# The Moon is a harsh mistress \[Beresheet failure\] **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [April 11, 2019, 9:02pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405 "2019-04-11T21:02:36Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![N9IWP](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/n9iwp/32/3154_2.png) [@N9IWP](https://boards.straightdope.com/u/N9IWP)\ **Post date:** [April 11, 2019, 9:02pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/1 "2019-04-11T21:02:36Z")
The first private attempt of a soft landing on the moon made a much harder impact. They successfully got the lander in orbit and things were going well until the main engine had issues (I 3watched teh webcast but I’m not 100% sure of the timeline. i think they lost/regained telemetry before the engine issue) They managed to restart thge main engine but it was too little too late > **[A private spacecraft from Israel crashed into the Moon Thursday \[Updated\]](https://arstechnica.com/science/2019/04/a-private-spacecraft-from-israel-will-attempt-a-moon-landing-thursday/)** > > No private company has ever achieved what SpaceIL is trying to do. I do hope we get a detailed analysis. Ad Astra per Aspera, Brian ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [April 11, 2019, 9:11pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/2 "2019-04-11T21:11:15Z")
The engine failed and the lander crashed, or did the engine explode at altitude? ---
**Author:** ![N9IWP](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/n9iwp/32/3154_2.png) [@N9IWP](https://boards.straightdope.com/u/N9IWP)\ **Post date:** [April 11, 2019, 9:18pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/3 "2019-04-11T21:18:44Z")
> [@Jason Davis](#): > > After what appeared to be a flawless initial descent, mission controllers announced Beresheet had a problem with its main engine. Real-time telemetry provided by SpaceIL showed the spacecraft was descending too quickly for its low altitude, and though the team was eventually able to restart the engine, it was too late. > **[Beresheet Comes Close before Crashing on the Moon](https://www.planetary.org/articles/beresheet-comes-close-crashes)** > > Mission controllers announced Beresheet had a problem with its main engine, and the spacecraft stopped transmitting shortly thereafter. Brian ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [April 11, 2019, 9:32pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/4 "2019-04-11T21:32:35Z")
It’s frustrating that so much of the mission was successful, and it apparently failed due to one glitch in the final moments, causing it to impact the moon at nearly 300 mph. After the failure of the ESA Mars lander a few years ago, it makes one appreciative of the marvelous things that NASA has done successfully. To be fair, enormous budgets are helpful. Even the “cheap” New Horizons mission cost $700-$900 million depending on who you believe, and the Curiosity rover cost $2.5-$2.8 billion. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 11, 2019, 9:38pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/5 "2019-04-11T21:38:42Z")
That’s Hebrew for “In the beginning”, right? ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [April 11, 2019, 9:41pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/6 "2019-04-11T21:41:17Z")
> [@Chronos](#): > > That’s Hebrew for “In the beginning”, right? That’s what it means. (It is the first word of “Genesis”) ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [April 11, 2019, 9:50pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/7 "2019-04-11T21:50:09Z")
Of course now they’ll have to rename it “Ohsheet.” ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [April 11, 2019, 9:57pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/8 "2019-04-11T21:57:06Z")
Apparently they [already had a contract](https://spacenews.com/iai-to-partner-with-ohb-on-lunar-delivery-services/). Not sure if that is permanently scuttled now, or if a deal is a deal? ---
**Author:** ![VOW](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/vow/32/3043_2.png) [@VOW](https://boards.straightdope.com/u/VOW)\ **Post date:** [April 11, 2019, 9:58pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/9 "2019-04-11T21:58:48Z")
^ +1 (to **Darren Garrison** ) (that was really good!) ~VOW ---
**Author:** ![MEBuckner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mebuckner/32/2896_2.png) [@MEBuckner](https://boards.straightdope.com/u/MEBuckner)\ **Post date:** [April 11, 2019, 10:17pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/10 "2019-04-11T22:17:24Z")
Well, dang. Sorry to hear about that, Israeli people! Yet Another Reminder of why “rocket science” has entered the lexicon to mean “complicated and really hard to do”. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [April 11, 2019, 11:27pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/11 "2019-04-11T23:27:49Z")
> [@wolfpup](#): > > After the failure of the ESA Mars lander a few years ago, it makes one appreciative of the marvelous things that NASA has done successfully. NASA has had some spectacular failures. I recall hearing once that only half of attempted Mars missions make it, whether to orbit or landing, and that’s inclusive of everyone who’s ever tried it. NASA had a spaceship catch fire on the ground and kill three people (Apollo 1), two space shuttles that came to grief, and its share of crashed probes and the like. The USSR had its share of failures, too. Space is HARD. The folks behind this mission should be applauded - successfully getting to Moon orbit is an achievement. I hope they try again. ---
**Author:** ![N9IWP](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/n9iwp/32/3154_2.png) [@N9IWP](https://boards.straightdope.com/u/N9IWP)\ **Post date:** [April 12, 2019, 3:55am UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/12 "2019-04-12T03:55:34Z")
From my Hebrew speaking/reading friend: The Hebrew language publications are writing that the initial analysis points to a failure of one of the accelerometers (IMU2), which seems to have provided incorrect data and caused the main engine to turn off prematurely. At an altitude of 150 m the spacecraft was still doing 150 m/s or 335 mph. They’re also noting that at such a high speed, the spacecraft likely created an impact crater 3 to 5 m in diameter, which means it should be visible from a lunar orbiter. Perhaps we will see a photo soon of the crash site. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [April 12, 2019, 4:20am UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/13 "2019-04-12T04:20:06Z")
Why would a single accelerometer be critical? Weren’t there at least a couple more? And couldn’t you derive your acceleration from the radar altitude, for instance, in a fail-safe situation in which less data than normal is available to estimate your system state (shutting down your engine way up high does not seem like optimal control in any case, even if you lose all instruments and have to extrapolate from your last known position and velocity). ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [April 12, 2019, 7:01am UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/14 "2019-04-12T07:01:37Z")
> [@MEBuckner](#): > > Well, dang. Sorry to hear about that, Israeli people! Thanks. It was not a fun experience, watching it live last night with my family. My son - who’s into space - was crying a bit, and I needed a few shots of bourbon myself to avoid joining him. Oh well. We’ll do better next time. ---
**Author:** ![MEBuckner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mebuckner/32/2896_2.png) [@MEBuckner](https://boards.straightdope.com/u/MEBuckner)\ **Post date:** [April 12, 2019, 7:31am UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/15 "2019-04-12T07:31:18Z")
> [@Alessan](#): > > Thanks. It was not a fun experience, watching it live last night with my family. My son - who’s into space - was crying a bit, and I needed a few shots of bourbon myself to avoid joining him. Oh well. > > We’ll do better next time. The US and the USSR had [a _lot_ of failures before any of us succeeded](https://en.wikipedia.org/wiki/List_of_missions_to_the_Moon#Missions_to_date). And neither the Soviets nor the Americans even _tried_ to land things on the Moon until they had perfected the art of crashing things into the Moon. Including [attempts to crash into the Moon, that wound up missing the entire Moon](https://en.wikipedia.org/wiki/Luna_1). ---
**Author:** ![Methyl\_Ethyl\_Death](https://avatars.discourse-cdn.com/v4/letter/m/b4bc9f/32.png) [@Methyl\_Ethyl\_Death](https://boards.straightdope.com/u/Methyl_Ethyl_Death)\ **Post date:** [April 12, 2019, 5:11pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/16 "2019-04-12T17:11:05Z")
> [@MEBuckner](#): > > Well, dang. Sorry to hear about that, Israeli people! > > Yet Another Reminder of why “rocket science” has entered the lexicon to mean “complicated and really hard to do”. Dammit, Smithers, this isn’t rocket science, it’s brain surgery. Now hand me that ice cream scoop. ---
**Author:** ![Malleus\_Incus\_Stapes](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/malleus_incus_stapes/32/3293_2.png) [@Malleus\_Incus\_Stapes](https://boards.straightdope.com/u/Malleus_Incus_Stapes)\ **Post date:** [April 12, 2019, 5:25pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/17 "2019-04-12T17:25:49Z")
Wisdom from my brother: Beresheet is a fitting name, because you always make mistakes in the beginning. Hopefully, the next one will go better. ---
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [April 12, 2019, 5:41pm UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/18 "2019-04-12T17:41:42Z")
> [@MEBuckner](#): > > The US and the USSR had [a _lot_ of failures before any of us succeeded](https://en.wikipedia.org/wiki/List_of_missions_to_the_Moon#Missions_to_date). And neither the Soviets nor the Americans even _tried_ to land things on the Moon until they had perfected the art of crashing things into the Moon. Including [attempts to crash into the Moon, that wound up missing the entire Moon](https://en.wikipedia.org/wiki/Luna_1). Pretty good pep talk, actually. The Beresheet people just need to retroactively define this as a “crash it into the moon” mission that almost failed into a “soft landing on the moon”. ---
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [April 13, 2019, 2:55am UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/19 "2019-04-13T02:55:38Z")
> [@N9IWP](#): > > From my Hebrew speaking/reading friend: > > The Hebrew language publications are writing that the initial analysis points to a failure of one of the accelerometers (IMU2), which seems to have provided incorrect data and caused the main engine to turn off prematurely. > > At an altitude of 150 m the spacecraft was still doing 150 m/s or 335 mph. > > They’re also noting that at such a high speed, the spacecraft likely created an impact crater 3 to 5 m in diameter, which means it should be visible from a lunar orbiter. Perhaps we will see a photo soon of the crash site. This is not the [first spacecraft named “Genesis”](https://en.wikipedia.org/wiki/Genesis_(spacecraft)) that had landing problems because of accelerometers: > [@Wikipedia](#): > > Due to a design flaw in a **deceleration sensor,** parachute deployment was never triggered, and the spacecraft’s descent was slowed only by its own air resistance. The planned mid-air retrieval could not be carried out, and the \*\*capsule crashed into the desert floor of the Dugway Proving Ground in Tooele County, Utah, at about 86 meters per second \*\*(311 km/h (193 mph)). ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [April 13, 2019, 5:01am UTC](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405/20 "2019-04-13T05:01:38Z")
In space flight, expecting engines, guidance, and communication systems to perform absolutely perfectly is a fantasy. (While it was a complicated chain of events, the recent airplane disaster illustrates all too well the dangers of automated systems relying on single sensors.) I understand that the point of this lunar lander demonstrator was to be as cheap as possible, but the technology was intended to deliver future scientific payloads to the moon’s surface, and in that case you absolutely need procedures to recover, to the extent possible, from various systems failures. I wonder if the recent failure was due to something as simple as a programming error? Even outside of amateur hour, plenty of space vehicles have been lost that way (Climate Orbiter, Ariane, Mariner, etc) and the procedures to minimize such risks are not trivial. Since the namers of this spacecraft insist on Biblical references: “And they said, Go to, let us build us a city and a tower, whose top may reach unto heaven; and let us make us a name, lest we be scattered abroad upon the face of the whole earth. And the Lord came down to see the city and the tower, which the children of men builded. And the Lord said, Behold, the people is one, and they have all one language; and this they begin to do: and now nothing will be restrained from them, which they have imagined to do. Go to, let us go down, and there confound their language, that they may not understand one another’s speech. So the Lord scattered them abroad from thence upon the face of all the earth: and they left off to build the city.” [Next page](https://boards.straightdope.com/t/the-moon-is-a-harsh-mistress-beresheet-failure/832405.md?page=2)