Japan’s ispace updates design of lunar lander

spacenews.com -- Aug 03

Japanese company ispace has updated the design of its commercial lunar lander while delaying its first flight by a year.

The company unveiled the revised design of its Hakuto-R lander July 30 as it completed the critical design review of the spacecraft. The lander is scheduled to make its first mission in 2022, launching on a SpaceX Falcon 9.

Since a preliminary design review in 2018, ispace has reduced the size of Hakuto-R. Previously 3.5 meters high and 4.4 meters wide with its landing legs deployed, the lander is now 2.3 meters high and 2.6 meters wide. The spacecraft’s mass has decreased from 1,400 to 1,050 kilograms, primarily by reducing the amount of propellant on board.

A smaller lander is less expensive to develop, said Ryo Ujiie, manager of the lander system engineering group at ispace, during a call with reporters July 30. It also reduces the size and complexity of the landing legs.

The spacecraft will use a different trajectory to go to the moon, employing a low-energy transfer orbit that requires less propellant but takes roughly twice as long as previously planned. “We had to pick a more propellant-efficient orbit” given the reduction in propellant, said Chit Hong Yam, manager of the mission design and operations group. “We’re confident that, with enough checking, we should be able to execute this orbit.”

While the overall lander is smaller, it still maintains a payload capacity of 30 kilograms. Once on the surface, likely at one of several mid-latitude sites on the moon under consideration by ispace, it will operate for 12 days.