ing Tool has GPI skeletons implemented.
These skeletons allow a one-click approach
to have fully-defined observations. A total of
12 GPI science programs now exist; requiring
72 hours of telescope time.
For many involved in the Gemini Planet Imager (GPI), recent efforts have concentrated
on preparation for the SPIE 2014 conference
in Montréal in which GPI had a huge presence. The extended GPI team delivered almost 20 presentations on various aspects of
the instrument. See all Gemini-related SPIE
abstracts here.
See updates in October 2014 (p. 37) and January
2015 (p. 35).
Gemini North Dome Repairs
In late May, the discovery that the second
dome shutter drive unit had failed at Gemini
North prompted an unscheduled shutdown
in order to make necessary repairs (Figure
11). Because this is the second of these drive
units to fail at Gemini North, the repairs went
relatively quickly and downtime was kept
to a minimum (in the earlier instance the
weather was also an issue; see article in the
previous issue of GeminiFocus for details on
repairs to the identical unit on the opposite
side of the dome top shutter). Work is ongoing to better understand why these units
both failed at Gemini North and to minimize
the possibility that they will do so unexpectedly at Gemini South.
April 2014
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 highpriority 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 12)
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
Figure 12.
The dome repair team,
just before lifting the
repaired gearbox back
into position.
For more details on this work, see the blog
that features highlights from the shutdown
(including a video illustrating the difficulties
of accessing the drive unit) available here.
January 2015
2014 Year in Review
GeminiFocus
41