A Sign From Above | In the Sky

A Sign From Above
Overview	On the Surface	In the Sky	Grand Finale




By far, the most significant piece of this installation is in the sky This is where all the magic and mystery happens. The system is based on a constellation of 8 satellites in sun-synchronous orbit. Each satellite is outfitted with a mirror that can be articulated enough to reflect the sun's energy onto the requested area on the planet surface. The mirror will be large enough (~2m²) to reflect sufficient light to enure that the resulting flare will be the brightest thing in the sky for the surface-bound viewer. A model of the satellite is shown below.



The 8 satellites wll be orbiting the planet in low-earth-orbits (LEO) at an altitude of approximately 400 miles giving them an orbital period of around 90 minutes. They will be arranged into 4 planes of 2 satellites each. The planes will be oriented at about 24° either side of the terminator (line of day/night). This gives a nice coverage of the surface in terms of where it is possible to project the flare. This coverage pattern along with the redundancy of 2 satellites in each plane ensures that there will be a satellite availble for any requested location at or near every 10 minutes. To get a better idea of how the orbits will be arranged, look at the animation below.



Notice that when a satellite passes close enough overhead to a particular location, It is possible to reflect a flare at that spot, indicated by the yellow line. The light colored ring around the satellite is the area that the satellite can service in terms of projecting the flare.