Artist's impression of Herschel TelescopeThe Herschel Space Telescope is now operational again following a bug that's suspected to be have been caused by space radiation.

The European Space Agency (ESA) telescope was launched into space in May 2009 but a glitch in its electronics made it non-operational after three months.

According to the BBC, scientists have switched the system to operate on a reserve electronics system. The same fault happening again isn't possible.

The techies managed to fix the glitch online - they believe that a cosmic ray hit one of the microprocessors in the electronics unit. That in turn caused a cascade of software and hardware faults that brought the unit down.

The astronomer Herschel discovered the planet Uranus. The BBC story is here.