Monthly Archives: July 2016

The week of July 11

Last week we reported on a incident with the HET tracker that put us in a hard skew condition and shut us down. We had recovered from that skew condition but the software issues that led to the skew had continued. This week I am happy to report that we have not only installed additional skew sensors but we have found the source of the software issues. The software teams in Austin and West Texas were able to perform a series of experiments which allowed them to isolate the problem as coming from the ethernet card inside the dSpace box. This is a very specialized ethernet card but thankfully we were able to swap out a different card for it and found that all of our TCS communications problems, hexapod faults, and loading trajectory errors have gone away. We will look into getting a spare card and send the card in to see what kind of fault occurred in the card.

With the improved tracker performance we were able to start our early science operations. We took our first science targets on the night of the 16th. Unfortunately, we are now headed towards full moon which is not the ideal time to do science targets with LRS2. However, it does give us a chance to work out any inefficiencies in our PI interface, night operations interfaces and queue tools so that we can be fully ready once we get some dark time a few days after full moon.

The week of July 4th

Two weeks ago we had a fairly serious tracker issue. While recovering from a fairly typical tracker failure, the telescope operator requested that the breaks be set but instead the tracker moved in X and generated a hard skew. This hard skew actually caused the bearing to come out of the bearing block. This occurred the day that the blogger and most of the chief engineers were going to their summer conferences. Upon the return the engineers were able to determine that no permanent damage was done to the bearings or the tracker in general. The engineering team was able to move the tracker back into the block using the tracker motors. Unfortunately, the software issues that led to the skew are still present and have not yet been sorted out. This has severely limited our ability to run trajectories for engineering or the start of early science operations.

In the mean time work continues on VIRUS enclosure 2 and with re-coating of the primary mirror segments.