Watch the UFO that made the headlines.
4 NFC enabled halo ads scattered around London, each contained a unique glyph puzzle for fans to unlock. When solved and brought together, they revealed the geo coordinates of Masterchief's location, where he's preparing for the ultimate battle against the evil extraterrestrial threat.
On location, Masterchief's prepared to fight along with hundreds of excited Halo fans.
The Glyph measured 50 feet (16 metres) in diameter and weighs 3.2 tons
A team of over 50 designers, engineers and fabricators created the Glyph.
It took approximately 8 weeks to design and construct: 2 weeks to design with the engineers, 4 weeks to build the aluminum structure and 2 weeks to apply the LED lighting.
There are 455 LED light strips mounted onto 37 panels and a total of 113,096 LEDs of a pure orange color
The 'UFO' consumes 20 KW of power
The dynamic lighting effects are all powered and controlled from an onboard electrical and computer system
The effects were orchestrated by a remote control system in a boat following the Glyph.
The helicopter flew at a height of 600 feet (183 metres) with the Glyph suspended 350 feet (92 metres) above the River Thames and required a special helicopter licensed pilot from Norway.