11. Another dead end came in attempts to use buckyballs as a fuel for ion engines . 12. Propulsion is provided by an R-4D-15 apogee motor, with four XIPS-25 ion engines for stationkeeping. 13. :The problem with an ion engine is, that it needs a lot of energy to work. 14. But if conventional rockets are the hares of the Space Age, ion engines are the tortoises. 15. "That's no way to run an ion engine ," 16. An ion engine would also allow access to multiple latitudes and altitudes to optimize relay contacts. 17. Written for a juvenile audience, they had a scientific foundation, anticipating such advances as ion engines . 18. At times, the ion engine will be turned off and the spacecraft will coast, engineers said. 19. Ion engines deliver 10 times more thrust than a conventional engine for a given amount of fuel.20. Despite the eerie blue glow it emits, Deep Space 1's ion engine hasn't hit warp speed yet.
