[rtkwe]

Not to take away from the great work of NASA engineers but EOL is kind of a misleading term when it comes to space science missions. At lot of mission end times are based off of funding and the lowest level science goals of the mission. While those are being completed they gather a case for continuing the mission and usually get it. Of course the main cost is getting the stuff there in the first place so why not add a relatively small amount to make it last?

[zymhan]

No, but given the short lifespan of these things due to radiation, literally other-wordly conditions, and the fact that you can never repair it, the fact that a rover on Mars can last a decade is a technical marvel.

You also have to pre-program the entire flight and find out half an hour later if your parachutes and retro-rockets deployed, or you made a relatively small crater.