RACE: laser-cooled Rb microgravity clock

RACE is a high performance Rb clock slated to fly on the International Space Station. RACE aims to realize high accuracy and short-term stability. The cold collision shift and multiple launching (juggling) have important implications for the design and the resulting clock accuracy and stability. We present and discuss the double clock design for RACE. This design reduces the noise contributions of the local oscillator and simplifies and enhances an accuracy evaluation of the clock.