Roman/WFIRST and the Astronomy Community

Preamble from 2020 for the Decadal submission of the memo and the letters

Roman/WFIRST is a problem child for us. It is costing as much as a substantial Flagship of the Chandra/Hubble class, and yet it is not seen as a Great Observatory by our science community. We risk a great deal by having a $4B mission that costs like a Flagship, but is of little direct interest to the broad astronomy community. Instead of being positioned to do contemporary science befitting of a Flagship in the 2026+ era, Roman/WFIRST is being stuck with a pre-planned survey science model like that of a sub-$1B Probe mission. This is very risky given the continuing cancellation of Roman/WFIRST by the Administration. And this mismatch between the narrow science approach and Roman/WFIRST’s very substantial cost provides a bad example for trying to sell future Flagship missions of the HabEx-Lynx-Origins-LUVOIR class.

Over the last six months I have been, along with a number of others, trying to have the Astrophysics Division recognize the lack of community interest in Roman/WFIRST, and the inappropriateness of the pre-planned survey science model for a powerful, and very expensive, Flagship. I have attached here a set of three letters that I have sent to Paul Hertz. There is also a short cover memo since the letters are (rather) long.

The three letters cover several aspects. The first letter, from November 17 2019, is short and really makes it obvious just how different Roman/WFIRST is from JWST in terms of community interest. This has been reinforced by numerous discussions that I have had, and by the clear lack of interest in Roman/WFIRST relative to JWST at recent AAS meetings. These discussions led me to give a broader analysis in my second letter of January 24 2020 about the lack of community interest, along with some thoughts for consideration by Paul and the NASA science team towards gaining community support for Roman/WFIRST. I then realized in subsequent discussions that the second letter was, in part, misinterpreted (my fault for not being sufficiently to the point and clear about the science model failings), and so I wrote a more focused third letter that was sent to Paul and the Roman/WFIRST team about two weeks ago.

Roman/WFIRST itself is developing well as a project, but scientifically Roman/WFIRST is not, and never will be, a Great Observatory unless the science program becomes more like that of Hubble, Chandra and Spitzer — that is, driven by the most interesting and important science of the late 2020s, selected through peer review that is contemporaneous with Roman/WFIRST's launch and operational epoch.

The Nancy Grace Roman Space Telescope (Roman/WFIRST)

Roman/WFIRST is a Hubble-sized telescope targeted for launch in the late-2020s. It could revolutionize astronomy by building on the science discoveries and technological leaps of the Hubble and James Webb space telescopes.


A Memo to the Astronomy Community


Memo To: Astronomy Colleagues

Re: The risk to Roman/WFIRST from the lack of support in the astronomy community

From: Garth Illingworth

Over the last couple of years I have become increasingly concerned about the lack of interest in Roman/WFIRST in the astronomy community. My concern about the narrow science model has grown in the last 6 months. The contrast with the development of the mission is marked. The Roman/WFIRST WIETR review process, the clarity of the recent transition to implementation (Phase C), and the excellent development efforts by the Roman/WFIRST Project team at GSFC have contributed to putting the Roman/WFIRST Program onto a sound programmatic and technical footing. The Project is progressing well (though Covid impacts are TBD). Nonetheless, the yearly cancellations do hang over the Program, and not having much astronomy community support adds greatly to the risk for Roman/WFIRST.

I have written three letters to Director Paul Hertz, Astrophysics Division NASA SMD, discussing various aspects of these concerns. These letters are attached (in one set). This memo also includes a summary below of the concerns and thoughts raised in the letters to Paul.

The first letter, from November 17 2019, is short and makes it obvious just how different Roman/WFIRST is from JWST in terms of community interest. This has been reinforced by numerous discussions. These discussions led me to give a broader analysis in my second letter of January 24 2020 about the lack of interest, along with some thoughts for consideration by Paul and his Roman/WFIRST team towards gaining community support for Roman/WFIRST. I realized in subsequent discussions that the second letter was misinterpreted (my fault for not being sufficiently clear), and so I wrote a more focused third letter re the science model that was sent to Paul and the Roman/WFIRST team in late April.

I should note that I do not have a “horse in this race”. My concerns here arise from my decades of effort helping to make the Great Observatories, and NASA Flagship missions in general, hugely successful scientific enterprises that are worthy of the support by policy-makers for the billions of dollars that the US, and our partners, spend on them on behalf of taxpayers.

The letters are long and so I have included here the summary that is in the third letter that I sent to Paul recently to give you an overview of my concerns (and those of many others):

Summary: Roman/WFIRST has the potential to be an exciting Flagship mission doing cutting-edge science by bringing the imagination of the community to bear. Roman/WFIRST can be a powerful Hubble-Class Flagship Observatory with a remarkable wide-field camera. Yet Roman/WFIRST is failing to be seen as a project worth spending $4B on by the science community. Why? Because the 2.4-m Roman/WFIRST/AFTA is being set up as a pre-planned limited-science survey mission that will serve a tiny fraction of the science interests of the astronomy community. Furthermore, it is a mission that is seen to have been captured by just a few percent of the community -- who are seen as the “haves” and “insiders”. This clearly is not what we should be doing for a powerful $4B Flagship.

How did we get into this situation? Roman/WFIRST/AFTA had its genesis in the mid-2000 timeframe when a number of probe-class missions were rolled up into a sub-$1B JDEM. JDEM was conceived to be a 1.5-m dark energy survey instrument, responsive to the Beyond Einstein process. This grew slightly in science scope in the Decadal survey, but still with a similar size mirror. When the AFTA opportunity arose, and Roman/WFIRST grew from the then 1.3-m to 2.4-m, its path was set to become a Flagship. The science opportunities should have expanded greatly beyond those for just a small-scale survey telescope. Yet the science opportunities remained like that for sub-$1B Probe or Fermi-like missions. The Roman/WFIRST science program is of direct interest to just a tiny fraction of the science community (~5%) and is seen to have been given to just a few percent (~2-3%) of the science community, as represented in the SITs and FSWG. While this group has done valuable service by defining detailed science approaches that have provided the technical requirements on Roman/WFIRST, the FSWG and SIT teams are seen as controlling the science program for Roman/WFIRST. Failing to take the AFTA opportunity to expand the science scope was a mistake that has led to the community seeing the now $4B Roman/WFIRST as a telescope for the “haves” and “insiders” and not as an Observatory that would provide access for the full-community by enabling cutting-edge contemporary science in the 2026-2031+ timeframe across all of astrophysics. The science model for Roman/WFIRST/AFTA should be Hubble/Chandra/Spitzer, not JDEM, or the similar probe-like capability of the Roman/WFIRST/Decadal, or of other sub-$1B scale missions like Fermi. We need to change Roman/WFIRST to a model of contemporaneous peer-review in the 2026+ timeframe, openly-competed across all astronomy, since that is the gold standard for doing the best science.

Key projects, covering a small fraction of the time, could be used to deal with any science areas that might, as we get closer, be seen as needing special treatment. But the justification would need to be exceptional to do so. For JWST, as recommended by the JSTAC, it was felt that the science goals that have long been used to justify and “market” JWST did not need special treatment. If they are of overwhelming contemporary science interest they surely will be selected through a well-designed TAC process.”

The bottom line is that the current pre-planned survey science model focuses just on a small (albeit important) area of astrophysics, and diverges from our well-established broad, contemporaneous science peer review process to define the science program. The current narrowly-focused survey science model is a mistake in a $4B Flagship Observatory that has Hubble-like power for doing cutting-edge science. For enabling our future Flagship missions (cf., HabEx, Lynx, Origins, LUVOIR), as well as for justifying the cost of Roman/WFIRST, Roman/WFIRST has to be seen as one of our ensemble of Great Observatories that have opened up new scientific frontiers and also provided new opportunities for the whole astronomy community – and particularly, offers such scientific opportunities through contemporary peer review for our upcoming young scientists, who, with the enhanced numbers of woman and minorities, are finally leading to more diversity in our community.

As my concluding sentence noted in my most recent letter: “The current narrow pre-planned survey science approach for Roman/WFIRST will not achieve these goals, and leaves Roman/WFIRST at significant risk of cancellation.”

Garth Illingworth

Distinguished Professor Emeritus, Department of Astronomy and Astrophysics, UCSC

Astronomer, University of California Observatories/Lick Observatory

Roman/WFIRST Field of View

The orange outline shows the enormous footprint of Roman/WFIRST superimposed on this Hubble Legacy Field GOODS-South mosaic. It would take just two Roman/WFIRST pointings to cover the entire region explored by Hubble in this mosaic at the same depth and image clarity. Roman/WFIRST’s unique ability to do wide-field surveys at space-based resolution will enable a very ambitious science program.

PDF Downloads

The preamble above, the memo and the three letters were written in late 2019 and early 2020 about my concerns regarding WFIRST, building on earlier letters in 2018 and 2019 to Paul Hertz, NASA Astrophysics Director, from a number of senior scientists, including Academy members. These later letters from me were similarly sent to Paul. These letters were also made available to the 2020 Decadal Survey, and so are now in the public domain (as the NAS requires of all input). Since “Roman" was known at the time of writing as “WFIRST", WFIRST was the name used throughout the original letters and memo. The renaming to Roman by NASA occurred in early summer 2020, after all these documents were written. To make them consistent with current usage I have done a global replace of “WFIRST” with “Roman/WFIRST”. The content is otherwise unchanged, other than minor reformatting and ensuring that links still work, and may be somewhat dated in places, but the core issues remain.

Roman/WFIRST Contemporaneous Science Peer Review

The three letters written in late 2019 and early 2020 that were sent to Dr. Paul Hertz, Director, Astrophysics Division, Science Mission Directorate, NASA Headquarters.

Nov 2019 Letter

Jan 2020 Letter

Apr 2020 Letter

Memo re Roman/WFIRST

Garth Illingworth's memo Re: The risk to Roman/WFIRST from the lack of support in the astronomy community.