the project but only for a day, Anderson said.
“I was sweating it out,” he said. “We had ‘excepted’ status, meaning we could stay here, but we couldn’t work, so we were waiting out every vote.”
After the shutdown struck at midnight Friday, the teams canceled a planned flight on Monday, but by Tuesday — after the shutdown was over — they were back to work.
During some of the flights, the German A320 burns standard jet A fuel with a 50 percent biofuel mix — alternative fuels produced from renewable feed stocks.
The NASA jet flies from 2.5 miles to 15-18 miles behind the German plane, said Wayne Ringelberg, a retired lieutenant colonel and former Air Force test pilot who is the chief DC-8 pilot for NASA during the project.
“Wakes can be fairly strong and dangerous things to fly in,” he said, but the NASA plane has experienced only moderate turbulence because it’s flying at a safe distance.
While it’s in flight, a small laser shines between the arms of two cloud probes on the DC-8 wingtips. “When ice particles pass through, it scatters light out and we measure that,” Anderson said. Tubes sticking out the sides and on top of the aircraft are used to draw in air samples. Researchers are measuring gases, aerosols and ice particles.
Ground experiments show that burning alternative fuels produces fewer soot particles, both German and NASA researchers said. Fewer soot particles emitted from aircraft produce larger contrail ice particles, Anderson said. Those particles, in turn, descend to lower altitudes more quickly and evaporate, shortening their presence in the skies.
“Right now we’re just doing research to understand the physics of the problem, and hopefully that will lead to technical solutions for addressing the problem,” he said.
While in Germany, NASA and the German Aerospace Center will conduct other flights to measure emissions from new and old aircraft engine types.