Mars Perimeter
The Mars Perimeter is an ultra massive, multi-layer defensive shield deployed just beyond the orbit of Mars and is one of the three primary inner system defensive shields created to provide an extra layer of protection for Earth, acting as the second to last defensive line in the protection of Earth. It is joined in its work by the Earth, Jupiter, Pluto and Sol Perimeters. It is one of five replacements build by the Brayburn Society to replace the flawed and failed Oort and Kuiper Perimeters, and is built from their parts, gathered together as first the Oort, and later the Kuiper perimeters were deactivated, disassembled, and their parts then brought into the inner solar system to be redeployed as part of the new shield perimeters there.