(meteorobs) re: Stardust Re-entry : radio attempt : inconclusive

[drobnock]

Tom:
Just a few comments on your observations on the uncertainty of forward
scatter reflections.

I reviewed the NASA video of the reentry ( NASA coverage on NASA video
feed) of Stardust and saw the jpg at spaceweather.com. There did not
appear to be a strong visual trail created during  reentry. This could
be an indicator of weak ablation of the vehicle's surface material. Is
it possible that the entry speed of 12.8 kms could have an effect on
creating weak ionization even though the maximum vehicle surface
temperature at about 61 km was to be between 2204 C to 2760 C? The
vehicle did have sufficient mass.

You may want to see if the tracking radar images for the reentry are
available and you may want to consult an amateur radio group to see any
one was attempting scatter communication. One group in November 2004
reported success with the Genesis reentry. see
http://www.bratsatv.org/milliwatt/mw_p8_2004_11.html.

I did not hear any reports -- could have missed them -- relevant to any
sonic boom being created.

George John Drobnock

January 15, 2006

  I attempted a forward scatter radio observation of the Stardust space
capsule
re-entry but my results are inconclusive as I write this quick report.

  From my observatory in north central New Mexico forward scatter
reflections could
have been marginally receivable from radio stations in the Pacific
northwest US.
Unfortunately, my location of 20 miles southeast of Santa Fe, NM means I
had to aim my
antennas towards the vicinity of Santa Fe itself which made it difficult
to tune past
local radio stations. The local FM dial from 88 MHz to 108 MHz is pretty
saturated
around here and I was limited to one space on the dial at 89.5 MHz.

  Between 0956 UT and 1000 UT I noted some distinct scatter reflections
but they
weren't coherent enough to conclusively be the Stardust capsule and
could have been
made by natural meteors.  I recorded until 1020 UT thinking there might
be a reflective
trail that remained in the sky.

  I will study my audio recording tomorrow with a fresher mind to see if
there is
anything significant or less obvious.

  I would be interested in any other scatter attempts, be they positive,
negative, or
inconclusive.

  Thomas Ashcraft
  Radio Fireball Observatory
  ashcraft(at)heliotown.com