Comment by PaulHoule | Hacker News Reader

Comment by PaulHoule | Hacker News Reader

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What effect does the small size of the satellite have on the cost and complexity of the terminal?

The small-aperture terminal market has been driven by GEO satellites getting bigger, a lot bigger. Yes, we can fit more satellite in a small package, and solar cells have gotten more efficient, but there are laws-of-physics issues involving the size of the antenna, power requirements, etc. that aren't going to go away.

Geosynchronous satellite spacing is determined by the ability of ground stations to resolve satellites so there is a certain number of satellites that can fly, so there is a pressure towards large high-performance satellites that can deliver the maximum capacity as opposed to launching fewer low-performance satellites. Already the high-capacity satellites have insufficient bandwidth to serve demand (otherwise people would just be getting satellite instead of asking for terrestrial internet) and I don't see how low-capacity satellites will actually help.

I see similar problem with the terminals for systems like the SpaceX constellation. To get "wireless equivalent" performance I see the ground terminal requiring some kind of electronically scanned array which would put the cost upwards of $6000.

There is a precedent for satellite services with a high-cost terminal, as back in the 1980s many people would spend about that much for an unlicensed satellite terminal to receive TV, but since that was pirate there was no subscription fee. Compare that to $100 a month for cable and that pays for itself in 5 years.

I have this funny feeling that next-gen satellite providers want to have the expensive terminal AND the expensive service -- possibly because of the "Juicero" issue that the people bankrolling them don't know what prices look like to the average customer.

I would love it if you could prove me wrong.

Hi there, great questions. The satellites are spec'd to deliver the same power (EIRP) on the ground as traditional large GEO's, with each of our satellites having a fraction of the capacity. This is a key point-- it will take several of our satellites to do the same job as one traditional large GEO. But that's not only ok, it's much better. It means we can put up a smaller chunk of capacity as needed and not do the "all or nothing" approach of a large GEO.

The high capacity satellites do have insufficient bandwidth to serve demand, on that I agree. But that's not a spectrum limitation, its a limitation on how many such large GEO's have been launched. Which is a small number because each one is so expensive. There is still plenty more spectrum we can use for GEO telecoms, and more with proper frequency re-use schemes.

The point you make about the drive to large GEO's holds true if you assume only one spacecraft will ever be in a single orbital slot. But that's not the case. There's plenty of orbital slots where multiple GEOs are co-located, and this will increasingly be the case in the future. I'd argue the drive to large satellites was more driven by various incentives and systemic issues in the industry that drove them that direction. A much longer conversation, but it's things that can all be fixed.

And to answer your last question, because our satellites are spec'd to provide the same EIRP on the ground, the ground terminals used are the same as those in use today for GEO telecoms. These terminals are all off-the-shelf and very low-cost compared to the terminals necessary for a LEO-based network.

Your first paragraph: So basically rather than a "typical" configuration which might be 24 x Ku-band transponders, 36 MHz capacity each, supported by the solar arrays and power systemon a giant 4000 kg geostationary bus.

You're putting the Tx power into the equivalent of just one or two 36 MHz Ku transponders per satellite? Fewer transponders per satellite in a tradeoff for greater Tx power in a smaller bus?

The key here is spot beams, right? The big satellites have dozens, maybe hundreds of spot beams covering multiple countries but yours has a handful? And multiple satellites can share the same orbital slot if their spot beams are pointed in different places, right?

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