Even if it was hoped that the robots would work for at least three months, their longevity in the freezing Martian conditions has surprised everyone.

 

The data obtained by the rovers has revealed much about the history of water at Mars' equator billions of years ago. Spirit is exploring a 150km-wide depression known as Gusev Crater, where it has found an abundance of rocks and soils bearing evidence of extensive exposure to water. Opportunity is on the other side of the planet, in a flat region known as Meridiani Planum, and its data shows that Mars sustained liquid water on its surface.

 

However, the rovers are now showing some serious signs of wear and tear even if, combined, the two have made more than 13 miles of tracks on Mars' dusty surface and sent a quarter-million images back to Earth. NASA says either rover could fail without warning.

 

Unfortunately, Spirit has to drive backwards everywhere it goes, and that's because of a jammed wheel. In addition, Opportunity's robotic arm has a glitch in a shoulder joint because of a broken electrical wire. Anyway, the vehicles managed to avoid the problem of power, even if they have been dangerously close on running short on power because of the dust covering on their solar panels.

 

NASA has recently delayed this year's launch of a much more capable vehicle, known as the Mars Science Laboratory (MSL), due to technical and budgetary problems. This came a little while after Europe put back its rover venture known as ExoMars. This is why we can say it's highly probable the next surface mission on Mars will be a joint venture for NASA and the European Space Agency (ESA), due to the high cost of getting spacecrafts down on to the planet.

 

As previously mentioned, even if nobody would have thought they would stay that long on Mars, the rovers have been on the Red Planet for five years now. In order to celebrate the anniversary, NASA put together a video. Besides the fact that they returned a quarter-million images and driven more than 21 kilometers (13 miles), the rovers climbed a mountain, descended into craters, struggled with sand traps and aging hardware, survived dust storms and relayed more than 36 GB of data via NASA's Mars Odyssey orbiter.

 

It remains to be seen how long will the two rovers manage to stay operational on Mars and what will NASA do after the two will 'retire' from their active duty.