Available for sale... contact me if interested:
This is an Eagle Picher manufactured Telemeter Beacon NICAD battery which flew onboard the October 1960 Key Hole (KH-2) Mission 9002 photo-reconnaissance satellite (more commonly referred to as Corona) film canister. The canister was debited after 2 days in space and recovered over the Pacific by an aircraft as it descended under parachute. The mission flew under the cover name of the Discoverer Science Program (as Discoverer 17).
Corona was designed at Lockheed's covert "advanced projects" facility at Hiller Aircraft in Menlo Park, California.
Discoverer 13 (which preceded Discoverer 17 by several months) was the first film Capsule successfully recovered from orbit earlier that year in 1960 (the preceding flights were all failures or non-orbital tests). Discoverer 13 is in the Smithsonian.
Discoverer 14 was also a successful capture – it resides at NRO (so no artifacts are available from that mission). 15 and 16 were not recovered (they failed).
So Discoverer 17 represents the first source of material successfully deorbited available to a private collector from a US spacecraft.
A very good CIA written Nomegraph of the Corona/early Keyhole Program, also Wikipedia has more program details.