Mars rover Curiosity returns to functioning after loss of orientation due to glitch

The Mars rover Curiosity suffered a glitch a few days ago that left the robot unable to orient and move. It has now become clear that the rover has been ‘patched up’ again and is ready to carry out the planned scientific investigations.

NASA scientist Scott Guzewich writes that a plan to give Curiosity enough knowledge about its orientation has been successful. He states that the rover has now been given an extensive plan with investigations, which should have been carried out earlier, before the problems arose. For example, the rover must conduct research with its Alpha Particle X-Ray Spectrometer to determine the chemical composition of samples. According to the plan, this spectrometer should also be used for a rare measurement of the amount of argon in the atmosphere.

It is unclear what exactly caused the problems. In any case, it’s clear that some of the data about the rover’s orientation was not entirely accurate, which prevented the robot from doing the essential safety assessments that are critical to its functioning. Thus the rover stopped moving, although it continued to send information to Earth. Based on that, NASA came up with a plan to inform Curiosity about its environment and orientation.

Robbers like Curiosity, like humans, need to be aware of exactly where their ‘bodies’ are in relation to the environment. Curiosity stores that data in its memory, including the orientation and angle of each “joint,” which instrument at the end of the robot arm is pointing down, and how close an instrument, such as the said spectrometer, is to the ground. Curiosity also stores data such as how steep a slope is and where there are large boulders. All that information is evaluated before an engine is activated. If the rover judges that a movement cannot be performed safely, the affected motor will not be activated. According to NASA, this conservative attitude helps to keep the robot safe and operational. This prevents Curiosity from hitting a boulder with its arm, driving over something dangerous, or pointing an unprotected camera at the sun.

A Hazcam photo showing Curiosity’s outstretched arm during spectrometer analysis.