https://en.wikipedia.org/wiki/Space_(Jimmy_Cauty_album) is interesting – was going to be the Orb’s debut album before Jimmy and Dr Alex fell out. You can hear lots of it in Ultraworld.
If it’s the electronica element of it you want to explore this is is a good compilation from that time – gives a few artists to check out. Not all of it is on Spotify.
https://www.discogs.com/release/215515-Various-The-Positiva-Ambient-Collection
If it’s the ambience/found sound then Brian Eno:
Starting in the 70′;s with Discreet Music / Music for Airports and many more through his discography. More than I know well. I really liked 2016’s The Ship
More conventional songs but a chilled mood – Another Green World is fantastic.
Not quite as ambient – My life in the bush of ghosts (with David Byrne) is early ‘found sound’ stuff but not so chilled out. I liked his album with Karl Hyde from Underworld (Someday World 2014) as well.
Sigur Ros ( ) album is another one I reach for late at night. Mostly much less bombastic that the stuff that gets played on the radio.
(DM if you want a rip of any of those or Chill Out, looks like I was only ripping as VBR mp3’s at the time, and I dumped my CDs bar a very small number – which includes Chill Out)