The tower, originally designed by Horden Cherry Lee but controversially taken over by BDP after the scheme was commissioned, has been plagued by problems throughout its five-year history.
At 127m high, the tower is the tallest free-standing structure in Scotland, and is the world's only building to rotate 360° from the ground up.
However, after opening in 2001 it closed in February 2002 and, following reopening, closed again in August 2004 due to problems with bearings on which it rotates.
The final time it closed was in January 2005, when a lift broke down trapping 10 people inside for more than five hours.
But, as revealed in the AJ, the Glasgow Science Centre had aimed to get the tower open again for Christmas ( Troubled Glasgow Tower 'could open for Christmas').
At the reopening on Wednesday (20 December), science centre chief executive Kirk Ramsay, said: 'We are thrilled to be reopening the tower in time for the holidays, and we look forward to extending a warm welcome to our customers.
'The views are spectacular and give a unique outlook over the city for Glaswegians and visitors to Glasgow alike.'