On Tuesday, the White House issued a policy memo directing NASA to develop a new lunar time standard by 2026. Lunar Time Coordinated (LTC) will establish an official time reference to help guide future lunar missions. Its arrival coincides with the outbreak of the 21st century space race between (at least) the United States, China, Japan, India and Russia.
The memorandum directs NASA to work with the Departments of Commerce, Defense, State, and Transportation to develop a strategy to put LTC into practice by December 31, 2026. International cooperation will also play a role, particularly with signatories to the Artemis Accords. Developed in 2020, they are a common set of principles developed between (currently) a growing group of 37 countries to govern space exploration and operations. China and Russia do not belong to this group.
“As NASA, private companies and space agencies around the world launch missions to the moon, Mars and elsewhere, we must establish safe and accurate celestial time standards,” said Steve Ware, OSTP deputy director for national security. “A consistent definition of time among space operators is critical to successful space situational awareness capabilities, navigation and communications, all of which enable U.S. government and international cooperation,” Steve Welby wrote in a white paper. House press release. The basis for interoperability between partners.”
Einstein’s theory of relativity shows that time changes relative to speed and gravity. Given the Moon’s weaker gravity (and the difference in motion between the Moon and Earth), time moves slightly faster on the Moon. Therefore, Earth’s clock on the moon’s surface appears to be faster by an average of 58.7 microseconds per Earth day. As the United States and other nations plan lunar missions to study, explore and (eventually) build permanent habitation bases, using a single standard will help them synchronize technology and missions that require precise timing.
“The clocks we use on Earth will move at a different rate on the Moon,” said Kevin Coggins, NASA’s director of space communications and navigation. Reuters. “Think about the atomic clocks at the U.S. Naval Observatory (Washington State). They are the heartbeat of the country, synchronizing everything. You would want to have a heartbeat on the moon.”
The White House wants LTC to be coordinated with Coordinated Universal Time (UTC), the standard by which all time zones on Earth are measured. The company’s memo said it hopes the new time zone will enable accurate navigation and scientific research. It also wants LTC to remain resilient when contact with Earth is lost, while providing scalability for space environments “beyond the Earth-Moon system.”
NASA’s Artemis program aims to return a manned mission to the moon for the first time since the Apollo missions in the 1960s and 1970s. The space agency said in January that Artemis 2 will carry four people around the moon and is currently scheduled to launch in September 2025. Artemis 3 is a mission to return humans to the lunar surface, currently scheduled for 2026.
Along with the United States, China aims to put astronauts on the moon by 2030 as the world’s two most important global superpowers engage in a space race. While no other country has announced a manned mission to the lunar surface, India (which placed a module and rover on the lunar south pole last year), Russia (a mission around the same time that went less well), the United Arab Emirates in recent years Since then, Japan, South Korea and private companies have all demonstrated their moon landing ambitions.
In addition to enabling further scientific exploration, technology construction and resource extraction, the moon can also serve as a key stop on the way to Mars. It could test technology and provide fuel and supply needs for eventual human missions to the Red Planet.
