3 ms·

I'm not sure why they're complaining when the SKA isn't even active yet. Once it's active Starlink will do just like they have for other radio telescopes, avoid

I'm not sure why they're complaining when the SKA isn't even active yet. Once it's active Starlink will do just like they have for other radio telescopes, avoid transmitting while they're in the boresight and in general don't transmit toward the antenna. This is a well practiced interaction at this point with scientific agencies in multiple countries. The only thing that they can't stop would be things like reflected unrelated ground communications off of the satellite, but that would be very weak.

aragilar 1y ago
Uh, given there's been radio telescopes there for longer than starlink has existed, I'm not sure why they haven't stopped broadcasting in that area then.
- mlindner 1y ago
  It's possible they haven't requested it yet. I've only heard SKA complaining loudly in the media while American radio telescopes have very obvious blackouts visible on SpaceX's map because they've requested them.
  - aragilar 1y ago
    So everyone needs to go beg every single satellite provider to respect the well known existing radio quiet zones? I suspect it's more likely Starlink is ignoring all other regulators and regulations other than the FCC, hence why the US-based observatories are considered.
    - mlindner 1y ago
      There's several blackout holes in Europe as well. Two in Germany, one in Spain and one in Sweden.
rickdeckard 1y ago
> avoid transmitting while they're in the boresight and in general don't transmit toward the antenna Not sure this will help against the mentioned unintentional electromagnetic radiation (UEMR) likely caused by the electronics of the satellites themselves. "This radio emission at lower frequencies from Starlink isn’t their downlink frequency, but instead unintentional electromagnetic radiation (UEMR), thought to be caused by the onboard electronics of the satellite."
perihelions 1y ago
One interesting complication is that it seems the propulsion, the electromagnetic ion thrusters, are one of the sources of unintended emissions, > "Communication with SpaceX engineers suggested the UEMR originated from the propulsion/avionics system of the satellites as they were orbit-raising at the time of detection."
- notahacker 1y ago
  That's quite a big deal actually, if the propulsion system is the major source of interference. Firstly the propulsion system's operation is infrequent (at least at individual satellite level, although if you've got a constellation as big as SpaceX's you'll have satellites doing orbital transfer somewhere a lot of the time). Secondly it isn't a critical part of SpaceX's tech, and other solutions exist for future Starlink generations which wouldn't compromise its service offering at all. Of course interference from a propulsion system is also less directional and tweakable...
  - deleted 1y ago
    [deleted]
  - m4rtink 1y ago
    They use a high efficiency low thrust hall effect engine - for those kinds of thrusters you might have to run it continuously, possibly continuously to ballance out the atmospheric drag at low altitude. For normal chemical thrusters you indeed use the for just a bit very occasionally (or else you run out of propellant very quickly). Still I agree it is fixeable - they can tune the hall effect thruster on newer sats to not radiate in this band & avoid running the thrusters when in the field of view of that one radio telescope at the times it is operating.
    - notahacker 1y ago
      They're not running thrusters continuously except during orbital transfer. Otherwise they'd run out of propellant pretty quickly even with a HET, and operating smallsats at 559km doesn't require that much orbital correction. They probably fire them far more often for conjunction avoidance than station keeping, but again that's a reported 300 total manoeuvres per day across 8k satellites, which gives them a bit of scope to time them for when they're unlikely to upset regulators

aragilar 1y ago

Uh, given there's been radio telescopes there for longer than starlink has existed, I'm not sure why they haven't stopped broadcasting in that area then.

mlindner 1y ago
It's possible they haven't requested it yet. I've only heard SKA complaining loudly in the media while American radio telescopes have very obvious blackouts visible on SpaceX's map because they've requested them.
- aragilar 1y ago
  So everyone needs to go beg every single satellite provider to respect the well known existing radio quiet zones? I suspect it's more likely Starlink is ignoring all other regulators and regulations other than the FCC, hence why the US-based observatories are considered.
  - mlindner 1y ago
    There's several blackout holes in Europe as well. Two in Germany, one in Spain and one in Sweden.

rickdeckard 1y ago

> avoid transmitting while they're in the boresight and in general don't transmit toward the antenna Not sure this will help against the mentioned unintentional electromagnetic radiation (UEMR) likely caused by the electronics of the satellites themselves. "This radio emission at lower frequencies from Starlink isn’t their downlink frequency, but instead unintentional electromagnetic radiation (UEMR), thought to be caused by the onboard electronics of the satellite."

perihelions 1y ago

One interesting complication is that it seems the propulsion, the electromagnetic ion thrusters, are one of the sources of unintended emissions, > "Communication with SpaceX engineers suggested the UEMR originated from the propulsion/avionics system of the satellites as they were orbit-raising at the time of detection."

notahacker 1y ago
That's quite a big deal actually, if the propulsion system is the major source of interference. Firstly the propulsion system's operation is infrequent (at least at individual satellite level, although if you've got a constellation as big as SpaceX's you'll have satellites doing orbital transfer somewhere a lot of the time). Secondly it isn't a critical part of SpaceX's tech, and other solutions exist for future Starlink generations which wouldn't compromise its service offering at all. Of course interference from a propulsion system is also less directional and tweakable...
- deleted 1y ago
  [deleted]
- m4rtink 1y ago
  They use a high efficiency low thrust hall effect engine - for those kinds of thrusters you might have to run it continuously, possibly continuously to ballance out the atmospheric drag at low altitude. For normal chemical thrusters you indeed use the for just a bit very occasionally (or else you run out of propellant very quickly). Still I agree it is fixeable - they can tune the hall effect thruster on newer sats to not radiate in this band & avoid running the thrusters when in the field of view of that one radio telescope at the times it is operating.
  - notahacker 1y ago
    They're not running thrusters continuously except during orbital transfer. Otherwise they'd run out of propellant pretty quickly even with a HET, and operating smallsats at 559km doesn't require that much orbital correction. They probably fire them far more often for conjunction avoidance than station keeping, but again that's a reported 300 total manoeuvres per day across 8k satellites, which gives them a bit of scope to time them for when they're unlikely to upset regulators