Difficult to imagine. Think about the guidance computer for example.
The Russians did it without even having a global tracking network. They didn't seem to mind wasting astronauts though.
The IBM computers on the ground were heavily transistorised.
There were no transistors that could do S-band RF of course. So even though the ranging achieved about 2 wavelengths accuracy, it was done with a bit rate under 1Mbps - just low-jitter edges.
Clifford Heath.
AlwaysWrong, you must work really hard to be this consistently wrong! Did they come home? Then the LEM Isn't at the landing site, you moron! They crashed the LEM into the moon after returning to the command module. The shock waves were then seen on the seismometers left on the moon.
Yes. I suggested to Dave that he make that video, and introduced him to the folk who could have given him the details - but he couldn't grab any of them (I did though!). Also to Stan Anderson (who was the fleet commander of the Snoopy aeroplanes, not just an "operator" as Dave says) the interview subject of another of Dave's videos.
Clifford Heath.
You are both right. The LM has two parts, the descent stage and the ascent stage. Only the ascent stage leaves the moon. The descent stage remains at the landing site.
It's pretty interesting that there were seven separate stages of the Apollo mission vehicles. Only one safely returns to the earth.
I also found out that the service module was supposed to fire thrusters to make sure it did not pass anywhere near the deorbiting command module. The re was a design problem so this didn't work. On reentry the Apollo 11 crew saw the service module fly past them as they descended, so it ended up in front of them as it disintegrated in the atmosphere. Potentially any part of the service module could have impacted the descending command module res ulting in the death of the astronauts.
-- Rick C. -+ Get 1,000 miles of free Supercharging -+ Tesla referral code - https://ts.la/richard11209
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e f n e
ansistor had not yet been invented? Sometimes I wonder how limited we are with the current technology.
claimed that even today (well, 10 years ago) there was no off the shelf tec hnology that would substitute for the TTL logic based design they used to t ie all the control center equipment together with the same level of fault p rotection and speed/latency. It was pretty interesting.
You could do anything that MSI TTL could do with enough discrete transisto rs.
One of my colleagues at Kent Instruments at Luton (1973-1976) had built a 1
28bit shift register as a stack of printed circuit boards loaded with discr ete transistors. He had been working for Peter Baxandall at the Royal Radar Establishment at Malvern at the time. The small market for that kind of ge ar - at the price it ended up costing - meant that it wasn't available off the shelf as such.Hardware that used that approach - like the first PDP-8 - was, and had been for a decade or so by then.
-- Bill Sloman, Sydney
This one time I got my first Kerbal into orbit on a Mercury-like rocket successfully, unfortunately I forgot to mount retro-rockets on the capsule to de-orbit it. Ooops.
Having the little guy jump outside for a little space-walk and give the capsule a good "shove" with the jets on his backpack, vaguely in the direction of the ground, seemed to do the trick along with atmospheric drag after about another three or four days of orbits. I hope he had snacks
Hell, in case of emergency you don't even need the capsule to get back home. Just pull the rip-cord on your inflatable heat shield, strap the spacesuit to the rear and do it live:
There was no way they could build a scan converter from SSTV to NTSC in hardware in those days. Back then a scan converter was just a camera in front of a CRT.
And of course the setup of the whole thing was extremely tricky. That is visible in the quality of the received pictures: both the contrast and the back-level were completely wrong.
After some time the picture switches from the Honeysuckle Creek receiver site to the Parkes site, where the converter apparently was aligned a lot better (of courst the could tweak it while the other signal was being broadcast), and it also had better SNR due to the larger dish.
But the picture quality still sucked. It is likely that when the original recordings of the SSTV signal had been preserved, we could make a much better scan conversion today. But the tapes have been lost.
I worked on that MK1 ranging machine by General Dynamics. It used dynamic logic, where a signal was a one, and no signal a zero. It had soldered board contacts, where if mission critical problems, you banged on it. I forget if that was still used on Apollo/Soyuz because sometime later they switched o tone ranging. Seems like Bill Wood was going down There, a Goldstone engineer. Pretty amazing guy.
Greg
Mike Dinn just got back to me about Mike, saying:
"Bill had an engineering career at Goldstone - Manned Flight and Deep Space. A very competent engineer - I knew him well. He?s been to other reunions, but couldn?t make this cos of medical problems. He?s written the best essay on Apollo and TV:
Clifford Heath.
On a sunny day (Wed, 24 Jul 2019 14:28:46 +1000) it happened Clifford Heath wrote in :
Thank you very much for that paper. Brings back the amazing old days.
Strange they made that gamma correction error, probably when scientists do not understand video. :-) I also clearly remember that problem with that camera pointed at the sun and it no longer working. We had whole discussions here about that, adjusting cameras was one part of my job back then. Would be nice to back to the moon with modern CCD an CMOS cameras, see how that behaves, High resolution, difficult lighting, bit of an invasion of seagulls yesterday, strange they are here this time of the year, normally only in winter looking for food:
I believe he PDFed the whole station equipment description SPF or something like that I don't know off hand. Sorry to hear of medical problems.
Greg
That was a Westinghouse colour camera that Alan Bean pointed at the sun while mounting it on the tripod. Not the B&W mono camera from RCA that went with A11. But I guess you knew that.
Clifford Heath.
Was that the one with the rotating colour-wheel?
piglet
On a sunny day (Wed, 24 Jul 2019 18:22:13 +1000) it happened Clifford Heath wrote in :
From what I remeber we (I ?) thought the color wheel was burned, but it now seems the tube target electrode was damaged. Vidicons were (was it a vidicon?) very sensitive to burn in. Those were used here in film editing tables, and after some time those had burn in and needed to be replaced. Also I did not know they used an image intensifier.
The head control room here, in the Netherlands, was in the old Vitus studio in Bussum, that studio later burned down. It was a TV studio, recording room, and above that the head control room. We recorded in the 1968 or so on these:
Funny the paper mentions the harddisk slow motion storage at some point, we had the HS100, a huge disc used for slow motion replay with 4 R/W heads moving in sequence:
There is more, do not get me started. That AVR1 was defective by default when you switched it on in the morning. So we finally decided to leave it on over night :-) Still took quite a few people to keep it running, was the first one with digital storage done by switching differrent length delay lines to counter head position switching skew and timing errors. Better stop here.
Only half the area was damaged, and it saturated the AGC. On returning it to earth, simply clipping the AGC wire made (half of) it work again.
....> Better stop here.
Amazing stuff, thanks.
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