| Recurring |
one_organization, multiple_organization |
(a) The software failure incident related to the Mars Climate Orbiter burning up in the Martian atmosphere due to a unit conversion error has happened again within the same organization. The article mentions that the Mars Polar Lander, which launched 23 days after the Mars Climate Orbiter, also disappeared on the way to the planet's surface due to a different reason, but with the underlying issue of overly ambitious projects within NASA [3508].
(b) The software failure incident related to spacecraft failures due to various reasons, including landing issues, has occurred at multiple organizations. The article mentions failures of Soviet missions such as Mars 1962B, Mars 2, Mars 3, Mars 6, Mars 7, and Mars 96, where landers failed to land successfully or lost contact with the probes [48591]. |
| Phase (Design/Operation) |
design, operation |
(a) The software failure incident related to the design phase is evident in the case of the Mars Climate Orbiter [3508]. The failure occurred because engineers failed to convert units from English to metric during the development phase. The software controlling the orbiter's thrusters calculated the force in pounds instead of newtons, leading to a miscalculation that ultimately caused the orbiter to burn up in the Martian atmosphere.
(b) The software failure incident related to the operation phase is seen in the case of the Mars Polar Lander [48591]. Mission controllers lost contact with the spacecraft, and it was later concluded that the lander had shut down its engine too early when it unfolded its legs, leading to its destruction on impact. This failure was attributed to the operation or misuse of the system during the landing phase. |
| Boundary (Internal/External) |
within_system, outside_system |
(a) The software failure incident related to the Mars Climate Orbiter was within the system. The failure was attributed to a software issue where the software controlling the orbiter's thrusters calculated the force in pounds instead of metric newtons, leading to a miscalculation in the thruster force [3508, 48591]. This internal software error ultimately caused the orbiter to burn up in the Martian atmosphere.
(b) The software failure incident was also influenced by factors outside the system. The underlying issue in the culture of NASA's space exploration at the time, characterized by the mantra of "better, faster, cheaper," played a role in the failure. This ambitious approach to space missions may have contributed to overlooking critical checks and conversions in the software development process [3508]. |
| Nature (Human/Non-human) |
non-human_actions, human_actions |
(a) The software failure incident occurring due to non-human actions:
- The software failure incident related to the Mars Climate Orbiter burning up in the Martian atmosphere was primarily due to a non-human action, specifically a unit conversion error in the software controlling the orbiter's thrusters. The software calculated the force the thrusters needed to exert in pounds of force, while a separate piece of software took in the data assuming it was in the metric unit newtons [3508].
(b) The software failure incident occurring due to human actions:
- The software failure incident related to the Mars Polar Lander losing contact with the probe was attributed to human actions. Mission controllers concluded that the lander had shut down its engine too early when it unfolded its legs, leading to its destruction on impact [48591]. |
| Dimension (Hardware/Software) |
hardware, software |
(a) The software failure incident occurring due to hardware:
- The Mars Climate Orbiter failure in 1999 was attributed to a software glitch where the force delivered by onboard thrusters was coded in imperial pounds instead of metric Newtons. This error originated from a hardware-related issue where the software controlling the orbiter's thrusters miscalculated the force needed [3508, 48591].
(b) The software failure incident occurring due to software:
- The Mars Climate Orbiter failure in 1999 was primarily a software failure incident. The glitch in the spacecraft's software, where the force delivered by thrusters was coded incorrectly, was the main contributing factor to the mission's failure [3508, 48591]. |
| Objective (Malicious/Non-malicious) |
non-malicious |
(a) The software failure incident related to the Mars Climate Orbiter was non-malicious. The failure was attributed to a mistake in the software controlling the orbiter's thrusters, where the force was calculated in pounds instead of metric newtons. This error led to the orbiter burning up in the Martian atmosphere [3508].
(b) The software failure incident related to the European Space Agency's Mars lander was also non-malicious. The failure of the Mars lander to touch down safely was part of a series of setbacks for scientists eager to learn more about Mars. The incident was not attributed to any malicious intent but rather to technical challenges faced during the mission [48591]. |
| Intent (Poor/Accidental Decisions) |
poor_decisions, accidental_decisions |
(a) The intent of the software failure incident was poor_decisions. The failure of the Mars Climate Orbiter was attributed to a poor decision made by engineers who failed to convert units from English to metric in the software controlling the orbiter's thrusters. The software calculated the force the thrusters needed to exert in pounds of force, while a separate piece of software took in the data assuming it was in the metric unit newtons [3508].
(b) The intent of the software failure incident was accidental_decisions. The failure of the Mars Polar Lander was due to an accidental decision made by the lander's engine shutting down too early when it unfolded its legs, leading to its destruction upon impact [48591]. |
| Capability (Incompetence/Accidental) |
development_incompetence |
(a) The software failure incident related to development incompetence is evident in the case of the Mars Climate Orbiter [3508]. Engineers failed to convert units from English to metric, leading to the orbiter burning up in the Martian atmosphere. The software controlling the orbiter's thrusters calculated the force in pounds instead of metric newtons, causing a critical miscalculation. This failure was attributed to a lack of professional competence in ensuring proper unit conversion, as it was a known issue that was not caught during development.
(b) The software failure incident related to accidental factors is seen in the case of the European Space Agency's Mars lander [48591]. The Mars lander failed to touch down safely, adding to a series of setbacks in Mars missions. This failure was not due to a specific error in software development but rather an accidental outcome of the complex process of landing on Mars, where various factors can contribute to mission success or failure. |
| Duration |
permanent, temporary |
(a) The software failure incident related to the Mars Climate Orbiter was permanent. The incident occurred because engineers failed to convert units from English to metric, leading to the spacecraft burning up in the Martian atmosphere and ultimately being lost for good [3508].
(b) The software failure incident related to the European Space Agency's Mars lander was temporary. The Mars lander failed to touch down safely, which was part of a series of setbacks for scientists eager to learn more about Mars. This incident did not result in a permanent loss of the spacecraft but rather a temporary setback in the mission [48591]. |
| Behaviour |
crash, omission, value |
(a) crash: The software failure incident related to the Mars Climate Orbiter can be categorized as a crash. The orbiter burned up in the Martian atmosphere because the software controlling the orbiter's thrusters miscalculated the force needed to be exerted, leading to the orbiter vanishing and ultimately crashing into the atmosphere [3508].
(b) omission: The software failure incident can also be categorized as an omission. The omission occurred when the software controlling the orbiter's thrusters failed to convert units from pounds to newtons, leading to a critical error in the calculations and the subsequent loss of the spacecraft [3508].
(d) value: The software failure incident can be categorized as a value failure. The software incorrectly calculated the force the thrusters needed to exert in pounds instead of newtons, leading to a fatal error in the spacecraft's trajectory and resulting in its destruction [3508]. |