itself, including significant work to improve
reliability of the mask exchange unit.
Finally, we replaced the large chiller, which
is used for the toughest cooling tasks in the
building (including the air handling units in
the dome itself ). This task was a major undertaking. It required a choreographed exchange between the existing chillers and
the new unit — one that enabled the new
one to be run in a test mode so that stability
could be achieved before we permanently
switched the units. The new unit appears to
work very well, and, because it is much more
efficient, we expect to realize significant savings on electricity costs.
Gemini North Safety Platforms
Following in the footsteps of Gemini South,
this summer, during necessary low wind
conditions, engineering staff at Gemini
North successfully installed its Shutter Service Platform (Figure 1). This structure is designed to provide a safe means to perform
critical periodic maintenance on the enclosure shutter drive motors, encoders, gearboxes, and chains.
The installation work required careful coordination and collaboration of four outside
contractors with the site team, plus necessary approvals and oversight of the Office of
Mauna Kea Management.
Figure 2 shows the 150-foot telescoping
crane required to pick up and place the platforms into position. For the crane to safely
perform the lift, Gemini had to excavate and
grade a level foundation pad and limit the
operation to wind speeds less than 20 miles
per hour; both items impacted the time and
cost of the installation work.
Thanks to the dedicated efforts of all, Gemini
now has a safe means to perform critical periodic maintenance on our important shutter drive systems.
October2013
DSSI Speckle Camera Visitor
Instrument
Gemini’s new visiting-instrument policy, developed jointly by the Observatory and the
Science and Technology Advisory Committee (STAC), allows a quick process for bringing a visiting instrument to the telescope
on a “once-off “ basis. It also allows for the
possibility of attracting a wider base of users
within the Gemini partnership, who may be
interested in the performance potential of
these instruments (without going the whole
way to facility class, which is a much larger,
and likely prohibitive, undertaking). The
policy, posted here: http://www.gemini.edu/
sciops/instruments/visiting-instrument-policy,
was put into action with the Differential
Spectral Survey Instrument DSSI; a speckle
GeminiFocus
Figure 1. (above)
View from the newly
installed Shutter Service
Platform installed to
facilitate safety and
accessibility during
Shutter motor servicing.
Figure 2. (below)
A 150-foot telescoping
crane was needed to
install the Shutter Service
Platform.
15