POLAR Telecon Agenda for March 7, 2008
Agenda:
0. Upcoming Polar Telecon
1. Operations
2. End of Mission Operations
3. Polar-retrospective symposium
4. THEMIS Conjunctions
5. MFE Data Processing Status
6. CAMMICE Science Report
0. Upcoming Polar
Telecon
Friday April 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/2008Mar07/
Future Polar Telecons
Next telecon: Friday April 25, 2008
Future Telecon Science Discussion Schedule
[Errors/omissions/preferences to: nicola.fox@jhuapl.edu]
April 2008: VIS
May 2008: TIMAS
June 2008: Hydra
July 2008: EFI
August 2008: MFE
September 2008: CEPPAD
1. Operations
If you have any concerns about Polar operations, please contact Nicky Fox (nicola.fox@jhuapl.edu)
Polar Out of Fuel during the February Maneuver
Polar ran out of hydrazine fuel during the first segment of a 180 degree maneuver
on Monday, February 11, 2008. Approximately 35 degrees of the 180 degree
maneuver were completed. This attitude was safe for Polar for only a few
days. On the following day, the FOT worked to get the last few drops of
fuel out of the backup attitude thrusters and then switched to the contingency
plan of thrusting using the cold Helium gas that is the inert pressurant in the
tanks. The direction of thrusting was
changed to maximize Earth viewing to support THEMIS and to allow safe operation
of the spacecraft through April 15. Any
other direction would have resulted in poorer Earth viewing or a quick end to
the Polar mission. Over the next 8 days,
Polar thrust on cold gas to achieve an additional ~ 28 degrees of attitude
change from the cold gas. This attitude
will allow Polar to be safe for instrument operations until April 15, 2008 with
a sun angle above 90 degrees. After
that, the sun angle will continue to decrease to 87 degrees by April 30. This is the minimum operational specification
for the spacecraft. Approximately 10% of
the cold Helium gas remains in the tanks at a pressure of 15 psi.
Final Polar maneuver
The sequence of maneuvers in February left Polar in an attitude where Polar can image only ~ 1 hour per orbit and most of those images are of the bright dayside away from the nighttime auroral oval. In order to support the THEMIS mission to the maximum extent possible, the Polar project would like to expend the remaining cold He gas in the tanks to obtain a better view of the southern auroral oval. The remaining pressure in the tanks will allow a few more degrees of rotation of the Polar attitude to obtain this better view.
In addition, this maneuver presents the possibility of an interesting experiment of Polar creating it’s own extremely rarefied neutral He cloud of ~300 grams released over the 6 day period. Pressures in the cloud are estimated to be less than ~10-9 Torr.
With the Polar SWGs concurrence, the maneuver will begin on Monday March 10 and continue through the week. Given the low impulse and the low expected pressure, it is recommended that the instruments be left in operational configuration and the spacecraft spend as much time in science mode as possible to determine if there are any interesting effects.
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. Due to the Polar running out of fuel and the increased burden on the Flight Operations Team, all other special operations will need to be reconsidered and likely cancelled.
3. Polar retrospective symposium
There has been a suggestion for the Polar Team to consider having a Polar retrospective symposium. One possibility may be to hold it in conjunction with the Cluster-THEMIS meeting September 22-26, 2008 at the University of New Hampshire. Many Polar team members would already be attending this meeting. If this is viable, does the SWG support the idea of a Polar symposium?
4. THEMIS Conjunctions
The THEMIS Team has looked
at the major conjunctions thus far.
Below please find their list with some comments.
================================
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
------------------------------------
5. MFE Data Processing Status
MFE Data Processing Status Report for March 7, 2008
6. The CAMMICE Science Report
CAMMICE Science Report for
March 7, 2008