HOW can you keep a single subsystem failure from turning a billion-dollar spy satellite into orbiting space junk? Break it into a cluster of modules, each of which can easily be replaced, suggests the US Defense Advanced Research Projects Agency (DARPA).
Today’s satellites carry multiple instruments and support systems. This integrated approach minimises weight and launch costs, but increases the chance of expensive delays such as those which clouded the launch of the Pentagon’s SBIRS surveillance satellites. Such complex units can also be disabled by the failure of a single subsystem.
DARPA programme manager Owen Brown envisages splitting complex…
