Hacker News Reader

Comment by alex_duf | Hacker News Reader

>prepare to spend a few years without cell phone reception, Internet, and a five-day weather forecast.

Aside from the weather forecast the rest doesn't need any sort of satellite.

It's incredible how many people still think mobile phones are using satellites! It's a ground antenna, connected via copper or fiber to a wider network of... antennas. If you call abroad, 99% chances your call goes through a submarine cable which is again copper or fiber.

Same with Internet, unless you really are in the middle of the Amazon forest, or (live in country side in the states)

View on HN

I still think there's lots of benefits to be had (and lots of money to be made) from replacing many of current satellites with high-altitude solar-powered UAVs. They'll be much cheaper to design and manufacture (no need for satellite-grade sterility, or engineering for microgravity environment), much easier to service and replace, and they'd offer some capabilities impossible for satellites (like not flying around the globe).

I've said that before, and got plenty of skeptical looks. I recently learned, however, that I'm not the only one thinking this - in fact the concept has been dubbed "atmosats", "pseudosats", or "HAPS". ESA seems to be into it now:

http://www.esa.int/Our_Activities/Navigation/Crossing_drones...

Have you heard of Facebook's Aquila drone? Sounds like something you are describing. https://en.m.wikipedia.org/wiki/Facebook_Aquila Also, Google's project loon comes to mind.

Yeah, they would both be good examples qualify.

LTE and beyond require very precise timing. There are roughly two options for this. The first is you install a GPS antenna on every tower and synchronize time that way. The second is that you distribute the time to the towers over the backhaul network, typically using PTP (Precision Time Protocol) which would not be affected.

Additionally, GPS satellites are in Medium Earth Orbit (20k km up or so) and wouldn't be heavily effected by a Kessler Syndrome developing in Low Earth Orbit (160-2000 km up).

Weather forecasts would be affected, but it wouldn't be the end of them. There are still ground weather stations relaying their wealth of data.

Your Satellite TV wouldn't be affected either, since those come from Geosync Satellites (GEOs), which orbit at 35,786 km. Communications satellites like Inmarsat (L-Band), Ku, and Ka typically operate in GEO. Iridium would be fucked though.

The most heavily affected application would be Spy sats. They have to orbit close to the Earth for focal length reasons.

Many things need a precise time reference, which nowadays often comes from the GPS satellites. AFAIK, the 3G and 4G cell phone standards need precise timing to work correctly. Which means that "without cell phone reception" is a bit of an exageration; there's always the older 2G GSM standard. Same with the Internet, some networks might need precise timing to work correctly.

I think some base stations use GPS time as time/frequency reference.

Reply on news.ycombinator.com