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/314N003-10786168-2.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?action=dlattach;topic=46255.0;attach=1541683;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://forum2.magnetofon.de/index.php?page=Attachment&attachmentID=24717&h=d57b5d6a8cd8c3b2b1942b23b70a7068139d6120
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
I have finally finished v1.0 of the archive for the NASA satellite tapes.
https://archive.org/download/SpaceData/Sat-53123114313-Version1.0.zip (Object photos, text file.)
https://archive.org/download/SpaceData/Sat-GFORKS-314N003-Version1.0.zip (Object photos, documentation, Akai RTR sample, visualized tracks)
https://archive.org/download/SpaceData/Sat-GFORKS-314N079-Version1.0.zip (Object photos, documentation, Akai RTR sample)
https://archive.org/download/SpaceData/Sat-GFORKS-330N100-Version1.0.zip (Object photos, documentation, Akai RTR sample)
https://archive.org/download/SpaceData/Sat-SNTAGO-120J827-Version1.0.zip (Object photos, documentation, visualized tracks)
https://archive.org/download/SpaceData/Sat-SNTAGO-314J019-Version1.0.zip (Object photos, documentation)
https://archive.org/download/SpaceData/Sat-WINKFIELD-330P001-Version1.0.zip (Object photos)
Topic title edited for clarity and generalization.
Some interesting new finds, did we play telemetry?
Last week I took the time to play some ESA tapes (1/2 inch 7-track) on my Akai X201D (1/4 inch 4-track)
The tapes played:
1.
SAT: ESRO 1A
TAPE ID: 680841-292-230
ESOC/Section TLM: 13496
DATE: 24 JULY 70
2.
SAT: 720,141
TAPE ID: 1135 05 10A
ESOC/Section TLM: 21554
DATE:
3.
SAT: TD-1
TAPE ID: 1117 09 08 B
ESOC/Section TLM: 16837
DATE: "Day 089"
4.
SAT: TD-1A
TAPE ID: 1118 07 09 A
ESOC/Section TLM: 16672
DATE:
http://'http://www.dd1us.de/historical%20sounds%20from%20space.html'
I made a video where I play the tapes and show it on an oscilliscope:
https://www.youtube.com/watch?v=_SnRvu9bfFk
Some remarkable details:
ESRO 1A has a lot of activity at the beginning, it looks like a reference signal that is being adjusted. There pitch changes and there are periods of noise. Eventually we receive a stable signal which is certainly more complex than a simple sine wave.
ESRO 1A:
Oscilliscope:
Spectrogram: seems to show a kind of square wave, would this be satellite data?
http://'https://archive.org/download/apollo16uvc_gmail_TD12/TD-1A-3.mp3'
The space between the signals is similar to track 6 of the ESRO 1A tape:
TD-1
Oscilliscope : The wave of this signal swells up and comes down again.
Spectrogram : And here you can see that too.
TD-1A
Oscilliscope:
This signal has two harmonic waves:
And when we zoom out, it has a kind of block pattern:
But when it is very interesting to delay the signal, it sounds like a morse code again.
Spectrogram:
http://'https://archive.org/download/apollo16uvc_gmail_TD12/TD-1A-3.mp3'
A lot of new information that will take some time to process.
It seems to me quite possible that this is the received data. If we find documents from the relevant satellite with information about telemetry, should it be possible to create a program or circuit that processes the signal?
A program could convert it to a spreadsheet. How much volts the battery outputs every second for example.
I do not know anything about it, but the ESA recordings do not seem to be FM-modulated, since such a wave looks very different.
The NASA recordings are usually not, so apparently AM and FM modulation was not common in recordings from this time.
The NASA documentation usually also has "Direct" recordings and not "FM"
I am looking for people who may be able to help with the relevant satellites, and who are more acquainted with this kind of work.
Niels
I love that you are interested in the fine details of early sat comm, preserving the nuances of actual comm that could be lost with time.
Here is an idea of how to convert the diagram into a bit stream:
Also between the two voice recordings, "1605" is sent in CW (morse code)
A data character is presumably https://en.wikipedia.org/wiki/Magnetic_tape_data_storage 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 https://en.wikipedia.org/wiki/Hamming_code or https://en.wikipedia.org/wiki/Gray_code 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) https://en.wikipedia.org/wiki/Non-return-to-zeroL. Any higher-level interpretation, like Manchester, can be derived from the NRZL character stream.
Thanks for constraining this further down!
A 100101, for example, in NRZL can be interpreted as a 01 in differential Manchester BP-M, with the initial 10 in (10)0101 as clock signal, the 00 in 1(00)101 encoding a 0, then 01 in 10(01)01 the next clock signal, 10 in 100(10)1 encoding a 1, then 01 1001(01) clock, and so forth. In BP-S, the same NRZL sequence would encode 10, if read from left to right.
So, you can just digitize the NRZL, and decide later, how to translate it into a Manchester bit stream of various possible types. If the tape is recording a sequential bit stream, it's possible that the direction of the recording is alternating with the tracks, meaning that, in principle, only one head is necessary to write and read the track. After reading the first track, the head is moved to the next track, and the tape is running backward. That's to be considered for decoding.
The next step would then look for a header or preamble in the recording, in order to see, whether it's defining some type of higher-level convention. But I'm not sure, which standards have been defined back in 1963.
Finally acquired some 7-track IRIG tape recorder heads, from an Ampex FR-600 no less! two 4-track 1/2 inch heads setup for interlaced 7-track. The 7-track IRIG standard allows for a single 7-track head, or two heads for interlaced 7-track.
Unfortunately not much luck with the Otari MX5050 III. Peter tried an other reel that he knows has audio recorded on it, and the Otari's VU meters do move. But there is still no audio coming out...
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