The reason for the failure of mankind’s first commercial moon landing was announced: the altitude calculation error was exhausted, the fuel was exhausted and the crash was provided by the Financial Associated Press

News from the Financial Associated Press on May 27 (edited by Shi Zhengcheng)On Friday night local time, the Japanese listed company ispace held a press conference to announce the investigation report on the disappearance of Hakuto-R (White Rabbit-R) in the final stage of landing on the moon last month.

As the first private company on Earth to deliver a payload to the moon, ispace’s lander launched aboard a SpaceX Falcon 9 rocket last December. After a five-month journey, in the early morning of April 26, Beijing time, he finally entered the final step of the plan-landing on the moon.

(Source: Live broadcast) But after the on-site data showed that the lander had reached the lunar surface, ispace did not announce the success of the mission. In the end, the company confirmed that the lander was out of contact, and it was speculated that the landing had failed.

Today’s press conference is to explain what happened at the last moment of the mission.

(Source: ispace) ispace said that according to the analysis of the navigation data, the lander successfully descended from a position of 100 kilometers from the lunar surface at the beginning, and successfully reduced the speed to within 1 m/s during the nearly one-hour descent. , as expected until this step.

But something unexpected happened to the lander’s altitude measurements during the final phase.Afterwards, it was found that when the data showed that the altitude was zero, the lander was actually 5 kilometers away from the surface of the moon. Therefore, after the scheduled landing time is reached, the lander continues to descend at a low speed until the propulsion system runs out of fuel. Then the lander lost control and it can be inferred that it hit the surface of the moon in free fall.

By further exploring the data, the researchers found that during the descent of the lander to the intended landing site, it passed a cliff (the edge of the crater) about 3 kilometers high, which caused the height measured by the onboard sensor to rise sharply, which was different from the previous design. There is a relatively large discrepancy between the given estimated altitude values.The on-board software incorrectly determined that the discrepancy was due to an anomaly reported by the sensor, which in turn intercepted the sensor’s data.The original intention of this function design is to ensure that the aircraft can continue to operate in the event of a sensor failure.

NASA also announced this week that it had photographed the wreckage of the lander scattered all over the place near the planned landing site of the White Rabbit-R through the lunar exploration satellite in orbit.

(Comparison before and after the landing site, source: NASA Moon) At the press conference on Friday, Ryo Ujiie, chief technology officer of ispace, told reporters that part of the software failure should be attributed to mission parameters and other settings. It is reported that this set of software is provided by Draper, an American space software developer. Shi Jialiang revealed at the same time,Company changes planned landing site seven months before moon landing. Shi Jialiang said: “If we don’t change the landing point, we may succeed this time, but this is just a hypothesis.”

fight again next year

The final investigation report is not all bad news, at least it proves that the lander can withstand a series of challenges before landing on the moon.

ispace CEO Takeshi Hakamada said: “The first mission demonstrated a lot of technical reliability, and the lander actually came very close to the lunar surface.Now we have also identified issues with the login process and have a very clear idea of ​​how to improve. “

ispace’s next moon landing is expected to take place in 2024. According to the current plan, starting from 2025, ispace will cooperate with Draper to send NASA materials to the moon, realizing the plan of establishing a “permanent lunar base” by 2040.

Before the lander arrived on the moon, ispace also completed its own IPO in April. Stimulated by the concept of landing on the moon, the stock price once soared 9 times to 2373 yen, but fell to 800 yen after the lander lost contact. , and has doubled since then.

(ispace daily chart, source: TradingView)