Digitizing NASA-ESA Taped Imagery, project to digitize 60s-70s data Options

[apollo16uvc]

Hello dear readers,

Here are some satellite telemetry tapes I have acquired. They are from the 60's to 70's.





These tapes contain the raw signal received from satellites at NASA tracking stations like GFORKS, STIAGO and WINKFIELD.

It seems that there 2 telemetry tracks, 4 misc tracks (Including a reference track) and one voice track.

I am working on getting a recorder to play these tapes. If you know the location of any 7-track instrumentation recorders (Ampex FR-100, FR-600) that would help.

Here is a sample of tape 3141/2N003 played back on a 1/4 inch 4-track Akai at 7.5 I.P.S: https://www.dropbox.com/s/k2jbyoka6n50yhh/3...168-2.flac?dl=0
The tape number on the boxes and documentation is 3141/2N003. The number on the reel itself is 10786-16-8.

Satellite: 1963-014A & B (ERS5)
Recorder: FR-100
Speed: 15 I.P.S
Station Name: GFORKS

Here is an other sample from a different tape: https://forum.nasaspaceflight.com/index.php...1683;sess=54302

Here is a video showing the tracks: https://youtu.be/I85-aZuupxM
With this we have proven that something is on the tape, and it can be picked up with a sound head. This is the case with most of my tapes.

I am currently talking with someone who has several 1/2 8-track studio tape recorders, and we are looking into getting an Otari MX-5050 8 unit working. This unit is most useful because it can play at both 7.5 I.P.S and 15 I.P.S, which is what we need. All mechanical functions seem to work fine, and the input VU meters register when the build-in tone generator is switched on. But... there is no sound from his tape! (His own audio, not a NASA tape)

This recorder is currently undergoing repairs.

Other tapes I have acquired are ESA tapes from the same era.
I have tested out three of the five ESA tapes with a magnetic viewing solution, and all three clearly showed 7 tracks like the NASA tapes. This means they have not been degaused or overwritten with an audio recorder. The tracks look like raw telemetry, not computer tapes. One tape has a label that clearly says it came from a tracking station. I think we should be able to digitize these too eventually. The tracks are very clear.

The tapes I have tested are:
TD-1 (Tape ID: 1117-09-08-
ESRO 1A (Tape ID: 800 645 08 10B)
HEOS A2 (Tape ID: 1115 06 11B)

I have made two videos on it in dutch.
First, a tutorial on how to make your town magnetic viewing solution.
https://www.youtube.com/watch?v=j_kA0cnkBLI


And finally, a video where I visualize the magnetic tracks on 3 tapes:
https://www.youtube.com/watch?v=LAjU2AHIksA

I have attached some photos of the tracks to this message. I promise I will publish a big archive with detailed scans and photos of all ESA and NASA tapes currently in my possession.

Macro photos (Large!)
https://imgur.com/a/rnlJH9P


So what are we looking for?
I am interested to know if its possible to determine the frequency of a track with the track photos.Is it possible to replace the 8-track head in an 1/2 inch Otari tape recorder with a 7-track head, perhaps from a computer tape drive?Is it possible to decode the digitized raw telemetry data into numbers, perhaps a spreadsheet or interactive database?Would people be interested to crowdfund some of the greater expenses that may be required?
Best regards,Niels

[Gerald]

A data character is presumably stored on the tracks in parallel. So, it will be difficult to make a decision on the basis of a single track. The 8th track might encode a parity bit. So, testing the outcome of several assumptions may resolve the question about the applied code. It's some Manchester, rather obviously. My first choice would be the differential code, since it's more resilent against polarity errors. But on the basis of a character stream, some higher-level encoding, like Hamming or Gray codes may still be possible.
A first milestone would be retrieving a stream of characters like they are on the tape on the most basic level in (polar) NRZL. Any higher-level interpretation, like Manchester, can be derived from the NRZL character stream.

[apollo16uvc]

A data character is presumably stored on the tracks in parallel. So, it will be difficult to make a decision on the basis of a single track. The 8th track might encode a parity bit. So, testing the outcome of several assumptions may resolve the question about the applied code. It's some Manchester, rather obviously. My first choice would be the differential code, since it's more resilent against polarity errors. But on the basis of a character stream, some higher-level encoding, like Hamming or Gray codes may still be possible.
A first milestone would be retrieving a stream of characters like they are on the tape on the most basic level in (polar) NRZL. Any higher-level interpretation, like Manchester, can be derived from the NRZL character stream.

The satellite tapes are all 7 tracks. And I don't think they are computer tapes, but original tapes recorded at a satellite tracking station with instrumentational recorders. My NASA satellite tapes clearly have documentation that states this. Unfortunately no documentation came with the ESA tapes, but one of the 5 tapes has a label stating its from a tracking station, and recorded at 7.5ips. Given the labels on this ESA tape match the ones on other ESA tapes, all are from a tracking station. I think computer tapes are variable speed, so they would not have 7.5 or 15 ips written on them.

(It needs to be clarified that I also have NASA COMPUTER tapes, but the tapes posted in this thread are NOT.

I have actually visualized the tracks on NASA and ESA tapes with a DIY magnetic viewing solution, see here a ESA TD-1A tape (Not sure which one)

And here from NASA tape Sat-SNTAGO-120J827:


Compare this to a computer tape, clearly different:

And the documentation that comes with most of the NASA tapes looks like this:


What I think has happened, is that the signal from TD-1A was processed into a bitstream, and this bitstream was recorded on tape with an instrumentational recorder.
So not a computer/digital tape per se, as it contains analog tracks with voice, timing, etc. So I don't think there will be a parity track, none stated anywhere.
I think the tracking station processed the satellite signal, encoded the telemetry bitstream as NRZL or manchester and this is what we are now reproducing. Of course it is all possible we are reproducing the wrong track and its actually a timing code, but I doubt that. The problem is that we got only 1 of the total 7 tracks. Looking for an instrumentation recorder, or just the 7-track head if possible. We don't even need a working one, as long as the head is in good shape I can transplant the 7-track head in a 1/2 inch Otari MX5050 III studio recorder for proper playback. The Otari is under repairs.

I thought manchester and NRZL were two separated methods of encoding, and not just two different levels?I think the signal we get with the tape recorder is about as low as we can go!