Actually probes often do not have cutting edge technology. Between the time it takes to design, test and launch the thing it is already behind. Much less the time it takes to get there. The MER rovers have 8 bit computers, gasp! Now they do have very unique items. For instance the MER solar panels are not the ordinary sort of solar panel. They were chosen for improved power output.<br /><br />Now as for just plugging in instrument, well in the case of an space probe or frankly almost any machine made by ,man, it isn’t simple to just plug something in. You can affect power consumption, heatingcooling, center of mass ect. Plus again it does no good if the instrument can not work properly due to spacecraft design. <br /><br />As for everything being a test flight, well frankly any time you launch a probe it is a test flight. Even if they are identical. The Voyagers, Pioneers, and MER all have things that went wrong on one probe, but not the other. <br /><br />As for unqiness, well there are lots of similarities between probes. Pioneer, Voyager, Galileo are all derived from the Mariners. The MER are derived from Pathfinder. <br /><br />As for more missions, well the deep space network is pretty busy these days. There are lots of instances where data is left on the probe because the probe is awaiting a time that it can transmit without interfering with another. In order to have more missions you would have to beef up ground support or have much shorter missions.<br /><br />Finally the volume of data is not quite as important as the quality. And sometimes you don’t need an armada to do the job. For instance the Viking orbiters mapped almost the whole surface of mars in the 70ies. All of that work done from just two probes. <br /><br />Also I question the idea of more is better. The USSR launched more missions to mars than the USA, but the USSR never had a succesful mars mission. If they had spent more time testing their technology and planning perhaps they would have done bett