Gene and Danny: Here is the time line for the next MEX BSR: day 128 (local time 07:20 PM Friday to approximately 01:00 AM Saturday) at DSS 43. This will be a very similar start to the other experiments we have done recently; but it is much longer (88 minutes), and the last half hour is very dynamic (SCHAN 3 FRO_X every minute). Surface echoes start on the high side of the carrier, and slowly drift higher. The region being probed is cratered terrain northwest of the large basin Hellas. At 05:57 the echo reaches its maximum separation from the carrier and starts to drift back. During the final half hour, the reflecting region races down the southwest edge of Hellas, then across its southern margin, ending in cratered terrain southeast of Hellas just before occultation. The incidence angle on the surface increases from 39 degrees at the beginning (LCP much stronger than RCP, but both weak) to 60 degrees at 06:12 (approximately equal RCP and LCP) to nearly 90 degrees just before occultation (echoes will be entirely RCP, possibly quite strong and moving rapidly back toward the carrier, which will also be strong because the HGA will be returning to Earth point at occultation). The SCHAN 3 X-Band FRO assignments I have made below are intended to keep the echo 2-8 kHz to the right of center in the 25 kHz window. If the echo gets too close to the upper edge, you may need to make some real-time adjustments; just remember to keep RCP and LCP synchronized. If the echo drifts into the left half of the window, there is no harm done. For playback, I recommend the following for the 25 kHz data (no segment longer than 88 minutes): Pre-cal Track until start of 100 kHz data Surface observations until end of 100 kHz data Remaining track plus post-cal For 100 kHz playback four 22 minute segments would be best; but I can carve these up at Stanford if you give me an 88 minute file from each RSR. I expect to be at home during this experiment. You can phone me at 650-494- 9272. Thanks, Dick 2010/128 (UTC) - - - - - - - 02:20 Begin Pre-cal at DSS 43 FGAIN = 60 dB (all channels, except X-RCP) 65 dB X-RCP FRO_X = 0; FRO_S = 0 (all SCHAN) Start 4-channel 25 kHz recordings after Step 5 (new NOP) Stop 25 kHz recording after Step 20 (new NOP) 04:20 Begin track X-Band should be OFF 04:26 X-Band AOS X-Band telemetry ON - ignore it 04:27 S-Band ON 04:42 Resume 25 kHz recording X-Band telemetry OFF Advise DSS 43 of switch to planetary coordinates at 04:55 Advise DSS 43 of start of MINICAL #1 at 04:58 04:51 Begin SLEW #1 04:55 DSS 43 switch to planetary coordinates FRO_X = +49000 Hz (SCHAN 3) FRO_S = +9000 Hz (SCHAN 3) FRO_X = +35000 Hz (SCHAN 4) 04:58 Begin MINICAL #1 05:13 End of MINICAL #1 (end of step 5) 05:15 End SLEW #1 05:16 Begin 100 kHz recording (SCHAN 4) 05:23 FRO_X = +53000 Hz (SCHAN 3) 05:36 FRO_X = +57000 Hz (SCHAN 3) 06:12 FRO_X = +53000 Hz (SCHAN 3) 06:18 FRO_X = +49000 Hz (SCHAN 3) 06:22 FRO_X = +45000 Hz (SCHAN 3) 06:25 FRO_X = +41000 Hz (SCHAN 3) 06:27 FRO_X = +37000 Hz (SCHAN 3) 06:30 FRO_X = +33000 Hz (SCHAN 3) 06:32 FRO_X = +29000 Hz (SCHAN 3) 06:34 FRO_X = +24000 Hz (SCHAN 3) FRO_S = 0 Hz (SCHAN 3) 06:36 FRO_X = +19000 Hz (SCHAN 3) 06:37 FRO_X = +16000 Hz (SCHAN 3) 06:38 FRO_X = +13000 Hz (SCHAN 3) 06:39 FRO_X = +10000 Hz (SCHAN 3) 06:40 FRO_X = +7000 Hz (SCHAN 3) Advise station of MINICAL#2 starting at 06:48 There will be no return to spacecraft pointing predictions 06:41 FRO_X = +4000 Hz (SCHAN 3) 06:42 FRO_X = +1000 Hz (SCHAN 3) 06:43 FRO_X = -2000 Hz (SCHAN 3) 06:44 End 100 kHz recording (SCHAN 4) X-Band LOS S-Band LOS 06:48 Begin MINICAL #2 07:03 End MINICAL #2 (end of step 5) FRO_X = 0 Hz (SCHAN 3) FRO_S = 0 Hz (SCHAN 3) 07:05 Early end of track (scheduled EOT 07:40) Go to zenith Begin post-cal when ready 08:40 End post-cal (or earlier, if post-cal complete) End 25 kHz recordings End of Activity