A team of researchers at the National Institute of Standards and Technology is set to begin work on an advanced laser-cooled cesium atomic clock slated to go aboard the international space station. The clock will employ the latest techniques for cooling atoms with laser beams. Cold atoms provide a narrower resonance linewidth, translating into improved long-term stability. The scientists estimate that the space clock will perform 10 times more accurately than the best Earth-based clocks. It will enable them to make gravitational measurements, test whether the speed of light is the same in all directions and perform other relativity experiments. It also is expected to improve the determination of satellite orbital parameters and the ability to compare and synchronize clocks at various locations on the Earth's surface.