Engine problems for Japan’s lunar lander company Ispace
According to company officials, the Japanese lunar lander company Ispace is having issues with the engine is has been developing for its next (and third) lander mission — a joint project with the American company Draper — problems that have now delayed the mission from ’26 to ’27.
In an earnings call discussing its fiscal third-quarter financial results this month, ispace executives said issues with development of the new VoidRunner engine could delay the company’s next lander mission. VoidRunner is a joint project between ispace’s U.S. subsidiary and Agile Space Industries, a U.S. space propulsion company, announced in May 2025. It replaced an Agile Space engine originally planned for use on the Apex 1.0 lander that ispace U.S. is developing.
Changing the engine required modifications to the lander design, Ispace said at the time, delaying its use on a mission led by Draper for NASA’s Commercial Lunar Payload Services, or CLPS, program from 2026 to 2027. That mission to the lunar farside is designated Mission 3 by Ispace.
Ispace has made two attempts to land on the Moon. In both cases, the mission worked perfectly until the last moments, resulting in a crash rather than a soft landing. In the first case software had the engines shut down when the spacecraft was still about three miles above the ground, while in the second case the spacecraft’s laser range-finder provided incorrect altitude data.
It presently has contracts for three more missions, the one for NASA working with Draper, a second for Japan in ’28, and a third for Europe in ’29. That it has had to replace the engines on the first (and might have to do it on the second) is a very bad sign. Usually it is best practice to build and test the engine first, get it right, and then build the spacecraft or rocket around it. Replacing an engine usually signals larger design problems that are difficult if not impossible to fix.
According to company officials, the Japanese lunar lander company Ispace is having issues with the engine is has been developing for its next (and third) lander mission — a joint project with the American company Draper — problems that have now delayed the mission from ’26 to ’27.
In an earnings call discussing its fiscal third-quarter financial results this month, ispace executives said issues with development of the new VoidRunner engine could delay the company’s next lander mission. VoidRunner is a joint project between ispace’s U.S. subsidiary and Agile Space Industries, a U.S. space propulsion company, announced in May 2025. It replaced an Agile Space engine originally planned for use on the Apex 1.0 lander that ispace U.S. is developing.
Changing the engine required modifications to the lander design, Ispace said at the time, delaying its use on a mission led by Draper for NASA’s Commercial Lunar Payload Services, or CLPS, program from 2026 to 2027. That mission to the lunar farside is designated Mission 3 by Ispace.
Ispace has made two attempts to land on the Moon. In both cases, the mission worked perfectly until the last moments, resulting in a crash rather than a soft landing. In the first case software had the engines shut down when the spacecraft was still about three miles above the ground, while in the second case the spacecraft’s laser range-finder provided incorrect altitude data.
It presently has contracts for three more missions, the one for NASA working with Draper, a second for Japan in ’28, and a third for Europe in ’29. That it has had to replace the engines on the first (and might have to do it on the second) is a very bad sign. Usually it is best practice to build and test the engine first, get it right, and then build the spacecraft or rocket around it. Replacing an engine usually signals larger design problems that are difficult if not impossible to fix.








