ACE Weekly 09/03/04 - 09/09/04 All ACE spacecraft subsystems are performing nominally. An attitude=20 maneuver was successfully executed on 09/03/04. The next attitude maneuver= =20 is scheduled for 09/10/04. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D Orbit Events: The ACE transit of the Solar Exclusion Zone (SEZ) continues through=20 09/11/04. The minimum Sun angular radius was 0.32 degrees (as seen from=20 Earth's center) on 08/30/04. Features of this transit are given in the=20 following table. 8/18 4.96 deg inbound 8/25 2.13 deg inbound 8/29 0.61 deg inbound 8/30 0.32 deg minimum SEZ angle this transit 8/31 0.41 deg outbound 9/05 2.30 deg outbound 9/11 4.78 deg outbound Some preliminary data in regards to Signal-to-Noise Ratios (SNR) for=20 contacts with DSS-27 at low (498 bps), medium (7968 bps) and high (87648 bps) downlink data rates: DOY SEV angle 498 7968 87648 --- ---------- ---- ------ ------- 241 1.03-1.00=B0 8.2 242 0.67-0.64=B0 4.1 243 0.35-0.32=B0 15.0 7.5 -2.5 (no data at hi-rate) 244 0.37-0.40=B0 17.8 13.0 2.8 245 0.67-0.70=B0 8.0 246 1.05-1.08=B0 9.5 From the last transit, we found that DSS-27 could get good lock with=20 SNR=3D0dB (noise as big as signal). Given this data and the data from the= =20 last transit, it looks like the following is a good rule-of-thumb: 0.3=B0-0.5=B0 50-50 chance of getting hi-rate with 34m/D27 >0.5=B0 likely to get hi-rate with 34m/D27 0.5=B0-0.8=B0 50-50 chance of getting hi-rate with 26m >0.8=B0 like to get hi-rate with 26m We have been able to get acquire low and medium rate at any SEV angle=20 (Sun-Earth-Vehicle). =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D OCRs Executed: None =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D Ongoing Activities: TAPS: - Installation of TAPS release 4.3 occurred on 07/20/04. FOT testing of=20 this release is ongoing. -- Of the 6 DRs fixed in release 4.3, all have been verified. -- Two (2) new DRs have been opened to date. ---------------------------------------------------------------------------- Automation (ROBOTT): - On 08/25/04, ROBOTT v0.8.1 was installed on String 1 (OCR GND-143). -- Operations is being conducted in the "auto" mode with the FOT closely= =20 monitoring and noting any discrepancies. - Testing of v0.8.1 by the FOT will continue on String 2. -- To date all DRs fixed in this release have been tested. One (1) DR has failed and eight (8) new DRs have been written against v0.8.1. - ROBOTT v0.9 is in development and is tentatively scheduled for delivery=20 to Strings 2 & 3 in the coming week. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D Extra Spacecraft Activities: None =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D Anomalies: DOY 04250 (09/06/04) ACE Anomaly G04-0103 - ROBOTT Failed To Run Script=20 FOT_RUN_ADS The FOT configured C&C to run the script FOT_RUN_ADS before BOT=20 occurred. After the procedure G_INITIAL_CONTACT was ran C&C failed to=20 execute the script FOT_RUN_ADS. IMPACT: FOT had to initiate a block=20 replay and execute the script FOT_RUN_ADS manually. DR CDSID# 00021051 DOY 04252 (09/08/04) ACE Anomaly G04-0088 (Appended) - ADS Failure Received error when attempting to start ADS. Killed processes on=20 workstation and rebooted the software. IMPACT: No impact to FDF. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Glen A. Miller ACE Flight Operations Observatory Engineer Honeywell Technology Solutions Inc. Goddard Space Flight Center Building 14, Room W10A Mail Stop 428.2 Greenbelt, MD 20771 Office: 301-286-7071 Pager: 800-425-3174 Fax: 301-286-1729 gamiller@pop500.gsfc.nasa.gov ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~