I am trying to identify a series of science fiction texts I read as a child. They were used as part of English classes, specifically English language comprehension, basically reading the passage and answering questions relating to the content of what was read.
These stories were read in the early 1980s at a UK primary school in the north of England. I mention location as different schools in different regions of the UK probably used different books.
The details I remember are very vague. Stories featured a space corp or some type, captains, officers, pilots etc. The characters may have been colour coded in a similar way to Captain Scarlet. There were crystals that may have controlled time and possibly space ships too. The most vivid detail I recall was the shock ending of one story in which the main character died, a male and a captain as far as I recall... It was mentioned that he controlled lots of crystals but they had somehow escaped his control. Another character, not realising he is dead, finds him at the controls of his spaceship and says something along the lines of "You look just like my father", implying he has died of old age.