These are so called "Analyst" objects:
Analyst objects are on-orbit objects that are tracked by the U.S.
Space Surveillance Network (SSN) with insufficient fidelity for
publication in the public satellite catalog (SATCAT). The lack of
fidelity may be due to infrequent tracking, cross-tagging (observation
association with closely-spaced objects), ...
While not directly "spaceflight" blockchain technology will be used in the aerospace industry very soon (if not already): for authenticity verification of components.
Many aerospace components are very expensive, produced in low lot numbers, and are engineered to ridiculous toleranxes. Particularly in the aircraft industry, selling counterfeit parts or ...
This answer is a stretch but according to Apollo Guidance Computer Restored, Used to Mine Bitcoin an Apollo Flight Computer has been used to implement blockchain itself!
The article begins:
Some people change the world with technology. Some people use technology to change the world. And some people find ways to mine Bitcoin on really, really, really old ...