Mars, with its wind-sculpted surface and possibilities of ancient life, has always held deep fascination for humans. Ever since the first Viking spacecraft landed there a quarter century ago and sent back the first pictures of the martian landscape, that fascination has only deepened. In 1997 the Mars Pathfinder became the latest visitor to land there successfully, enchanting the public at home with a series of visually stunning panoramic shots that have whetted the appetite for future and more extensive exploration of the red planet. What the public didn’t know was just how difficult those shots were to engineer and to get back to Earth. The Pathfinder could send data at an average of only 30 megabits a day, meaning one panorama could take many days to relay.