An Ion Drive for Deep Space 1 . ... Credit Copyright: New Millennium Program , JPL , NASA Explanation: Space travel entered the age of the ion drive in 1998 with the launch of Deep Space 1 , a NASA mission designed primarily to test new technologies. Although the ion drive on Deep Space 1 provided acceleration much smaller than we feel toward Earth , it gradually gave the spacecraft the speed it needed to travel across our Solar System . ... The spacecraft was retired in December 2001 . ...