Flight duration to the Moon: what you need to know

The flight time from Earth to the Moon varies depending on a number of factors, including fuel supplies, the characteristics of the lunar orbit, and the objectives of a specific mission.

A spacecraft can reach the Moon in a period of 8 hours to 4.5 months depending on the chosen trajectory and technical specifications.

History of Moon Flights

A flight to the Earth's natural satellite is a complex task. The Moon orbits our planet at an average distance of 384,400 km. Based on lunar missions from recent decades, travel time varies significantly. The fastest artificial object to fly near the Moon was the "New Horizons" probe, launched by NASA in 2006 to study Pluto. According to scientific sources, the spacecraft passed the Moon approximately 8 hours and 35 minutes after launch.

For missions aimed directly at the Moon, the journey takes longer. In 1959, during the first human mission to the Moon, the Soviet spacecraft "Luna-1" took 34 hours to reach its destination. The unmanned mission was supposed to perform a controlled impact with the lunar surface, however, the spacecraft veered off course, flying at a distance of 5995 km from the Moon. After the batteries were depleted, contact with the spacecraft was lost, and it remains in space to this day.

In 1969, when the historic landing of astronauts on the Moon took place, the crew of Apollo 11 needed 109 hours and 42 minutes from launch to the moment when Neil Armstrong took his famous first step on the lunar surface.

Factors Affecting Flight Time

The duration of the flight to the Moon significantly depends on many factors, among which one of the most important is the amount of fuel used. Aerospace engineers have discovered an interesting pattern: using less fuel leads to an increase in flight time, but makes the mission more economically efficient. At the same time, there is an opportunity to use the natural gravity of celestial bodies, primarily Earth, to conduct the spacecraft along a longer but energetically advantageous path.

For example, in 2019, Israel sent an unmanned spacecraft "Beresheet" to the Moon. After launch, the spacecraft orbited the Earth for about six weeks on a gradually expanding orbit before gaining enough speed to transition to lunar orbit. Although the mission did not end as planned by the Israeli Space Agency, as communication with the spacecraft was lost and "Beresheet" crashed onto the Moon's surface 48 days after launch, it demonstrated an alternative approach to interplanetary flights.

The record for the longest flight to the Moon belongs to NASA's CAPSTONE probe. This 25-kilogram cubesat took 4.5 months to reach the Moon. During this time, it made several orbits around the Earth before finally entering lunar orbit in 2022. CAPSTONE (Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment) was sent to test the orbit that NASA plans to use for the future Gateway space station.

Stages of the lunar mission

Regardless of the chosen route, each mission to the Moon goes through several important stages. Notably, 60-90% of the launch mass of any space mission consists of the fuel needed to overcome Earth's gravity and reach space.

Upon reaching orbit, the spacecraft must use a minimal amount of fuel to achieve the optimal flight trajectory to the destination. The more fuel the spacecraft carries, the heavier and more expensive the entire mission becomes. In the final stage, the spacecraft needs to expend additional fuel to leave Earth's orbit and transition to lunar orbit.

According to Mark Blanton, head of the analysis and evaluation department of NASA's "Luna-Mars" mission, one of the main factors determining flight time is the mission's objective. "The space agency evaluates the types of available rockets and their ability to propel the spacecraft. The capabilities of the launch vehicle and the mission tasks determine the size and characteristics of the spacecraft. After determining all requirements, experts develop the optimal route," the specialist explains.

Thus, all parameters of the spacecraft and flight — the exact size of the vehicle, the number of crew members, the distribution of fuel, and many other technical details — can significantly affect the overall duration of the flight to the Moon.