# Lockheed D-21

> 1962 American Mach 3+ reconnaissance drone

**Wikidata**: [Q2454458](https://www.wikidata.org/wiki/Q2454458)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Lockheed_D-21)  
**Source**: https://4ort.xyz/entity/lockheed-d-21


## References

1. [Source](https://archive.org/details/darkeagles00curt/page/122/mode/2up)
2. [Source](https://archive.org/details/lockheedblackbir0000jenk/page/22/mode/2up)
3. [Source](https://www.nro.gov/Portals/65/documents/foia/declass/D-21/SC-2018-00037_C05114806.pdf)
4. [Source](https://archive.org/details/lockheedblackbir0000jenk/page/22/mode/2up?q=length)
5. [Source](https://theaviationist.com/2025/07/23/d-21-drone-and-operation-senior-bowl/)
6. [Source](https://archive.org/details/lockheedblackbir0000jenk/page/24/mode/2up)
7. Freebase Data Dumps. 2013
8. [Source](https://archive.org/details/darkeagles00curt/page/130/mode/2up)
9. [Source](https://archive.org/details/lockheedblackbir0000jenk/page/28/mode/2up)
10. [Source](https://archive.org/details/lockheedblackbir0000jenk/page/100/mode/2up)
11. [Source](https://ntrs.nasa.gov/api/citations/20090007797/downloads/20090007797.pdf)
12. [Source](https://pacificcoastairmuseum.org/aircraft/d-21-drone/)
13. KBpedia