Roll Maneuver 1997/03/20-21 THURSDAY-FRIDAY, MARCH 20-21, (DOY 79/DOY 80) ---------------------------------------------- Beginning of 1 degree offpoint/trim in Normal Mode: 10:13:39 UT from Nominal (+ 1.781) to the 1 degree OFFSET (+2.783) End of 1 degree offpoint in Normal Mode: 11:10:47 UT from Nominal (+ 1.781) to the 1 degree OFFSET (+2.783) NOTE: In RMW mode from 079/12:00:59 to 080/03:46:40 = ~ 15 hours 46 minutes 3 hours 40 min at +90 position for SWAN Transition from Normal Mode to RMW Mode at 12:00:59 UT ROLL #1: Roll from OFFSET POSITION (2.783) to delta +30 degrees Command sent to start the slew: 12:24:00 UT Slew Start: 12:24:51 UT Slew Stop: 12:30:36 UT FDF value of Roll Angle: +32.773 ROLL #2: Roll from delta +30 to delta +60 degrees Command sent to start the slew: 13:01:59 UT Slew Start: 13:02:51 UT Slew Stop: 13:08:50 UT FDF value of Roll Angle: +62.771 ROLL #3: Roll from delta +60 to delta +90 degrees Command sent to start the slew: 13:41:39 UT Slew Start: 13:42:33 UT Slew Stop: 13:48:18 UT FDF value of Roll Angle: +92.789 ROLL #4: Roll from delta +90 to delta +120 degrees Command sent to start the slew: 14:22:40 UT Slew Start: 14:23:31 UT Slew Stop: 14:29:31 UT FDF value of Roll Angle: 122.793 UT ROLL #5: Roll from delta +120 to delta +150 degrees Command sent to start the slew: 15:01:32 UT Slew Start: 15:02:14 UT Slew Stop: 15:08:14 UT FDF value of Roll Angle: +152.799 ROLL #6: Roll from delta +150 to delta +180 degrees Command sent to start the slew: 15:39:31 UT Slew Start: 15:40:12 UT Slew Stop: 15:46:12 UT FDF value of Roll Angle: +182.799 ROLL #7: Roll from delta +180 to delta +210 degrees Command sent to start the slew: 16:17:32 UT Slew Start: 16:18:26 UT Slew Stop: 16:24:10 UT FDF value of Roll Angle: +212.799 ROLL #8: Roll from delta +210 to delta +240 degrees Command sent to start the slew: 16:55:37 UT Slew Start: 16:56:24 UT Slew Stop: 17:02:24 UT FDF value of Roll Angle: +243.010 ROLL #9: Roll from delta +240 to delta +270 degrees Command sent to start the slew: 17:33:34 UT Slew Start: 17:34:22 UT Slew Stop: 17:40:22 UT FDF value of Roll Angle: +272.754 ROLL #10: Roll from delta +270 to delta +300 degrees Command sent to start the slew: 18:12:51 UT Slew Start: 18:13:35 UT Slew Stop: 18:19:35 UT FDF value of Roll Angle: +302.741 ROLL #11: Roll from delta +300 to delta +330 degrees Command sent to start the slew: 18:55:49 UT Slew Start: 18:56:33 UT Slew Stop: 19:02:32 UT FDF value of Roll Angle: 332.375 ROLL #12: Roll from delta +330 to OFFSET position Command sent to start the slew: 19:34:38 UT Slew Start: 19:35:31 UT Slew Stop: 19:41:16 UT FDF value of Roll Angle: 2.713 At this point in the timeline, from the OFFSET position, we turned the spacecraft in the counterclockwise (negative x direction) and go in steps (deltas) of 90 degrees. ROLL #13: Roll from OFFSET to delta of -90 degrees Command sent to start the slew: 20:19:21 UT Slew Start: 20:20:14 UT Slew Stop: 20:35:58 UT FDF value of Roll Angle: -87.229 ROLL #14: Roll from delta -90 to delta -180 degrees Command sent to start the slew: 21:09:28 UT Slew Start: 21:10:12 UT Slew Stop: 21:25:56 UT FDF value of Roll Angle: -177.189 ROLL #15: Roll from delta -180 to delta -270 degrees SWAN +90 degree roll) Command sent to start the slew: 21:56:58 UT Slew Start: 21:57:40 UT Slew Stop: 22:13:39 UT FDF value of Roll Angle: -267.118 ROLL #16: Roll back to nominal SoHO observing position Command sent to start the slew: 02:16:03 UT Slew Start: 02:16:58 UT Slew Stop: 02:33:00 UT FDF value of Roll Angle: + 1.949 Command Sent to go from RMW to NM at: 03:46:40 UT. ------------------------------------------------------------------------ WHEEL SPEEDS AT VARIOUS TIMES (RECORDED) DURING THE ROLL FOR MDI TEAM ( provided by Helmut Schweitzer, and Jean-Philippe Olive) ---------------------------------------------------------------------- Please find hereafter a summary of the roll maneuver (about the wheels and with the roll angle). Notice that the time are not exactly the dwell starting time. Best regards. The times given are somewhere during the dwell, sometimes at the start of the dwell. Time w1 w2 w3 Roll Degree ------------------------------------- 12:02 2565 -3103 1738 NM to RMW 12:31 1728 -3088 2650 32.773 13:10 592 -2250 2853 62.771 13:50 -543 -805 2549 92.789 14:30 -1370 853 1717 122.793 15:10 -1658 2287 591 152.799 15:49 -1349 3103 -533 182 799 16:28 -506 3093 -1354 212.799 17:12 629 2256 -1642 243.010 17:58 1765 810 -1338 272.754 18:22 2586 -847 -506 302.741 19:04 2890 -2277 629 332.375 19:59 2575 -3098 1754 2.713 20:37 1770 810 -1327 -87.229 21:27 -1333 3098 -517 -177.189 22:15 -522 -805 2565 -267.118 02:39 2613 -3087 1743 1.949 end of Roll