For our large project which we call “Facility Thermal Management project” Veliz Construction began the mounting of the access stairway that serves the LN2 tank. ARC was onsite to continue the pipe insulation and insulation protection. Weathers Electric landed the Advantage Chiller power line into the HET main panel and replaced the 400 amp fuses in the the 112 KVA transformer disconnect panel with 350 amp fuses. Weathers Electric made the final connections for the new telescope Advantage Glycol chiller 3 phase power. This glycol chiller will help us cool the tracker motors and keep all of the electronics in the tracker at ambient temperature.

We continue to work on the VIRUS Safety system which will have alarms for dealing with the large liquid nitrogen tank behind the control room. It senses liquid nitrogen flow and oxygen levels around the facility. It is a fairly fast system that will take more than another week to complete its installation.

This week we began cleaning up the spectrograph room including moving around the large air tanks to make more room for the HRS insulation and the HPF enclosure, which will show up the 2nd week in November. Our goal is to hold the inside of the HRS enclosure to a very tight tollerance so we are current experimenting with RTD temperature sensors for the Spectrograph room to monitor how tightly we can control the temperature with the new air conditioning system recently installed.

This week we had some night time engineering work using the CAT (Celestron Alignment Telescope). This small telescope is mounted in some V-blocks near the center of the tracker where the future corrector will go. This small telescope will allow us to test guiding metrology and TCS software on the sky. This week we spent the time trying to align the telescope parallel to the rho axis, moving it to the center of the rho axis and then finding the offsets to align it along the central optical axis of the primary. Once done we were able to take a quick image of an open cluster, NGC 869, and confirm the plate scale and orientation and do some preliminary analysis of the newly installed TCS commands for rho, theta, phi, RA and DEC offsets. We have some debugging to do but this is a big step forward and will allow us to get valuable feedback before the corrector arrives in January.

For the Facility Thermal Management Project, Veliz construction spent the week preparing and finally pouring the concrete pad for the large liquid nitrogen tank which will feed VIRUS and eventually the HPF.

Veliz Construction pours the LN2 concrete slab

Weathers Electric began working on the Krabben hut exhaust fan wiring after ARC installed the fan early in the week. Veliz Construction also finished the cinder block wall around the new Mitsubishi compressors out in the remote thermal area.

One of the engineers from Austin came out this week to work on the tracker mount model using the laser tracker. They were able to run several long tests at night and will start the analysis of the data.

The work to clean and rejuvenate the hair seals continues. The newest
technique involves removing the seal clean it and then reinstall it such that the hairs are not curled the opposite direction as before. We are about one third complete with this effort.

Our new Opto-mechanical technician started today. She joins us from Austin and has already driven the JLG above the mirror and done an inspection of the coating tank in the clean room.

We received the work platforms for the VIRUS enclosures. These go on the inside of the enclosure but outside the truss. We found that the top set of platforms are to wide and will have to be modified.

This week has been fairly slow largely because we are cleaning up after last weeks VIRUS enclosure installation and because we have had many large rain storms.

In the Mirror Strip and Wash room we are making some modification to make it more user friendly and preparing for commissioning of the acid stripping process once the contractors have the acid vapor duct in place and the fan working. This should be ready to start sometime in the next two weeks.

Veliz Construction finished the Liquid Nitrogen slab backfill and sleeving for water line that must run under this slab. ARC also started the installation of the K-Hut exhaust fan. Weathers Electric continues running conduit between the pipe vault and the indoor breaker panel to support power lines to the dry cooler, Advantage Chiller and convenience outlet.

ARC Mechanical working with the Mitsubishi rep, tested out the HVAC system and it is now fully functional. This means we now have new air conditioning capability in the lower electrical room where all of the new tracker electronics are located as well as more powerful cooling capability in the spectrograph room. This will allow us to put the High Resolution Spectrograph in a cold bath which will help us keep a more constant temperature and improve velocity stability. Air conditioning has also been restored to the HET offices and the clean room.

Next week we will repeat of the 97-pt laster tracker test measuring only the hexapod control point, and a repeat of the 21-pt grid, measuring the control point as well as tip-tilt of the hexapod. This will provide an independent verification of the mount model imposed several weeks ago by the software and telescope controls group.

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.