- NASA’s four-member Artemis crew is scheduled to fly around the moon in 2025 in preparation for the space agency’s mission to land on the moon again.
- To support such missions, the White House Office of Science and Technology Policy (OSTP) has directed NASA to establish a Coordinated Lunar Time (LTC) to standardise time-telling on the moon.
- The LTC will be the standard to measure cislunar operations with the earth’s UTC Coordinated Universal Time (UTC).
- The idea for the UTC was formulated in the 1960s. The UTC was designed to accommodate the difference between solar time and atomic time and is kept within 0.9 seconds of solar time to follow the earth’s rotational variations and within an exact number of seconds of the TAI.
- Atomic clocks are known for their extreme accuracy. A weighted average of hundreds of atomic clocks produces the International Atomic Time (TAI).
- Solar time on the other hand is calculated by measuring the earth’s rotation relative to the Sun and is variable in nature.
- Currently, moon missions follow the time of the country that operates the spacecraft, while clocks on the International Space Station run on the UTC.
- There is currently no standardised time for cislunar operations.
- The LTC must possess traceability to the UTC, scalability beyond the earth-Moon system, accuracy for precision navigation and science and resilience to loss of contact with the Earth.
Dig Deeper: Which element is used in an atomic clock and how does it calculate each second?
