There are a couple of planetry science missions that have become iconic of the skill our spacecraft engiiners can show if they choose. We all know about Voyager, but I think the Mars rovers are fast heading the same way.

I have strong memories around Christmas 2003 and into Jan 2004 of te excitment about the Mars rovers. The long drawn-out process of the NASA engineers waking up their rovers, starting them up and driving them accross the red planet. Wow.

I don't think anybody in their wildest dreams thought that we'd be three and a half earth years down the line, and have both rovers going strong. Spirit and Opertunity have both just survived one of Mars' periodic planet-wide dust storms. Although the solar panels which the Rovers depend upon for electronic survival are coated with dust, enough power is getting through to permit a small amount of science activity.

I think the Spirit and Opertunity Mars Rovers are very similar to the Voyager space probes. Both are really well engineered spacecraft which have kept on working way beyond the expected lifetime. It is not easy: I am sure that the Mars rover team need the same creative approach to problem solving made famous by the Voyager engineers to overhome the hurdles met on an extended mission.

It must be very difficult, from an engineering point of view, to foresee the problems and design solutions to them. If you are making a car, you can at least go and drive it on a typical road for 150,000 miles and see what breaks down. This option doesn't really exist for the Mars Rover engineers. Geting to Mars is both expensive and difficult.

Much kudos and karma to the clever chaps at NASA.