Interesting that on June 3, the FCC requested information from SpaceX on its recent modification request. SpaceX responded the next day with the information.
In opposition to @SpaceX's request to lower altitude of all #Starlink orbital planes @amazon argues in @FCC letter SpaceX should inform public about percentage of sats working nominally, warns sats will intersect with one another & those of #ProjectKuiper:licensing.fcc.gov/myibfs/downloa…
Astonishing that @SpaceX may have used outdated models & data to assess #spacedebris impact risk for Starlink. Equally astonishing that the assessments do not account for its own satellite footprint, or those from other proposed constellations. Simply not good enough.
SpaceX has found that acquiring all 60 satellites in a launch package upon initial insertion is very challenging, and failure to establish contact quickly can mean that a healthy satellite will reenter the atmosphere and be lost.Accordingly, SpaceX requests that the STA extension authorize its satellites to transmit TT&C signals in the 12.15-12.25 GHz band at a slightly higher power level so that they are easier to acquire after insertion. At present, SpaceX satellites transmit TT&C signals at 14 dBm upon orbital insertion at 280 km altitude. SpaceX proposes to boost the power to 23 dBm under the following circumstances. In this regard, it is important to note that all SpaceX satellites are programmed not to transmit until they have been contacted by an earth station. For the first 24 hours after insertion, the satellites would be programmed to respond at the current nominal power level. If they have not established a link within that timeframe, they will then respond at the higher power level if contacted within the next 48 hours. At the end of this 72-hour cycle, the satellites will reboot and repeat the 24/48 hour power cycle. At any point in this process after the satellites establish contact with SpaceX’s TT&C earth station, they will quickly revert to their authorized (lower) power levels.SpaceX estimates that in the large majority of cases its satellites will need to transmit for approximately five seconds at the higher power level before reducing back to the currently authorized level. That should be sufficient to downlink trajectory information so that SpaceX’s TT&C ground station can track the spacecraft and maintain contact. In a small number of cases, it is possible that the satellite may be unable to close the link for the full five second period, and thus will continue to transmit bursts of trajectory information until it is either successful or passes out of the TT&C earth station’s view.
SpaceX withdrew 3 gateway applications. I marked them with yellow color on the map. I'll wait for a few days to see if they refile at the same locations. If not I'll move the gateways to a hidden by default layer.
That is a map of where a satellite can talk to a ground station, not a coverage map.To have a connection you need to be able to see a satellite, and it needs to be able to see a ground station.Not only do you want to be inside the orange lines, but you want the entire 900 km circle centered on you to be within the orange lines.Consider a customer near Mexico City. They can see satellites in a 900km radius circle, but almost half of those (to the south) will not be able to see a ground station. So they would either need almost twice as many satellites, or a ground station in or south of Mexico City (Acapulco would be good).Similarly if you are outside the orange lines in Cancun roughly half the satellites you can see would be in range of a ground station, so you would have about the same connectivity as in Mexico CityYou have the same issue, but to a lesser extent, near Miami. Occasionally you would be able to see a satellite south of Cuba, but it would not be able to see Cape Canaveral (or any other ground station).If they don't want ground stations outside the US, there would be slight, perhaps insignificant, improvements in coverage of small parts of the contiguous US by putting ground stations near the remaining "corners" -- Nogales, AZ; Grand Isle, LA; Key West; Hatteras; Cape Cod.
Two new gateways in the southeastern US.Baxley, GA: https://fcc.report/IBFS/SES-LIC-INTR2020-01527Robertsdale, AL: https://fcc.report/IBFS/SES-LIC-INTR2020-01528
My suspicion is that these gateways are predominantly located on existing Internet backbone cabling or at major switching nodes. The Baxley, GA location looks to define a Y with a Jacksonville, FL leg, an Atlanta, GA leg and a Charleston,SC leg. Even though the cities are small (only a few thousand inhabitants) they are flush with Internet access.You are correct about the Pizza on a stick UTs. They are likely Ku band only. The Gateway would need higher gain Ka band antennas with little to no RFI between antennas to function correctly to be able to connect to many sats at once. The FCC licenses are probably related to these Ka band antennas and their much higher ERP (Effective Radiated Power).
49.5. Not my worst wild guess of the week. 50W into a 50db antenna seems kind of excessive for that short a distance. But I don't have any experience at that kind of data rate. And, a better photo.
