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which axis is which?

PostPosted: Thu Jan 15, 2015 2:39 am
by vk2byf
I'm new at this so I'm allowed to ask a few dumb questions.

Now that I am successfully downloading regularly good data from
FUNcube-1 this question keeps coming up.

When they talk about X+ and X- solar arrays or temperature sensors Y or Z

Which axis is which in say the relation to the satellite's orbit or whatever
other reference system in use by satellites as they fly around the earth?

I have tried to research this myself but am getting conflicting answers.

I am trying to establish how the satellite spins and tumbles and why when it has a magnetic
earth sensor (bar magnet)?

Bob VK2BYF South Coast NSW Australia

Re: which axis is which?

PostPosted: Thu Jan 15, 2015 9:33 pm
by Phlash
Hi Bob,

FUNcube orientation has X and Y axes along the aerials (sorry - don't know which axis corresponds to which dipole), Z axis orthogonal to the plane of the aerials. The passive stabiliser is intended to align the Z axis with the Earth's field, so FUNcube should rotate 'end over end' twice per orbit, however there is no stabilization on rotation about the Z axis.

At this point the actual space scientists will jump in and correct me :)

Phil (software guy)..

Re: which axis is which?

PostPosted: Fri Jan 16, 2015 4:31 am
by vk2byf
Thanks Phil
I'm trying to make sense of the data from the bird.
So X & Y are the 4 solar panels which are at 90 degrees to the plane of the 4 antennas.
As the satellite spins or tumbles about the Z axis which I assume is a line from the earth though the satellite into deep space
The power from the 4 solar panels fluctuate at the rate of Z spin.

I believe the satellite also spins/tumbles about the X & Y axis'? Which makes it even more interesting.

Thanks again Phil
Regards Bob VK2BYF