MDM Trouble Report for 2016 Jan 29

Telescope: 2.4m
Observer(s): Nunez, Douglas (Columbia University)
Instrument: Modspec/Echelle

Problem(s) Encountered:
As we were trying to put our target star into the slit and start guiding, we noticed that 
the telescope started jumping around in little squares. It would last about one second or 
two and then it would stop. This would happen whether we were guiding or not.
We also noticed that the airbag forces were jumping around in the range 15-70 in all 
three hard points. This would last for a few seconds and coincided with the times when 
the telescope appeared to be jumping around. This all happened while we were pointed 
at one target, we weren't slewing around.  

One incident lasted for at least 10-20 seconds, and so we decided to send the 
telescope back to zenith. The hard point forces went back to normal and stayed that 
way for a while. So we slowly moved back to our target position, checking the pointing 
stability on bright stars along the way. The pointing and airbag forces seemed stable 
after that, so we continued observing. We had guiding problems on one or two other 
stars, but otherwise everything worked well.

At closing, we forgot to return the rotator to 0, and so we re-opened the mirror covers
to send it home. At this point, the west mirror petal (our old friend!) failed to open. 
Based on suggestions in the telescope manual, we tried to enlist the help of gravity 
by slewing to the west, but to no avail. We then used the ladder and the rope and 
hook in the dome to pull the cover open. Then we returned to zenith, sent the rotator 
to 0, and the mirror covers closed properly. 

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Submitted on 2016 Jan 30 [6:49:30]