Gene, Danny:

Here is the time line for the MEX BSR on day 234 (local time Saturday 2 AM to
approximately 8:30 AM).

Except for the pre-cal, minicals, and the post-cal, this one could be
scripted.  Almost nothing happens.  There is an option for collecting 1-1/2
hours of telemetry between BOT and the beginning of BSR activities and
another 12 minutes at the end.  The last 17 minutes of the track has the
spacecraft transmitters off.  I'll leave it to you and the NOPE whether you
pursue the telemetry.  The station should NOT change the microwave
configuration to collect telemetry.

During the 'echo' hour we move from cratered terrain at (19N, 12W) almost due
north across what is known as the north-south dichotomy to an end point in
northern plains at (52N, 15W).  The spacecraft is near its maximum altitude
when we start and the cratered terrain is likely to be rough.  The altitude
has decreased to about half at the end, and the plains should be smooth.
Throughout, we have close to grazing incidence on the surface (73-80 deg from
vertical).  So I expect you will see relatively narrow echoes with increasing
strength during the hour; and RCP will be much stronger than LCP.  The echo
is 2 kHz below the carrier at the beginning and only 4 kHz below at the end,
so we don't need to chase it with FROs.

I'll  plan to call in, but it will probably be toward the end.  If you need
to reach me, try 650-494-9272.

Thanks,
Dick


2009/234 (UTC)
- - - - - - -

09:05  Begin Pre-cal at DSS 14
       FGAIN = 60 dB (all channels, including X-RCP)
       FRO_X = 0; FRO_S = 0 (all SCHAN)
       Start 4-channel 25 kHz recordings after Step 4
       Stop 25 kHz recording after Step 18

11:05  Begin track (X-Band should be 1-way; ranging ON, telemetry ON)

11:52  Apoapsis (spacecraft at greatest altitude above Mars)

12:20  S-Band ON

12:35  X-Band ranging OFF, telemetry OFF

       Resume 25 kHz recording (SCHAN 3)

       Ask station to switch to 'planetary' coordinates at 12:40

12:40  Station switch to 'planetary' coordinates

12:42  FRO_X = +25000  (SCHAN 3)
       FRO_S = +25000  (SCHAN 3)

       Begin MINICAL #1

12:53  Begin SLEW #1 (not visible in 25 kHz)

12:57  End MINICAL #1 (end of step 5)

12:58  End SLEW #1

       FRO_X =  0 Hz (SCHAN 3)
       FRO_S =  0 Hz (SCHAN 3)

       Begin 100 kHz recordings (SCHAN 4)

       Begin surface reflections
       Expect S-Band echoes to be much weaker than X-Band
       RCP echoes much stronger than LCP

13:25  Reflecting region moving from craters to smoother plains

14:00  Advise station of upcoming MINICAL #2 (starts 14:05)

14:05  FRO_X = +25000 Hz (SCHAN 3)
       FRO_S = +25000 Hz (SCHAN 3)

       End 100 kHz recordings (SCHAN 4)

       Begin SLEW #2 (not visible in 25 kHz)

       Begin MINICAL #2

14:13  End SLEW #2 (not visible in 25 kHz)

       Advise station of upcoming return to spacecraft coordinates (14:20)

14:20  End MINICAL #2 (end of step 5)

       FRO_X = 0 (SCHAN 3)
       FRO_S = 0 (SCHAN 3)

       Return to spacecraft coordinates (DSS 14 pointing)

14:30  X-Band range modulation ON, telemetry ON

       S-Band OFF

14:42  X-Band OFF

       End of track

       Go to zenith

       Begin post-cal when ready

16:00  End post-cal (or earlier, if post-cal complete)

       End 25 kHz recordings

       End of Activity