Stargate

Stellar gates use massive amounts of solar power in order to warp spacetime in such a manner as to literally reduce the distance beteen two such gates. Currently, seven are planned for the Solar System, each with the intent of reaching nearby, major star systems. These giant megastructures reside some distance outside Neptune's orbit, though only the Centaurus Gate is fully active.

The massive energy required for these hundred-thousand kilometer behemoths makes it nearly impossible to use them around a red dwarf star, as even with the aid of mobius patterns, the construction of seven gates will require well over half of the sun's energy, averaging a need for thirty yottawatts of power each. The last of the local gates was completed in 2221, to Epsilon Indi.

The seven gates so far planned lead to the following star systems:

• Alpha Centauri - Remote gate completed in 2219 via the Centaurus Mission. Now fully active.
• Tau Ceti - Remote gate under construction, due in 2227.
• 61 Cygni - Remote gate under construction, due in 2224.
• Procyon - Remote gate completed in 2217, activation will finish in early 2222.
• Sirius - Remote gate under construction, due in 2223.
• Epsilon Indi - Remote gate due in 2229.
• Epsilon Eridani - Remote gate due in 2228.

Each of these will remain the seven largest megastructures created by human hands for some time, at least in terms of raw dimensions. The Great Rings and Ouranos Prime are all significantly more massive.