Word: spacecrafts
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...spacecraft have their own personal quirks, and 204 had been balky from the start. As an Apollo engineer said: "The first article from the factory cannot come out without birth pains." The spacecraft gave repeated trouble. The nozzle of its big engine shattered during one test. The heat shield of the command module split wide open and the ship sank like a stone when it was dropped at high speed into a water tank. Certain kinds of fuel caused ruptures in attitude-control fuel tanks. The cooling system failed, causing a two-month delay for redesign. But all the bugs...
Circadian Rhythms. NASA has suggested that such nighttime illumination would be useful in search-and-rescue work, in spacecraft-recovery operations and in lengthening short winter days at high latitudes. But its spokesmen have carefully avoided discussing another obvious application: military use in Viet Nam. A single mirror satellite in synchronous orbit over Southeast Asia could cast light on an area stretching from Saigon all the way to Pointe de Camau, at the southern tip of Viet Nam, thus depriving guerrillas of the protection of darkness...
...trajectory on Nov. 1, 1979, would be picked up by Jupiter's gravity and hurled to Neptune - like a skater at the end of a crack-the-whip line - in only 8.1 years. The scientists also discovered that the outer planets would be so fortuitously positioned that a spacecraft launched on Oct. 7, 1978, could actually make a 8.9-year "grand tour," passing close to Jupiter, Saturn, Uranus and Neptune in turn and receiving a gravitational boost from each...
While the use of the interplanetary billiard technique drastically cuts travel time, Stewart says, it does little to reduce the large amounts of fuel and great initial thrust required to send a spacecraft to the distant planets. But another rapidly developing propulsion system, the solar-powered ion engine, may well solve that problem in time for the flights of the 1970s. Using electricity generated by solar panels, these engines produce a stream of ions (charged atomic particles) that provide a minute amount of thrust - usually measured in hundredths of a pound...
...chemical rockets, which burn most of their fuel in a few minutes, ion engines can operate continuously for months and even years on an incredibly small amount of fuel. One experimental ion engine recently completed 341 days of steady operation. Thus, after a powerful chemical rocket has boosted a spacecraft beyond the earth's gravitational pull, the ion engine can take over, gradually and steadily accelerating the craft to its planned velocity over the months and years of a long space trip...