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Author
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Topic: Apollo 11 surface camera in high resolution mode
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Space Cadet Carl
Member Posts: 225
From: Lake Orion, Michigan
Registered: Feb 2006
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posted 11-12-2010 11:13 AM
   
Has anyone commented on the fact the Neil Armstrong and Buzz Aldrin never had the time to switch their Westinghouse lunar surface TV camera to it's high resolution (1,280 scan line) mode? I know the entire moonwalk was sent to Earth at ten frames per second at 320 line resolution. I'm a bit surprised Westinghouse and NASA went through the effort of adding this special high resolution mode to the lunar surface camera without even attempting to try it out for a minute or two during their moonwalk. |
Glint
Member Posts: 1044
From: New Windsor, Maryland USA
Registered: Jan 2004
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posted 11-12-2010 12:25 PM
My understanding was that the lunar cameras had no external controls. Remember hearing that from a member of the Westinghouse team, at least with respect to the A12 color camera. He said the A12 camera could have been reset following solar exposure, except that the reset button, along with other controls, were only accessible internally.If that's the case, unless they had the necessary tools, the A11 camera had to be left in its pre-configured mode. But why low resolution instead of high? I don't know the answer to that one. |
SpaceAholic
Member Posts: 4494
From: Sierra Vista, Arizona
Registered: Nov 1999
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posted 11-12-2010 12:46 PM
Don't know if this was the rational, however a benefit of going with a lower resolution scan on the initial lunar surface TV feed included increased probability of successful transmission via the USB link (more robust signal being received, less bandwidth, decreased likelihood of timing issues). |
moorouge
Member Posts: 2458
From: U.K.
Registered: Jul 2009
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posted 11-12-2010 02:18 PM
I think your answer may lie here - it was to do with time constraints, aerials, battery life and ground receivers. |
Dwight
Member Posts: 577
From: Germany
Registered: Dec 2003
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posted 11-13-2010 04:12 PM
A bunch of ex-engineers and space historians (myself included) discussed the level of readiness the feature had in January of this year. The Apollo Lunar Surface Journal notes this result: In addition to a framing rate switch, the top of this camera has marks to indicate the field-of-view when either the "35 degree Lunar Day lens" or the "80 degree Wide Angle lens" was in use. On the left, a two-position allows a choice of framing rate of either 10 frames per second or 0.625 fps. The latter was never used on the Moon. In January 2010, Mike Dinn initiated what became an extended exchange of e-mail about the 0.625 fpd mode. The discussion ultimately included Dinn, Dick Holl (Bendix/OTC), Colin Mackellar (editor of the HSK website), Dick Nafzger (GSFC), John Sarkissian (Parkes), John Saxon (HSK), Dwight Steven-Boniecki (author of Live TV from the Moon, and Bill Wood (GDS). Early in the exchange, Wood remember that, while he was doing a final edit of the restored telecast combined with the Flight Director's loop, "I noted Network telling Flight ... that they were ready to handle the super-slow scan rate during the start of Neil's TV Panorama. To me that indicates they planned to support that mode if needed." Nafzger added, "we had the capability to handle the .625 mode and it was intended to look at rocks, etc. as a basic still shot..we did test it and it was fine, but once they started using the 10fps and the worldwide excitement built, Stan (Lebar) said they didn't want to take any chances switching modes!!! They were afraid that they couldn't get back to live tv!!" Holl said, "I remember testing (the 0.625 fps mode) in our downstairs lab (at Australia's Overseas Telecommunication Commission facility at Paddington in Sydney) and it worked fine." Hope that helps. More details of the Westinghouse camera are found in my book "Live TV From the Moon". |
Space Cadet Carl
Member Posts: 225
From: Lake Orion, Michigan
Registered: Feb 2006
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posted 11-13-2010 08:03 PM
Thanks, Dwight. That's probably the most authoritative answer I could possibly hope for. So, it really sounds like the guys in the back room were preparing to have Neil Armstrong switch the camera to it's high-definition 1280 mode before Neil performed the 360 degree camera pan. But I also understand their "fear" that the camera wouldn't switch back to standard mode after Neil finished the pan. If I was in their shoes with a billion people watching live at home, I probably would have made the same decision. Thanks again. |
moorouge
Member Posts: 2458
From: U.K.
Registered: Jul 2009
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posted 11-14-2010 02:28 AM
I have no wish to disagree with Dwight's explanation but the source previously mentioned seems to make it clear also that 10fps was all that the equipment on '11' was capable of handling, switches on the camera nothwithstanding. Hi-res tv was only possible from the CSM with its more powerful S-band aerial and greater electrical supplies from the fuel cells. |
Dwight
Member Posts: 577
From: Germany
Registered: Dec 2003
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posted 11-14-2010 06:21 AM
Your query is exactly what we were discussing in January. We knew the camera was capable of the hi-res mode, but were unsure if the system could actually transmit the end signal. More importantly, had any training been afforded to the tracking station folk in the event of using the hi-res mode. According to the TV guys involved, the system was capable of handling the hi-res mode, it was more a matter for the antenna at the ground station to pickup the sync signal which was essential to decoding the picture. There were special Fairchild monitors in place for the specific purpose of photographing the hi-res image. Also the RCA scan converter had the switch enabling conversion of those hi-res images. |
moorouge
Member Posts: 2458
From: U.K.
Registered: Jul 2009
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posted 11-21-2010 04:12 AM
A full report on the Apollo TV system and its development can be found in document NASA TN D-7476. |
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