AMSAT – more geosync dreaming

Just a few random thoughts falling out of my head about a ham radio communications package onboard a geosynchronous satellite. Several pros and maybe one con – and every bit of it nothing more than wild conjecture on my part. We don’t have enough specific details about the project just yet so for now, it’s just dreaming…

As mentioned previously, ground station requirements will be completely foreign to present day satellite enthusiasts. Standing in the backyard pointing a handheld antenna skyward won’t cut it – neither will a handy-scratchy. For AO-40 I seem to recall we used 400 watts EIRP as the base requirement for 23cm.

But AO-40 didn’t spend its entire life at apogee so let’s assume a bit more that that. Don’t let the power scare you, much of it can be made up with high-gain antennas.

So we spend more on antennas, and at least one of them will likely be a dish, but here’s good news – there’s no need to steer them. Not if this satellite is your only interest in space. No expensive azimuth and elevation rotor required — just a fixed position mount and you’re set.

Oh, and since the bird doesn’t appear to move in the sky, relative to your position on earth, there should be no issues with Doppler — and no tracking required. It’s just always there at the same place in the sky, 24/7.

It may seem short-sighted to every satellite operator since the practice began not to employ multiple antennas, Az-El rotors, and tracking software. In days of old operators had a fleet of satellites to choose from and access to as many of them as possible provided a broad diversity of operation. In other words, one of them was always failing so there was strength in numbers.

But I’m looking at this from the perspective of someone only interested in using this one satellite. In that case, unique as it may seem, the ground station requirements will be considerably more than what is required today, but considerably less complex than what was required for previous Phase 3 (AO-10, AO-13, AO-40) operations.

No rotors, no Doppler, no tracking, no orbital schedule to determine what days the bird will be in view – it will always be in view. All very positive results from getting to a geosynchronous orbit.

What’s the downside?

Only one I can think of and it’s related to amateur radio’s role with emergency services. If someone were to ask should we make this platform available to support emergency traffic on an as-needed basis, our immediate response would be “certainly!” Amateur radio exists in large part to support emergency communications “when all else fails” and what better way to do that then via a satellite parked in the sky overhead.

Except, it will be parked in a place that affords it access from multiple continents at the same time. Chances are better than just pretty good that over many continents emergencies will arise on a daily basis. In just one week we’ve seen a major, catastrophic earthquake on one continent, a Tsunami on another, and a spewing volcano on yet another.

Is it possible that the new bird might end up spending most of its bandwidth resources and lifetime providing useful emergency services? I think that may be one scenario that deserves consideration. It’s going to suck a lot of the joy out of an ideal communication platform for hobbyists if every time you turn the radio on the bird is being used for emergency service with regular use suspended.

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Author: Jeff Davis