Many folks would like to see us back on the Moon and developing its resources.

Monday, March 06, 2006

Good day,

I received an e-mail from Dr. Turyshev at JPL this morning about their efforts to hear from Pioneer 10. (see below)

Doesn't look like they saw anything in the real-time signatures but they will run the recorded track through some software to search for a signal.

In looking at graphs of the bus voltage from the old Master Data Record files you could draw an extended line on the drop off of voltage and guess that you would be at about 26 volts today in 2006.

That is where it was thought the transmitter might not work so no surprise if they can't find any signal.

The last time we saw the carrier was back in January of 2003 but no data lock.

PIONEER 10 SPACECRAFT SENDS LAST SIGNAL After more than 30 years, it appears the venerable Pioneer 10 spacecraft has sent its last signal to Earth.

Pioneer's last, very weak signal was received on 23 January 2003. NASA engineers report that Pioneer 10's radioisotope power source has decayed, and it may not have enough power to send additional transmissions to Earth.

NASA's Deep Space Network (DSN) did not detect a signal during the last contact attempt on 7 February 2003. The previous three contacts, including the 23 January signal, were very faint, with no telemetry received. The last time a Pioneer 10 contact returned telemetry data was 27 April 2002. NASA has no additional contact attempts planned for Pioneer 10.


Distance makes a difference too. The 8 watt transmitter wouldn't be putting out a full 8 watts (a night light of power) and the signals seen at Earth were buried down in the noise you get from just pointing an antenna out into space. It is like looking for a needle in the front lawn down in the grass.

One spike looks a lot like the one next to it.

If you see something you think is your needle you can narrow the band pass filter and magnify what you are looking at. You don't see anything next to it though and so you have to look back and fourth and hope you recognize your needle.

The power source on Pioneer 10 finally degraded to the point where the signal to Earth dropped below the threshold for detection in its latest contact attempt on 7 February 2003. No more attempts at contact are planned at this time. The previous three contacts had very faint signals with no telemetry received. Pioneer's last, very weak signal was received on 23 January 2003. The last time a Pioneer 10 contact returned telemetry data was on 27 April 2002.

Project Manager: Larry Lasher


If I hear more about the analysis of the recorded tracks, will let you know.

Thanks for looking up with me.

Larry Kellogg

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e-mail from Dr. Turyshev at JPL - LRK -

Dear Larry, Colleagues,

We carried out the observations of the Pioneer 10 spacecraft, per our proposal that was approved by NASA earlier last week, on Friday and Saturday nights (local time). There was no real-time detection of a carrier signal from the spacecraft.

We have carried out open-loop (RSR) recordings of the two passes for archiving. We will process the recordings using parameters that would increase the resolution over the real-time spectral reporting by the receiver and search for a signal.

At this time, our team does not suspect any errors in our planning, pointing, uplink strategy or ground receivers tuning predictions. If the signal is not detected in the post-pass processing then there is speculation that spacecraft components have degraded faster than thought or the RTG output was no longer sufficient to power the S-band TWT amplifier.

Now we are getting very close to start analysis of the entire data set that was recently assembled at JPL.


[Second page of a 12 page Power Point presentation describing the upcoming support. - LRK -]

* Three Supports performed over three days
-- DOY 062, 063, and 064 (March 3, 4, and 5)
* 70-m antenna used
* 400 kW uplink power
* Three different tune profiles for capturing the transponder
* Antenna's low noise path utilized
* Radio Science monitoring downlink for signal detection
* DTT system configured for throughput mode if acquisition is achieved.
* NOPE monitoring supports in ROC
* The Pioneer 10 RTLT is 24:56:25 (hh:mm:ss)


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