The software group continues to test different aspects of the TCS. They found many of the bugs that stopped us from generating trajectories last week. We should now be able to generate trajectories at any Az and for normal sidereal objects and for geostationary satellites (useful for diagnostics). We do
continue to run into some small teathing problems with the new tracker as we start running it through its paces, e.g. loose connectors, cables that are not routed the correct way and blown fuses.

The electrical and mechanical teams worked in the Krabbenhut this week and was able to remove the old Champion compressor, install new vertical air tank and move the Power-X compressor which supplies the instrument air. This was all done to make room for the Nitrogen Vaporizor which will generate very pure N2 gas for instrument purging from our large LN tank.

Our electronics tech continues to work with the Ultra-pure water system trying to add reliability and consistency to the system. He can now produce 17.1 Mohms water (any reading above 10 Mohms is considered is considered Ultra High Purity for water, with 18.2 Mohms being the ultimate maximum).

The mirror team finished the piston work this week and we hope to have the next round of piston be done with the DMI rather than with the sphereometer.

In the Facility Thermal Management Project Veliz Construction completed the welding of pylon frames (to support ducting) together in place over side of the mountain and ARC is working on the ducting next to the Krabbenhut and down the side of the mountain. ARC mechanical has completed the WFU glycol manifold at the outside of the dome. This is the point where HET personnel will continue the piping layout into the dome.

This week the mirror team began making piston moves of the individual segments that make up the primary mirror. We began with the central mirror, of which we base most mirrors moves, and then moved to those mirrors which had small enough piston moves to be controlled by SAMS. Next week we will move on to those mirrors whose piston will require us to make moves outside of the capture range of SAMS including those mirrors where the piston moves are out of range of the actuators and thus requires moves of the M30 frame screws. These were not completed this week because the mirror team is also interviewing two candidates for the Opto-mechanical position.

Veliz Construction continues placing the pylons to support the K-Hut exhaust duct and fan. They are working on the pylons over the side of the mountain. ARC Mechanical is busy building the HDPE piping run around the control/service building slab for the WFU glycol system. They also began welding the copper pipe in place in the pipe vault for the Mitsubishi compressors.

We have also begun integrating the structure sub-system into requested trajectory generation and execution. Having some problems with satellite and ephemeris trajectories.

Much of the rest of the team was working on preparations for a move of the instrument air compressor inside the Krabbenhut to make room for the Nitrogen Vaporizor. Other work includes installing Anemometers, purge lines for the new tracker, transient suppression for the tracker electronics and other various activities to keep the place running.

This week John Good, a mechanical engineer in Austin, is back out to run the 97 point test to characterize the shape of the sphere that the tracker traces out above the primary mirror. Several weeks ago we attempted to run this test but found that the number of measurements we were taking per point was to many and we were only able to get a 21 point test. This time the tracker is running more reliably and we are going to take fewer measurements per point. This test will be conducted at night and we expect it will take 3 nights.

We no longer need the four mirrors that we removed from the array for laser tracker work. The optics team will begin to replace these last 4 mirrors, at which time we should have a fully populated array.

The mechanical contractors on site continue to work on the pipes in the vault. This week they will be putting insulation around the pipes. The dirt works contractors are working on the base of the piers which will hold the acid vapor from the strip and wash room and heat ducts from the Krabenhut.

In the past week the remote thermal area contractors finished the work on the remote concrete pads and the trench between these pads and the vault. This week the contractors will work on the Al tape coating for the roof of the control and services building to reduce the emissivity and avoid the super cooling of the roof. The mechanical contractor will work on the conduit that lead into the building from the vault.

We have had the departure from the opto-mechanical team. We will start the hunt for a new technician as soon as HR approves our new job posting.

This week we will be installing the DMI, tip-tilt camera and VAT on the telescope. In a previous week the VAT and mounts were test fit so we hope that all of the components go on easily. The software team will also be coming out and we expect to turn the VAT towards the sky and have a first track and guide using the TCS software.

In the past week we have had a number of very strong thunder storms one of which blew out one of our 480 V contactors in the new tracker electronics. We found we don’t have a spare for this relatively inexpensive components so we are ordering a replacement and several spares. We hope to have this in place in the next day or so. Once back up we will continue to work on the TCS trajectory generation.

Next week we have some of the engineers and most of the software team coming out from Austin for a first attempt at running trajectories with metrology. The DMI is back from France and ready to be installed on the test mass along with the tip-tilt camera and the Video Alignment Telescope (VAT). This week we are just making sure all of the communications and power connections are in place for this set of tests.

We have four different contractors on site this week working on the Remote Thermal Area project. One is building the forms for the remote concrete pads, another is digging a trench between those pads and the vault which was completed last week, another is putting in ducting in the vault and the last is installing ducting inside the spectrograph room, lower and upper electrical rooms. The afternoon storms are slowing the work slightly.

The rainy season has begun in West Texas. In the last week we only opened once at night; during that night we were able to capture the mirrors taken out for the 21 point test. Mirror alignment is now routine.

The rain is also having a small impact on the contractors working in W. Texas on the remote thermal area. The large pipe vault has become a nice reflecting pool and it is clear that we will need a french drain at the low end of this vault even though the expectation is that the vault with be mostly sealed to the runoff. The concrete vault has been completed and this week the electrical and mechanical contractors are placing conduit in the vault.

This week the Distance Measuring Interferometer (DMI) arrived from France and the engineering team in Austin made sure that it will fit into the test mass mounts which will come out in the 2nd week in July. The DMI will arrive in W. Texas on Thursday so that we can get it setup in the coming week both for the test mass and for the CCAS tower.

Work on the TCS (telescope control software) continues this week. The team hopes to be generating trajectories using RA/DEC or Alt/Az by the end of the week.

This last week the two engineering teams from Austin worked both days and nights to get their work done. The day time team was able to get the mounts for the Tip-Tilt camera, VAT and DMI on the telescope. They were able to get the VAT installed and found that the center mirror is just 30 mm off from the center of the X and Y tracker encoder ranges. We still need to determine where the encoder ranges are with respect to the upper hex which brings us to the work of the other engineering team. This team worked most of the nights this past week including weekends to get the 97 point test started. They determined that to take a set of 18 laser tracker data points at each tracker position takes far longer than anticipated and so descoped to a 21 point test instead of a 91 point test. Even with this descope the 21 point test took 15 hours of work.

This week the Austin engineering teams have departed and are working on new mounts for the test mass based on lessons learned from this past week. The data from the 21 point test needs to be analyzed and we will followup any questions that analysis may bring up with further laser tracker measurements.

The mirror teams are swapping two mirrors into the array this week and later this week the cabling teams will be putting on the clamps in the Azimuth cable wrap and fixing any cabling problems that might have developed with the full range to tracker motion that we can now make.

The contractors from Veliz Construction made substantial progress this past week. They completed the first concrete pour for the pipe and electrical vault and this week they will be setting up the forms for the second pour (which will be the walls of the vault. We will also have the electrical contractor on site to complete some Phase I punch list items and review the site for the Phase II electrical work. We will also have Gaffey Crane on site to work on the dome crane box which must have a new form factor to avoid collisions with the stinger from the Y-drive.

A great deal of effort was put into fixing small problems with the tracker software and hardware last week. By the end of the week we were able to run a mock 97 point test and even a mock trajectory. There are still some small problems using the GPS timing signal which is needed for running a true trajectory but this is a significant step forward. This week we will have two sets of engineers from Austin. One group will work on the 97 point test which will map out the tracker sphere in space and tie that sphere to the mirror truss through the use of the laser tracker. This will be done at night so that significant temperature changes do not alter the results. The corrections to tie the tracker and mirror truss spheres together will be the first components of our mount model.

The second team will be installing the mounts for the Video Alignment Telescope and the DMI on the corrector. Once these items are in place and we can run trajectories we will will begin to tie the tracker sphere to the central mirror and then refine the mount model further.

The contractors did not begin the “vault” cement pour as expected this last Friday. Delays caused by the significant heat and a small delay in the rebar arrival have put that off until this coming Wednesday.

The night operations team has been able to get all of the mirror with current electronics installed into the stack. As soon as more SAMS (Segment Alignment and Maintenance System) electronics cards come in from the contractor the remaining segments will be brought into the array.