NASA's Phoenix Mars Lander lands on Mars May 25

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I would not say that completely the problem, NASA has been forced in resent years to use "off the shelf" to save money, but RAD hardening the testing of equipment does mean nasa has to use technology that is many years behind it time: the RAD750 is just a radiation harden G3 processes and despite the fact that is has nearly 1/100 the processing power of todays computer its still the best CPU nasa can get for space, the next mars rover MSL will have a RAD750.

 

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Most commercial off the shelf products are build to withstand vibrations while being transported on trucks while cushioned in styrofoam, to withstand only tiny radiation doses, and for operation at room temperature. Even equipment intended for use on Earth in extreme environments costs dearly. Ruggedized equipment is expensive. The most rugged environments on Earth pale in comparison to the vibrations induced by launch and Mars entry. Equipment receives a huge radiation dose between Earth and Mars and continue to receive a very high radiation dose while on Mars. Mar's weather is anything but room temperature. Whatever is sent to Mars has to be small and very miserly with respect to power consumption.

The avionics equipment are of the vehicle components most sensitive to vibration, radiation, and temperature. The kinds of avionics equipment that does meets these requirements is expensive and very far from state of the art. Now compound that with the fact that the avionics equipment is one of the earliest design decisions made in any space venture because the avionics are one of the vehicle components most critical to the mission. The avionics equipment is selected early on the mission design, and selected from equipment that is already out-of-date because of the need for rad and vibration hardening. Compound this with the fact that it takes time to design and build the vehicle, time to test it, time to transport it for launch, and time to transport it to Mars. It should come as no surprise that the equipment we send to Mars is ten years or so (or more) out of date.

 

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What in the world (or more appropriately, out of this world) makes you think we don't?

 

The rovers have to be able to maneuver on their own and take pictures on their own. They had better proceed slowly as there is no repair depot on Mars and as it can take up to 45 minutes between the time when something goes awry to the time a human override command arrives back from Earth. The rovers are autonomous vehicles, the first of their kind. So once again, what in the world makes you think NASA doesn't have new logics in place?

The Mars Phoenix Lander is a different kind of vehicle. It isn't a rover, for one thing. NASA has to trade off functionality and scientific outcome versus cost and feasibility for every space mission. Flying something to Mars is not cheap. We do not have the capability to send everything we want there. We have to pick and choose. In the case of the Phoenix Lander, that the vehicle had to make a landing argued against packing a whole lot of functionality into the vehicle for a couple of reasons. Firstly, landing a big hulking vehicle is a lot harder than landing a small, compact vehicle. The vehicle had to have limited functionality to have any chance at landing successfully. Secondly, we hadn't done a landing for decades, and our success rate was never particularly good. When one gambles in Vegas it is best not to hock the house. Landing on Mars is a big gamble.

Kmguru, in asking "why are our probes so stupid/limited/clunky?", you and MetaKron are asking a loaded question, one along the lines of "when did you stop beating your wife?".

 

why can't they have a separate module within the rover which will act as a repair instrument on its own wheel and with its own arm? All it has to do is charge with the solar arrays of the lander and than go around repairing and brushing off dust from the solar arrays.

Or maybe we can just introduce electrostatic pulses along the array to get rid of the sand.

 

too bad...that would cust the costs many times.

 

When did you stop beating your wife, then?

 

You know of course that we can only have the right kind of graphite around a nuclear reactor...

 

'cause it weighs to much and does little for vibration protection? it makes sense though I would envision a Europa orbiter needing such protection even with existing radiation hardened hardware.
Here the specs on RAD750 the present best in space bound CPU.

 

Aaah wikipedia, source of questionable generlizaed information, SOMETIMES WITH LINKS TO MORE REPUTABLE SOURCES (Like BAE brochure)!

 

You need to be spoon fed?

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The bottom panel in the graphics posted by ElectricFetus gives a clue: "Customization of the PowerPC 750 to improve SEE hardness required replacement of the circuitry while maintaining identical logic function".