AO-73 : Funcube-1

Rotation Period

14 Jan 2022 = 3.60 seconds (from the Sun Sensor Data)
15 Jan 2022 = 3.38 seconds (from the Sun Sensor Data)
16 Jan 2022 = 3.24 seconds (from the Sun Sensor Data)
17 Jan 2022 = 3.11 seconds (from the Sun Sensor Data)
18 Jan 2022 = 2.92 seconds (from the Sun Sensor Data)
19 Jan 2022 = 2.85 seconds (from the Sun Sensor Data)
20 Jan 2022 = 2.78 seconds (from the Sun Sensor Data)
21 Jan 2022 = 2.70 seconds (from the Sun Sensor Data)
22 Jan 2022 = 2.70 seconds (from the Sun Sensor Data)

AO-73 has now has returned to a relatively stable attitude spinning about the Z-Z axis with the Z-Z axis slowly precessing about AO-73’s centre of mass.

73 de Colin VK5HI.

AO-73 : Funcube-1

Rotation/Tumbling Period

07 Jan 2022 = 4.82 seconds (from the Sun Sensor Data)
08 Jan 2022 = 4.91 seconds (from the Sun Sensor Data)
09 Jan 2022 = 4.82 seconds (from the Sun Sensor Data)
10 Jan 2022 = 4.56 seconds (from the Sun Sensor Data)
11 Jan 2022 = 4.15 seconds (from the Sun Sensor Data)
12 Jan 2022 = 4.08 seconds (from the Sun Sensor Data)
13 Jan 2022 = 3.60 seconds (from the Sun Sensor Data)

During this this last week AO-73 has remained in a tumbling attitude.

73 de Colin VK5HI.

AO-73 : Funcube-1

Rotation/Tumbling Period

31 Dec 2021 = 4.90 seconds (from the Sun Sensor Data)
01 Jan 2022 = 5.30 seconds (from the Sun Sensor Data)
02 Jan 2022 = 5.09 seconds (from the Sun Sensor Data)
03 Jan 2022 = 5.45 seconds (from the Sun Sensor Data)
04 Jan 2022 = 4.86 seconds (from the Sun Sensor Data)
05 Jan 2022 = 4.50 seconds (from the Sun Sensor Data)
06 Jan 2022 = 4.78 seconds (from the Sun Sensor Data)

During this this last week AO-73 has remained in a tumbling attitude.

73 de Colin VK5HI.

AO-73 : Funcube-1

Rotation/Tumbling Period

24 Dec 2021 = 5.05 seconds (from the Sun Sensor Data)
25 Dec 2021 = 4.82 seconds (from the Sun Sensor Data)
26 Dec 2021 = 5.10 seconds (from the Sun Sensor Data)
27 Dec 2021 = 5.33 seconds (from the Sun Sensor Data)
28 Dec 2021 = 4.88 seconds (from the Sun Sensor Data)
29 Dec 2021 = 4.87 seconds (from the Sun Sensor Data)
30 Dec 2021 = 5.18 seconds (from the Sun Sensor Data)

During this this last week AO-73 has remained in a complex tumbling attitude.

73 de Colin VK5HI.

AO-73 : Funcube-1

Rotation/Tumbling Period

17 Dec 2021 = 4.95 seconds (from the Sun Sensor Data)
18 Dec 2021 = 5.09 seconds (from the Sun Sensor Data)
19 Dec 2021 = 5.09 seconds (from the Sun Sensor Data)
20 Dec 2021 = 5.50 seconds (from the Sun Sensor Data)
21 Dec 2021 = 5.00 seconds (from the Sun Sensor Data)
22 Dec 2021 = 4.95 seconds (from the Sun Sensor Data)
23 Dec 2021 = 5.14 seconds (from the Sun Sensor Data)

During this this last week AO-73 has remained in a complex tumbling attitude.
The graphic below is from the 23rd December and highlights the randomness of the tumble observed during the last week.


73 de Colin VK5HI.

AO-73 : Funcube-1

Rotation/Tumbling Period

10 Dec 2021 = 5.1 seconds (from the Sun Sensor Data)
11 Dec 2021 = 4.9 seconds (from the Sun Sensor Data)
12 Dec 2021 = 4.9 seconds (from the Sun Sensor Data)
13 Dec 2021 = 5.2 seconds (from the Sun Sensor Data)
14 Dec 2021 = 5.0 seconds (from the Sun Sensor Data)
15 Dec 2021 = 5.3 seconds (from the Sun Sensor Data)
16 Dec 2021 = Data unavailable

During this this last week AO-73 has remained in a complex tumbling attitude.

73 de Colin VK5HI.

AO-73 : Funcube-1

Rotation/Tumbling Period

03 Dec 2021 = 6.8 seconds (from the Sun Sensor Data)
04 Dec 2021 = 6.6 seconds (from the Sun Sensor Data)
05 Dec 2021 = 6.4 seconds (from the Sun Sensor Data)
06 Dec 2021 = 6.5 seconds (from the Sun Sensor Data)
07 Dec 2021 = 6.2 seconds (from the Sun Sensor Data)
08 Dec 2021 = 6.5 seconds (from the Sun Sensor Data)
09 Dec 2021 = 6.2 seconds (from the Sun Sensor Data)

During this this last week AO-73 has remained in a complex tumbling attitude.

73 de Colin VK5HI.

AO-73 : Funcube-1

Rotation/Tumbling Period

26 Nov 2021 = 10.0 seconds (from the Sun Sensor Data)
27 Nov 2021 = 10.3 seconds (from the Sun Sensor Data)
28 Nov 2021 = 8.6 seconds (from the Sun Sensor Data)
29 Nov 2021 = 8.2 seconds (from the Sun Sensor Data)
30 Nov 2021 = 8.0 seconds (from the Sun Sensor Data)
01 Dec 2021 = 7.2 seconds (from the Sun Sensor Data)
02 Dec 2021 = 7.0 seconds (from the Sun Sensor Data)

During the latter stages of last week I suspected that AO-73 had become very unstable and was on the verge of entering a tumbling phase.
I have now confirmed it had indeed commenced tumbling and has remained as such during this week.
My analysis of all the Sun Sensors X, Y and Z Axes confirms that observation.
However the various WOD downloads, when you are fortunate to grab one error free, do make interesting viewing.
The one displayed below was captured from the 1916utc 2nd December pass over VK.
There are times when X and Y Panels exhibit a short spin period of nominally 450 seconds and at other times there is very minimal spin.

When analysing a specific VK download it has become very evident that the thermal characteristics of the solar cells has become an issue in the ongoing analysis.
Because AO-73 is now tumbling so fast I suspect that the cells are not releasing their total heat load per revolution and be an accurate measurement of spin.
This has been noted and clarified all this week. A typical clarification is:-
Using my normal panel temperature analysis for the 2nd December.
X Panel Temperature (only data available) = 17.5 seconds Sun Sensors (All Channels) 7.0 Seconds.

73 de Colin VK5HI.

AO-73 : Funcube-1

Rotation Period
05 Nov 2021 = 68.4 seconds (from averaged panel temperatures)
06 Nov 2021 = 61.5 seconds (from averaged panel temperatures)
07 Nov 2021 = 55.4 seconds (from averaged panel temperatures)
08 Nov 2021 = 47.0 seconds (from averaged panel temperatures)
09 Nov 2021 = 45.3 seconds (from averaged panel temperatures)
10 Nov 2021 = 40.9 seconds (from averaged panel temperatures)
11 Nov 2021 = 36.8 seconds (from averaged panel temperatures)
12 Nov 2021 = 33.4 seconds (from averaged panel temperatures)
13 Nov 2021 = 29.9 seconds (from averaged panel temperatures)
14 Nov 2021 = 27.0 seconds (from averaged panel temperatures)
15 Nov 2021 = 24.8 seconds (from averaged panel temperatures)
16 Nov 2021 = 22.6 seconds (from averaged panel temperatures)
17 Nov 2021 = 20.3 seconds (from averaged panel temperatures)
18 Nov 2021 = 18.4 seconds (from averaged panel temperatures)
19 Nov 2021 = 18.6 seconds (from averaged panel temperatures)
20 Nov 2021 = 16.8 seconds (from averaged panel temperatures)
21 Nov 2021 = 17.9 seconds (from averaged panel temperatures)
22 Nov 2021 = 16.9 seconds (from the Sun Sensor Data)
23 Nov 2021 = 13.7 seconds (from the Sun Sensor Data)
24 Nov 2021 = 12.2 seconds (from the Sun Sensor Data)
25 Nov 2021 = 9.5 seconds (from the Sun Sensor Data)

AO-73 is spinning about the Z-Z axis in the reversed direction with a slow secondary motion about AO-73’s offset centre of mass of approximately 250 seconds.

73 de Colin VK5HI.

AO-73 : Funcube-1

Rotation Period

29 Oct 2021 = 143.2 seconds (from averaged panel temperatures)
30 Oct 2021 = 125.3 seconds (from averaged panel temperatures)
31 Oct 2021 = 110.8 seconds (from averaged panel temperatures)
01 Nov 2021 = 100.7 seconds (from averaged panel temperatures)
02 Nov 2021 = 97.2 seconds (from averaged panel temperatures)
03 Nov 2021 = 79.6 seconds (from averaged panel temperatures)
04 Nov 2021 = 70.9 seconds (from averaged panel temperatures)

AO-73 remains in a stable attitude and is spinning about the Z-Z axis in the reversed direction.

73 de Colin VK5HI.