Can the Hubble Telescope Be Saved?

besides taking care of altitude and direction, will have to regulate the entire electrical system and govern allocation of incoming energy. Of course, construction of the plane will depend on the latest in ultralight, multifunctional materials. But the plane’s electrical requirements pose the most demanding engineering challenges. “It’s really a war against all the losses we will have in the power system from the solar cells to the motors,” EPFL’s Perriard told IEEE Spectrum. Most helpful of all would be batteries with higher energy densities. Right now, off-the-shelf lithiumion batteries provide just under 200 watthours per kilogram, enough to support a plane with a single pilot. Two pilots would be safer and more fun, but that would require getting the capacity up to 250 or, ideally, to 300 Wh/kg. Piccard, who is currently looking for sponsors for the project, has assembled a separate team of specialists—including meteorologists, aerodynamicists, and pilots—whose job it will be to actually design and build the aircraft. Prototypes will be constructed over the next two years, with short test flights to begin in 2006. Ultra-long-distance flights are planned for 2009. “It will take an elegantly crafted vehicle, flown in meteorological conditions that are hard to find,” says AeroVironment’s MacCready, “but it’s doable.” In the 1930s, Piccard’s grandfather Auguste pioneered manned balloon flight into the stratosphere and invented a submersible he called a bathyscaph. In 1960, his father, Jacques, and a fellow diver set a world record by plunging 11 km to the deepest point of Earth in a later-model bathyscaph. Piccard, who by his own account has “piloted many things,” has an even grander vision for Solar Impulse. He wants to channel the public’s enthusiasm for a major technological development into support for renewable energy. People usually associate renewable energy with having to give something up, says Piccard. “But the goal [of Solar Impulse] is to pull them into a big adventure.” —GISELLE WEISS Can the Hubble Telescope Be Saved?