back to Destination Mars
Adapted from Marcia Dunn's article A spacecraft that is equipped with an ion engine and can think for itself
rocketed away from Earth on Saturday, October 24, 1998. The quest included
technologies straight out of Star Trek. NASA's Deep Space 1 soared through clouds aboard an unmanned rocket,
bound for an asteroid 120 million miles away. The successful morning launch
kicked off NASA's New Millennium program of "high risk, high payoff"
technology missions that the space agency hopes will lead to frequent, affordable
trips into space. Besides the ion-propulsion engine, Deep Space 1 is flying 11 other futuristic
technologies, including a self-navigating system, powerful lens-covered
solar wings, and a radio beacon designed to inform ground controllers how
the spacecraft is doing without being asked. Deep Space 1 is the first deep-space probe to rely on ion engines for
primary propulsion. The ion engine will provide the extra kick needed for
the drum-shaped spacecraft, which weights just over 1,000 pounds, to rendezvous
with asteroid 1992 KD next July. It will travel an estimated 450 million
miles before catching up with the moving rock. Here's how the solar-powered ion engine will work: Xenon gas is bombarded
by electrons. The resulting xenon ions are drawn toward high-voltage grids
and spewed into space at a speed of more than 62,000 mph. This glowing blue
stream of xenon ions is what provides the gentle yet constant acceleration
for months, even years. If it weren't for the ion engine, Deep Space 1 would need 10 times more
fuel to reach the asteroid. As it is, the spacecraft carries a scant 180
pounds of xenon gas to run the engine, reducing the size of the probe and,
consequently, the cost of the mission. |