Operation High Altitude Test aimed to emplace a 123-lb plutonium-powered SNAP-19C telemetry unit on Nanda Devi mountain.
Notes on verification
Multiple independent sources (The Wire, Deccan Herald, Wikipedia, defense forums) corroborate both the operation codename and the ~123-125 lb SNAP-19C plutonium-powered telemetry unit intended for Nanda Devi.
Sources
- How the United States Lost a Nuclear Device and Recovered an Indian Friend (warontherocks.com)
- https://m.thewire.in/article/security/inside-the-nanda-devi-nuclear-spy-mission-what-the-nyt-revisited-and-what-it-missed (m.thewire.in)
- https://www.deccanherald.com/india/cia-tried-plant-surveillance-device-2303164 (deccanherald.com)
- https://www.strategicfront.org/forums/threads/operation-hat-how-cia-lost-a-nuclear-device-in-india-while-spying-on-china-and-almost-polluted-ganga.2014/ (strategicfront.org)