Set of 20 Space Shuttle Mission Cloth Crew Patches

Description

I am a space enthusiast and worked as an aerospace engineer for NASA for 37 years and am selling some items in my collection.
Offered for sale here is a collection of 20 Space Shuttle cloth crew mission patches.
The patches range in size from 3 inches in diameter to 4 x 5 inches in size.
The key to the missions is as follow in the first photo:
Row 1: STS-4, 6, 41C, 41D, 41G, 51D, and 51B
Row2: STS-61C, 51, 52, 55, 57, 58, and 92
Row3: STS-100, 108, 109, 112, 114, and 129
Space Shuttle flights were numbered sequentially from STS-1 to STS-9 and then a different code was assigned to each mission.
STS-10 was STS-41B (the 4 indicated fiscal year 1984, 1 was a Kennedy Space Center (KSC) launch, and B indicated the scheduling sequence in that year).
The second letter code was 1 for a KSC launch and 2 for a Vandenberg Air Force Base launch, but no launches were ever flown from Vandenberg.
Although NASA never admitted it, this re-numbering change was made to avoid an STS-13 mission because of the bad outcome on Apollo 13.
After the Challenger accident, NASA returned to using a sequential numbering system beginning with STS-26 and many flights were flown out of numerical order.
Please check out my other auctions of space memorabilia