That engineering test article will never go into space. Instead, it will land in a museum. The big expense with these Mars rovers was not the hardware cost but the technology research and development costs. That's been paid for on what has been proven to be a very successful design. NASA is planning on sending a big rover to Mars in 2009. This new vehicle is called "Mars Science Lab" or MSL. After the smoke clears, MSL wil probably cost about a billion dollars. Many believe the design of MSL is fatally flawed. The so called "sky crane" concept used by MSL will probably cause it to auger-in. If a billion dollars was allocated towards MER clones, NASA could probably get dozens of them on the surface of Mars. There's no doubt in my mind that a dozen MER clones would provide far more science payoff than one augered-in MSL.

Gary