5 ms·

Huh? A lot[0,1,2] has been done considering how little we know about what has actually happened and a trivial search would enlighten you. Also, real-time strea

by chem83 4y ago

Huh? A lot[0,1,2] has been done considering how little we know about what has actually happened and a trivial search would enlighten you. Also, real-time streaming of GPS position for the thousands of flights in the air at any given time is not a trivial problem (but technology is improving and ICAO is pushing for such solution[3]). [0] https://www.cnn.com/2019/03/08/us/mh370-fifth-anniversary-malaysia-flight-370-space-based-global-tracking/index.html https://www.cnn.com/2019/03/08/us/mh370-fifth-anniversary-ma... [1] https://www.cntraveler.com/stories/2014-04-10/malaysia-airlines-flying-regulations https://www.cntraveler.com/stories/2014-04-10/malaysia-airli... [2] https://www.cbsnews.com/news/malaysia-airlines-flight-370-probe-sparks-new-security-measure https://www.cbsnews.com/news/malaysia-airlines-flight-370-pr... [3] https://www.theverge.com/2016/3/9/11184544/un-flight-tracking-system-malaysia-airlines-mh370 https://www.theverge.com/2016/3/9/11184544/un-flight-trackin...

geysersam 4y ago
Satellite phone text messages cost about $1 each. Sending one every 5th minute seems sufficient. That's $120 for a 10 hour flight. Seems technically quite doable with existing technology at a reasonable price? I imagine there are optimization that could be done to reduce the cost further. Big customers with constant rate usage can probably negotiate a more favorable price etc.
- TheCondor 4y ago
  How much did they spend trolling random places in the Indian Ocean? There are some pretty substantial saving to be reaped just from the making the search more sane. I suspect that there are some extra costs making it "flight ready" and all that stuff, but the fact of the matter is that GPS chips are cheaper and more plentiful than ever, we have Starlink coverage in Antarctica now, and they're send more and more satellites up every week now. There are costs in securing it and then receiving the data and such but it all seems really inepensive compared to the planes, the insurance payouts and the search and recovery efforts.
- wkat4242 4y ago
  Iridium short burst data messages are much much cheaper in bulk than that :)
lxgr 4y ago
Given that the very flight in question had Inmarsat equipment on board, I think it's fair to be at least somewhat surprised by the lack of periodic location updates. But technology in aviation moves (generally for very good reasons!) at a different pace than in many other industries, and in this case it unfortunately meant having an operational satellite communications system on board (used for engine performance data telemetry transmitted to the manufacturer), but not having it wired up to ADS-C, an existing standard which allows automated position reporting over that same connection. Inmarsat has modified their offerings [1] since MH370: One free ADS-C position report every 15 minutes for planes that do support it (implying that transmission cost is a concern for not activating the option unless required for air traffic control via FANS), and the ability to piggy-back a position report onto a "handshake/ping" for those that don't, which would presumably have included MH370. For aircraft not equipped with any Satcom, some satellite constellations (including e.g. the latest generation of Iridium satellites) include payloads that allow direct tracking of ADS-B signals as well. [1] https://www.icao.int/Meetings/GTM/Documents/Inmarsat.pdf https://www.icao.int/Meetings/GTM/Documents/Inmarsat.pdf
- XorNot 4y ago
  I will say it seems utterly bonkers, given the cost of airliners, that we're talking about transmission costs on the order of minutes and not doing per-second updates. Admittedly a lot of this was before our new era of satellite constellations, but surely the future should now be "per second updates and streaming audio/video via satellite"?
  - dale_glass 4y ago
    Airliners are expensive, but satellites are even more so. Also there's a whole lot of air traffic.
    - lxgr 4y ago
      You don't need one satellite per airplane, just like you don't need one base station per mobile phone. Modern satellites can shift terabits per second. They can handle a lat/long pair every couple of minutes sent by every oceanic flight in the air comfortably (even when only using the L-band, which needs much smaller and simpler antennas than those used for in-flight Wi-Fi).

by chem83 4y ago

geysersam 4y ago

Satellite phone text messages cost about $1 each. Sending one every 5th minute seems sufficient. That's $120 for a 10 hour flight. Seems technically quite doable with existing technology at a reasonable price? I imagine there are optimization that could be done to reduce the cost further. Big customers with constant rate usage can probably negotiate a more favorable price etc.

TheCondor 4y ago
How much did they spend trolling random places in the Indian Ocean? There are some pretty substantial saving to be reaped just from the making the search more sane. I suspect that there are some extra costs making it "flight ready" and all that stuff, but the fact of the matter is that GPS chips are cheaper and more plentiful than ever, we have Starlink coverage in Antarctica now, and they're send more and more satellites up every week now. There are costs in securing it and then receiving the data and such but it all seems really inepensive compared to the planes, the insurance payouts and the search and recovery efforts.
wkat4242 4y ago
Iridium short burst data messages are much much cheaper in bulk than that :)

lxgr 4y ago

Given that the very flight in question had Inmarsat equipment on board, I think it's fair to be at least somewhat surprised by the lack of periodic location updates. But technology in aviation moves (generally for very good reasons!) at a different pace than in many other industries, and in this case it unfortunately meant having an operational satellite communications system on board (used for engine performance data telemetry transmitted to the manufacturer), but not having it wired up to ADS-C, an existing standard which allows automated position reporting over that same connection. Inmarsat has modified their offerings [1] since MH370: One free ADS-C position report every 15 minutes for planes that do support it (implying that transmission cost is a concern for not activating the option unless required for air traffic control via FANS), and the ability to piggy-back a position report onto a "handshake/ping" for those that don't, which would presumably have included MH370. For aircraft not equipped with any Satcom, some satellite constellations (including e.g. the latest generation of Iridium satellites) include payloads that allow direct tracking of ADS-B signals as well. [1] https://www.icao.int/Meetings/GTM/Documents/Inmarsat.pdf https://www.icao.int/Meetings/GTM/Documents/Inmarsat.pdf

XorNot 4y ago
I will say it seems utterly bonkers, given the cost of airliners, that we're talking about transmission costs on the order of minutes and not doing per-second updates. Admittedly a lot of this was before our new era of satellite constellations, but surely the future should now be "per second updates and streaming audio/video via satellite"?
- dale_glass 4y ago
  Airliners are expensive, but satellites are even more so. Also there's a whole lot of air traffic.
  - lxgr 4y ago
    You don't need one satellite per airplane, just like you don't need one base station per mobile phone. Modern satellites can shift terabits per second. They can handle a lat/long pair every couple of minutes sent by every oceanic flight in the air comfortably (even when only using the L-band, which needs much smaller and simpler antennas than those used for in-flight Wi-Fi).