from Hacker News

Starlink plans to use mercury propellant, 100s tons expected to enter atmosphere

by throwaway2048 on 3/28/22, 10:11 PM with 12 comments

  • by matheweis on 3/28/22, 10:37 PM

    This is an extremely editorialized title.

    The thread is about a law firm that got a un resolution passed to ban the use of mercury as a satellite propellant, on the basis of a company that used it in their thrusters, that was in the process of selling the tech to spacex.

    What it doesn’t say:

    * whether spacex bought it or not

    * whether spacex ever used it or not

    * whether spacex still plans to use it or not

    … and if I’m reading it right, it sounds like the resolution was passed, which ought to mean that spacex doesn’t plan to use it, because that’d be a violation of un treaty.

  • by perihelions on 3/28/22, 10:58 PM

    This thread offers no evidence that SpaceX plans (or had ever planned) to use mercury as an ion propellant. I think the "Starlink plans" part of the title is an unjustified editorialization.

    Starlink thrusters use krypton,

    https://en.wikipedia.org/wiki/Starlink

    edit: If you look at the text of the legal complaint, the only mention of SpaceX mercury is a *pure hypothetical*:

    https://peer.org/wp-content/uploads/attachments/11_19_18_FCC...

    - "If a corporation such as SpaceX, OneWeb, or another major space company were to deploy an entire proposed LEO constellation with cheaper and more powerful mercury-fueled thrusters on-board, they could be launching as much as 198 tonnes of mercury into orbit, which will then be fired off into the upper atmosphere."

  • by jka on 3/29/22, 12:02 AM

    Potentially relevant FCC complaint from November 2018: https://ecfsapi.fcc.gov/file/111998371507/11_19_18_FCC_compl...

    "Apollo tested several fuel types and found that if the corrosive effects of mercury on the spacecraft could be controlled, and they could keep the use of mercury secret, the ACE could seriously outperform its competitors indefinitely. To date, no other electric propulsion thruster can match the efficiency or power of the ACE, and leading experts in the plasma and fusion fields are convinced that Apollo has made a miraculous breakthrough because they all assume that the ACE uses xenon as a fuel source."

  • by Gravityloss on 3/28/22, 10:48 PM

    Mercury is actually a very old electric thruster propellant.

    Xenon is a later invention, revealed in public only after the fall of the soviet union.

  • by aluminum96 on 3/28/22, 10:34 PM

    What is the impact of "hundreds of tons" divided over the world's surface area? It of course sounds like a lot, but the Earth is also quite large, so it's hard to know if these are trace amounts, or large enough to have real health impacts.
  • by bob2222 on 3/28/22, 11:14 PM

    Lol this poor sap actually thinks the UN matters. Does he not know about the past 70 years?