During high winds this afternoon, the shutter panels in the observatory dome roof blew open. This is the second time this has happened since our rotation has started. The method stated in the observatory manual proved insufficient to support the shutters in the very strong winds that we are currently experiencing. There are a few reasons for this, but among the most important is that the top panel is missing five of its six bottom wheels used to hold it on its track (this means it is only being held in place by one small wheel on the front left corner). It appears that the other wheels have been ripped out of their holes at some previous point, explaining why this is a frequent problem. To make things worse, the thin plug used to cover the hole in the top panel (and to hold this panel in place) was attached by a wood screw with an eyebolt on it. The aerodynamic loads on the shutters actually ripped the eyebolt out of the wood. Fortunately we were there to catch the top panel and keep it from blowing away (we were very lucky). If the screw had come loose at any other time, we probably would have lost the top panel. We employed the following strategy to secure the dome for the rest of our rotation:

1. One ratcheting tie-down was used to secure the bottom panel. A piece of cloth was placed between the ratchet and the dome to prevent scratching. This tie-down is hooked onto bolt ends which extend through the sides of the dome. These bolts were placed through pre-existing holes and have large washers on both head and nut for sufficient strain relief.
2. One ratcheting tie-down was used to secure the top panel. This tie-down uses a different set of bolts, but is otherwise just like the one just described.
3. The orange and black rope previously used to keep the top panel on (it was attached to the wood screw that was ripped out) was run from a tie-down point within the dome (the cleat originally meant for the blue cord use to move the top panel), through the hole in the top, and attached to the tie-down securing the bottom panel. This rope serves a double purpose: it keeps the lower tie-down from slipping off the lower panel and provides extra securing force to the upper panel.
4. The hole in the top was covered with plastic from a heavy duty freezer bag; it is being held down by duct tape from underneath. For redundancy, duct tape was also used to seal off the inside of the dome hole. This assembly is shaped such that any water that comes through flows along the black/red rope down to the side of the dome and clear of the telescope equipment.
5. The tarp covering the telescope was secured such that if panels were to open again, the tarp would not fly off leaving the telescope unprotected.

It is worth noting that all the tie-downs and restraints are attached to the rotating portion of the dome. This is good because if someone forgets to remove the restraints, the dome could be rotated without any damage to the motors. It is, however, unlikely that restraint removal will be forgotten because the shutter cannot be opened until all restraints are removed.

The crew strongly recommends repairing the wheels on the top panel and devising a permanent method for restraining BOTH panels in high winds.