Structure and Evolution of the Universe Subcommittee (SEUS) Minutes 5-6 Mar 2001

Letter to Structure and Evolution of the Universe Director Dr. Alan Bunner from Dr. Bruce Margon, Chair of SEUS

Dear Alan:

The Structure and Evolution of the Universe Subcommittee (SEUS) met at NASA HQ on March 5-6, 2001. All members except Simon Swordy, Harvey Tananbaum, Gordon Garmire, and Brad Peterson were in attendance.

At the time of our meeting, the FY02 budget blueprint was available, but not the detailed budget. While we are disappointed that the Cosmic Journeys initiative cannot move forward at this time, we understand that this is a government-wide issue, unrelated to the merits of SEU programs. We are very pleased at the prospect of new FY02 funds for SEU technology development (designated as “high energy astrophysics” in the blueprint). These are urgently required by the theme, especially for high priority projects such as Constellation-X and LISA, and we look forward to learning more details on plans for its use. We hope that a new start for Cosmic Journeys in FY03 will be aggressively pursued by all in OSS.

SEUS urges Code S to accommodate the XRS on ASTRO-E2 if at all possible. Launch failures should not dictate scientific priorities, and we are now presented with a unique recovery opportunity. The current situation is a classic MO: the opportunity has arisen suddenly and requires a timely commitment. The XRS investigation has succeeded at numerous peer reviews beginning with selection for AXAF in 1984, and most recently (2000) as a successful SMEX Phase A selection. A recently-completed GSFC study confirms that accommodating the XRS on ASTRO-E will halve the cost of the Joule SMEX investigation while providing superior science. Paul Hertz also informs us that OSS is committed to select two SMEX investigations for flight regardless of the ASTRO-E2 decision. In addition, the XRS is a vital technology path to future SEU high priority missions such as Constellation-X. We believe this action is consistent with the tradition of strong peer review in the Explorer program. Finally, we note that the party tasked with making the MO recommendation (the Board of Directors) is the identical group charged with the SMEX downselect recommendation shortly thereafter.

We heard with great interest Ed Weiler describe tentative plans for reorganization within Code S. One area discussed by SEUS is how best to offer community scientific advice to the new organization.Ê We believe that one astrophysics advisory committee of size comparable to the current SEUS or OS would be very hard-pressed to perform this role. The range and diversity of OSS astrophysics activities have grown substantially even during the past few years. Areas such as fundamental physics, gravitational wave astrophysics, astrobiology, and particle astrophysics are now active disciplines in OSS astrophysics. Further, detectors at all wavelengths have grown ever more complex and arcane. If there is a single scientific advisory committee to the new astrophysics division, it will surely need standing, as opposed to ad hoc, subcommittees to fairly cover all the fields. The lack of parallelism with SECAS and SSES may then be a concern. Committees organized along separate scientific themes, as are SEUS and OS, may be the best compromise.

The FY02 budget blueprint indicates that ISS may be descoped, perhaps jeopardizing opportunities for OSS experiments. We wish to reiterate that ACCESS and EXIST, both currently requiring ISS accommodation, are important and intrinsic parts of the SEU Roadmap and the OSS Strategic Plan; both are also highly ranked by the NAS Decadal Survey. We urge you to continue efforts to enable the science of these two important projects.

We learned of new budget pressures on GLAST, our high-priority mission under development. While certain of these problems are specific to the program, others, such as the need for deorbit propulsion (and consequently a larger launcher), as well as accommodation of NIAT concerns, are agency-wide policy issues that could not be foreseen at the time of initial budgeting. We are also aware of severe pressures on OSS caused by GP-B, and wish to state that our scientific priorities clearly favor GLAST.

The SEUS reviewed and discussed a draft of the high energy astrophysics R&A “cluster proposal.” This was a useful activity, and SEUS would welcome the opportunity to read and comment on drafts of other SEU-related cluster proposals before submission, preferably by early April 2001.

SScAC, Code S, and the relevant advisory subcommittee chairs have received some letters from the community regarding the future of optical and UV spaceborne astronomy, and whether the structure of the advisory process influenced the outcome of these disciplines in the recent roadmapping process.ÊÊ At the request of SScAC, we discussed the situation and concluded that the deliberations were fair, and there was adequate representation of the relevant disciplines. The NAS Decadal Survey independently determined similar scientific priorities.

ÊWe deferred setting a date for the next SEUS meeting, but will do so shortly. Sincerely,

Ê
Bruce Margon
Chair, SEUS