Santa, Father Christmas or St Nicholas – however he is known, the big man in red and his trusty reindeer are for many the highlight of the festive season, especially for the young or young at heart. However, there comes a time in every child’s life when they start to question the existence of Santa. Indeed, my young nephew recently asked, very precociously: “If America can detect weapons of mass destruction where there aren’t any using their satellites – why can’t they find santa?” After a moment of disbelief, he clearly read the Guardian more than the Beano, I started desperately searching the nooks of my imagination for a plausible answer - one that wouldn’t completely destroy Christmas for him.

Then it hit me - they do, and have done for the past 50 years! This came as some relief for my nephew, who was immediately convinced and went back to writing the eighth page of his wish list for the now irrefutably real Santa.

For more than 50 years the North American Aerospace Defence Command (NORAD) and its predecessor, the Continental Air Defence Command (CONAD) have tracked Santa. Legend has it that the tradition began after the Roebuck & Co store in Colorado Springs, US, put up an ad for children to call Santa on a special hotline - however an inadvertently misprinted telephone number sent the callers wishes to an unlikely - and probably slightly confused - recipient. Instead of Santa, the phone number put the expectant kids through to the CONAD commander-in-chief’s operations hotline. The director of operations, Colonel Harry Shoup, received the first Santa call on Christmas Eve 1955. Realising what had happened, Colonel Shoup had his staff check radar data to see if there was any indication of Santa making his way south from the North Pole.
Since that time, workers at NORAD have responded to phone calls from children - and the world-wide media - personally.

NORAD proudly announce that they use four high-tech systems to track Santa - radar, satellites, jet fighter aircraft and the slightly less formidable “Santa Cams”. Detecting Santa all starts with the NORAD radar system called the North Warning System. This powerful radar system has 47 installations strung across the northern border of North America and NORAD makes a point of checking it closely for indications of Santa Claus leaving the North Pole on Christmas Eve.
With slightly frightening efficiency, NORAD say that: “The moment our radar tells us that Santa has lifted off, we use our second mode of detection, the same satellites that we use in providing warning of possible missile launches aimed at North America.”

These satellites are located in a geo-synchronous orbit 22,300 miles above the Earth whereby they are always fixed over the same spot on the Earth’s surface. The satellites have infrared sensors, allowing them to detect heat when a rocket or missile is launched. As it turns out, Santa and his entourage of reindeer aren’t the stealthiest of operations. Apparently, Rudolph’s nose gives off an infrared signature similar to a missile launch - let us hope the good people of NORAD don’t get too merry on Christmas cheer and confuse the two.

Once detected, Canadian NORAD fighter pilots take off out of Newfoundland to intercept and welcome Santa to North America. About a dozen NORAD fighters in Canada and the United States are equipped with Santa Cams.

Quite why the US go to such lengths to “welcome” Santa in such militaristic fashion each year in not entirely clear. Perhaps Santa’s Lapland base is rich in oil and they are keen to form an alliance their own inimitable way. Why ever they do it, it provides perfect fodder to whip children across the globe into a frenzy of excitement as they track Santa to their home town.

So it seems that NORAD have got Santa’s movements on Earth pretty much wrapped up. But, what about interplanetary deliveries? As technology develops and humans once more turn their gaze to other planets – will St Nick have to expand his Christmas Eve travels to include other celestial bodies?   
    
The European Space Agency believes that by 2025, the technology will exist to send humans to Mars. Santa - if you are reading, here is a wake up call. If there are children on Mars, or any other planet for that matter, they will expect to see that a certain visitor has been on Christmas morning - assuming they have been good boys and girls of course. So Mr Claus, by way of a rough guide, here is what you need to know when extending your yuletide rounds to include the rest of our solar system:
     
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By Phil Prime, Deputy Editor Laboratory News.