• 12 Posts
  • 21 Comments
Joined 1 year ago
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Cake day: June 15th, 2023

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  • Some satellites and rovers have used Radioisotope Thermoelectric Generators (RTGs), which are very different from a nuclear reactor. They use polonium-210, which generates heat, and that heat is converted to electricity with thermocouples. They are low power and inefficient.

    To my knowledge no satellite, with an RTG, has ever used ion propulsion. Few interplanetary satellites have ever even used ion thrusters. Dawn, Hayabusa, and Deep Space 1 are the only I can think of, and they all used solar arrays.

    Ion thrusters are super efficient, but produce extremely small amounts of thrust. They aren’t practical for getting large spacecraft to Mars. These proposed nuclear engines produce large thrust while have efficiency somewhere between regular chemical propulsion and ion propulsion.






  • Ah, I understand now. At least 1 person on this instance has to be subscribed to the community on another instance for it to federate and show up here. All the communities that show up in “All” on this instance are ones that have been subscribed to by at least 1 user on this instance. It is one of the downsides of federation on a small instance, you don’t have a very good “All” to see popular content form communities you aren’t subscribed to.

    There are some tools out there that will force federation with all communities, but the problem with that is it blows up storage requirements.



  • There may be some instances that manually defederated during the whole bot situation. I know there was a tool someone made that automatically updates the defederated list, but I already verified we were off that naughty list. So, it would only be instances that manually defederated that we may still be blocked on. In that case we’d have to message the instance owners and ask to be removed from the list.

    I’m not sure I’m seeing any less communities though, could just be general federation issues. Any specific instances/communities you think are missing?







  • Don’t delete from the local_user table. You only need to delete from the person table, the rest of the tables will be updated automatically and user count will update automatically.

    Edit: The below command will delete all unverified users. NOTE: If you do not have email verification turned on then all users are unverified, therefore all users will be deleted. It also appears with v18 when you enable email verification all existing users remain unverified.

    This is a destructive command, use at your own risk and don’t go fucking with the database if you don’t have backups.

    DELETE FROM person WHERE local = 'true' AND id IN (SELECT person_id FROM local_user WHERE email_verified = 'false');

    In the parenthesis you can add your AND to only select unverified accounts of a certain age.


  • Yes, person table is top level. Delete from person table and it cascades down and deletes from other tables. User count also automatically updates. Just be careful because person table also contains federated users. There is a “local” column to determine if they are local users or not.

    I had about 6k bot accounts, but they were all unverified, so I just deleted all local unverified accounts from the person table.

    Just don’t go messing with the database without backups. My host supports snapshots so I did a quick snapshot before messing with anything.