Space Cover 673: Ukraine Unofficial FDC.It is common in USA find many thousands of unofficial First Day Covers (onwards FDC).
FDCs produced by dealers, collectors and even particulars with different kind of illustrations (printed designs, rubber cachets, hand painted drawings, add-ons) postmarked from designated official city or from different places are seen around all States.
However, it is very uncommon mainly in Europe and maybe in other world places as FDC are not enough valued. They are considered only philatelic material (no postal material) with less interest in front of other postal documents like revenues, aerograms, postcards...
For this reason, it is difficult to find unofficial FDC for European issues. All documents available are official FDCs issued by Postal Administration, and nothing more.
Sometime ago, I found above depicted FDC which represents an unofficial FDC for the first day of issue of this 70k stamp by using a different illustration than official.
On April 12, 2007, a pair of Ukranian stamps was issued (70k Zenit 3SL rocket launched from Sea Launch platform and 70k Leonid Kadenjuk First Cosmonaut of Independent Ukraine) inside the Soviet tradition of commemorating the "Day of Cosmonautics" (each April 12 in memory of first space flight by Yuri Gagarin).
As comparison, below the official Ukranian FDC for this stamp.
Both covers postmarked at Dnipropetrovsk, where Yuzhnoe Design Bureau is located. There, Zenit rockets are designed.
As unofficial FDC bears an USA address, maybe this person was who made this cover. Anyone knows?