The real enigma is why several dishes reported signals for 5 minutes after landing.
Quote from: Svetoslav on 04/25/2023 07:39 pmThe real enigma is why several dishes reported signals for 5 minutes after landing.I may well be wrong, but to me the lander seemed a bit behind their published timeline. So were the signals after the actual landing time?
which signals, from which dishes, reported where?
Status Update on ispace HAKUTO-R Mission 1 Lunar Lander26 Apr, 2023TOKYO—April 26, 2023—ispace, inc., (ispace) a global lunar exploration company, issued an update on the status of the HAKUTO-R Mission 1 Lunar Lander.The HAKUTO-R Mission 1 Lunar Lander was scheduled to touchdown on the surface of the Moon at approximately 1:40 a.m. JST. As of 8:00 a.m. JST, April 26, 2023, the communication between the lander and the Mission Control Center was lost, although it was expected even after the touchdown, and it has been determined that Success 9 of the Mission Milestones is not achievable.Based on the currently available data, the HAKUTO-R Mission Control Center in Nihonbashi, Tokyo, confirmed that the lander was in a vertical position as it carried out the final approach to the lunar surface. Shortly after the scheduled landing time, no data was received indicating a touchdown. ispace engineers monitored the estimated remaining propellant reached at the lower threshold and shortly afterward the descent speed rapidly increased. After that, the communication loss happened. Based on this, it has been determined that there is a high probability that the lander eventually made a hard landing on the Moon’s surface.To find the root cause of this situation, ispace engineers are currently working on a detailed analysis of the telemetry date acquired until the end of landing sequence and will clarify the details after completing the analysis.For Mission 1, it has been determined that Success 9 of the Mission 1 Milestones, successfully landing on the Moon and establishing communications, is no longer achievable. Despite this, the mission has already achieved Success 1 through Success 8. In addition, while attempting the completion of Success 9, the Mission Control Center was able to acquire valuable data and know-how from the beginning to nearly the end of the landing sequence, which will enable a future successful lunar landing mission. It is strongly believed that this is a great leap forward to future lunar exploration and an important milestone to advance space development by the private sector toward the next level not only in Japan but also the world.ispace will continue to make the most of the data and know-how acquired during the operation and landing sequence through Success 8, aiming to dramatically improve the technological maturity of Mission 2 in 2024 and Mission 3 in 2025.“Although we do not expect to complete the lunar landing at this time, we believe that we have fully accomplished the significance of this mission, having acquired a great deal of data and experience by being able to execute the landing phase. What is important is to feed this knowledge and learning back to Mission 2 and beyond so that we can make the most of this experience,” said Takeshi Hakamada, Founder and CEO of ispace. “To this end, we are already developing Mission 2 and Mission 3 concurrently and have prepared a foundation that can maintain this continuity. I would like to thank once again all the employees who have contributed to this mission from its inception to the present, all the families who have continued to support it, and all the shareholders, HAKUTO-R partners, customers, suppliers, and many others who have continued to believe in ispace’s vision. We will keep moving forward.”“Today, ispace’s HAKUTO-R” Mission 1 became the first private company to attempt to land on the Moon, but unfortunately, the landing could not be realized, said Hiroshi Yamakawa, President of the Japan Aerospace Exploration Agency (JAXA). “As a fellow Japanese space enthusiast, I am proud of ispace’s challenge and respect the efforts of everyone involved. ispace will analyze the data obtained from this mission and use it as a foundation for the next mission. JAXA will continue to make steady progress together with ispace, the industry and organizations challenging space, and our international partners, and will contribute not only to space exploration activities but also to the sustainable development of human society.”“The Mission underpins the successful cooperation between ESA and ispace. Such collaboration schemes between new space companies and space agencies open up exciting opportunities for the future of lunar exploration and other domains. Accounting for new space approaches is also a central element of ESA’s agenda 2025. I’m convinced that the HAKUTO-R Mission 1 is only the beginning of many fascinating projects and activities to come,” said Josef Aschbacher, Director General of the European Space Agency.“ispace has already accomplished a tremendous feat by entering lunar orbit and attempting a fist landing. What they are trying to do is so complex and at the cutting edge of technology that success is not guaranteed at the first attempt. The experience and unique expertise gained by the team will help make the next mission a success,” said Marin Sion, CEO of ArianeGroup.Draper released the following statement: “The historic maiden commercial mission of ispace inc.’s M1 HAKUTO-R achieved numerous significant first-time achievements, but ultimately fell short of its goal of landing safely on the Moon. M1 HAKUTO-R experienced an anomaly, ending the mission prematurely. Though the mission did not achieve its ultimate goal, by successfully reaching cislunar space and orbiting the Moon, the mission represents an important step forward for the international space economy. Draper serves on ispace’s team for the M1 HAKUTO-R mission and will collaborate on missions M2 and M3. We look forward to our ongoing partnership with ispace, both now and in the future.”
From the press conference on Wednesday it looks like the onboard navigation systems didn't trust the altimeter measurements enough, which is weird. There is no question a mission like this must use an altimeter, because the altimeter measurements are by far the best indication of height. There is something quite wrong with the navigation if it was not relying on those measurements and fully aligning its own altitude estimates with the altimeter measurements (there is some art in this, because while altimeter measurements are critical for a safe landing, there is a lot of topography in certain areas so the data is highly variable for a while and must be used with care...). In the press conference they refer to being at negative altitudes for a bit before the fuel was completely expended (and radiotelescopes also indicate near-zero Doppler rates - stationary flight - for a bit, followed by lunar gravity-like acceleration, then chaos and an end to the incoming signal), but why was there even one negative altitude estimate? Clearly radar measurements cannot be negative...
There has been additional information given out at ispace's press conference in Tokyo earlier today, here are some snippets that I was able to pick out (as much as I could), plus personal speculations:https://twitter.com/Cosmic_Penguin/status/1651094438524096513
Quote from: Xentry on 04/28/2023 08:56 amFrom the press conference on Wednesday it looks like the onboard navigation systems didn't trust the altimeter measurements enough, which is weird. There is no question a mission like this must use an altimeter, because the altimeter measurements are by far the best indication of height. There is something quite wrong with the navigation if it was not relying on those measurements and fully aligning its own altitude estimates with the altimeter measurements (there is some art in this, because while altimeter measurements are critical for a safe landing, there is a lot of topography in certain areas so the data is highly variable for a while and must be used with care...). In the press conference they refer to being at negative altitudes for a bit before the fuel was completely expended (and radiotelescopes also indicate near-zero Doppler rates - stationary flight - for a bit, followed by lunar gravity-like acceleration, then chaos and an end to the incoming signal), but why was there even one negative altitude estimate? Clearly radar measurements cannot be negative...This sounds like Schiaparelli-like mode.Back in 2016 Schiaparelli crashed on Mars due to negative values - they actually showed like the lander is under the surface. The computer turned off the engines while still high in the air.
We would like to express our gratitude for the many messages of support and encouragement that we have received following our lunar landing attempt. It means a lot to have such a wonderful, global community cheering us on and believing in our vision. (1/2)#ispace #HAKUTO_R
We are proud of our team's contributions toward all that we accomplished during M1. Our commitment to the world is to make the most of the data and know-how acquired during M1, and we will keep moving forward toward Missions 2, 3, and beyond. Never Quit the #lunarquest! (2/2)
Is there nothing like a squat switch on the legs as a fail-safe to prevent engine shutdown while still at altitude?
NEW: Japan’s ispace to share details on what happened during its Hakuto-R Mission 1 lunar landing failure on May 26, 9am, in an online media briefing.
9am ET
Analysis of HAKUTO-R Spacecraft Landing on the Moon https://amsat-dl.org/en/analysis-of-hakuto-r-spacecraft-landing-on-the-moon-2023-apr-25/ — The @ispace_inc #HAKUTO_R M1 spacecraft mission was planned to land on Earth’s Moon in or near Atlas crater at 2023-04-25 16:40 utc. But the HAKUTO-R M1 signal ceased abruptly at 16:45:09 utc, and it was immediately clear that the spacecraft had not landed as planned. The final of doppler shift profile indicated free fall, followed by a destructive landing on the Moon.Thanks to Iban Cardona @eb3frn, Daniel Estévez @ea4gpz, Peter Gülzow @amsatdl, Edgar Kaiser @df2mz , James Miller G3RUH and @SternwarteBO for this detailed and time consuming report, which demonstrates what amateur observers are able to do.
