Accelera is an all-caps typeface shown by Photo-Lettering in their Alphabet Thesaurus Vol. 3 from 1971, without individual design credits. The extrabold rounded sans is distinguished by a triple South shade. It was offered in five variants named A to E. In A, letterforms and shades are all open. B has open letterforms and solid shades. It’s reversed in D. In Accelera C, the first and third shades are filled in. Finally, all parts are solid in E.
The most extensive use of Accelera that I’m aware of is for a series of science fiction novels by Andre Norton (1912–2005), published in paperback by Fawcett Crest between 1979 and 1981. Apparently three shadows were considered insufficient to hint at the depth of Norton’s adventures in space: in the first volumes, the number of typographic echoes was cranked up to a whopping eight, printed in alternating colors. In later additions, it was decided that a double shadow is enough.
No typographer is credited. The cover art is by Scottish artist Ken Barr (1933–2016).