Japan tries a different approach to the Moon with iSpace

Japan's second attempt at a lunar landing is being made by the company specializing in lunar exploration, Ispace. Departing last January aboard a SpaceX rocket, its five-month journey is entering its final phase. The Hakuto-R lunar lander has just entered lunar orbit, after spending some time orbiting Earth to gain speed. Unlike the American company Firefly Aerospace, which carried its own lunar lander aboard the same Falcon 9 rocket as Ispace, the journey is longer because it follows a more fuel-efficient approach.

Thus, Firefly Aerospace only took 45 days to land on the lunar surface. Ispace will take longer, with a journey announced from the outset to last five months. “First and foremost, we are extremely pleased that the Resilience lander successfully reached lunar orbit as planned today,” said Takeshi Hakamada, founder and CEO of iSpace, in a statement. "We will continue our operations with caution and rigorous preparations to ensure the success of the lunar landing."

Ispace's more economical approach to the Moon

Ispace presents its journey to the Moon as a "low energy transfer," meaning an economical transfer from one orbit to another. The recipe for this is simple: draw an elliptical trajectory large enough to be on the Moon's path (Highly Elliptical Orbit), a process that takes longer than the classic process of a few days and requires a lot of fuel. Then, you have to wait for the encounter with the Moon, to achieve its gravitational capture (provided you have a sufficiently low speed). Once in lunar orbit, it is then enough to reduce the speed again to land this time.

In addition to saving fuel, Ispace also saves space and weight on its module, freeing up space for other instruments. For its mission, the Japanese are aiming for the northern part of the Moon, in an area called Mare Frigoris ("Sea of Cold"). With this lander, Ispace would celebrate its first success, and Japan a second. In January 2024, the country already celebrated the success of the SLIM ("Smart Lander for Investigating Moon") spacecraft.