POLAR Telecon Agenda for March 23, 2007

POLAR Telecon Agenda for March 23, 2007

Agenda:

0. Upcoming Polar Telecon

1. Operations

2. Polar SWT Meeting

3. Polar Mission Status

4. Polar-THEMIS coordination

5. Resident Archives – presentations by TIDE and TIMAS

6. MFE Data Processing Status

7. TIDE Science Report

0. Upcoming Polar Telecon

Friday March 23, 2007

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: 1-888-790-3547

Password: Polar Telecon

(Leader: John Sigwarth)

The web site for the final agenda will be:

http://pwg.gsfc.nasa.gov/polar/telecons/2007Mar23/

Future Polar Telecons

Next telecon: Friday April 20, 2007

Future Telecon Science Discussion Schedule

[Errors/omissions/preferences to: nicola.fox@jhuapl.edu]

April 2007: PIXIE

May 2007: UVI

June 2007: MDI

July 2007: CAMMICE

August 2007: VIS

September 2007: TIMAS

October 2007: EFI

November 2007: Hydra

December 2007: MFE

January 2008: CEPPAD

February 2008: TIDE

1. Operations

If you have any concerns about Polar operations, please contact Nicky Fox (nicola.fox@jhuapl.edu)

Successful Polar Sun Angle maneuver

To the amazement of everyone involved, Polar's spin axis is now at orbit normal and back in its original flight orientation. Last month's attitude maneuver #11 was highly successful and beyond anyone's expectations. The main maneuver, spin trim and final attitude correction were all completed on fuel with little evidence for gas expulsion. The one possible exception was an apparent brief bubble of gas that was expelled near the beginning of the attitude trim and lasted a few 10s of seconds. There was no further evidence of gas flow for the remainder of the maneuver which had duration of approximately 18 minutes. Polar is now well positioned to work with THEMIS in its early mission phase. Congratulations to the Polar Flight Operations Team on a well executed maneuver.

Pre-maneuver planning estimated that 3632 pulses were needed to get to orbit normal. Segment 1a used 2014 pulses on Feb 26, 2007. The plan for the second day was to target the difference and use gas to get the rest of the way. Segment 1b used 1618 pulses on Feb. 27, 2007. A sun angle of 98.5 degrees was achieved. The target sun angle was 99.2 degrees. The spin rate following segment 1 was 10.0274 RPM. A spin down maneuver was executed at 14:57:25 to get the spin down to ~9.973 RPM.

A final trim maneuver to orbit normal was successfully executed on March 1, 2007. Telemetry indicated that the maneuver was completed on fuel. Due to high thruster efficiencies, the maneuver plan was changed to execute 177 pulses (instead of 186). The spin rate after the maneuver was at 9.983 RPM.

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. Polar SWT Meeting

Based on inputs from the science teams we have decided to delay the Science Working Team meeting until mid-September. Please look at your calendars and be ready to suggest suitable dates

Please send ideas for agenda items to Nicky (nicola.fox@jhuapl.edu)

3. Polar Mission Status

An effort has been initiated to re-analyze the Polar fuel status. Previous estimates of Polar fuel used a bookkeeping method that calculated cumulative thruster time-on and nominal fuel flow rates to determine the fuel used and the fuel remaining in the tanks. However, there exists additional information on the status of fuel in the Polar tanks in the form of pressure and temperature. The fuel remaining can be estimated from these values by using the ideal gas law (PV=nkT). Preliminary analysis using these pressures and temperatures indicates that Polar may have ~20 kg ± 9 kg remaining in the system (see the figures on Polar fuel remaining). Approximately 6.8 kg of fuel are required to achieve a 180° flip. Consequently, it is likely that enough fuel remains to perform 2 flips of 180°.

The Polar project and NASA headquarters are considering the feasibility of operating Polar beyond the September 2007 time frame to perhaps as late as April 2008 in support of the THEMIS prime science magnetotail campaign. The THEMIS tail campaign will occur from January through April 2008 with February and March being the optimal months. In order to be considered for a possible extension beyond the current end of mission date of September 30, 2007, the Polar team will need to draft a one-page science rationale for a mission extension and a clear plan for completing the data processing. I am, therefore, requesting from each Polar PI and all interested Co-Is a list of suggested science topics that can be used to justify extending the Polar mission to April 2008. Specific topics for THEMIS-Polar coordination should be emphasized.

It is clear from discussions with NASA/HQ that any Polar support of the THEMIS tail campaign will need to be accomplished, as much as possible, within the present Polar budget guidelines. Each Polar PI should be prepared to estimate the bare-bones cost for such a mission extension with a creative eye toward leveraging other personnel and missions wherever possible to reduce direct-costs to Polar.

4. Polar-THEMIS coordination

As we reported last month, the Polar mission has been granted an extension to September 2007 by NASA/HQ. In this extension the Polar Project has been directed to support the THEMIS mission to the maximum extent possible. Since our most recent Polar maneuver returned the spacecraft to orbit normal, Polar is again collecting auroral images for approximately 12 hours out of each 18.5 hour orbital period and the Polar apogee is high over the South Pole and will remain in that region for the next few years.

Some of the ideas for THEMIS-Polar coordinated science were discussed at the January Polar telecon. These ideas included a magnetopause campaign and an auroral acceleration campaign with THEMIS ground-based and in-situ tail observations and Polar in-situ observations of the acceleration region. If Polar can operate through April of 2008, it will be in position to support the main magnetotail science of THEMIS.

A telecon with members of the THEMIS team is scheduled for Friday March 23, to discuss these coordination ideas. Results from this will be reported at the Polar telecon.

5. Resident Archives.

Please note:

The call for resident archive maintenance (i.e. the follow-on funding for your resident archive) is in the current ROSES FY2007 solicitation, appendix B9, section 1.3. The notice of intent is due September 12, 2007 and the proposals are due November 15, 2007. The Polar funding will be running out by the time these proposals are selected so propose to this call for maintenance of your resident archives beyond the end of the Polar mission.

As we discussed at the telecon in February, we need to return to the issue of finalizing the resident archive plans and their implementation. The Polar Science Team had agreed previously on the following Guiding Principles to aid in the development of the Polar resident archive environment:

1. The resident archives are to be distributed at the PI institutions or their designated locations where the expertise in handling the specific data resides.

2. The resident archives should provide the highest available resolution (spatial and temporal).

3. The resident archives should be designed for minimal human support.

4. The data in the resident archive should be available to a requestor without human intervention.

5. The archive should provide for virtual observatories dynamic access to the full data set.

6. Every site should allow plots of the data, either previously made or made on demand.

7. Every archive should allow ASCII downloads of low and high resolution data for re-plotting by the requestor.

8. Positional and attitude information for the Polar spacecraft should be provided at one or more sites.

9. Every site should provide direct links with brief descriptions of every other Polar site.

10. Documented procedures for producing scientifically useful data from the Polar instruments will be made available and will be a fundamental element of the resident archives.

In this telecon we will review the TIDE and TIMAS resident archive status reports. At the April telecon we will ask that the CEPPAD and UVI teams to provide similar reports.

These status reports should cover: What products need to be made available to the community [images, survey plots, custom plots, analysis software, documentation, etc.]? What is the best method to provide these products? Do we need to poll the broader community for input?