The Time Bridge was conceived by Constantine Stark so that the Templars could see into the future, to determine whether they had survived and whether their vision of a universe without genetic engineering had been fulfilled. So, Constantine Stark started to build the Time Bridge, which was a massive undertaking because of the raw amount of material needed in order to simply construct it. He had smugglers bring him hundreds of metric kilotons of Nickel and Cobalt to build the Time Bridge, but was lacking several key resources: manpower and the requisite minds to make time travel a reality. Although Constantine Stark knew how to achieve time travel, he needed a talented engineer to understand and implement his plan, and work out the details of it. Manpower was acquired by enslaving random people in crimes of opportunity, but the Templars learned about Seamus Harper from an engineer that they had kidnapped, named Woody. Woody was the person who taught Harper to program back on Earth, when Harper was younger. Meanwhile, the Andromeda Ascendant was trying to pursue the smugglers who were stealing and moving the ore needed for the construction of the bridge, with Harper, Telemachus Rhade, and Dylan in the Eureka Maru and the rest of the crew in the Andromeda. While the group in the Maru were searching for a smuggler, they were ambushed by 3 Templar fighters and captured. They were brought to the base of the bridge, which was also the main base for the Templars and the location of their laboratories. Harper was put to work under threat of death, while Rhade and Hunt were put to work in the radiation scrubbers. Finally, Dylan managed to get loose and contacted the Andromeda. The Andromeda came, but not before Harper managed to complete the bridge and opened a window into the future, where Magog from the future slipped through before the Andromeda destroyed the bridge.
The bridge is actually being built 100 years ahead of schedule, as the bridge (coming from the planet) will not be able to meet the Moon for at least 100 years. So, the bridge actually needs to be built to go across time.
The bridge itself is in fact a simplified counterweight, like a pendulum. The planet is on one end, and there is a spacedock at the end of the bridge in space which is serving as that counterweight. As the bridge spins around, the g-forces at the end of the bridge increase, so anything at the end of the bridge would be subjected to those forces. Constantine Stark wants to place a tachyon, a particle which moves faster than the speed of light, at the end of the bridge. The tremendous forces at the end of the bridge would slow down the tachyon and there would be time dilation as a result. As a result, a window through time would be established.
The equation for time dilation using a tachyon through the Grand Unified Theory is: