COMMStellation

COMMStellation is a communications constellation of microsatellites being developed by a consortium of organization designed and led by Microsat Systems Canada Inc. (MSCI’s). It is being developed to bring additional backhaul for communications and to connect remote areas of the earth. It is scheduled to be launched in 2015.
COMMStellation will be comprised of 78 microsatellites aligned on 6 orbital planes separated by 30 degrees of longitude, and will orbit the earth at an altitude of 1,000 kilometres. 6 redundant microsatellites (1 per orbital plane) will be launched in addition to the 78 microsatellites. COMMStellation will provide 100% global coverage and will be connected to terrestrial telecommunications networks through 20 located around the earth. The microsatellites are designed for cost-effective and green deployment enabling fourteen to a launcher. Six launchers will be required to deploy the entire constellation.
The Physics Behind Covering the Earth
COMMStellation is a polar oriented constellation. Polar orbiting Microsatellites pass approximately over the north and south poles along lines of longitude. Imagine shining a flashlight on a globe at a simulated 1,000 km above the earth surface. The diameter of the beam on the earth will cover 4,819 km assuming a 10 degree slant angle. If you were to draw a square within that footprint such that each corner of the square just touches the edge of the circle, each side of the square will have a length of 3,407 km. With the 12 spaces (found between the six orbital planes) multiplied by 3,407 km, the coverage of the squares equals 40,884 km. The circumference of the earth at the equator is approximately 40,075 km. As such, the squares will overlap each other at the equator providing complete coverage. As you move toward the poles, the circumference of the earth’s east/west orientation decreases as the cosine of the latitude resulting in more overlap. In addition, if we include the area between any side of the square and the edge of the circle, the overlap from one satellite footprint to another is greater. The overlap at the equator covers an area of approximately 1,480 km. The strength of the beam at the surface varies with the square of the satellite altitude according to the inverse-square law.

Main Menu

See Also

Main Menu