Medium orbit – O3B Satellite

[Pi314]

This satellite will have 10 beams at 1.2 Gbps per beam.

The approximate orbit for the O3B internet satellites will be about 5,000 miles. I am curious what type of fuel/thrusters can make this happen over a long period of time.

http://www.bbc.co.uk/news/science-environment-23028083

 

[Stargazer]

Google has some involvement with this along with weather balloons that they just started working on.

 

[grohgreg]

MEO satellite orbits are either circular or elliptical. Circular is specified when time and distance factors are critical, and is indeed more fuel-hungry. In a strictly cell-phone application, time and distance aren't strong considerations. In an elliptical orbit, the perigee (lowest altitude) of an elliptical-orbit satellite is much less than its apogee (greatest altitude). The orbital speed is much greater near perigee than near apogee. Gravity overcomes speed, and the satellite is pulled back toward the apogee. This speed versus gravity situation creates a slingshot effect that is repeated during each orbit. No fuel expended. What fuel is onboard is pretty much limited to station-keeping. IE: re-orienting the antennas and/or solar cells if/when they rotate out of position, or thrusting a satellite back into the optimum orbit if/when the apogee and/or perigee points exceed parameters.

//greg//