3

An Example of Combining Collaboration and Competition

In Chapter 2, the CAA advocated a combination of collaboration and competition leading to the final selection of Roman’s observing plan. Here the committee gives an example of how such a combination might work.

The committee was briefed on NASA’s preliminary plans for the collaborative process that would lead to the formation of Roman’s science observing plan. According to these plans, NASA would form three subcommittees, one for each CCS. Each of the subcommittees would collect community input and design each of the surveys. A steering committee would negotiate and resolve conflicts among CCS teams, if they arise. NASA will fund some of these activities, although the expectation is that some community members may volunteer their efforts as occurred in the development of the Legacy Survey of Space and Time for the Rubin Observatory.

The CAA endorses key elements of this plan and proposes to augment it with new elements that align with the principles outlined in Chapter 2. The committee suggests establishing four community working groups (WGs); see Figure 3.1. Three WGs would correspond to each of the current CCS, and a fourth would coordinate GA science surveys. The WGs would consist of funded and volunteer members of the community and would be managed by a leadership team, part of which would be appointed following a solicitation process, and part would be chosen by WG members. Each of the CCS WGs would be composed of subject-matter experts and would include GA scientists. The leadership team of each of the CCS WGs would include GA representatives. To optimize the CCS, and the overall science return of Roman, it is important to include GA scientists throughout the survey design processes.

The WGs would be charged to prepare several survey options each and to quantitatively map science deliverables to the observing time required for each of the survey options. As described in Chapter 2 (Principle 6), one of the options would be “minimal”—in the sense that it would quantify the minimum time a survey would require to achieve the Astro2010 science objectives. Other options could include longer surveys that would yield additional GA science enhancements. The GA WG would be encouraged to propose large, unique GA surveys that require observing resources beyond those available to GA within the CCS. For GA scientists, there would still exist the option to apply for GA observing time, as has been planned all along.

An independent STAC reviews all applications for Roman observing time and makes the final survey selections that will form Roman’s initial observing plan. Subsequent TACs make determinations about later GA calls for proposals. The STAC consists of members that have a broad range of expertise, and its operation and handling of conflicts of interest may be similar to the practice with executive TACs that have been setup for prior space missions such as Hubble, Chandra, and Spitzer. The STAC would be balanced in multiple dimensions, including science interests and membership of underrepresented populations. It has broad latitude in optimizing Roman’s observing time. Although it would have a range of options for each survey, it would also have at its disposal quantitative information allowing it to make choices that deviate from the provided options. To optimize the overall program, the STAC may decide on a two-step proposal process. The first step could be used to encourage consolidation of surveys by teams that have not already identified potential synergies. Such consolidation could strengthen proposals and enhance the overall science return. The final selection would be done in the second step. The CAA recognizes the significant effort it would take to participate in the STAC. However, the level of effort

does not seem significantly greater than the investment by TACs for Hubble or Chandra. Some of the STAC work may be off-loaded to sub-panels with additional members, as done for Hubble, Chandra, and Spitzer. The structure outlined in Figure 3.1 refers only to the process of establishing Roman’s initial observing plan.