Unfortunately there is zero evidence to explain a) how the virus came to be in space in the first place, b) why it's so similar to known terrestrial viruses, or c) how it could survive the extreme radiation.
There's a brief summary of the theory here: https://www.space.com/coronavirus-not-from-outer-space.html
... or you could go straight to the 'serious' scientific paper: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7358766/
Image below is a photo of the Covid Mothership*.
*Correction: Sorry... I forgot to include the word 'not'. This is not a photo of the Covid mothership. Or indeed a photo.