MILLEDGEVILLE — Even if you’re not a satellite TV subscriber you’ve probably seen the commercials of one company where two not-too-bright astronauts are switching on a new broadcast satellite.

Well, it’s nowhere near as much fun or that easy.

Since the space shuttle has been dedicated to ISS assembly and science missions, there really isn’t any way for astronauts to visit communications satellites — besides, where those kind of technological marvels hang out the shuttle can’t even go.

Let’s review.

The shuttle was designed for low-Earth orbit missions, which are generally around 120-300 miles above the surface. TV satellites populate areas around 20,000 miles above the surface. There are very good reasons for those height differences.

At roughly 120 miles altitude the shuttle careens along at 17,500 miles an hour, circling the Earth every 90 minutes. This means it can cover a lot of ground, and that’s ideal for observational sciences. Plus, closer to home is always good, in case of an emergency. The closer to Earth you are the more you are protected from radiation by Earth’s magnetic field, communication is easier and it takes less fuel to get to your goal.

At 20,000 miles altitude it takes you 24 hours to orbit the Earth once. That means, if you sat on a TV satellite and looked down on Earth you would always look at the same spot. And that’s exactly why communications satellites have to be so high up. You want to make sure that satellite is always at the same spot in the sky, so that once you aim your satellite dish it can stay pointed in that direction. What a pain it would be otherwise! If your satellite TV programs came from a shuttle orbit you’d have a few minutes of clear reception a few nights in a row, and then nothing at all for days, even weeks.

So, said satellite TV company has just launched a brand-new machine to join its fleet of other broadcasting spacecraft, and this one is indeed a cut above the rest. Launched aboard a Russian Proton rocket it climbed into orbit and then performed a long series of rather complicated rocket motor burns to get into a highly elliptical orbit, over 22,000 miles at its farthest distance from Earth, and almost 4,000 miles at the narrowest points.

Once it has reached this track the satellite will use its own engines to slowly over time circularize the orbit, tilted away from the equator by 18.7 degrees. This will take a while, and in the meantime the engineers have a lot of tests to run, so when the satellite has finally arrived in its final orbit it’s ready to go and beam high definition TV programs directly into the homes of subscribers.

EchoStar 15 — that’s the official name of the satellite — will use approximately 20,000 watts of power to deliver TV programs. At 300 watts per channel that’s about one third more than its older colleagues. In this case, more is always better.

Of course a lot of planning had to go into this endeavor, because unlike in the cute commercial, there will be no astronauts on hand to fix anything if there’s a problem. Everything has to be pre-programmed and there are multiple redundant systems in place, designed to take over if any of the primary systems should fail. Still, these days so much high-tech science and engineering goes into these high-flying talkies that there’s always the possibility of failure. After all, while you can test all you want on Earth before launch it’s quite a different situation when your machine is 22.300 miles away (EchoStar 15’s intended altitude) and completely out of reach for all times.

What happens to old TV satellites who have either croaked or outlived their

usefulness?

Some of them will be left in orbit; they’re so high up that atmospheric friction is practically nonexistent, and once on the way they could theoretically circle the Earth forever. However, solar storms will eventually, over very long periods of time, change the trajectory of a satellite, and then it has to be dealt with. The easiest thing to do is to de-orbit them, that is, drop them back into Earth’s atmosphere, where they burn up in a blaze of mechanical glory. Of course you want to do this while you still have fuel to maneuver, so you can direct the fiery plunge towards an empty patch of open ocean, and not — as it happened with Skylab — accidentally squish an endangered Australian jack rabbit — or worse.

And of course, with so much of our technology moving into the skies, the geostationary orbit areas are getting pretty crowded. You don’t want a dead machine up there, taking up valuable orbit space that could be used for another communications satellite. So — down it goes!

Even if you personally won’t benefit from EchoStar 15’s business, it’s still a fascinating piece of technology and well worth a second look, so check it out at http://www.satbeams.com/satellites?id=2481   

And if you’re a hopeless communications satellite geek, go hang out with your fellow satellite aficionados at http://www.satelliteguys.us/

Yes, there really are fan websites for EVERYTHING.