Need help digitizing NASA tapes

[DSD-13]

I have got great news on the new ESA tapes!

I have tested out three of the five 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 tapes I have tested are:
TD-1 (Tape ID: 1117-09-08-B)
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.

And finally, a video where I visualize the magnetic tracks on 3 tapes:

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.

I am interested to know if it is possible to determine the frequency of a signal by the macro photos, any ideas?

Best regards,
Niels.

Redu TD 1-5

• DSD-13
• Feb 28, 2019

Redu TD 1-7

• DSD-13
• Feb 28, 2019

HEOS A2-44

• DSD-13
• Feb 28, 2019

HEOS A2-34

• DSD-13
• Feb 28, 2019

ESRO 1A-17

• DSD-13
• Feb 28, 2019

ESRO 1A-15

• DSD-13
• Feb 28, 2019

ESRO 1A-09

• DSD-13
• Feb 28, 2019

ESRO 1A-07

• DSD-13
• Feb 28, 2019

 

[DSD-13]

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:

To give you an idea of how satellites sounded in the 60's and 70's check out this website with recordings.


I made a video where I play the tapes and show it on an oscilliscope:

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?

Signal played at 20% original speed, sounds like morse code.


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:

Signal played at 15% original speed, sounds like morse code again.

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

 

[Lavane]

Very cool. I knew someone that worked on population systems from the Apallo missions into the shuttle missions. He told me so much was lost or just tossed.

 

[DSD-13]

Gerald from the unmannedspaceflight forum has the following idea:

When coding the upper potential with 1, and the lower potential with 0, with a more or less fixed clock rate, we get pairs 01 or 10, never 00 or 11. So such a pair, or transition, seems to code a bit .
So it should be fairly easy to convert the signal into a bit stream.

Then it only requires us to find the relevant documentation so that we can write a computer program.

WWV Voice found on beginning of NASA tape

On satellite tape 'Sat-SNTAGO-120J827' a voice can be heard briefly at the beginning. The voice probably tells us the recording time. "The time is 11 5 AM" This is WWV time signal that was THE time standard in the US. It was broadcasted around the US.

The satellite is Upsilon 61, the recording date was Sept 7, 1961

I had to play the recordings backwards.
Here the fragment as an MP3 file.

Between the two voice recordings, "1605" is sent in CW (morse code)

 

[Chip Chester]

Sounds maybe like FSK -- frequency shift keying -- as used on old-school TDD (Telecommunication Device for the Deaf -- the original texting)?
Used on the occasional modem as well. Handy for data over voice-quality links.

 

[djwhy60]

Holy Cow.....this is very interesting!

 

[Pio1980]

Sounds maybe like FSK -- frequency shift keying -- as used on old-school TDD (Telecommunication Device for the Deaf -- the original texting)?
Used on the occasional modem as well. Handy for data over voice-quality links.

Teletype also, dunno about pre-digital fax.

 

[bryans12v]

This is very interesting!

 

[DSD-13]

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...

 

[CoastinHome]

I would imagine these tapes are recorded with an absolute time/date reference encoded onto one of the tracks. Very likely what you have is (or is very similar to) SMPTE (Society of Motion Picture and Television Engineers) Linear Time Code.

The film, recording and broadcast industries have for decades used SMPTE Time Code to provide an accurate frame reference for locking audio to film and as an audio/video cataloging and editing reference. The terms “SMPTE” and “Time Code” are used almost interchangeably. Although analog audio needn't otherwise be represented in intervals, it is necessary to quantize it and assign it a string of unique addresses for video synchronization purposes.

SMPTE Time Code is an adaptation of the time coding that was in use by NASA to track space flight. In its current form it is referenced to video frames (roughly 1/30th of a second) and is based upon a 24-hour cycle. Within the 24-hour period each "frame" is identified by the exact time with a unique SMPTE address number in hours, minutes, seconds, and frames. Sub-frames are also addressed (each frame contains an "even" and an "odd" "field" -- representing the interlace of video lines in each frame). There can also be extended data which represents the date, GPS location, etc.

The SMPTE timecode signal is comprised of a string of 80-bit digital words that can be recorded on an audio track of a video or audio tape recorder using a modulated audio carrier -- or alternatively inserted into the blanking interval of the video signal to later be decoded.

SMPTE linear (or longitudinal) timecode "LTC" is recorded lengthwise on the tape as an audio track. When played back as audio from an analog tape it sounds about the same as a fax or modem sounds when it's transferring data.

(You'll also run into "VITC" (pronounced vit-see). Vertical interval timecode is embedded in the video content. On old TVs were you can adjust the vertical hold and see that black bar (the vertical blanking interval), you will sometimes see the upper edges of that black bar flickering between black and white as the frame data changes.)

It sounds like you'll need a SMPTE linear time code reader to decode the time reference track.

Horita made some small, portable, reliable and relatively inexpensive units In the early days of digital. A good choice of the Horitas would be a TRC-50PC -- as this will allow you to log the data to a PC. Without the PC interface the audio timecode can only be regenerated and/or converted into a "window burn" -- that familiar HH:MM:SS:FF (hours minutes seconds frames) window you will occasionally see on archived footage. So you might want to be able to log it to a PC -- or as a minimum choose a SMPTE linear time code reader which has a panel display so you can see how the linear time code data is being interpreted. Otherwise you will need to add a video monitor to be able to view the window burn. Depending on the content on the other tracks you may want to record a video of whatever you are using to interpret the other tracks -- and use the time code reader to overlay (create a "window burn") of the time reference.

If you need to get into the technical details, you might want to look at a book called "The Time Code Handbook".

Cool project!