After 15 years on Mars, the mission of NASA’s Mars rover Opportunity appears to have come to an end. The wheeled explorer was only supposed to function for 90 days, but it went on to assist in many discoveries about ancient conditions on Mars, becoming the longest-lasting robotic explorer sent to another planet.
The rover has been silent since June when a planet-wide dust storm prevented sunlight from reaching its solar panels; lacking energy, Opportunity could not stay awake. The hope was that the rover would revive when the skies cleared, but it has not responded after months of efforts to contact it.
On Tuesday night, NASA made one last call to Opportunity. On Wednesday, the space agency is expected to announce that it is wrapping up the mission.
What happened to the Opportunity rover?
Because the rover is solar-powered, it needs sunlight to run its computers, instruments, motors and, most importantly, heaters. During the dust storm, the fiercest in years, Opportunity simply ran out of energy after its solar panels were covered.
A self-portrait taken by Opportunity in March 2014, showing that wind had blown off much of the dust that had covered its solar panels.CreditNASA/JPL-Caltech/Cornell Univ./Arizona State Univ.
What has NASA done to try to wake the rover?
Once the storm cleared, NASA resumed sending commands to Opportunity and listening for any communications from the vehicle. The rover, if it woke up, was supposed to go through preprogrammed sequences to get back in touch with Earth.
But its radio might have malfunctioned and was unable to call home. Or the rover may not have known what time it was, and was unable to sync up with spacecraft that relay its signals from Martian orbit.
In January, NASA began sending a new set of commands to address these possibilities, with no success. On Tuesday night, mission staff at the Jet Propulsion Laboratory attempted to raise the rover one last time.
Are there any other rovers and landers on Mars right now?
A larger, more capable rover, Curiosity, landed on Mars in 2012. That one is powered by heat generated from a chunk of plutonium, not solar panels, and thus was not affected by last summer’s dust storm. A NASA lander, Insight, set down in November; it is in the middle of deploying its instruments to measure marsquakes — geological vibrations that will tell about the planet’s interior.
In addition, a flotilla of spacecraft orbit Mars, studying the red planet from space.
Opportunity’s twin, Spirit, also far exceeded its intended three-month mission, but it got stuck in a sand trap in 2009 and fell silent the following year.