Box cover is illustrated with picture of Earth and Moon and space satellite, with "Astro Blitz" in a kind of stencil font.
This edition lists copyrights of 1968 and 1969 in various places; this author is unsure where the 1971 date for this entry came from. It may well apply to this edition, or not.
Published by House of Games Corporation, which was an alternate or subsidiary name for Waddingtons at the time. Says Made in Canada and lists Don Mills, Ontario as the address.