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The Primordial Polarization Program Definition Team (PPPDT) is formally chartered by the Astrophysics Research Program at the level of the Portfolio Project Manager for Infrared and Submillimeter (IR/Submm) Astrophysics. The PPPDT reports to the Astrophysics Research Program Manager at NASA Headquarters.
Background and Purpose
NASA's long-range plans include the study of the polarization signal imprinted on the Cosmic Microwave Background (CMB) by gravitational waves emanating from the earliest moments after the Big Bang. A mission to perform this study has been identified as one element of the Beyond Einstein Program. The basic scientific goals and concepts for such a mission can be found in the 2005 report from the Task Force on Cosmic Microwave Background Research (http://www.nsf.gov/mps/ast/tfcr_final_report.pdf). In addition, NASA solicited concept studies for such a CMB polarization experiment and will use information from these concepts studies to inform the work of the panel. While insufficient funds are presently available to initiate a NASA project for a CMB mission, the task force report and subsequent studies make it clear that progress towards such a mission can be made both through technology development plus precursor ground and balloon-borne investigations.
This document establishes the charter and membership of the PPPDT to make it relevant to the further concept development and science planning prior to the establishment of a formal project within NASA. It provides guidelines on composition, allows for rotation of PPPDT membership, and assures continuing involvement by the astronomical community to promote wide support for the goals of CMB experiments. If NASA elects to develop a CMB Polarization mission, the PPPDT will be replaced by a competitively selected flight Science Working Group.
PPPDT Duties
Members of the PPPDT will work in collaboration with NASA Headquarters, the National Science Foundation (NSF), Department of Energy (DoE), NASA Field Center scientists and engineers and the astronomical community to provide input during conceptual development of a CMB polarization mission. The PPPDT will help provide the astronomy community input on questions relating to the science capabilities of a potential mission and will help disseminate information about the mission concept to the community. PPPDT members are expected to be knowledgeable in observational and theoretical astrophysics relevant to defining and focusing the scientific objectives for studying the cosmic microwave background, or in the technical details specific to such an investigation.
Specific tasks of the PPPDT may include, but are not limited to:

  1. Assessing refinements of CMB polarization (CMBPol) experiment designs and requirements as embodied in the CMBPol concept studies, to study the effects of altering experiment parameters (orbit, mission duration, instrument complement, etc.) on the science goal.
  2. Working with NASA, NSF and DoE on a program of ground, balloons, and space precursor experiments and technology development in the area of CMB polarization studies that will be beneficial to understanding the requirements for a space based experiment.
  3. Evaluating potential science requirements and performance metrics for a CMB polarization experiment, instrumentation, software, operations, and other aspects of such a program.
  4. Providing scientific assessments of design concepts and implementation plans for their impact on the overall scientific performance of such a mission.
  5. Developing and assessing potential project plans, and the philosophy for defining and conducting the science program.
  6. Explaining the goals of a CMB polarization experiment to the larger astronomy community and in preparing materials for review by external scientific advisory groups and oversight committees.
  7. Providing NASA with a yearly report summarizing the panel's findings related to the technologies relevant to CMB polarization experiments and progress of the field relative to the goals outlined in the Astronomy and Astrophysics Advisory Committee's 2005 Task Force on Cosmic Microwave Background Research Final Report.
  8. Traveling to meetings in support of these efforts.

NASA will provide logistic support for the PPPDT, including arranging meetings, compiling agendas, and issuing minutes. Travel to meetings will be funded by NASA Headquarters, and therefore be subject to NASA policies and availability of funds. Any foreign partner expenses for non-U.S. PPPDT members will come from their respective countries.
PPPDT Membership
The PPPDT membership will be broadly representative of the astronomy community. An informal "Dear Colleague" letter will be issued by NASA for soliciting participation in the PPPDT. Selection criteria will be contained in the letter and are likely to include broad scientific excellence in disciplines relevant to CMB science, the ability to represent the astronomy community's interests, or technical expertise in areas relevant to the experiments.
The PPPDT Chair will be appointed from its membership by NASA Headquarters.