The technologies worked well enough that NASA is considering using them on future missions.
The ion propulsion drive allowed the craft to reach Braille with just 1,000 pounds of fuel - less than a tenth of what a conventional engine would have burned. Though advertised on Star Trek as a souped-up system of propulsion, the ion drive actually is slow but efficient - making it ideal for otherwise fuel-guzzling flights that need to go long distances and perform precision maneuvers, said engineer Rayman.
The ion drive might, for example, make possible the long-sought goal of landing a craft on a comet, getting it to scoop up a sample of the planet's icy body, then returning to Earth.
When the concept was mentioned in a 1968 episode of the original Star Trek series, ion drive was considered better even than warp drive.
It was used in an alien ship, said Rayman, who went back and noted the references to ion drive. In the episode, titled "Spock's Brain," the crew of the Enterprise is puzzling over an alien ship.
Spock's assessment: "Configuration unidentified, ion propulsion, high velocity, unique technology."
To which Scotty replies: "I've never seen anything like her, and ion drive at that!"
But Deep Space 1 is not science imitating television. Science came up with the idea first. Television was simply faster to deploy it.
Ion drives were being developed in Ohio at the John Glenn Space Flight Center and tested in modest, suborbital missions as early as the 1960s, said Rayman, "but [the technology] was so different from conventional chemical propulsion that no one was willing to take a chance on it."
Thirty years later, NASA decided to start a series of missions for the express purpose of testing new technology. Deep Space 1, launched last October, was the first.
The principle behind the ion drive, also called solar-electric power, actually is very simple. The fuel is xenon gas, which is similar to the gas used in neon lights. And, much as they are in the process that energizes the neon in a light, electrons are shot in to knock additional electrons off the atoms, leaving them with a net positive charge. (The term ion refers to any electrically charged atom.)
Solar power is used to charge up metal grids at the back of the engine, grids that then push on the now positively charged xenon gas, accelerating the gas toward the back of the craft. There, it is shot out into space in a thin, glowing blue stream.
The thrust is so small that it amounts to no more than the force of a piece of paper resting on your hand, NASA reported. Such a small force would require four full days to accelerate the craft from a stop to 60 m.p.h. But over many days, that can add up to speeds of 8,000 miles per hour - fast enough to get to a relatively nearby asteroid in a few months.
It is not clear whether this is what the Star Trek writers meant by ion drive, but for anyone planning to venture into the blackness of interstellar space, the current reliance on solar panels would be a problem. "If you're going to leave the solar system, this is not the technology of choice," Rayman said.
NASA engineers say they also are pleased with several other new technologies that were tested on Deep Space 1.
The autonomous navigation system, or AutoNav, made this the first craft to reach a distant goal without any instructions from Earth. Deep Space 1 used distant stars and closer asteroids as reference points to get it to asteroid Braille. "This is the first craft to figure out where it is on its own," said Rayman.
Though the AutoNav got the craft to within 16 miles of the asteroid, at 1.3-by-0.6 miles the smallest body ever approached in space, it failed to aim the camera in the right direction. AutoNav can use several different reference points while in space, but it had only weak reflected light from the asteroid to tell it where to point the camera, and this turned out to be too slight to register.
Still, the other instruments were able to get valuable science data. At a news conference last week, NASA said analysis showed the Braille's composition matched that of a larger asteroid called Vesta, indicating a common origin.
The mission also tested a computer capable of taking control of the spacecraft. Scientists have called this "remote agent" - a predecessor of the infamous HAL of another science-fiction classic, 2001: A Space Odyssey.
NASA engineers let the remote agent fly Deep Space 1 by itself for a couple of days in May. Though it might not be as smart as 2001's HAL, this computer was at least better behaved than the fictional one, which ran amok and killed off a crew of astronauts.
Now past Braille, Deep Space 1 is continuing toward a nearby comet and another asteroid. If NASA approves additional funding, the spacecraft will gather more data and try again for pictures. Without funding, it will just keep on going.
