Some of the same people who brought you the human-powered aircraft Daedalus are at it again.
They have teamed up to produce an unmanned airplane designed to climb into the upper atmosphere to take scientific measurements.
MIT's Daedalus set world records in Greece on a 72.4 mile flight from Crete to the Island of Santorini on April 23, 1988. The manager for that remarkably successful project was a four-degree MITer, Dr. John S. Langford. He now heads Aurora Flight Sciences Corp., a small aircraft company based in Manassas, VA, that built the new aircraft for the National Aeronautics and Space Administration at a cost of about $1.5 million.
While the human-powered Daedalus never flew much above 30 feet on its course over the Aegean Sea, the new plane-also named for a Greek mythological figure, Perseus-is expected to climb to a record-setting altitude of 18 miles in its quest for scientific data.
The information it gathers, if all goes well, will be used for a number of purposes-for example, to deduce the health of the Earth's ozone layer and to ascertain the potential effects on the upper atmosphere of the proposed high-flying hypersonic passenger plane.
Daedalus and Perseus are different types of aircraft with different purposes, but the experience of building Daedalus contributed greatly to the new project, Dr. Langford said in a telephone interview.
Especially important was the earlier work involving computer-aided aerodynamic design and extremely lightweight materials.
The same people involved in both projects include Professor Mark Drela of MIT, who did the aerodynamic design of both craft; Greg Zack, one of the Daedalus pilots; Tom Clancy, who worked on Daedalus as a UROP undergraduate and is the lead engineer for Perseus; and Brian Duff, who helped organize Daedalus and is now a director of Aurora.
Testing of Perseus is expected to begin ths spring, Dr. Langford said, with Zack at the "controls."
He will guide the aircraft from the ground, "essentially using a set of computer screens," Dr. Langford said. One reporter likened the setup to "a giant and very sophisticated radio-controlled model airplane." Actually, the plane is designed to fly with or without human intervention, and on high-altitude scientific flights would be on its own most of the time guided by pre-programmed on-board computers. In those circumstances, the pilot on the ground would intervene only for takeoffs and landings.
While the motor-less Daedalus weighed 68 pounds and had a wingspan of 112 feet, the gasoline- and liquid oxygen-powered Perseus weighs about 1,500 pounds and has a 59-foot wingspan, resembling the dimensions and look of a sailplane. Dr. Langford expects it to break the world altitude record for unmanned aircraft of 67,028 feet (12.7 miles) and the record for altitude in horizontal flight by an airplane of 85,069 feet (16.1 miles).
Daedalus took its name from the mythical Greek architect and engineer who escaped imprisonment with his son, Icarus, by fashioning wings for them.
The origin of the name Perseus, as explained by Dr. Langford, is somewhat more subtle and wry. He was the mythical figure who cut off the head of Medusa, the snaky-haired gorgon whose glance could turn a beholder into stone.
The role of the aircraft Perseus, Dr. Langford said, is to change the thinking-in a somewhat more genteel manner-of the scientific and aviation bureaucracy, which until now has given a cold stare to the idea of unmanned high altitude flight.
"There have been previous attempts to build such an aircraft," remarked Dr. Langford, "but they were pretty much all turned to stone before they could achieve their goals."
A version of this article appeared in the January 6, 1993 issue of MIT Tech Talk (Volume 37, Number 17).