Do spin-stabilized satellites have attitude drift?

Do spin-stabilized satellites have attitude drift requiring
periodic correction?

If not, why? Even inertial navigation platforms have drift.

If yes, how do they correct their attitude? Thrusters?
Reaction wheels?

Sorry if this is a re-post; for some reason my previous attempt
never made it

-- Joe D.

I do not believe you will see what you term "attitude drift" because the
satellite is acting like a large gyroscope. Once you have spun up the
satellite you have a stable spinner if you have designed your mass
properties appropriately. You do need to deal with nutation (tendency to go
into a flat spin) if you didn't design for absolute stability. We used
thrusters on the Hughes satellites to perform attitude adjustments and
nutation control.


"Joe D." wrote in message
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Do spin-stabilized satellites have attitude drift requiring
periodic correction?

If not, why? Even inertial navigation platforms have drift.

If yes, how do they correct their attitude? Thrusters?
Reaction wheels?

Sorry if this is a re-post; for some reason my previous attempt
never made it

-- Joe D.

On 12/13/05 9:36 AM, in article ,
"Joe D." wrote:

Do spin-stabilized satellites have attitude drift requiring
periodic correction?

Generally, yes. Solar pressure applies a torque, and the satellite spin
axis changes as the result of precession. How often depends on the asymmetry
that is causing the torque, the mass properties, and the angular momentum of
the spin.


If yes, how do they correct their attitude? Thrusters?

Most I have seen/operated used thrusters, fired 90 degrees out of phase
to the spin axis error. Of the programs I have first-hand knowledge (oblate
spinner with a large despun antenna platform) it was about once a month to
take out about 0.1 deg error.

Prolate spinners need something a lot more complicated to prevent them
from going into a flat spin.

Brett