Brand/Issuer: Ukraine postal service in cooperation with the National Space Agency of Ukraine (НКАУ) and NASA.

Type: Registered illustrated space-themed postal cover commemorating the STS-87 Space Shuttle Columbia mission and Ukrainian research cosmonaut Leonid Kadenyuk, postmarked Khotyn, Chernivtsi region, 6 December 1997.

Left-side cachet artwork: large vertical blue panel titled "КОСМІЧНА ВАХТА АРГОНАВТА СУВЕРЕННОЇ УКРАЇНИ" ("Space Watch of the Argonaut of Sovereign Ukraine") with a space shuttle flying above a stylized regional map naming Zalishchyky, Zastavna, Kitsman, Khotyn, Klishkivtsi, and Chernivtsi above a detailed vignette of the medieval Khotyn fortress.

Additional printed design elements: simple framed registration box at upper right with "P" and "Хотин", fine border around the cachet, and cream envelope stock providing a neutral background for the blue illustration.

Postage labels: vertical 40k "UKRAINA 1997" stamp depicting Space Shuttle Columbia launching with Ukrainian and United States flags and text "Спільний експеримент Columbia", paired with matching label for mission STS-87 bearing the circular "COOPERATIVE UKRAINIAN EXPERIMENT" patch, bilingual "НКАУ NASA" inscription, and Ukrainian legend naming cosmonaut-researcher of Ukraine L. Kadenyuk.

Cancellation: black commemorative shuttle cancel struck over the stamp pair with stylized orbiter silhouette, stars, and Ukrainian text referencing the Ukrainian-American space experiment, with locality and date text "Хотин, РВЗ Чернівецька обл. 06.XII.1997".

Reverse side: full-panel block of Ukrainian text in blue describing Ukraine's role in space exploration from earlier cosmonauts to the STS-87 cooperative experiment, biographical notes on Leonid Kadenyuk, and the "Космічна вахта Аргонавта" program, with publisher's imprint at the bottom crediting "Дивосвіт" (Dyvosvit), copyright 1997, and listing the artist and text author.

Color: Multi-Color; Certification: Uncertified; Grade: Ungraded; Quality: Used; Type: Cover; Country/Region of Manufacture: Ukraine; Place of Origin: Ukraine.

Keywords: 1997 Ukraine Columbia STS-87 Kadenyuk space cover, NASA НКАУ joint shuttle experiment, Khotyn Chernivtsi Argonaut series, Ukrainian space thematics postal history.