Solar System
Earth Federation Space Force Large-scale "Laser" Weapon
Seeing the continual threat of another Colony Drop from the Zeon Duchy, Earth Federation higher ups needed some kind of method to deal with the possibility that, at any time, Zeon armed forces personnell could theoretically send another giant mass hurdling towards Earth. Taking the principle of the Archimedes Mirror into consideration, the monstrocity called "Solar System" was laid down.
Simply put the Solar System is roughly 750,000 individual mirrors, each about the size of three Magellan-class battleships stacked alongside each other. Each mirror has its own set of thruster arrays and a broadband antenna with which to communicate with the Control Ship. A modified Columbus-class transport acts as the Control Ship itself. It is fitted with a number of transmitting antennas, and its holds, usually utilized to transport cargo or Federal war machines, are packed full of powerful computers needed to compute proper trajectories for all of the mirrors to follow. Of course, the mirrors can be controlled manually (if the Control Ship should be damaged or lose its antennas) but the efficiency of the attack will suffer greatly.
The mirrors themselves fold for transport; despite this, it still requires hundreds of Columbus-class transports to move the array to a combat zone. As such, the Solar System is only intended for use against high-priority, preferably stationary, targets. The entire process of setting up the mirrors themselves takes about four hours; it's not exactly a timely weapon in the slightest sense of the word.

The Solar System can fire continuously for about ninety seconds before it has to re-align to match the ever-moving sun; these periods can last anywhere from two to six minutes.
The Solar System itself is able to generate a wide field of beams towards its target. Depending on the target in question, the mirrors can project a wide beam several dozen kilometers in diameter as a means of incinerating multiple targets, or narrow down into a very small beam with a diameter about the size of a single battleship; highly useful in creating holes in space colonies or even asteroid fortresses.
Given the sheer number of mirrors, the Solar System is capable of functioning even if great numbers of them have been blown off or otherwise incapacitated. Obviously, its power begins to deteroriate as the number of functioning mirrors decreases, but as long as at least half of them are still operational, its ability to destroy will still be maintained.

Another useful factor that the Solar System enjoys is its ability to fire through friendly units that are near its surface. Due to the fashion in which the Solar System operates, the beam is not nearly intense enough to damage units within a certain safe distance from the mirrors themselves (this is the area considered to be outside the Solar System's focus). In this capacity, warships and mobile suits acting in defense of the Solar System can defend it from enemy incursion right up to the Solar System's firing.
A truly massive weapon, the Solar System at full capacity can not only cover a battlefield, but also destroy one. The heat from its focus beam can near-instantly decimate mobile suits and armors, and destroy even the toughest Battleship within seconds. Space Colonies and Asteroid Bases may require a thinner focus alignment, but are not safe from the blast regardless.

There are disadvantages to such an immensly powerful weapon, however. It takes extremely long amounts of time to organize all the vessels required to move a Solar System, forcing the fleet of Colombus class transports necessary to carry it to move at a much slower speed than most conventional fleets. Plus, due to the time constraints in unpacking the system, if the fleet is ambushed while moving it will be nigh-impossible to defend.
In addition, while it can be aligned in such a way to fire at a target over and over, due to the time to unpack, pack, align, realign and move the entire System, it can only fire on one target per day.
What the Solar System lacks in these conveniences, however, it makes up in range. Due to the nature of the blast, the array can fire effectively on targets hundreds of kilometers away, with essentially zero time delay to the target. It merely requires a more precise focus.

The final advantage is that the Solar System is completely legal under the Antarctic Treaty - It does not use objects of extreme mass, Nuclear, Biological or Chemical weapons to damage its target. However, it is still capable of causing as much damage as an entire fleets compliment of Nuclear missiles.

The final disadvantage is cost. The Solar System is a truly monstrous weapon, and all that glass is in no way cheap. However, the Solar System is a completely terrifying and effective weapon, both for attack and defence.