AMSAT-NA (Amateur Radio Satellite Corporation, North America) announced a deal with IntelSat which will allow amateur payloads to be carried on IntelSat communications satellites to geosynchronous orbit, when on-board space allows. This is fantastic news. Let's look at what it really means...

In the history of amateur satellites all the way back to OSCAR 1, most have been secondary payloads hitching a ride to orbit when extra weight was needed to balance a rocket whose primary payload was paying for the whole flight. There was one exception - AMSAT's Phase 3-D, renamed AMSAT OSCAR 40 "AO-40" in 2000 because it was the 40th amateur satellite to successfully achieve orbit, was so big that it had to pay part of its way.

Up until now, all the launches that amateur satellites have been able to hitch a ride on have been to LEO, or low-Earth orbit. That's just hundreds of miles up. Ham Radio operators who practice the satellite niche of the hobby have needed complicated tracking equipment to use these satellites as they whiz by at 17,000 mph (27,000 km/h). At those speeds and relatively low altitudes, a satellite's orbit takes it across the sky from horizon to horizon in no more than 10 minutes for the really low birds. Some AMSAT birds, including AO-40, have used modified Molniya orbits, a Russian-invented orbit to cover northern latitudes with a highly elliptical and inclined orbit, successfully made those satellite passes go more slowly and put more power on the satellite to compensate for its additional distance away.

But geosynchronous orbit has never been accessible to Hams. There is no way that satellites built by volunteers and funded by donations could raise that kind of funding. It would simplify the tracking - it stays in the same place in the sky all the time. That's the definition of geosynchronous orbit - at 23,300 miles the satellite is far enough away that it has to cover more distance at its orbital speed. Its position over the ground matches the rotation of the Earth, making it stay in the same place in the sky from our point of view on the ground.

AMSAT is calling the new program Phase 4 Lite. We'll all have to keep an eye on it! Donations to AMSAT are tax-deductible in the US.