Hakuto-R lunar lander crash was caused by computer software design error

by | May 30, 2023 | exploration, Reliability Info

I-Space (Japan) has reported the results of its investigation into the landing failure of its HAKUTO M1 lunar lander on 25 April 2023.

At 1533 GMT the Hakuto M1 Lunar lander moved to a 25 x 100 km orbit and at perilune around 1627 GMT it began a braking burn to descend towards crater Atlas Unfortunately, the lunar lander Hakuto-R (with RASHID and SORA-Q lunar rovers aboard) crashed on the surface of its destination after communication with the Japanese spacecraft was lost just moments before its planned touchdown at around 1640 GMT on 25 April 2023. It is thought that the spacecraft fell to the lunar surface in an unpowered fall.  Initial indications were that the spacecraft had run out of propellants.  However, the true cause was software design.

How the Hakuto-R landing should have taken place. Courtesy: iSpace via Twitter

As the spacecraft crossed a rim of the Atlas crater within which it was supposed to land, the altitude was measured by a laser rangefinder and the relatively low clearance height made the software believe that a landing was imminent.  But as the lander moved away from the rim, the laser rangefinder then showed the altitude as rising suddenly by 3 km  This sudden change was unexpected by the software and it was programmed to regard the rangefinder as faulty. The result was that as the flight continued under inertial measurements without further accurate altitude readings, the lander’s control system, using the rim altitude reading and the landing plan, thought that a landing had either happened or was imminent while it was actually still at 5 km above the surface. Thus, in thinking that it was about to land, the spacecraft’s control system set it to only descend slowly at about 1 m/s, using up its propellant as it went.  In the end, it ran out of propellant with its still at a high altitude and it fell onto the lunar surface crashing into it at a velocity of above 100 m/s.

The software was designed by the US firm Draper with modifications/specifications being made by the I-Space team who take the blame.  The failure is thought to be partly attributable to the change of landing zone from a flat plain area in Lacus Somniorum, to one inside the Atlas crater.

 

 

 

About Seradata

Seradata produces the renowned Seradata database. Trusted by over 100 of the world’s leading Space organisations, Seradata is a fully queryable database used for market analysis, failure/risk assessment, spectrum analysis and space situational awareness (SSA).

For more information go to https://www.seradata.com/product/

Related Articles

Categories

Archives

Tags

nasaspacexecoreviewsissesaArianespacevideochinaFalcon 9v1.2FT Block 525virgin galacticULAfalcon 9RoscosmosevaspacewalkDGAaviation weekInternational Space StationaressoyuzIGTRocket LabBlue OriginBeidouawardsStarlinkspaceSatellite broadcastingAirbus DSrussiaboeingmoonOneWebCargo Return VehicleISROmarsblogresearchspaceshiptwojaxaorionmarsimpactdelayhyperbolaEutelsatdemocratrocketlunarhypertextobamagoogle lunar prizelaunchVegaSESthales alenia spacetourismbarack obamaconstellationfiguresnorthspaceflightIntelsatnode 2fundedRaymond Lygo2009Lockheed MartinExpress MD-2Elon MuskAtlas Vromess2dassault aviationaviationLucy2008wk2sstlukradiosuborbitaltestmissiledocking portexplorationAriane 5 ECAVirgin OrbitinternetLong March 2D/2sts-122ElectronSLSChina Manned Space EngineeringAriane 5Northrop Grummanmissile defensenewspapercotsgalileospace tourismflight2010Long March 4CspaceportExpress AMU 1buildspace stationaltairsoyuz 2-1aProton Minternational astronautical congressshuttlespace shuttlescaled compositesIntelsat 23European Space AgencyLauncherOneCosmosnew yorkrulesAriane 6hanleybudgetatvVietnamshenzhoucongressMojaveboldennew shepardLong March 2CInmarsatOrbital ATKcnesiaclunar landerGuiana Space CenterkscApollolawsUS Air ForceSpace Systems/LoralUK Space AgencyLong March 4BKuaizhou 1AILSdarpaprotonTalulah RileyElectron KSFalcon 9v1.2 Block 5Vega CNorth KoreaeuAstriumSkylonpicturebaseusaastronautdragonlanderfiveeventTelesatSSLAprilSNC50thinterviewLong MarchSea LaunchfalconWednesdaycustomerlinkatlantissuccessor

Stay Informed with Seradata

Stay informed on the latest news, insights, and more from Seradata by signing up for our newsletter.