WFCAM Engineering History

WFCAM Engineering History

Filters History

SemesterDatesFilter Installed
05AMar – May 05Z Y J H K H2 Bg
05B Sep 05 – Jan 06Z Y J H K H2 Bg
06A May – Jul 06Z Y J H K H2 Bg
06BNov 06 – Dec 06Z Y J H K H2 Bg
07AJan 07 – May 07Z Y J H K H2 Bg
07BAug 07 – Nov 07Z Y J H K H2 obj
08AFeb – Jun 08Z Y J H K H2 Bg
08BSep – Nov 08Z Y J H K H2 nbH
12AFeb – May 29, 2012Z Y J H K H2 nbH
12BMay 30 – … 2012Z Y J H K H2 1.644FeII

Mechanical history

September 27 – October 20, 2004 HST (inclusive) 
WFCAM commissioning 
October 21 – Nov. 29, 2004 HST (inclusive) 
WFCAM engineering 
November 30 – December 12, 2004 HST (inclusive) 
Closed, WFCAM removed, Cassegrain instruments installed 

March 07 – 09, 2005 HST (inclusive) 
Engg. shutdown. WFCAM was mounted on the telescope. 
March 10 – 16, 2005 HST (inclusive) 
WFCAM eng 
March 17 – 30, 2005 HST (inclusive) 
Closed 
March 31 – April 06, 2005 HST (inclusive) 
WFCAM eng 
June 20 – 23, 2005 HST (inclusive) 
Engg. shutdown. WFCAM was removed from the telescope for the start of the cassegrain block. 

August 22 – 24, 2005 HST (inclusive) 
Engg. shutdown. WFCAM was mounted on the telescope for the start of the WFCAM block. 

February 06 – 08, 2006 HST (inclusive) 
Engg. shutdown. WFCAM was removed from the telescope for the start of the cassegrain block. 

April 24 – 27, 2006 HST (inclusive) 
Engg. shutdown. WFCAM was mounted on the telescope for the start of the WFCAM block. 

August 01 – 02, 2006 HST (inclusive) 
Engg. shutdown. WFCAM was removed from the telescope for the start of the cassegrain block. 

October 23 – 24, 2006 HST (inclusive) 
Engg. shutdown. WFCAM was mounted on the telescope for the start of the WFCAM block. 

May 21 – 22, 2007 HST (inclusive) 
Engg. shutdown. WFCAM was removed from the telescope for the start of the cassegrain block. 

July 30 – Aug. 02, 2007 HST (inclusive) 
Engg. shutdown. WFCAM was mounted on the telescope for the start of the WFCAM block. 

August 31 – Sept. 10, 2007 HST (inclusive) 
Engg. shutdown. for WFCAM cold head work. (mini warm up of the instrument). 

December 3 – 4, 2007 HST 
Engg. shutdown. WFCAM was removed from the telescope for the start of the cassegrain block. 

February 4 – 5, 2008 HST (inclusive) 
Engg. shutdown. WFCAM was mounted on the telescope for the start of the WFCAM block. 

June 16 -17, 2008 HST (inclusive) 
Engg. shutdown. WFCAM was removed from the telescope; start of the cassegrain block 

August 22 – September 16, 2008 HST (inclusive) 
Engg. shutdown. UKIRT primary was aluminised. WFCAM was installed on the telescope to start a WFCAM block. 

December 1 – 2, 2008 HST (inclusive) 
Engg. shutdown. WFCAM was removed from the telescope; start of the cassegrain block 

January 26 – 27, 2009 HST (inclusive) 
Engg. shutdown. WFCAM was mounted on the telescope for the start of the WFCAM block. 

September 13 – 29, 2009 HST (inclusive) 
Engg. shutdown 

May 24 – June, 2010 HST (inclusive) 
UKIRT was closed for aluminisation of the primary mirror. WFCAM was taken out of the telescope and installed back during this time. 

January 25, 2011 
On Jan 22, a large (0.5+) mag extinction was noticed in the wfcam data even though the sky was clear. On Jan 24, upon investigation by the ETS, it was noticed that the WFCAM cryostat window was iced up. The Field lens module was removed on Jan 25 and was installed back after removing the ice from the cryostat window. The zero points returned back to nominal values after that. (The ice formation is the first reported; it occured during the prolonged period of poor weather with freezing temperatures in mid January. It was not clear if the dry nitrogen purging was somehow not working when it happened). See the associated fault report

June 30, 2011 
UKIRT was closed from June 27 to July 20 2011 HST (inclusive) for engg. wrok. On June 30 2011 WFCAM was opended up for troubleshooting the J filter paddle problem. Two changes were implemented: (1) the locations of the Z and J filters were swapped (locations 5 and 6 for Z and J respectively after the swap); (2) The park positions of all filters are changed from 950 to 850 so that they will make proper contact with the microswitches when parked – this change will not have any effect on the image quality since the changes affect the positions of the filter paddles when they are not in the beam only. See the associated fault report

September 2, 2011 HST 
Large extinction and aparent tilt were seen in the WFCAM data on Aug. 31, 2011; this was due to ice formation on the cryostat window due to a failure in the dryer unit. On Sept 2 HST, the field tower was removed and the ice was cleared. Dry air purging is temporarily replaced with LN2 purging. See the associated fault report

April 13, 2012 HST 
On 20120413 UT, during night time observtions, we started getting extinction of 0.3-0.5mag in the middle of the observations after a brief period of high humidity (the sky was clear). Inspection during the following day Apr 13 HST revealed a 10-inch diameter patch of ice coating on the cryostat window. The air dryer supplying dry air had failed. The field tower was remvoed and the ice coatind was removed from the cryostat window (WFCAM was cold and was on the telescope). It was kept on dry nitrogen purging since the dryer failed. See the associated fault report

April 16, 2012 HST 
On 20120416 HST, a routine inspection by the day crew revealed marks on the cryostat window which appeared to be ice build up. The field towe was again removed and found that it was really a watermark leftover from icing. The window was CO2 cleaned. This did improve on the watermarks and some dusting it got. (WFCAM was cold and it was on the telescope. Only the field tower was removed). See the associated fault report

May 30, 2012 HST 
UKIRT was closed from May 24 to June 12 2012 (inclusive) for engg. work. On may 30, 2012, WFCAM was opened; the 1.619nbH filter was replaced with a 1.644FeII filter.  

August 22, 2013 HST 
UKIRT was closed from Aug. 02 to Aug. 20 2013 HST (inclusive) for WFCAM cold head replacement. The field tower was removed, WFCAM was taken out of the telescope and put back. 

February 17-19, 2015 (inclusive) 
Engg. shutdown. WFCAM was removed from the telescope for the Cassegrain run. The field tower was separated from the cryostat. 

April 1, 2015 
WFCAM cold head was changed 

April 27-29, 2015 HST (inclusive) 
Engg. shutdown. WFCAM was mounted back on the telescope for the WFCAM block. 

August 31, 2015 – September 2, 2015 HST (inclusive) 
Engg. shutdown. WFCAM was removed from the telescope for the Cassegrain run. The field tower was separated from the cryostat. 

November 30, 2015 – December 2, 2015 HST (inclusive) 
Engg. shutdown. WFCAM was mounted back on the telescope for the start of the WFCAM block. 

August 01, 2016 – August 03 2016 HST (inclusive) 
Engg. shutdown. WFCAM was removed from the telescope for Cassegrain operations. The field tower was separated from the cryostat. 

October 03, 2016 – October 04 2016 HST (inclusive) 
Engg. shutdown. WFCAM was mounted back on the telescope for the WFCAM block. 

December 29/30, 2016 – WFCAM warmed up due to compressor problem and cryostat vacuum deterioration. Chiller fixed and instrument was pumbped and cooled down. 

January 24/25, 2017 – WFCAM warmed up due to coldhead problem and vacuum deterioration. The instrument was pumbped and cooled down. 

February 6, 2017 – WFCAM is warmed up and moved from the telescope to the dome floor for temporary UKIRT shutdown. Coldhead to be swapped next week. 

February 20, 2017 – WFCAM coldhead is replaced. The instrument is pumped, but will not be cooled down until it is time to re-start WFCAM operations. 

April 4, 2017 – Started cooling down WFCAM for re-starting the observations 

April 17, 2017 – WFCAM is is installed back on the telescope. 

August 6, 2018 HST – WFCAM was warmed up in preparation for the cass run (but still on the telescope, could not remove it as the Hyster forklift was not operational due to battery problems). 

Sept 6, 2018 HST – Started cooling down WFCAM again (still on the telescope) as the Cass run was cancelled. 
Sept. 19, 2018 HST – cold enough for operations 

Mar 28, 2018 HST – Started warming up WFCAM for cold head swap 
Apr. 1, 2019 HST – WFCAM moved from the telescope to the doom floor for cold head swap 
Apr. 15, 2019 HST – WFCAM cooled down and back on sky.
Status of the array#4 defect after the thermal cycle – 

Sept 16, 2019 – Start of Mirror coating engg shutdown: WFCAM was moved from the telescope to the dome floor. WFCAM Helium line leaked and warmed up at the start of the engg work. 
Sept 26, 2019 – Started cooling WFCAM back down; cold by 2019-Oct-11. WFCAM is on the doom floor.on the doom floor.on the doom floor.on the doom floor. 

Oct 16, 2019 – WFCAM was installed back on the telescope. Mini warm up when the cooling was shut down for some time during the installation of WFCAM on the telescope. Stage-2 temperature went above 90K. Cooled back to the nominal temperature by Oct 17. 

May 27–29, 2020 – WFCAM field tower was removed (the instrument stayed cold), the secondary mirror unit was brought down and disassembled, all three piezos were changed since one piezo was giving problem. All assembeled back on May 29 HST.

March 14 — May ?? 2022 – WFCAM warm up was started on 20220314 HST; removed from the telescope, installed on the dome floor stand; field tower is separated from the cryostat. 20220407 HST: WFCAM moved to the manipulator, coldhead and Turbo changed, moved back to the stand.

July 19 2022 – WFCAM field tower was removed to clear the ice from the cryostat window; installed back on the same day.

Controllers/Electronics history

Fully described here.

Software/Waveforms history

September 10, 2009. 
New gui allows remote start and stop of the four gaia windows running on wfdisp. Complete details can be found here. By J. Kemp.

March 2010.
        New waveforms are being used.
wfcam_ndr_dsp.xml.040007 
wfcam_cds_dsp.xml.040007 
——————————— 
Code version        = 040007 
Pixel time              = 7us 
RD_TIME            = 928ms 
SYNC                    = 1 before each ND read

Cooling/Warming history

DescriptionDatesReason
Cooldown2006 04 10
Cooldown2007 02 26Power outage
Warm-up2007 08 28Cold head replacement
Warm-up2009 07 25Power outage on MK. Arrays reached 130K
Warm-up2010 08 22Power outage on MK. Arrays reached 145K
Warm-up2011 06 27 — 2011 07 13Warmed up to room temperature for filter paddle maintenance
Warm-up2012 05 24 — 2012 06 08Warmed up to room temperature for installing the 1.644FeII filter
Warm-up2013 08 02 — 2013 08 19WFCAM cold head replacement
Warm-up2018 08 06 — 2018 09 19Warmed up for a possible Cass run and mirror coating. Cooled back to operational temperatures by Sept. 19
Warm-up2019 03 28 — 2019 04 14 HST; back on sky on UT 20190416WFCAM cold head replacement
Warm-upWFCAM cold head replacement
Warm-up2021 07 05 – WFCAM warmed up due to power issues following a 5.2 mag earthquake. Some electrical components of the panel supplying power to the compressors and chillers were damaged. Pumped with an external turbo pump, and the cooling was started on 20210714 HST after repairing the panel.
Warm-up2022 03 14 – Warmed up started on 20220314 HST. WFCAM was removed form the telescope, installed on the stand on the dome floor.
Cool down was started keeping WFCAM on the dome floor on 20220527 HST. Cooling was interrupted for a few hrs on 20220602 HST while installing WFCAM on the telescope.
2022 04 07 – cold head replacement
2022 04 07 – the old failing turbo replaced with a new one.

Field Lens Cleaning History

Jan 08, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
Jan 28, 2009. Primary mirror CO2 cleaning and Liquinox field lens wash.
Feb 17, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
Mar 03, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
Mar 25, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
Apr 08, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
May 06, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
May 21, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
Jun 03, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
Jun 18, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
Jul 27, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
Aug 13, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
Nov 02, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
Dec 01, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
Dec 16, 2009. Primary mirror and WFCAM Field Lens CO2 cleaning.
Jan 12, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Feb 10, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Feb 25, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Mar 12, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Mar 24, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Apr 06, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Apr 22, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
May 06, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Jul 15, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Aug 26, 2010. Due to lack of CO2, only the field lens could be cleaned.
Sep 15, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Sep 30, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Oct 19, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Nov 17, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Dec 16, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Dec 29, 2010. Primary mirror and WFCAM Field Lens CO2 cleaning.
Jan 24, 2011. Primary mirror and WFCAM Field Lens CO2 cleaning.
Feb 08, 2011. Primary mirror and WFCAM Field Lens CO2 cleaning.
Mar 24, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Sep 20, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Apr 12, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Apr 28, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
May 17, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Jun 08, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Jun 22, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Jul 07, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Jul 25, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Aug 16, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Sep 06, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Sep 20, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Oct 18, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Dec 01, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Dec 28, 2011. Primary Mirror and WFCAM Field Lens CO2 cleaning.
Jan 10, 2012. Primary mirror and WFCAM Field Lens CO2 cleaning.
Jan 24, 2012. Primary mirror and WFCAM Field Lens CO2 cleaning.
Feb 07, 2012. Primary mirror and WFCAM Field Lens CO2 cleaning.
Mar 01, 2012. Primary mirror and WFCAM Field Lens CO2 cleaning.
Mar 15, 2012. Primary mirror and WFCAM Field Lens CO2 cleaning.
Apr 12, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Apr 16, 2012. WFCAM cryostat window CO2 cleaning.
Apr 26, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
May 10, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
May 30, 2012. WFCAM cryostat window CO2 cleaning (when it was taken down for FeII filter installation).
Jun 13, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Jul 03, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Jul 19, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Aug 02, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Aug 15, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Sep 06, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Sep 27, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Oct 11, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Nov 01, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Nov 29, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Dec 13, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Dec 27, 2012. Primary mirror and WFCAM Field lens CO2 cleaning.
Jan 16, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Jan 31, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Feb 14, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Feb 28, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Mar 20, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Apr 04, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Apr 18, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
May 02, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
May 16, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Jun 06, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Jun 20, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Jul 03, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Jul 18, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Sep 26, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Oct 24, 2013. Primary mirror and WFCAM Field lens CO2 cleaning.
Nov 20, 2013. Primary mirror (north half only due to a tech. issue) and WFCAM Field lens CO2 cleaning.
Jan 02, 2014. Primary mirror and WFCAM Field lens CO2 cleaning.
Feb 24, 2014. Primary mirror and WFCAM Field lens CO2 cleaning.
(Inspected; no ice noticed on the field tower lens) Mar 12, 2014. Wfcam field lens CO2 cleaning.
Mar 13, 2014. Primary mirror CO2 cleaning.
May 15, 2014. Primary mirror and WFCAM Field lens CO2 cleaning.
May 29, 2014. Primary mirror and WFCAM Field lens CO2 cleaning.
Jul 10, 2014. Primary mirror and WFCAM Field lens CO2 cleaning.
Aug 28, 2014. Primary mirror CO2 cleaning (Cassegrain block, so no field lens cleaning).
Sep 18, 2014. Primary mirror CO2 cleaning (Cassegrain block, so no field lens cleaning).
Oct 21, 2014. Primary mirror and WFCAM Field lens CO2 cleaning.
Nov 18, 2014. Primary mirror and WFCAM Field lens CO2 cleaning.
Dec 18, 2014. Primary mirror and WFCAM Field lens CO2 cleaning.
Jan 15, 2015. Primary mirror and WFCAM Field lens CO2 cleaning.
Mar 18, 2015. Primary mirror CO2 cleaning.
Apr 01, 2015. Primary mirror CO2 cleaning.
Apr 30, 2015. Primary mirror and WFCAM Field lens CO2 cleaning.
Jun 08, 2015. Primary mirror and WFCAM Field lens CO2 cleaning.
Jul 16, 2015. Primary mirror and WFCAM Field lens CO2 cleaning.
Aug 20, 2015. Primary mirror and WFCAM Field lens CO2 cleaning.
Sep 24, 2015. Primary mirror CO2 cleaning.
Oct 22, 2015. Primary mirror CO2 cleaning.
Dec 02, 2015. Primary mirror and WFCAM Field lens CO2 cleaning.
Dec 29, 2015. Primary mirror and WFCAM Field lens CO2 cleaning.
Jan 27, 2016. Primary mirror and WFCAM Field lens CO2 cleaning.
Feb 24, 2016. Primary mirror and WFCAM Field lens CO2 cleaning.
Mar 30, 2016. Primary mirror and WFCAM Field lens CO2 cleaning.
Apr 28, 2016. Primary mirror and WFCAM Field lens CO2 cleaning.
May 31, 2016. Primary mirror and WFCAM Field lens CO2 cleaning.
Jul 28, 2016. Primary mirror CO2 cleaning (most probably WFCAM field lens too).
Aug 17, 2016. Primary mirror CO2 cleaning.
Sep 08, 2016. Primary mirror CO2 cleaning (Cassegrain block, so no field lens cleaning).
Sep 22, 2016. Primary mirror CO2 cleaning (Cassegrain block, so no field lens cleaning).
Oct 17, 2016. Primary mirror and WFCAM Field lens CO2 cleaning.
Nov 17, 2016. Primary mirror and WFCAM Field lens CO2 cleaning.
Dec 23, 2016. Primary mirror and WFCAM Field lens CO2 cleaning.
Jan 18, 2017. Primary mirror and WFCAM Field lens CO2 cleaning.
Apr 20, 2017. WFCAM Field lens CO2 cleaning (primary mirror cleaning was not done due to high humidity)
Apr 27, 2017. Primary mirror (only) CO2 cleaning.
May 22, 2017. Primary mirror and WFCAM Field lens CO2 cleaning.
Jun 22, 2017. Primary mirror and WFCAM Field lens CO2 cleaning.
Jul 27, 2017. Primary mirror and WFCAM Field lens CO2 cleaning.
Aug 24, 2017. Primary mirror and WFCAM Field lens CO2 cleaning.
Set 25, 2017. Primary mirror and WFCAM Field lens CO2 cleaning.
Oct 19, 2017. Primary mirror and WFCAM Field lens CO2 cleaning.
Nov 22, 2017. Primary mirror and WFCAM Field lens CO2 cleaning.
Dec 28, 2017. Primary mirror CO2 cleaning. (WFCAM Field lens could not be cleaned because the forklift battery was dead.) 
Feb 12, 2018. Primary mirror CO2 cleaning. (WFCAM Field lens could not be cleaned because the forklift battery was dead.) 
June 07, 2018. Primary mirror and WFCAM Field lens CO2 cleaning.
July 17, 2018. Primary mirror and WFCAM Field lens CO2 cleaning.
Sept 19, 2018. Primary mirror and WFCAM Field lens CO2 cleaning.
Nov 01, 2018. Primary mirror and WFCAM Field lens CO2 cleaning.
Dec 05, 2018. Primary mirror and WFCAM Field lens CO2 cleaning.
Jan 02, 2019. Primary mirror and WFCAM Field lens CO2 cleaning.
Mar 01, 2019. WFCAM Field lens CO2 cleaning.
Mar 14, 2019. Primary mirror and WFCAM Field lens CO2 cleaning.
May 09, 2019. Primary mirror and WFCAM Field lens CO2 cleaning.
June 13, 2019. Primary mirror and WFCAM Field lens CO2 cleaning.
July 11, 2019. Primary mirror and WFCAM Field lens CO2 cleaning.
Dec 12, 2019. Primary mirror and WFCAM Field lens CO2 cleaning.
Jan 30, 2020. Primary mirror and WFCAM Field lens CO2 cleaning.
Feb 27, 2020. Primary mirror and WFCAM Field lens CO2 cleaning.
May 29, 2020. Primary mirror and WFCAM Field lens CO2 cleaning.
July 02, 2020. Primary mirror and WFCAM Field lens CO2 cleaning.
Sept 10, 2020. Primary mirror and WFCAM Field lens CO2 cleaning.


Feb 11, 2021. Primary mirror and WFCAM Field lens CO2 cleaning.
June 02, 2021. Primary mirror and WFCAM Field lens CO2 cleaning.
Aug 18, 2021. Primary mirror and WFCAM Field lens CO2 cleaning.
Oct 14, 2021. Primary mirror and WFCAM Field lens CO2 cleaning.
Jan 11, 2022. Primary mirror and WFCAM Field lens CO2 cleaning.
June 8, 2022. Primary mirror CO2 cleaning.
July 19, 2022. WFCAM Field lens CO2 cleaning.