POLAR Telecon Agenda for January 25, 2008
Agenda:
0. Upcoming Polar Telecon
1. Operations
2. End of Mission Operations
3. THEMIS Conjunctions
4. MFE Data Processing Status
5. MDI Science Report
0. Upcoming Polar
Telecon
Friday January 25, 2008
4 pm ET, 3 pm CT, 2 pm MT, 1 pm PT
PIs and their designated representatives will be telephoned
at their usual numbers.
Other participants may call in at: 1-800-988-9524
Password: Polar Telecon (Leader: John Sigwarth)
The web site for the final agenda will be:
http://pwg.gsfc.nasa.gov/polar/telecons/2008Jan25/
Future Polar Telecons
Next telecon: Friday February 29, 2008
Future Telecon Science Discussion Schedule
[Errors/omissions/preferences to: nicola.fox@jhuapl.edu]
February 2008:
CAMMICE
March 2008: VIS
April 2008: TIMAS
May 2008: Hydra
June 2008: EFI
July 2008: MFE
August 2008: CEPPAD
September 2008: TIDE
October 2008: PIXIE
November 2008: UVI
December 2008: MDI
1. Operations
If you have any concerns about Polar operations, please contact Nicky Fox (nicola.fox@jhuapl.edu)
Polar Loadshed event
The Polar spacecraft
executed a loadshed event this morning, January 24, 2008 between 0435 UT and
0830 UT. All instruments were shut off by the loadshed and the stored
command table was suspended. Consequently, the Polar spacecraft did not
bring up the radio frequency carrier as expected on the contact scheduled for
0830 UT. This pass occurred during unattended operation. On the
next pass, the Flight Operations Team manually commanded the Polar transmitter
on. Telemetry was received immediately and the Polar FOT began diagnosing
the problem. Telemetry indicates that the spacecraft had experienced an
Under-voltage-1 condition leading to the loadshed. The trip point for the
under voltage condition has been commanded from 21.0 V to 19.6 V. This
can be lowered to 19.1 V or deactivated if necessary. At this time, all
indications are that the Polar spacecraft is operating nominally.
The FOT is still in
the process of determining the exact cause of the under-voltage condition, but
the working hypothesis is that this problem is related to the eclipse season that
Polar began on 1/20/2008. The scheduled contacts are being extended to
allow the instruments to be brought back on line quickly and staffing
arrangements are being made for the weekend. The last loadshed event for
Polar was July 29, 2004.
The Polar Instrument
Teams should begin preparations for bringing their instrument back on
line. Rick Hudson has sent a mail message to each of the instrument’s
point of contact. The tentative order of
reactivation is:
The following is the
tentative plan for Polar instrument recovery following
the Loadshed
anomaly:
DOY
024 2240z - 2310z - PWI
DOY 025 2025z - 2200z - 2030 -
2155 HYDRA
DOY 026 1320z - 2055z - 1320 -
1430 TIDE
- 1430 -
1540 TIMAS
- 1540 - 1610 EFI
- 1610 - 1720 MFE/magnetics
- 1720 - 1830 DPM recovery
- 1830 - 1940 UVI
- 1940 - 2010 CAMMICE/HIT
- 2010 - 2040 CEPPAD
DOY 027 1605z - 1705z - VIS
DOY 027 2215z - 2315z - VIS
DOY 028 1845z - 1935z - VIS
DOY 029 1555z - 1834z - VIS
DOY 030 1130z - 2040z - VIS
DOY 031 1100z - 1425z - VIS
Please be ready and
prepared to work with the Flight Operations Team to execute the recovery as
quickly as possible. Some teams will be asked to support the recovery
Saturday and/or Sunday. With your help
we hope to have Polar back in full operation by the middle of next week.
The eclipse season will continue until 3/5/2008. The longest
eclipses are no more than 45 minutes.
Next Polar Sun Angle maneuver
The upcoming flip maneuver (#18) will be conducted in two segments (provided there is enough fuel).
The first maneuver segment is planned for February 11 (DOY 042) from 2100 - 0001 UTC (~3hrs 1min).
The second segment is planned for February 12 (DOY 043) from 1900 – 0038 UTC (~5hrs 38min).
A maneuver trim would be conducted on February 14 (DOY 045) during the support from 2145 - 0050 UTC.
Should the hydrazine be depleted before reaching the intended target attitude, we will attempt to vent the cold helium gas as a method to thrust Polar in the appropriate direction. These "maneuvers" would take several more hours (over the course of several days) to complete.
The Instrument maneuver timeline for a nominal burn will be sent out this week.
Unattended Weekends
The 12 hour shifts during the weekdays are still being
covered as usual and the MOC staff has a pager to cover emergencies on the
weekend.
MOC staff pager: 301-224-0386
Mike Machado should be contacted by cell phone for
instrument emergencies.
Mike's cell phone: 443-694-4317
2. End of Mission Operations
Instrument operations will cease on 4/15/08 and spacecraft
operations on 4/30/08. A number of teams have requested special operations for
their instruments prior to shut down. These include:
EFI – deploying booms to full extent
TIMAS – operate during a maneuver
HYDRA – test other high voltage levels
PIXIE – attempt to power the instrument
TIDE - exercise some high voltage supplies for Start MCPs
If any other teams wish to conduct instrument “tests” during
this period, please email Nicky (nicola.fox@jhuapl.edu)
as soon as possible.
3. THEMIS Conjunctions
The THEMIS Team has looked
at the major conjunctions thus far.
Below please find their list with some comments. A wiki page will be created for people to put
in their own comments and put together a more comprehensive list towards the
end of next week. THEMIS is holding a science
gathering at Berkeley next Tuesday to discuss any observations or findings
regarding these events. In particular they are interested in the determination
of meridian of the activity.
================================
Major Conjunction
Substorm List
Criteria:
AE>100nT
Fast Survey
B&C likely
bracket Rx site
================================
Comments
2008-01-09 07:00 Twd
flows on B at 23Re
2008-01-05 03:00 Twd
flows on B at 14.5Re
08:00 Twd flows on B at 16.2Re
2008-12-28 01:20 Twd PSBL beams at 14.5Re
04:30 Twd PSBL beams at 14.5Re
2008-12-20 04:00 Probes clustered: inner Msphere
Other Major
Conjunction Activations
------------------------------------
Comments
2008-01-01 01:30
No SS but injections/twd flows
03:50 SS injections/ no twd
flows
04:00
SS injections/ no twd flows
11:30
No SS / Ewd but no twd flows
2008-12-24 05:50 Tail activity earlier,
THEMIS AE >250nT,
AE quiet
------------------------------------
Cluster Conjunction
Activations
------------------------------------
2008-01-11 05:50 Minor Conjunction
------------------------------------
4. MFE Data Processing Status
5. The MDI Science
Report