"We chose...not to do these other things not because they are [hard],
but because they are [expensive], because that goal will [not] serve to organize and
measure the best of our energies and skills, because that challenge is one that we are
[not] willing to accept, one we are...willing to postpone, and one which we [have no
intention] to win." -- President John F. Kennedy, 1962
The functions of telemetry, command and ranging are handled by two identical S-band transponders. On ISEE-3 one transponder was designed to operate continuously, transmitting PCM telemetry. The second transponder is used only for ranging; however, the PCM telemetry can be switched to the second transponder in the event of failure of the first transponder. The choice of S-band over VHF for ISEE-3 was dictated primarily by stringent telemetry downlink requirements such as the long range and a view angle near the solar direction. The uplink frequencies are 2041.95 and 2090.66 MHz; the downlink frequencies are 2217.50 and 2270.40 MHz. The transmitter output power is 5 watts. Both transponder transmitters can transmit through the medium gain antenna simultaneously, although they will radiate with opposite circular polarizations. This antenna has a 9-dB gain and a vertical beam width of 18 degrees.
Can we tell the spacecraft to turn back on its thrusters and science instruments after decades of silence and perform the intricate ballet needed to send it back to where it can again monitor the Sun? The answer to that question appears to be no.
Several months of digging through old technical documents has led a group of NASA engineers to believe they will indeed be able to understand the stream of data coming from the spacecraft.
I found http://ipnpr.jpl.nasa.gov/progress_report/42-76/76K.PDF which indicates that ICEE-3 was never designed to use the DSN for communications and a special filter had to be added to the Block V masers at DSS-14 and DSS-63 in the mid-80s to communicate with it. According to http://deepspace.jpl.nasa.gov/dsndocs/810-005/101/101E.pdf the maser was replaced at DSS-14 (Goldstone) in 2010 but the one at DSS-63 (Madrid) isn't going to be until this November, but S-band uplink isn't supported at Madrid because of frequency conflicts.
first and foremost: spacecraft back then spoke IRIG-106 ( these days they speak CCSDS, but that didn't exist back then ).
Back then, satellites were primitive by todays standards - there were no on board processors, just sequencers with hardwired sequences.
Encryption back then wasn't an issue. Forget about
What it comes down to is:
- Get the spaceprobe command/telemetry docs
( what command does what, what data are on what channel ).
- Get a USRP/umTRX/BladeRF/HackRF Jawbreaker
- Get a sufficiently strong power amp
- Get a preamp with preselection filter
- Get GNURadio or RedHawk and use their graphical
design environment and design a transceiver (or modify one of the existing designs like multimode, gqrx or the like.
- Hack on the above IRIG-code
- Get a big antenna, e.g. this one:
It has the advantage to come with a crew of hams who pull off just anything, like this:
In the above project they cooperated with NASA
One of the key guys:
My proposal: GSFC should contact James Miller,
G3RUH and tell him what they want and work with
him. I'm pretty sure they will like that project.
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