MTA Monitoring Report 12/27/24 - 01/02/25

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Radiation

Dec 31st Radiation Telecon and Summary:
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Due to elevated ACE P3 rates, a telecon was held at 11:45am today. At the time of the telecon, the 2 hr average P3 rate was slightly above the alert limit of 50000. One of the two predicted CME's had passed, and one more was expected.
Based on the elevated rates and expectation for continued high rates for another day, the consensus was to protect the science instruments by manually activating SCS-107. SCS-107 ran nominally, starting at 2024:366:17:17:09.
It is expected that the radiation will quiet down in the next two days. The current target for uplink of return to science loads is the comm pass on DSS-65 at 10:15 PM Thu 02-Jan (2025:003:03:15:00). The current plan is for a "pickup" replan, following the original DEC2324 two-week loads and potentially appending the JAN0625 loads. This is subject to evaluation by FOT and SOT MP.

Detrended CTI

Although we prefer to quote CTI values of the cleanest data (FT <= -119.7 C, int time > 7000sec), the data that fulfills these conditions are getting rare. We now quote CTI based on temperature corrected data for Focal plane temperature <= -118.5 C).

The unit is now CTI/year not CTI/day.

ACIS Warm Pixels

We display all bad pixels that have showed up in past, and, if any, previously unknown bad pixels appeared in the last 14 days. We also list hot pixels (defined as 1000 above the average of bias background). Warm columns 509-514 are probably due to boundaries.

New definitions of warm pixels and flickering pixels (May 15, 2014). If a pixel displays the level beyond a threshold for more than 70% of the time in the past two weeks, the pixel is categorized as a "warm" pixel. If a pixel is above the threshold more than 30% of time but less than 70% of the time in the past two weeks, the pixel is categorized as a "flickering" pixel.

ACIS Focal Plane Temperature

For this period, 6 peaks are observed.

Day (DOY)	Temp (C)	Width (Days)
359.40	-116.00	0.11
359.64	-108.74	0.62
360.32	-107.97	0.53
361.04	-106.31	0.74
361.94	-109.86	0.97
363.66	-103.10	4.25

Weekly focal plane temperature with sun angle, earth angle, and altitude overplotted. Sun angle is the solar array angle, that is the angle between the sun and the optical axis (+X axis). The earth angle is the angle between earth and the ACIS radiator (+Z axis). Altitude varies from 34 kkm to 128 kkm.

SIM Movements

17 TSC moves this period

weekly average time/step	0.00135 s
mission average time/step	0.00132 s

Telemetry

New violations or new extrema are shown in blue cells.

IRUs

Gyro Bias Drift	Gyro Bias Drift Histogram

Recent Observations

Trending

This week's focus is Gratings

Last reported on Oct 17.

Only the most interesting or representative msids are shown below. For a full listing choose the bulletted link.

• Gratings

If you have any questions, please contact: swolk@head.cfa.harvard.edu