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Lee Armus
Franz Bauer
Tiziana DiMatteo (by phone)
Tim Kallman
Carol Lonsdale
Hironori Matsumoto
Paul Martini
Jon Miller (Chair)
Rachel Osten
Feryal Ozel (by phone)
Pedro Rodriguez (ESA)
Martin Weisskopf (by phone)
The CUC was informed that Harvey Tananbaum will be stepping down as
Director. On behalf of the entire community of users, we wish to
express our sincere gratitude to Harvey for his leadership. His is an
excellent example of how to shepherd a large mission through the
approval, construction, launch, and operations phases, and the success
of the observatory is a reflection of his enormous dedication.
We are ready to support and advise the new Director in the many years
ahead.
The CUC received thorough reports from Roger Brissenden and Sabina
Hurley concerning the overall health of the observatory.
The most important finding is that the spacecraft and instruments are
still in excellent shape, with no issues that will impact the
completion of a 20 year mission, nor even a longer mission.
The CUC notes that the mission is proactive in anticipating events and
trends that could potentially impact the operation of the spacecraft
and operations, and developing workarounds and mitigations in advance
of any difficulties. A particularly good example is the move from the
degraded EPHIN radiation monitor, to monitoring with the HRC and ACIS
instruments themselves.
Another good example is switching from the aging A-side Momentum
Unloading Propulsion System (MUPS) to the B-side MUPS, and exploring
ways of combining A and B MUPS thrusters. The CUC notes that 6 of 8
thrusters currently work well; while only 3 are strictly required for
normal science operations, loss of additional thrusters may reduce
observing efficiency and would increase risk if certain other failures
were to occur.
Recommendation: Flight operations and mission planning and scheduling is clearly quite
complex, especially with regard to the interplay between
instrument/spacecraft heating and observatory pitch angle, and the
manner in which observations are conducted now can impact the
longevity and efficiency of the mission. Efforts have already been
made to exploit efficiencies in the staffing (e.g. cross-training
different tasks). But it is also clear that any further reduction in
staffing levels will have a negative impact on the mission now, and
going forward. NASA and Chandra should continue to recognize the
importance and value of maintaining staffing levels in flight
operations, and in mission planning and scheduling.
The CUC requests continued updates in future meetings, from these
segments of the mission.
The CUC was updated on the status of E/PO by Roger Brissenden. The
situation is clearly a complex one, with unclear direction provided in
proposed presidential budgets and continuing resolutions. The E/PO
team has continued to deliver in a difficult situation.
Recommendation:
The CUC strongly endorses all efforts made by Chandra to connect with
the public and to communicate the science done by the mission. The
Great Observatories are flagships for science in the US, and they have
a special obligation and ability to communicate the unique science
that they achieve. We are particularly impressed by the way in which
Chanda shares science with the public through the web and social
media, and hope to see these efforts continue.
The CUC encourages any and all efforts made by the Chandra E/PO team
to partner with other NASA missions in articulating the importance of
their efforts to NASA and other organizations.
The CUC heard a summary of recent DDT observations from Harvey
Tananbaum. This program remains a particularly important means of
optimizing the science returns of the mission. It promotes flexibility
and enables unique investigations.
Recommendation:
The CUC looks forward to the continuation of the DDT program under a
new director.
The CUC heard from Belinda Wilkes an update on the Cycle 15 peer
review and future plans. The CUC notes that the oversubscription
remains very high (5.3), that 636 total proposals were submitted, and
that approximately 20 Ms of observing time was allocated. The
oversubscription clearly signals that the scientific relevance and
centrality of the mission continue at a high level.
Recommendation:
The mission should continue to pursue existing and new joint programs
in order to maximize its scientific reach.
The CUC reiterates its support for the theory and archive proposal
categories. These should be retained even in the event of future
mission funding reductions.
Supporting the community to analyze Chandra data is the primary way
that forefront science is achieved. The CUC would like to discuss any
future budgetary reductions in an effort to ensure a balanced approach
that does the utmost to preserve general observer funding.
The CUC endorses the plan to create one final XVP category in Cycle 16
by allocating 2 Ms from Cycle 17. This will take advantage of the
evolving orbital parameters that will provide a small amount of
additional observing time in the next two cycles.
With some very large XVPs approved, and with continued high
oversubscription in the LP category, we urge that panelists and
pundits evaluating XVPs explicitly compare them against the most
highly-ranked but unapproved LPs, with the chance of approving a few
such LPs instead of lower-ranking XVPs. XVP programs should not
allocate time from the LP category.
Sherry Winkelman presented new efforts to track data use, grant awards, and publications. This effort was undertaken partly based on prior advice from the CUC, and we are grateful for this quick and effective response. It is early, but there are already indications that these efforts are yielding an improved view of how Chandra data are used. We look forward to a report in 2014.
The CUC was provided with an update on the Chandra Source Catalog by
Ian Evans. We wish to thank the team for their efforts, especially
given the difficulty of the tasks.
Prior releases of the source catalog are clearly of high value and
help astronomers who work in other wavelengths to make use of Chandra
data. The catalog efforts are an important means of expanding the
reach of the mission, and have had positive ancillary impacts
including the development of valuable new software tools in the CIAO
suite. The addition of command-line access to the Chandra Source
Catalog should allow a larger fraction of the user community to gain
rapid and efficient access to many useful catalog products.
Release 2.0 of the catalog is behind schedule, and will likely be
completed over the next 12-24 months. The delays are the result of the
specific demands of making robust detections of fainter sources, the
complications of stacking fields, and other functions. Reductions in
staffing have contributed to these delays.
Recommendation:
The CUC endorses the efforts being undertaken to complete Release
2.0. The mission has clearly been responsive to the CUC in making
improvements over prior releases. The mission continues to prioritize
the GO program and the CIAO suite over the source catalog, in the face
of staffing reductions. We support this prioritization but we urge the
completion and release of the catalog, and recommend a hard look at
essential catalog aspects versus ideal catalog aspects. We also urge
the consideration of staged releases, where certain parts of the sky
(those that overlap with large survey efforts in other wavelengths,
for instance) might be released ahead of others. Finally, the CUC was
told that there are computing limitations, and we urge that the
observatory explore this, as improved capacity must be available with
only modest costs.
Larry David presented the committee with a summary of ongoing and new
calibration efforts. The calibration team was very responsive to
prior recommendations, for which the CUC is grateful. The dedication
of the calibration team is one of the reasons why Chandra is a remarkable
mission.
Particularly impressive efforts were undertaken to understand the
nature of the PSF anomaly. Its nature remains uncertain, but it does
not likely derive from simple mirror misalignment. The most important
outcome of these investigations is that the anomaly is small, well
characterized, and likely represents as little as 1% (or less) of the
flux in the PSF core.
Recommendation:
Chandra will continue to be an important spectroscopic mission over
the next 10 years. Even after Astro-H launches, Chandra will offer the
best spectral resolution below 4 keV. We strongly endorse the efforts
of the calibration team to improve the characterization of various
HETG modes and observations. An improved characterization of the
zeroth order image and spectrum, in all aspects, will have broad
positive impacts.
We request an update on cross-calibration efforts with other missions,
in addition to updates to internal calibration efforts, at the next
CUC meeting.
Jonathan McDowell presented updates and improvements to the CIAO
suite.
As before, the CUC is impressed by CIAO and ongoing efforts. The team
continues to add helpful new tools, and to simplify the execution of
important existing tools.
The development of the "srcflx" script is particularly important in
that it will help astronomers with no prior X-ray experience to get
model-independent flux estimates from sources in Chandra mission. This
tool will improve the reach of the mission.
The HELPDESK is particularly efficient at resolving problems.
We look forward to the upcoming release of CIAO 4.6.
Recommendation:
The CIAO teams continues to deliver an excellent software suite in an
efficient manner, and to make sensible and useful improvements. Please
keep it up.
Especially in an era of reduced staffing, it is clear that the
HELPDESK staff cannot be expected to provide advice and assistance
that is not directly related to Chandra data and software tools, and
the team should allocate its time accordingly.
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