I have an interesting S.O.H.O. question for those who can answer it., page 1
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reply posted on 9-11-2009 @ 09:49 AM by Soylent Green Is People
It's a planned roll maneuver of the spacecraft itself. They do this once in a while for maintenance purposes (I don't know the specific reason).

I found this press release about a roll maneuver on October 26 that also mentions another roll maneuver for Nov. 7 (the date of the OP's images):

SOHO will perform a special 360-degree science roll maneuver on 26-Oct-09 between 13:50 and 23:50 UT. The roll comprises 10 segments (10 degrees, 8 x 45 degrees, -10 degrees), after which SOHO will be back in its nominal roll attitude. During the manuever, images and movies will also appear rotated. The next quarterly 180-degree roll maneuver is scheduled for 7-Nov-09.

Source (scroll down to bottom of page)

It seems from the information above that they do a planned quarterly (4 times per year) 180 degree roll of the spacecraft, but the October 360 degree roll event was special.

I couldn't find specific information on the 180 degree rolls -- hopefully someone on ATS knows why this roll is required.

I realize the orientation on the "after roll" image is the same as the "before roll" image (i.e., it's not upside-down), but perhaps the SOHO people rotate the images themselves to a common orientation (with the top being Solar North) before releasing them to the public.


[edit on 11/9/2009 by Soylent Green Is People]


reply posted on 9-11-2009 @ 03:05 PM by Phage
reply to post by Ophiuchus 13

The SOHO satellite has had a problem with aiming its high-gain antenna since 2003. The antenna can only be moved on one axis instead of two. The purpose of the rolls is to keep the antenna pointed at Earth as much as possible. Even so, there are periods of time (called "keyholes") when the satellite is unable to transmit data.
www.spaceref.com...




[edit on 11/9/2009 by Phage]



reply posted on 2-2-2010 @ 08:15 AM by Ophiuchus 13
reply to post by Ophiuchus 13



SMH again more pics. Magically lost. Interesting indeed my ABOVE FRIENDS.

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