Figure 5 ( left ). How the shutter was immobilized . Simple , but effective .
Figure 6 ( right ). The Acquisition and Guidance unit , extracted from the heart of the telescope for maintenance .
The summit team ( led by Gemini North Mechanical Engineering Group , and supplemented with occasional help from the Science Operations Specialists group ) worked through their well-choreographed plan almost exactly to schedule . The weather largely cooperated , and after starting on July 10th , we were back on sky as planned on August 25th .
We expect work of this scale to produce some surprises , and one that came up late in the project was a 10- to 12-millimeter misalignment of the lower shutter . We ’ re still working to understand this . Until we ’ re certain , the lower shutter will be kept out of normal operations at night . Meanwhile , the upper shutter is working more smoothly than anyone can recall , and night-time operations are going well .
In parallel , we took advantage of the closed time to carry out essential maintenance on a wide variety of instruments and telescope systems . The work involved essentially all disciplines , from mechanical to instrumentation , and from electronics to software . We worked on all the following needs : maintenance of instrument optics , replacement of part of the mechanism for the Gemini Multi- Object Spectrograph on-instrument wavefront sensor , refurbishment of the Gemini Near-InfraRed Spectrometer cold heads and work on its filter wheel and focus mechanisms , and inspection of the helium hoses within the Cassegrain Rotator . We also carried out upgrades of various processors in the Enclosure Control System and made a lot of progress on our project to counter obsolescence in our real-time control systems .
Upgrading the Observatory Control Software
When it comes to observing ( and preparing for observing ), virtually everything Gemini and its users do relies on the Observatory Control Software ( OCS ) — most of which has been around for more than a decade and a half . The user software ( Observing Tool and Phase I Tool , referred to as OT and PIT , respectively ) are large Java packages that require users to download hundreds of megabytes per semester . New users find the organicallygrown OT over-complex and opaque . Even more youthful items , such as the PIT ( which was completely rewritten in 2012 ), have significant scope for improvement and better integration with other user tools , such as the integration time calculators .
At the business end , we store observation definitions in a very non-standard database , which does not scale well ; it also feeds a “ Sequence Executor ” ( which runs the telescope and instruments ) written in TCL / TK — now essentially a dead and unsupportable language .
October 2017 GeminiFocus
20
Figure 5 (left).
How the shutter was
immobilized. Simple,
but effective.
Figure 6 (right).
The Acquisition and
Guidance unit, extracted
from the heart of
the telescope for
maintenance.
The summit team (led by Gemini North Me-
chanical Engineering Group, and supple-
mented with occasional help from the Sci-
ence Operations Specialists group) worked
through their well-choreographed plan
almost exactly to schedule. The weather
largely cooperated, and after starting on
July 10th, we were back on sky as planned
on August 25th.
We expect work of this scale to produce some
surprises, and one that came up late in the
project was a 10- to 12-millimeter misalign-
ment of the lower shutter. We’re still work-
ing to understand this. Until we’re certain,
the lower shutter will be kept out of normal
operations at night. Meanwhile, the upper
shutter is working more smoothly than any-
one can recall, and night-time operations are
going well.
In parallel, we took advantage of the closed
time to carry out essential maintenance on
a wide variety of instruments and telescope
systems. The work involved essentially all
disciplines, from mechanical to instrumen-
tation, and from electronics to software. We
worked on all the following needs: mainte-
nance of instrument optics, replacement of
part of the mechanism for the Gemini Multi-
Object Spectrograph on-instrument wave-
front sensor, refurbishment of the Gemini
Near-InfraRed Spectrometer cold heads and
work on its filter wheel and focus mecha-
nisms, and inspection of the helium hoses
October 2017
within the Cassegrain Rotator. We also car-
ried out upgrades of various processors in
the Enclosure Control System and made a lot
of progress on our project to counter obso-
lescence in our real-time control systems.
Upgrading the Observatory
Control Software
When it comes to observing (and preparing
for observing), virtually everything Gemini
and its users do relies on the Observatory
Control Software (OCS) — most of which has
been around for more than a decade and a
half. The user software (Observing Tool and
Phase I Tool, referred to as OT and PIT, respec-
tively) are large Java packages that require
users to download hundreds of megabytes
per semester. New users find the organically-
grown OT over-complex and opaque. Even
more youthful items, such as the PIT (which
was completely rewritten in 2012), have sig-
nificant scope for improvement and better
integration with other user tools, such as the
integration time calculators.
At the business end, we store observa-
tion definitions in a very non-standard d )х͔ݡ́Ё͍ݕ쁥Ёͼ)́qMՕᕍѽˊtݡչ)ѡѕ͍յ̤ɥѕ)Q
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