As scientists mull President George W. Bush’s bold new space proposal, nuclear power stands out as one of NASA’s best understood and most controversial options for powering the next generation of spacecraft. Included in Bush’s space initiative, still vague in the details, is a call for “new power generation (and) propulsion” systems for a ship the President has called the Crew Exploration Vehicle.

The king’s blacksmith used goat’s urine. These days Washington University’s Ken Kelton uses an electrostatic levitator. In both cases, the two were trying to control a process called crystallization, to make a better product. The smithies wanted to make better swords. Kelton’s research could have an impact on matters as diverse as energy consumption and the manufacture of artificial joints. It’s featured on the cover of the July issue of Physics Today and was highlighted in a recent issue of Science magazine.