For the first time ever, an optical clock has traveled to space. The experiment—designed by researchers from Menlo Systems working in conjunction with research groups at Ferdinand Braun Institute Berlin and Humboldt University of Berlin, Johannes Gutenberg University of Mainz, and Airbus Defense & Space GmbH—was successfully executed in April of 2015, proving that this precise technology can be effectively used in space.
Before this experiment, it was believed that an optical clock was far too fragile to survive the journey into space, and that was largely true. One of the biggest engineering hurdles was the frequency comb, an essential intermediary between an optical clock and microwave-based reference atomic clocks. Frequency combs have historically been large, complex contraptions housed in laboratories, so the team at Menlo Systems developed a smaller, more robust frequency comb just 22cm in size, 22kg in weight, and with a power consumption of just 70 watts, making it perfectly suitable for satellite use. Combining this new comb with an atomic cesium clock and a rubidium optical clock, the system was flown on a research rocket and functioned perfectly in microgravity. Although the system used in the test is less accurate than current atomic systems on Earth, researchers are already working on a new version for 2017 that is expected to greatly improve accuracy.
The discovery is incredibly exciting, as these new frequency combs hold great potential in “future space-based optical clocks, precision metrology and Earth observation techniques.”
To read more about this development, visit Optica.
For more information on atomic time and optical clocks, read our overview.