bolyongó

User Tools

Site Tools

Trace: • talatan_pv_park • mco
en:passport:mco

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

en:passport:mco [2026/07/16 11:10] – Automatic translation vamsanen:passport:mco [2026/07/16 21:53] (current) – vamsan
Line 1: Line 1:
 ====== The tragic failure of the Mars Climate Orbiter (MCO) programme ====== ====== The tragic failure of the Mars Climate Orbiter (MCO) programme ======
  
-In September 1999, after a journey to Mars lasting nearly 10 months, the Mars Climate Orbiter broke up and burned up in the Martian atmosphere. On a day when NASA engineers and onlookers were preparing to celebrate, champagne in hand and holding their breath. +In September 1999, after a journey to Mars lasting nearly 10 months, the Mars Climate Orbiter broke up and burned up in the Martian atmosphere. On a day when NASA engineers and onlookers were preparing to celebrate, with champagne in hand and holding their breath. 
  
 Reality on Earth, however, dealt a harsh blow; the rush and cost-cutting had not paid off, and above all, the banal fact that one part of the design team had used the metric system whilst the other had used imperial units for their work, and this //"forgot"// to discuss this with one another.  Reality on Earth, however, dealt a harsh blow; the rush and cost-cutting had not paid off, and above all, the banal fact that one part of the design team had used the metric system whilst the other had used imperial units for their work, and this //"forgot"// to discuss this with one another. 
Line 14: Line 14:
 The Mars Climate Orbiter’s (MCO) journey to Mars took a total of 286 days, or approximately nine and a half months. The probe was placed into a so-called Type 2 orbit, which meant that it travelled more than 180 degrees around the Sun before reaching Mars; this allowed for a slower arrival velocity, as the Sun’s gravity slowed the spacecraft down.  The Mars Climate Orbiter’s (MCO) journey to Mars took a total of 286 days, or approximately nine and a half months. The probe was placed into a so-called Type 2 orbit, which meant that it travelled more than 180 degrees around the Sun before reaching Mars; this allowed for a slower arrival velocity, as the Sun’s gravity slowed the spacecraft down. 
  
-Subsequent analyses revealed that a navigation error occurred during every single orbit correction and during the minor thruster firings used to maintain the probe’s stability. As these were minor deviations individually, they did not appear critical during the daily routine, but they accumulated over the course of the nine-month journey, resulting in a deviation of 170 kilometres. Members of the navigation team noticed during the journey that the probe’s orbit was not exactly where it should have been. They did raise their concerns with their superiors, but as the reports were not submitted in accordance with official protocol, management did not attach much importance to them, and no substantive action was taken.+Subsequent analyses revealed that a navigation error occurred during every single orbit correction and during the minor thruster firings used to maintain the probe’s stability. As these were minor deviations individually, they did not appear critical during the daily routine, but they accumulated over the course of the nine-month journey, resulting in a deviation of 170 kilometres. Members of the navigation team noticed during the journey that the probe’s orbit was not exactly where it should have been. They raised their concerns with their superiors, but because the reports were not submitted in accordance with official protocol, management did not attach much importance to them, and no substantive action was taken.
  
 The mission was based on the **“Faster, Better, Cheaper”** (//faster, better, cheaper//), which led to the teams being overburdened, communication being patchy, and several important checks simply being omitted or rushed.  By the time the engineers calculated, 24 hours before arrival, that the probe’s altitude was critical (just 57–110 km instead of the planned 226 km), it was already too late to adjust the trajectory. The mission was based on the **“Faster, Better, Cheaper”** (//faster, better, cheaper//), which led to the teams being overburdened, communication being patchy, and several important checks simply being omitted or rushed.  By the time the engineers calculated, 24 hours before arrival, that the probe’s altitude was critical (just 57–110 km instead of the planned 226 km), it was already too late to adjust the trajectory.
Line 27: Line 27:
  
 ==== MPL ==== ==== MPL ====
-The **Mars Polar Lander (MPL)** reached Mars on 3 December 1999, but it too vanished without trace during the landing manoeuvre, and contact with it was never re-established. This was the second major loss for the **Mars Surveyor ’98** programme, following the failure of the Mars Climate Orbiter. +The **Mars Polar Lander (MPL)** reached Mars on 3 December 1999, but it too vanished without a trace during the landing manoeuvre, and contact with it was never re-established. This was the second major loss for the **Mars Surveyor ’98** programme, following the failure of the Mars Climate Orbiter. 
  
 {{ passport:mco_2.png |Mars Polar Lander (MPL)}} {{ passport:mco_2.png |Mars Polar Lander (MPL)}}
  
-The most likely scenario in this case was a software fault. When the probe deployed its landing legs during descent, the resulting vibration was mistakenly interpreted by the on-board computer as the vehicle having already touched down. As a result of this false signal, the software shut down the braking rockets whilst the probe was still at an altitude of approximately 40 metres. The probe thus crashed into the surface in free fall and was destroyed.+The most likely scenario in this case was a software fault. When the probe deployed its landing legs during descent, the resulting vibration was mistakenly interpreted by the onboard computer as the vehicle having already touched down. As a result of this false signal, the software shut down the braking rockets whilst the probe was still at an altitude of approximately 40 metres. The probe thus crashed into the surface in free fall and was destroyed.
  
 ==== Investigations ==== ==== Investigations ====
-The investigation was carried out by three independent groups: Firstly, the Jet Propulsion Laboratory (JPL) conducted its own internal investigation, which had already identified the probable cause of the fault by 30 September 1999. NASA also set up an independent investigation committee, led by Arthur G. Stephenson, then director of the Marshall Space Flight Centre.  A group comprising external experts and JPL staff was formed to investigate system-level faults. +The investigation was carried out by three independent groups: Firstly, the Jet Propulsion Laboratory (JPL) conducted its own internal investigation, which had already identified the probable cause of the fault by 30 September 1999. NASA also established an independent investigation committee, led by Arthur G. Stephenson, then the director of the Marshall Space Flight Centre.  A group comprising external experts and JPL staff was formed to investigate system-level faults. 
 The committee published its first report (Phase I) on 10 November 1999, in which it concluded the following:   The committee published its first report (Phase I) on 10 November 1999, in which it concluded the following:  
 Metric units were not used consistently when coding the software file named ‘Small Forces’. Lockheed Martin provided the acceleration data in imperial units (ft/s²), whilst JPL’s navigation software expected metric values (m/s²). In other words, one team used metric units whilst the other used imperial units, and this //"forgot"// to coordinate with one another. This rather trivial error led to the destruction of the probe, which was worth 327.6 million dollars (610–630 million dollars at today’s value). Metric units were not used consistently when coding the software file named ‘Small Forces’. Lockheed Martin provided the acceleration data in imperial units (ft/s²), whilst JPL’s navigation software expected metric values (m/s²). In other words, one team used metric units whilst the other used imperial units, and this //"forgot"// to coordinate with one another. This rather trivial error led to the destruction of the probe, which was worth 327.6 million dollars (610–630 million dollars at today’s value).
Line 50: Line 50:
 Following the twin failures (MCO and Polar Lander), NASA suspended its Mars missions for two years in order to rebuild the programme from the ground up, which ultimately led to the highly successful Mars Odyssey and Mars Exploration Rovers (Spirit and Opportunity) missions. Following the twin failures (MCO and Polar Lander), NASA suspended its Mars missions for two years in order to rebuild the programme from the ground up, which ultimately led to the highly successful Mars Odyssey and Mars Exploration Rovers (Spirit and Opportunity) missions.
  
-{{page>passport:great_bugs}}+{{page>en:passport:utolso_bejegyzesek}}
  
-{{page>passport:lablec}}+{{page>en:passport:lablec}}
  
 ===== Sources ===== ===== Sources =====
Line 61: Line 61:
 Wikipedia: [[https://en.wikipedia.org/wiki/Mars_Climate_Orbiter|Mars Climate Orbiter]] Wikipedia: [[https://en.wikipedia.org/wiki/Mars_Climate_Orbiter|Mars Climate Orbiter]]
  
-===== Recommended ===== 
-Similar posts can be found on **‘Interesting Stories’** tag: {{topic>érdekes_történet&nodate&nouser}} 
  
-{{tag>2026 MCO Mars_Climate_Orbiter érdekes_történet tech USA NASA Lockheed_Martin_Astronautics 1999 Faster,_Better,_Cheaper Mars_Polar_Lander MPL Jet_Propulsion_Laboratory JPL Small_Forces end-to-end_test Dan_Goldin }}+{{tag>2026 MCO Mars_Climate_Orbiter tech USA NASA Lockheed_Martin_Astronautics 1999 Faster,_Better,_Cheaper Mars_Polar_Lander MPL Jet_Propulsion_Laboratory JPL Small_Forces end-to-end_test Dan_Goldin }}
  
 ~~NOCACHE~~ ~~NOCACHE~~
-Number of post views: {{passport:counter|total}}+Number of post views: {{counter|total}}
  
en/passport/mco.txt · Last modified: by vamsan