# April 27, 1950 — White Sands Proving Ground, NM — Cinetheodolite Film Taken by Tracking Station

**URL:** https://uapdiscovery.discourse.group/t/april-27-1950-white-sands-proving-ground-nm-cinetheodolite-film-taken-by-tracking-station/572
**Category:** Blue Book Unknowns
**Created:** [April 26, 2026, 9:35pm UTC](https://uapdiscovery.discourse.group/t/april-27-1950-white-sands-proving-ground-nm-cinetheodolite-film-taken-by-tracking-station/572 "2026-04-26T21:35:21Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![jeffknox](https://avatars.discourse-cdn.com/v4/letter/j/e47c2d/32.png) [@jeffknox](https://uapdiscovery.discourse.group/u/jeffknox)
#### Post date: [April 26, 2026, 9:35pm UTC](https://uapdiscovery.discourse.group/t/april-27-1950-white-sands-proving-ground-nm-cinetheodolite-film-taken-by-tracking-station/572/1 "2026-04-26T21:35:21Z")

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![image](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/f/fb440172a883890dab5771dea288b2f2985d017a.jpeg)

April 27, 1950 — White Sands Proving Ground, NM  
While preparing for an MX-776A Shrike air-to-ground missile test at White Sands Proving Ground, New Mexico, Charles Riggs, a member of the Project Twinkle cinetheodolite camera crew supplied by Land-Air Inc., sees, tracks, and manages to film four high-flying objects streaking across the sky. Another station also tracks the objects. The photos show only a smudgy dark object, but the triangulation results in a calculation by mathematician Wilbur L. Mitchell and Capt. Perry Bryant of the objects’ size as 30 feet in diameter and 150,000 feet in altitude. [Eberhart]

Documents:

 ![04271950-WhiteSandsNM-Document-1](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/2/260e14e3754cc5b890aebb677deb9808d6d17beb.jpeg)

 ![04271950-WhiteSandsNM-Document-2](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/f/fb9920596d057f35c6af06099848e2d68197dbef.jpeg)

Sources:  
Brad Sparks, Blue Book Unknowns Catalogue, Case 367, p. 88;

 ![04271950-WhiteSandsNM-Sparks-Case367-p88](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/a/a68e24d3873ef7d22c56782a5b756648fe02f249.png)

Edward Ruppelt, The Report On Unidentified Flying Objects, 1956, p. 88;

 ![04271950-WhiteSandsNM-Ruppelt-p88](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/2/2df49970085fd4589627a0585807ec3e81e4b7c7.jpeg)

Timothy Good, Above Top Secret, pp. 354–355;

 ![04271950-WhiteSandsNM-GoodATS-p354](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/0/0dc5c31327f9ba0abb7bc53b0018b53353cf95bd.jpeg)

 ![04271950-WhiteSandsNM-GoodATS-p355](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/e/e7730fdb3817f749a7bde2fc5170617a368d80a0.jpeg)

Loren E. Gross, UFOs, a History: Volume 6, April–July 1950, The Author, 1990, pp. 35-37;

 ![04271950-WhiteSandsNM-Gross-p36](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/d/d65d01ca1ffd0f853cce42d5a5b10a80c197fe7d.png)

 ![04271950-WhiteSandsNM-Gross-p37](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/f/f5dea10130e9fa97851753b40f62dba37512d233.png)

Bruce Maccabee, “The White Sands Films,” IUR 21, no. 1 (Spring 1996): 22–25;

 ![04271950-WhiteSandsNM-IURv21n1-p22](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/5/5802133009ebbcbb9fa350e42c4070c68ad4f973.jpeg)

 ![04271950-WhiteSandsNM-IURv21n1-p23](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/9/9b3734c6bd2b29f37103854e1cf5adfb4ea84595.png)

 ![04271950-WhiteSandsNM-IURv21n1-p24](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/5/5776c925592310ed5f902872eb39fce76ac3b9a1.jpeg)

 ![04271950-WhiteSandsNM-IURv21n1-p25](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/c/c33535e9976b6cce5d9ca0a45d437e3f8edd833c.png)

Thomas Tulien, ed., Proceedings of the Sign Historical Group UFO History Workshop, Sign Historical Group, November 2001, p. 44;

 ![04271950-WhiteSandsNM-SHGProceedings-p44](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/9/905f3147aaed3f59af6a3c035927e48a180ad97c.png)

Jerome Clark, The UFO Encyclopedia, 3rd Ed., pp. 544–545;  
Jerome Clark, The UFO Encyclopedia, 4th Ed., p. 602;

 ![04271950-WhiteSandsNM-ClarkIII-p544](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/7/74145a89865153480512b4a51936d382bc3d8905.png)

 ![04271950-WhiteSandsNM-ClarkIII-p545](https://canada1.discourse-cdn.com/flex011/uploads/uapdiscovery/original/2X/1/16633be7e9400a248140c8a63320d3354e31849b.png)

Michael Swords File, 9F;

NICAP, “Cinetheodolite Film Taken by Tracking Station”;  
[Various other documents and sections from books not included in this thread]

> **[UFO Report](http://www.nicap.org/500427whitesands_dir.htm)**