of the collimator and part of the Multi-Object
Spectrograph’s dewar) was fractured.
To both determine the root cause and initiate
mitigation paths (new lens procurement, etc.)
the team immediately began an escalation
activity. We have also gathered a committee
of external reviewers from the community to
advise us on our analysis and confirm the best
steps forward. Additionally, our colleagues
at the University of Florida have joined us to
help the situation.
Figure 2.
Unfortunately, despite a lot of brainstorming and analysis, it has proved very difficult
to identify one single root cause. Instead, we
have identified several possible causes that
we are addressing with mitigation strategies.
During the escalation, we applied a few standard tools and methodologies.
Example of MOS
spectra observed
with FLAMINGOS-2
in January 2012.
For example, to design the new repair and understand the new schedule, we performed a
careful Kepner-Tregoe analysis of the possible
causes, and a PERT analysis of the critical path
(three-point estimates to find out the optimistic and pessimistic, expected and optimistic, end dates).
As of the end of May 2012, we are conducting thermal experimentation (temperature
sensors were epoxied on the broken, but rebonded, lens) and thermal modeling to measure the thermal stress in the glass. This will
increase our confidence level in the new design with real in-