The wonderful Curiosity rover on Mars has been much in the news lately, but let's not forget about the previous rover generation! Opportunity landed on Mars nine Earth calendar years ago
today on 25 January, and it still works fine. Its mate Spirit was mobile on the Red Planet for over five years and then functioned as a stationary science platform for another year before getting killed off by a Martian winter it couldn’t avoid. Amazing engineering that keeps working year after year without a technician so much as touching it.
Oppy is still on the rim of Endeavour crater, the area where it's spent the past year, and is currently taking measurements at a spot called Copper Cliff. Check out the project's web site for news! And meanwhile, elsewhere on Mars, Curiosity's hammer drill is being prepared for its first outing...
I thought Spirit Landed today and Opportunity landed later in January?
You're right! Thanks for the correction.
NASA has some spectacular failures, but the stuff that does work tends to keep going way beyond specifications. I admire the people running these probes who have to deal with hardware that degrades and fails piece by piece and all they can do is software modifications on hopelessly obsolete computers with small capacity to try to use the parts that still work. These are true hackers!
It is a testament to good design and engineering that both Spirit and Opportunity exceeded their design mean times of 90 sols and operate for hundreds instead.
I agree that the rovers Spirit and Opportunity have lasted exceptionally well, but the 90-day mission requirement was never the same a mean design life. The rovers were well over-designed to ensure that they lasted at least beyond the 90 days main mission success criterion.
The limiting factor was originally expected to be dust accumulation on the solar panels, as I recall it. Fortunately Mars itself has been kind in this regard and many times dust has been cleaned off the rovers by the Martian atmosphere.
Here is a link to Ethan Siegel's blog:
"How Many Planets Are In The Universe?" http://scienceblogs.com/startswithabang/2013/01/05/how-many-planets-are…