SOAR Engineering Shutdown

The SOAR Telescope will be in Engineering Shutdown from 05 October to 27 November 2009. During this time we will be re-coating all three mirrors, the Primary mirror in the coating plant at Gemini South, and the smaller secondary and tertiary in the aluminizing tank of the 1.5m telescope on Tololo. The Mirrors have not been re coated since they were originally installed in the telescope in January 2004. (Updated 10 November 2009)

The SOAR Telescope will be in Engineering Shutdown from 05 October to 27 November 2009. During this time we will be re-coating the Primary (M1), Secondary (M2) and Tertiary (M3) mirrors. M1 will be re-aluminized in the coating plant at Gemini South while M2 and M3 will be re-coated in the aluminizing tank of the 1.5m telescope on Cerro Tololo. The mirrors have not been re-coated since they were originally installed at the SOAR Telescope in January 2004.

In addition to re-coating the mirrors at SOAR, we will also be working on other improvement and maintenance activities that can only be done while the telescope is out of service. These activities include a major upgrade of the Telescope Control Software (TCS) that builds on the work done to port the original SOAR TCS to the CTIO 4-m Blanco telescope on Cerro Tololo in preparation for the arrival of DECAM.

During the shutdown our webcams will be relocated to provide a view of the activities underway. They will be moving around as the work progresses, so check back periodically to see what is going on.


(Left) The process of installing the tertiary mirror (M3) in the telescope in March 2004. We expect to be removing M3 during the week of 5-10 October. (Middle) The SOAR primary mirror (M1) on its cell being lifted through the hatch which connects the equipment receiving and handling area to the observing level before its installation on the telescope in February 2004. We anticipate removing the M1 during the period 13-18 October. (Right) The SOAR primary mirror being washed prior to the first coating in the Gemini coating plant in January 2004. We expect the primary will return to Gemini for re-coating during the week of 19-23 October.

10 Nov 2009

The SOAR Primary mirror was successfully reinstalled in the telescope today.

(1) The Primary mirror active support system operates throughout the installation process allowing control and monitoring of the forces actiong on the optic (2-7) A spreader bar attached to the dome crane is used to lift the cell so that it first pivots on its handling cart, and is then lifted clear, continuing through the hatch in the floor of the observing level (8) Finally the primary mirror is back where it belong in the telescope - to a precision of a small fraction of a millimeter

3 Nov 2009

The SOAR Primary mirror was removed from the Gemini coating chamber yesterday. All measurements of the coating quality indicate that it is at least as good as the original coating when it was freshly applied in January 2004. The optic was then successfully transported back to SOAR, where it is now being reintegrated with its cell and active support system

(1) The Gemini coating chamber is opened revealing the freshly coated mirror (2) The mirror lifter is positioned to lift the mirror out of the coating chamber (3) The mirror and lifter suspended from the dome crane (4) The mirror crate is positioned to receive the mirror (5) Roberto Tighe and Esteban Parkes wrap the mirror crate like a sandwich to prevent dust entering during transport to SOAR (6) Eduardo Serrano directs as the mirror crate is gently lowered on to the truck (7) Victor Robledo helps the truck on its way back to SOAR while Eduardo Serrano celebrates (8) Safe inside the SOAR building the sandwich is unwrapped by Eduardo Serrano and Gerardo Gomez (9) The mirror is lifted out of the crate (10) Reunited with is cell, the mirror is attached to its active support system (11) Esteban Parkes installs one of the 120 axial actuators, while (12) Mike Warner monitors the force on the mirror to ensure the actuator is not overloaded.

30 Oct 2009

Success ! Coating of the SOAR primary mirror began around noon today. Reflectometer measurements taken with the mirror still in the chamber show reflectivity around 89-90% in the visible within the expected range, and the cosmetics look very good. The Mirror will be left in the coating chamber over the weekend, and then transported back to SOAR on Monday.

(1) The uncoated mirror at the start of the process illuminated by the glow discharge from the mangetron (2) As the mirror rotates on the turntable Aluminum is deposited on the outer annulus of the mirror (3) the fully coated mirror (4) and with the chamber now open (5) Tomislav Vucina measures the reflectivity near the center hole of the mirror

29 Oct 2009

Gemini's efforts cleaning the mangetron were rewarded by success and as a result we obtained test coatings with reflectivity well within the normal range for freshly deposited aluminum. The SOAR primary mirror was therefore blown off with CO₂ snow to remove any accumulated dust, its rear surface was cleaned before reinstalling it in the coating chamber. It will be left pumping down over night, and the coating operation will be performed in the morning.

(1) Blowing off the last dust with CO₂ snow. (2)Tomislav Vucina, inside the coating chamber, checks the position of the mirror relative to the magnetron (3) Meanwhile Daniel Holck runs the coating chamber controls

28 Oct 2009

We are currently waiting for the results of more tests of the reflectivity of test glass in the coating plant at Gemini South. The Gemini staff have aided our efforts to understand the lower-than-expected values of the reflectivity of our test glass by completely stripping down and reassembling the magnetron in the aluminization chamber in order to resolve a contamination problem which is suspected to be the cause of lower than expected reflectivity.

Meanwhile M2 was successfully installed in the telescope today, and M3 was reinstalled on to its turret and work is underway to verify proper function of the tip-tilt system.

(1) Gerardo Gomez, Roberto Tighe, and Eduardo Aguirre Check M2 in its lifting fixture.
(2) Eduardo Serrano, Gerardo Gomez, Eduardo Aguirre and Alberto Pasten prepare to install the M2 baffle
(3) Mike Warner and Guillermo Dubbo check the balance of M3 prior to testing the tip-tilt servo loop

22 Oct 2009

The SOAR primary mirror was successfully removed from its cell, transported the 300m from SOAR to Gemini South on 21 Oct 2009.

The primary mirror was thoroughly washed and stripped of its old aluminum coating on 22 Oct 2009. A careful inspection of the mirror, however, established that there were some residuals of the old coating (probably contaminants deposited by the magnetrons along with the Aluminium) which had not been removed by the normal stripping process. Consequently, a second wash cycle was carried out employing a more aggresive approach used by Gemini on their mirrors on 23 Oct 2009. This was completely succesful, and the mirror is now beautifully clean and ready for the application of a new coating. Final tests are being performed on the coating chamber over the weekend, and we expect to install the optic on Monday, pumping it down over night, and perfrom the coating, which only takes about an hour on Tuesday morning.








(1) The mirror lifter is carefully lowered into place to remove the optic from the cell. (2) The primary mirror hangs from the mirror lifter clear of the cell. (3) E. Serrano's morning calisthenics. (4) The mirror is set down in its crate on the back of the flat bed truck. The empty cell with its 120 axial actuators is on the right-hand-side of the picture. (5) Off to Gemini. (6) Ditto. (7) Cranes-eye view of the mirror crate in Gemini. (8) The primary is off the truck. (9) The primary is at Gemini and it is ready strip. (10) Washing the primary with Orivis soap. (11) Removing the aluminum with HCl. (12) Look, no Aluminuim. (13) Now cleaning M1 with KOH. (14) A final rinse. (15) And a blow dry [wash, rinse, repeat, always repeat, hmmmm]. (16) Just like reality. (17) Cleaning underneath with Acetone. (18) Into the Gemini South coating chamber (19) Ditto (20) CO2 cleaning is performed as the chamber is closed. (21) ..... to be continued

15 Oct 2009

The Primary mirror (M1) has been successfully removed from the telescope and is resting on the mirror handling cart.





Figures from Left-to-Right and Top-to-Bottom: (1) Mike Warner and Omar Estay use the active optics control system to monitor the forces on M1 during the entire removal process to ensure the optic has a gentle ride at all times. (2) Eduardo Aguirre & Christian Dias unfasten some of the bolts which attach the cell to the telescope. Not all are easy to reach. (3) Gerardo Gomez guides the cell as it is slowly moved away from the telescope by the dome crane. (4) M1 is rotated through 90 degrees so that the glass faces away from the telescope. (5) M1 is lowered through the hatch to the ground floor. (6) Ditto. (7) Ditto. (8) M1 "lands" on the mirror handling cart. (9) Front row left-to-right: Patricio Ugarte, Omar Estay, Esteban Parkes, Mike Warner, and Christian Dias. Back row left-to-right: Nelson Cortes (Paramedic), Alberto Pasten, Eduardo Aguirre, Gerardo Gomez, Steve Heathcote, Eduardo Serrano, and Victor Robledo. The yellow structure reflected in the mirror is the "spider" which will be used to lift the optic once out of its cell. (10) The mirror is lowered slowly so that it tips backward onto the handling cart. (11) The mirror is safe and sound in the handling area.

14 Oct 2009

M3 has been successfully coated in the 1.5m re-aluminization chamber on Cerro Tololo with a measured reflectivity matching the values expected for freshly deposited bare aluminum. The re-coated M3 reflectivity is 92.75% at 470nm, 92.42% at 530nm, 90.49% at 650nm, and 87.91% at 880nm. These values are very close to the nominal fresh aluminium curve.

Meanwhile, at SOAR, we are wrapping-up preparations for the removal of the M1 in its cell tomorrow. The final tweaks are also being made to the operation of the Gemini coating plant to receive the SOAR M1 optic next week.



(Upper Left) M3, in the coating chamber being prepared for re-coating, is seen illuminated by the glow discharge. (Upper Right) Oscar Saá & Patricio Ugarte inspecting the freshly deposited coating on M3. (Lower Left) Roberto Tighe measures the reflectivity. (Lower Right) Robert Tighe & Oscar Saá remove the M3 optic from the coating chamber.

09 Oct 2009

M2 has been successfully re-coated in the 1.5m aluminizing chamber. M3 will follow next week.



(Upper Left) Oscar Saá and Roberto Tighe strip off the old coating of M2. (Upper Middle) Oscar Saá and Roberto Tighe installing M2 into the aluminizing chamber. (Upper Right) M2 in the aluminization chamber illuminated by the glowing filaments. (Lower Left) Daniel Maturana taking the pictures of taking the pictures. (Lower Middle) Roberto Tighe measuring the reflectivity of the new coating. (Lower Right) Roberto Tighe, Hugo Ochoa, and Steve Heathcote inspect the finished product.

06-07 Oct 2009

The Secondary and Tertiary Mirrors have been successfully removed from the telescope, and are now on Cerro Tololo where they are being prepared for re-coating


(Left) The Secondary Mirror (M2) is being inspected by Roberto Tighe after its removal from the telescope. (Middle) Gerardo Gómez steadies the Tertiary Mirror (M3) assembly as it is being removed from the telescope. (Right) The M3 assembly being secured to an optical bench in preparation for removal of the optic.

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SOAR Engineering Shutdown