Apollo Lunar Surface Journal Banner

Ground Controlled Television Assembly (GCTA or "Gotcha") Engineering Notebook

Copyright 2008 by Eric M. Jones. All rights reserved.
Last revised 1 March 2008.
Scanning by Dave Bohlmann. PDF formatting by Dave Bohlmann and Bill Wood.

Frontispiece from Ground-Controlled Television Assembly: Final Report ( 8.6 Mb PDF )

Ground Controlled Television Assembly (GCTA or "Gotcha") Engineering Notebook ( 7.1 Mb PDF )


ALSJ Contributor Dave Bohlmann has contributed an engineering notebook compiled by his uncle, Richard Bohlmann and colleagues at the Manned Spacecraft Center. Dave writes, "the notebook contains about 50 pages and has entries dated 8-Apr-1971 thru 13- Apr-1972. It looks to be a lab book concerning final integration testing of the LRV's Ground Controlled Television Assembly (GCTA) and the Lunar Communications Relay Unit (LCRU). It's a bit interesting to compare the notebook with the GCTA Interim Final Report (linked above). For instance, one entry says 'data drop-out during rover running at 10 km/hr'."

"It looks like several people used it, but my uncle (he calls himself "Dick" on the inside cover) made most of the entries, it seems. He and several guys used it to track test results with each other"

"I copied only those pages with writing on them. They skipped pages, I think once they realized their felt marker was coming through, they stopped writing on both the front and back of a sheet. You can see some of the writing from other sheets still coming through, though, which is why I'm making a black/white version to maybe help readability. The sheet having pages 21/22 was torn out of the book."

"They refer to Apollo 15, 16 and 17 as Flite 1, 2 and 3, it looks like. It's mainly about crystal oscillators, transmitters and computer commands -- things that did not work per spec, of course. I've got a bit of RF experience, and they use typical abbreviations for local oscillators and RF kind of stuff. Comparing with the GCTA Interim Report (linked above), the dates mentioned in there, where the equipment was sent to KSC, matches (more or less) the dates in the notebook."

Olin Graham, who worked at MSC during Apollo, has examined the notebook. He says that the team was working at KSC to clear discrepancies / anomolies that arose in either the qualification units or flight units. Some of the people mentioned in the notebook are Andy Anderson, the RCA Lead Engineer under contract to NASA; Charlie Coe, Lockheed, who normally worked in Building 44 at MSC in Houston; and John Miller, a MSC engineer who also worked out of Building 44.

Bill Wood, who was lead USB Engineer at the Goldstone Tracking Station during Apollo writes, "I used the same FSN notebooks during my Apollo career. I still have six on my bookshelf. Very interesting reading. It may have been used at KSC during the checkout of the LRV's, (the reason being that) there are references to signals received at GMIL, which was the MSFN station at KSC)."

Journal Home Page