Japanese SLIM module lands on Moon, but upside down: What is the reason?

The Japanese Aerospace Exploration Agency (JAXA) has provided details about the landing of the SLIM module on the Moon. The descent was gentle, but ultimately, the spacecraft overturned. Apparently, at an altitude of 50 meters during an obstacle avoidance maneuver, one of the two main engines of the module lost thrust, leading to an emergency landing. However, this doesn't mean all hope is lost. There remains a chance for the module to charge its batteries and continue operations.

The SLIM module touched down on the Moon at a speed of 1.4 m/s, well within the acceptable range. The landing was executed smoothly even with only one of the two engines functioning. This achievement makes Japan the fifth country in the history of space exploration to successfully land a descent vehicle on our satellite. However, due to the failure of one engine and deviation in the module's horizontal orientation, a significant lateral speed resulted in the module tipping over.

The SLIM module flipped upside down, more precisely, it landed on its head. Unfortunately, the solar panels ended up fully turned away from the Sun. This was the most unfavorable scenario, and it happened purely by chance. There is hope that the Sun will gradually move, allowing its rays to illuminate the back of the module, where the solar panels are rigidly attached.

The module landed on the lunar surface at 00:20 local Tokyo time. Power to the systems was cut at 00:57 when telemetry data and camera images were captured. Further draining of the limited battery resources was not possible. The mission team reserved some energy for potential equipment reboot if the battery charge is restored.

Another objective of the SLIM mission was to land with a deviation of no more than 100 meters from the target point. Although data is still being refined, the module successfully accomplished the task by deviating approximately 55 meters from the target point. A more precise estimation of the deviation will be available later.

All scientific equipment on the module was operational, at least as long as it remained connected to power. During its operation, the multi-beam camera's low-resolution optics (MBC) were activated, and even in an inverted position, it traversed the lunar surface, identifying targets for subsequent scanning by the high-resolution spectral camera. In case power is restored, the equipment can thoroughly study interesting objects.

Additionally, the successful deployment of two miniature probes, LEV-1 and LEV-2, was achieved. The latter, created in collaboration with Sony in the form of a ball that splits into two halves, captured a side-view image of the landing module. Expectations are for further updates, as JAXA promises to keep everyone informed of all events, especially considering the uncertainty regarding the failure of one of the engines.