Andy Adamson
Operations Corner
Shutter Work Completed at Gemini North
In late December 2013, Gemini North joined the significant group of telescopes that have
suffered major failures in their dome systems. A top shutter drive unit had a critical failure
with one of its spherical bearings. These drive boxes are designed to last 50 years under
normal operating conditions, so clearly it was a faulty mechanism and had to be replaced.
Because this failure rendered the dome unusable, repairing the unit became a high-priority
project — one that needed to be completed before science operations could recommence
at Gemini North. Removing this system proved extremely challenging. The Gemini North
engineering team (Figure 1) worked with external consultants to develop an entirely new
set of procedures to pin the shutters in place and extract the broken drive box (which weighs
more than two tons and is not amenable to in-situ repair). Bad weather hampered an already
difficult situation — winds well over 100 miles per hour were encountered in January, and
there was significant snowfall during the period. The team finally extracted the unit from the
dome at the end of January. Work then progressed very quickly as the unit was inspected,
potential causes of the failure identified, repairs made, and the drive box rebuilt and reinstalled. By February 15th, Gemini North was once again ready for observations.
Read a complete summary at: http://www.gemini.edu/node/12160
Large and Long Proposal Mode Piques Interest
Interest from our user community in the new Large and Long Programs (hereafter “Large
Programs” or LPs) mode is excellent. These Principal Investigator-defined and -driven programs generally either require significantly more time than a partner typically approves for
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GeminiFocus
April 2014