- "A thousand years we could labor and still the work would not be done... The first tower was never completed, the project abandoned... We moved on. But while we labored on other endeavors, a few returned. They thought to automate the process... Metal might finish what flesh could not..."
- ―Juno, 2012.[src]-[m]
Although they failed in their initial purpose, the added time and the automation of the construction process allowed the towers to successfully defend the Earth against the 2012 coronal mass ejection.
Around the time of the Human-Isu War, the Precursors who decided not to get involved in the conflict started to investigate in possible solutions to save the planet and their civilization. One of these consisted of building four towers that would redirect the solar flares into the Grand Temple to dispel it. But unfortunately, it was considered as a failed solution due to the fact that the process of constructing even one of these towers would take too long. The project was abandoned and the Isu moved on to other endeavors in their seek for salvation.
Nevertheless, while others were tasked to search for other alternatives, a few Isu returned to finish the constructions. With the help of automated machines, they managed to prolong the process until long after the Great Catastrophe, and eventually, the four towers were built, hidden in chasms, so no one could ever disturb them. These would be later connected to the Global aurora borealis device in order to generate the planetary shield.
On December 21, 2012, Desmond Miles, understanding the consequences of his actions, decided to give his own life by touching the device that started the whole system. He saved the world but released Juno in the process.