STS-51-D was the sixteenth flight of NASA's Space Shuttle program, and the fourth flight of Space Shuttle Discovery.[1] The launch of STS-51-D from Kennedy Space Center (KSC), Florida, on 12 April 1985 was delayed by 55 minutes, after a boat strayed into the restricted Solid Rocket Booster (SRB) recovery zone. STS-51-D was the third shuttle mission to be extended.
This is an apparent modern reproduction, single piece patch, fully merrowed edge.
This STS-51D patch could be manufactured by Eagle Crest Emblem Inc. (formaly Swissartex Emblem Inc.). Swissartex manufactured a one piece vacuum sealed backed version nearly identical to the image above. The one shown above has a shiny plastic coated backing to it which fits in with Eagle Crest Emblem Inc. patches.