I've been asked a few times about space resources available online for primary education, so I'm going to try to collate a list here - this is non-exhaustive, so please feel free to offer suggestions!
The European Space Agency have a range of activities for different key stages:
https://www.stem.org.uk/esero/resources
https://discoverydiaries.org/resources/
Some of my colleagues also helped to provide videos for the STEMLearning Youtube channel, in case that provides ideas:
https://www.youtube.com/c/STEMLearning
There’s a competition on right now to design artwork for the side of the rocket launching JUICE, a Jupiter mission I’ve been working on for the past decade:
https://www.esa.int/kids/en/learn/Our_Universe/JUICE/Juice_Up_Your_Rocket!_art_competition
Some ideas for Space Resources for KS2:
https://www.ogdentrust.com/about-us/news/bringing-deep-space-to-the-primary-classroom
https://www.greatscienceshare.org/weekly-themes-2021-week-2
Destination Space, funded by UKSA:
