Word: xenon
(lookup in dictionary)
(lookup stats)
Dates: during 2000-2009
Sort By: most recent first
(reverse)
...propulsion sidesteps that whole mess. Rather than rely on common combustible fuel, it uses xenon gas, a comparatively light 937 lbs. (425 kg) of it loaded into a compact 72-gal. (273 L) tank. A jolt of electricity energizes the gas, causing xenon ions to shoot out the back of the ship at 77,000 m.p.h. (124,000 km/h). A stream of charged atoms has somewhat less oomph than a burst of fire--less force than the weight of a single piece of paper, in fact--but over time it adds up. "It's acceleration with patience," says Rayman...
...ease itself into a six-month orbit around Vesta, then climb gradually back out and fly on to Ceres, which it will orbit for about five months. This is the part that would have been simply too fuel intensive for an ordinary spacecraft. Dawn, by contrast, should have enough xenon left over after its Ceres stay that mission planners might even consider sending it on to a third destination...
...pollution because, unlike fossil fuels, it does not emit greenhouse gases. Yet in order to enrich the uranium needed to produce nuclear energy, huge amounts of carbon dioxide are released into the environment. Furthermore, even during normal operation, power plants emit radioactive particles, including gases such as krypton, xenon, tritium, and argon, all of which can cause genetic diseases and gene mutations, not to mention iodine-131 (which causes thyroid cancer), strontium-90 (which causes leukemia and bone cancer), and cesium-137 (which causes muscle cancer). Then, of course, there is plutonium-239, which is so toxic that just...
...mission involves other innovations. The Hayabusa ("falcon") spacecraft is powered not by a conventional liquid chemical rocket but by an ionized-xenon-gas engine, a propulsion system that is 10 times more efficient. Just as novel is a half-kilogram rover that Hayabusa will dispatch to roam the asteroid for several days. The robot, named Minerva, will use its miniature cameras and thermometers to send data back to the mothership. Since wheels are useless on such low-gravity surfaces, the coffee-can-sized machine will maneuver using an internal pendulum?a swinging weight that will let the bot hop about...
...around itself? As music and movies become more and more digital, the entertainment business is transforming into a software business, and somebody has to build the master platform on which all that software runs, and the hardware through which it flows. Turn to page 13 in your "Book of Xenon," please: "As the world's software leader, Microsoft is among the best suited to enable and capitalize this transformation. This is our opportunity to lose...