Reference
The US directed NASA to establish a Coordinated Lunar Time (LTC) to standardize cislunar operations with Earth's universal time to promote scientific missions.
Lunar missions by various nations - In September 2025, NASA's four-member Artemis Crew will fly around the Moon.
- China will send its astronauts to the Moon by 2030.
- India plans to send humans to the Moon in the year 2040.
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related facts
Time frame for LTC: The US has set a deadline of December 31, 2026 for NASA and its international partners to formulate a strategy for LTC implementation. NASA has been directed to engage with the 39 countries that have signed the Artemis Agreement for this project.
- Demand for Unified Lunar Time: In November 2022, the need for a globally unified lunar time was emphasized by space agencies and academic organizations, who agreed on 'A Common Lunar Reference Time'.
Coordinated Lunar Time (LTC)
- Standards for cislunar operation: LTC will be the standard for measuring cislunar operations (space activities between the Moon and Earth) along with Coordinated Universal Time (UTC), the global time used to regulate time on Earth.
Artemis Accord- Introduction: It is a US-led alliance that seeks to facilitate international cooperation in planetary exploration and research.
- Member: The agreement has been signed by 26 countries so far. China and Russia are not part of this initiative.
- Artemis Accords Principles
- Not to use the space for military purposes.
- To provide cooperation on matters of safety of space assets and astronauts.
- Sharing scientific data from space missions.
- Artemis Program: Its goal is to go to the Moon, establish a permanent station there and then use it for deep space exploration.
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- LTC Requirement: In the year 2023, the European Space Agency has set out to design satellites for astronauts and robotic explorers. 'Moonlight' (Moonlight), which will be used to support NASA's Moon mission 'Artemis'.
- During the course of the project, discussions were held about establishing a unified time zone for the Moon and approaches to achieving it.
- A 24-hour day is considered based on the rotation of the Earth. However, the Moon rotates very slowly i.e. one rotation every 29.5 Earth days.
- Due to its slow rotation, it would be possible to enforce fewer time zones than Earth's 24 time zones.
- This concept mirrors the structure of Coordinated Universal Time (UTC).
- Establishing a permanent human presence on the Moon: Space agencies around the world aim to establish a permanent human presence on the Moon, hence the need for LTC.
- With LTC, commercial operations involving transactions and logistics on the lunar surface will be more reliable.
- Atomic clocks: Devices that measure time based on the vibration of atoms are known for their extreme accuracy in measuring time.
- Solar time: Calculated by measuring the Earth's rotation on its axis relative to the Sun, which is variable.
Coordinated Universal Time (UTC)- Introduction: UTC was designed to accommodate the difference between solar time and atomic time.
- It is kept within 0.9 seconds of solar time and to an exact number of seconds of International Atomic Time (TAI) to follow the Earth's rotation variations.
- The weighted average of hundreds of atomic clocks produces International Atomic Time (TAI).
- Currently, Moon missions follow the time of the country that operates the spacecraft, while the International Space Station (ISS) operates on UTC. However, a standardized time is not followed for space and the Moon.
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- Role of LTC in lunar navigation and coordination: A dedicated global satellite navigation system (GNSS) for the Moon is to be developed by the year 2030.
- This system will work in the same way as the Global Positioning System and other navigation networks work on Earth.
- Thus, Moon missions from different agencies will need official lunar time to communicate with Earth-based stations and each other.
- All of these must be linked to the same time reference, otherwise coordination will become challenging.
Features required for time standard
- Ability to detect UTC: lunar time regional time on earth (Terrestrial Time) (TAI+ corresponds to 32.184 seconds). Similar to terrestrial time, lunar time can be determined through a set of clocks on the Moon.
- This time standard i.e. LTC can directly employ or distribute the required UTC offset to maintain local and UTC time within tolerance limits.
- Scalability beyond the Earth-Moon system: Using the above approach to setting LTC it will be possible to convert LTC to UTC for operations involving interaction with the Earth.
- This approach is also extendable to space environments beyond the Earth–Moon system. For example, Mars planet
- Accuracy for precise navigation and science: The LTC cislunar space will give users a reference time standard close to the gravitational environment in which they operate.
- Space assets can synchronize with each other with precision for navigation.
Global Positioning System- It is a satellite-based radio-navigation system, used for surveillance and control.
- Modern GPS consists of 24 satellites revolving around the Earth in six orbits.
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Issues related to defining and implementing LTC
- Gravitational Pull of Moon: The process of defining lunar time is complicated by the effects of the Moon's gravitational pull.
- According to the theory of special relativity, due to the Moon's weak gravitational pull, a clock on the Moon will run faster than a clock on Earth.
- Effect of lunar surface position on clock speed: Due to the rotation of the Moon, the clock's speed will also change depending on its position on the lunar surface.
- Any clock on the Moon will gain 56 microseconds in 24 hours. Each lunar day lasts about 29.5 Earth days.
- Addressing this challenge is essential for long-term stays, with the Artemis program aiming for a Moon landing as early as 2026.
- It has been estimated that at least three master clocks that synchronize with the natural movement of the Moon would need to be established. These clocks with algorithms are expected to produce more accurate time standards.
