Gene, Danny, and John:

Here is the time line for the MEX BSR on day 256 (local time 13 September,
Sunday midnight to approximately 5:45 AM).

This is almost identical to the one we did on day 255 except that the
longitudes are shifted about 60 degrees eastward.  Not much will happen for
the first 50 minutes.  The reflecting region drifts slowly from about (56N,
123W) to (72N, 88W).  Then the spacecraft starts moving in toward periapsis
and we have to do some FROs during the final 17 minutes.  We end at (56N,
45W).  As on day 255, there is an approach to the PHOENIX landing site; but
we only come within about 270 km, and that happens about 26 minutes into the
observation.

There may be about 37 minutes of X-Band telemetry after BOT and another 23
minutes before EOT; I'll leave it to you and the NOPE whether you pursue
these.  If you skip the post-BSR telemetry, you could have EOT at 11:35 (30
minutes early).  The station should NOT change the microwave configuration to
collect telemetry.

If you need to reach me, try 530-426-3536.  I will probably not call in
unless I am completely sleepless.

Thanks,
Dick


2009/256 (UTC)
- - - - - - -

07:00  Begin Pre-cal at DSS 63
       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

09:00  Begin track (X-Band telemetry ON)

09:22  S-Band transmitter ON

09:37  X-Band telemetry OFF

       Resume 25 kHz recording (SCHAN 3)

       Ask station to switch to 'planetary' coordinates at 09:42

09:42  Station switch to 'planetary' coordinates

09:44  FRO_X = +25000  (SCHAN 3)
       FRO_S = +25000  (SCHAN 3)

09:45  Begin MINICAL #1

09:55  Begin SLEW #1 (not visible in 25 kHz)

10:00  End MINICAL #1 (end of step 5)

       End SLEW #1

       FRO_X =  -7000 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

10:26  Passing about 270 km from the PHOENIX landing site

10:54  FRO_X = -2000 Hz (SCHAN 3)

10:58  LCP echoes becoming stronger than RCP

10:59  FRO_X = +3000 Hz (SCHAN 3)

11:03  FRO_X = +8000 Hz (SCHAN 3)

11:05  Advise station of upcoming MINICAL #2 (starts 11:08)
       Advise station of return to spacecraft coordinates (11:25)

11:07  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)

11:08  Begin MINICAL #2

11:23  End MINICAL #2 (end of step 5)

11:24  FRO_X = 0 (SCHAN 3)
       FRO_S = 0 (SCHAN 3)

11:25  Return to spacecraft coordinates

11:28  End SLEW #2

11:35  Optional early EOT (to skip post-BSR telemetry)

11:37  X-Band ranging ON

11:42  X-Band telemetry ON

       S-Band OFF

12:05  X-Band OFF

       End of track

       Go to zenith

       Begin post-cal when ready

13:05  End post-cal (or earlier, if post-cal complete)

       End 25 kHz recordings

       End of Activity