NASA Hopes Soar on Pilotless Craft : Science: The planes, built by a small aerospace firm, have been designed to gather scientific data at 85,000 feet.
Two pilotless planes that look like white gliders are poised to soar higher than any aircraft has ever flown--above 85,000 feet.
“So far as we know, they’re the first airplanes that have ever been designed specifically for science and actually been built,” said John S. Langford, president of Aurora Flight Sciences Corp.
If launched as scheduled, the computer-controlled craft, fitted with scientific instruments and powered by a single propeller behind the tail, will investigate the ozone layer high above Australia in 1994.
Both Perseus A craft, costing $1.5 million each, were made for the National Aeronautics and Space Administration by Aurora, a small aerospace company based near the Manassas Airport in Virginia.
Long, thin, tapering wings and lightweight, composite bodies will enable the planes to fly for six hours and reach heights of 82,000 feet or more. Future versions will stay airborne much longer, but at lower altitudes.
The current high-altitude record of 85,000 feet is held by the SR-71 Blackbird, a former U.S. Air Force reconnaissance jet recently acquired by NASA. “We hope to break that record with Perseus,” Langford said.
But everyone involved with the new aircraft insists that the goal is science, not record books.
“Initially we’ll use instruments on the Perseus A to investigate ozone in the stratosphere over Australia as part of a large atmospheric program in the Southern Hemisphere,” said Philip B. Russell, NASA’s chief of atmospheric chemistry at the Ames Research Center in California. “We want to get more definitive data on the chemical processes occurring up there.”
During the last decade, chemicals--in particular, widely used industrial chlorofluorocarbons--have thinned the protective ozone that filters out much of the sun’s harmful ultraviolet radiation. The loss is greatest over the South Pole, so one of the aircraft may eventually fly over Antarctica.
Scientists also want to determine whether a new generation of supersonic passenger transports that would fly at altitudes of 60,000 to 65,000 feet would damage the ozone layer. Commercial jets now reach heights of 35,000 to 40,000 feet.
“NASA is particularly interested in research to see if it is possible to build a supersonic transport engine whose emissions will not harm the ozone layer,” said the agency’s administrator, Daniel S. Goldin. “Perseus will help us find out.”
Aurora is also developing two Perseus B drones that look like the A’s, but have more staying power. The planes will be leased to groups of scientists for weather and climate studies, beginning in 1994.
Designed to operate for as long as three days at 65,000 feet--well above most major weather systems--Perseus B could improve hurricane warnings and help solve mysteries about climate change and global warming.
“I think the aircraft will produce something of a small revolution in meteorological observations,” predicted Kerry Emanuel, a meteorology professor at the Massachusetts Institute of Technology.
Manned aircraft that now probe hurricanes are expensive to operate and usually cannot fly high enough to obtain such vital data as wind speed, water-vapor content and temperature from the entire storm system.
Pilotless planes will lead to more accurate tracking of hurricanes, and “that will have a big payoff,” Emanuel said. He foresees the time when unmanned aircraft will be routinely deployed about three days or so before a hurricane’s expected landfall.
The craft may aid long-term forecasting. “We’re really in bad shape when it comes to collecting weather data over the oceans,” Emanuel said. “I see unmanned aircraft flying at high altitudes as being a quantum leap in our ability to collect vital information and understand how the climate works.”
On some long-distance ocean flights, data accumulated by the aircraft will be relayed to small satellites that would beam information back to ground stations. On shorter hops, data will be sent back by one of the drone’s three radios.
An on-board computer about the size of a pocket calculator will direct the Perseus aircraft on their missions. Working from a ground station, a “pilot” will closely monitor takeoffs and landings, but once airborne, the planes will follow pre-programmed computerized instructions.
The airplanes are designed “in essence as autonomous craft that follow the instructions they’ve been given and go about their business,” Langford said. “A computer is always flying the plane.”
