The JWST Advisory Committee (JSTAC): The Impact of a Long 12-Month Proprietary Period

Garth Illingworth (Chair, JSTAC), gdi[at]

In a prior STScI Newsletter (Volume 33, Issue 01) I gave a broad overview of the JSTAC's recommendations over the seven years of its life since its inception in 2009. As outlined in that first article, the JSTAC's charge in advising the STScI Director can be distilled down to: "maximizing JWST's scientific productivity." As promised in the June Newsletter, this article focuses on the question of the length of the proprietary time1 for JWST. This topic has been extensively discussed by JSTAC since its very earliest letters in 2010 (the JSTAC letters are public and can be found on the JSTAC webpage). JSTAC's role, of course, is just to make recommendations that STScI can then take into consideration in its decisions, and in discussions with NASA and the JWST partner agencies. The discussion in this article reflects the views and recommendations of JSTAC, and should not be considered to be STScI views or policy.

The proprietary time issue in a nutshell

The JSTAC recognized very early in its deliberations that a long 12-month proprietary period would impact the scientific productivity of a mission like JWST. What so seized the JSTAC's attention in 2010 (see page 1 of the June 2010 letter), and for the past seven years, was the realization that "… for data with a one-year proprietary period, the Call for Proposals for Cycle 4 is the first wherein the full Cycle 1 dataset is public and so can be used as the basis for follow-up proposals by all members of the science community."

The impact of a long proprietary period on JWST science was enunciated in JSTAC's earliest letters to the Director in 2010 (see e.g., February 2010 letter), and then extensively discussed in JSTAC's March 2014 letter. Two presentations to the JWST Science Working Group also highlight this issue (SWG July 2013 and SWG April 2014). A comprehensive summary given to JSTAC at its December 2015 meeting is in this early 2016 Status Presentation. This gives updates on happenings regarding proprietary time since the 2014 JSTAC letter recommendations.

JWST is baselined as a five-year mission, with the expectation that it will extend to approximately 10 years (on-board propellant-limited). Even if we are fortunate to have JWST for its full life, introducing an approximately two-year delay into the ability of the broad science community to follow-up on observations and discoveries seems unwise. In addition, we need to consider the risks of life-terminating events that can happen unexpectedly during any space mission. This makes it even more important, particularly early in the life of the mission, to maximize the opportunities and minimize the time for follow-up of scientific discoveries.

Follow-up of scientific discoveries

In a new, extraordinarily powerful mission like JWST, rapid follow-up of science discoveries is a key part of "maximizing JWST's scientific productivity." If the science community cannot quickly follow up discoveries with new approaches and new observations, it will have a significant impact on the scientific returns from JWST. Fortunately, rapid follow-up will be possible for a class of programs that will likely constitute around 25% of JWST's observing time in its early Cycles. The JSTAC recommended that the proprietary period for large, Treasury/Legacy, and Director's Discretionary (DD) time continue to be zero, as they have been for Hubble (and Spitzer and Chandra). Since the indications are that such programs will continue with zero proprietary time for JWST, the discussion within JSTAC focused on the 12-month proprietary period for the medium and small programs that constitute the large majority of all programs (note that the GTOs will have a 12-month proprietary period; the JSTAC discussion was only for the GOs). These medium and small programs are particularly important since they are expected to explore—and reveal—a huge range of new science, and they will dominate the JWST observing time, particularly in its early phases.

The "have vs. have-not issue"

A long proprietary period can lead to a "haves" vs. "have-nots" situation. Those who are able to get data in Cycle 1 on key topics or sources can use the knowledge gained to out-compete others who cannot see the actual data before subsequent GO proposal cycles. This can continue for many cycles. Such a limitation is not conducive to the best scientific outcomes. Broad communities of innovative scientists evaluating datasets and planning for new tests and observations in a competitive environment will clearly enhance the scientific productivity of a mission. In contrast, long proprietary periods are exclusionary, and are not conducive to maximizing the science return from JWST.

What is an appropriate compromise between proprietary period and data availability?

A simple figure shows the impact of a 12-month proprietary period. With a 12-month proprietary period, Cycle 4 proposals are the first able to use all Cycle 1 data to do follow-up (see Figure 1). The fraction that is available about two months2 before the Cycle 3 proposal deadline depends on the fraction of time that is allocated to open datasets. If there were no open datasets, only about 30% would be available. This is not what is expected, of course. The open datasets from Director's Discretionary time alone would raise this to about 37%. An assessment of the likely time allocated to Large and Treasury with their expected open datasets would further raise this to about 48%.3 The remaining half of the Cycle 1 data would then not be available for follow-up until Cycle 4.

Figure 1: The fraction of the data available at each proposal deadline for the nominal 12-month proprietary period is shown (this figure is taken from the March 2014 JSTAC letter). This includes 0.2 cycle as the lead-time needed to process the new data after its release, evaluate new results and write proposals. In reality, there will be more data available than the 0.3 of Cycle 1 at Cycle 3 (and also for later cycles), since some data will be taken with zero proprietary time. The zero proprietary time datasets would include Director's Discretionary Time (DD time), and probably any data from Large or Treasury programs. If the only open access data was DD time, 10% of the Cycle 1 data would be open data. The more likely situation is that about 25% would be open access data from DD time and Large programs (based on consideration of the likely fraction of the GO time that will be in Large and Treasury—all GTO data is 12 months). These open datasets would increase significantly the amount of data available—increasing the fraction of Cycle 1 data in Cycle 3—from 0.3 to 0.37 and 0.48, respectively. It still takes until Cycle 4 for all data from Cycle 1 to be available, and to Cycle 5 for all data from Cycle 2. The nominal Cycle timing shown here (April–April) may change depending on the actual mission timing and conclusion of commissioning activities, but this would not change the data availability by Cycle.

After extensive deliberation and consideration of many different approaches through charts like Figure 1 (e.g., less than one-year proposal cycles) and other input, the JSTAC recognized that the only truly beneficial approach that was not extremely disruptive of the proposal process and the natural yearly timing of JWST target visibility, was to recommend a change to a shorter proprietary period. Fully open datasets, with zero proprietary periods, for all JWST data were discussed, and initially recommended just for Cycle 1, with six-months thereafter. But in the end, a six-month proprietary period became the baseline. This modest change (12 months to 6 months) makes a substantial difference. Most of the Cycle 1 data will be available by Cycle 3 and most of Cycle 2 available by Cycle 4 (in Fig. 1, with a six-month proprietary period, 0.8 of Cycle 1 would be available in Cycle 3 and, of course, all of Cycle 1 plus 0.8 of Cycle 2 by Cycle 4). The fraction improves further from 0.8 to about 0.85 when factoring in the likely fraction of datasets with zero proprietary time. See the JSTAC's March 2014 letter for more detail and discussion (though the increased fraction resulting from the open datasets was not discussed in that earlier letter).

Time to publication

An additional factor that both was very surprising and also very influential for the JSTAC's thinking, arose from the unexpectedly long time (more than two years) to publication of science data (see Figure 2). While this figure was shown in the June Newsletter (Volume 33, Issue 01), we have reproduced it here since it is an important aspect of the discussion regarding the length of the proprietary time. The long publication timescale indicates that the proprietary period is not a driving factor, yet a long proprietary period does affect science opportunities.

The increasing interest among policy-makers that science data be released as quickly as possible also was a consideration for JSTAC. Interestingly, across all of NASA space science, Astronomy stands out for having the longest proprietary periods. Earth Science and Heliophysics have zero proprietary period through international agreements with a number of agencies, including ESA, and the majority of planetary missions are short (typically zero). More details are given in the JSTAC's March 2014 letter, where the committee noted that "For its major missions, NASA Astrophysics stands out for its use of a consistently long proprietary/exclusive access period." JWST, with its 12-month proprietary period, stands out in Astrophysics now that Hubble will have a 6-month proprietary period.

Figure 2: There is a substantial delay (more than two years typically) in the time between the acquisition of Hubble data and its publication. This period timescale is longer than any proprietary period under discussion, and does not depend on data type, proprietary period from 0 months to 12 months, or PI geographic location. There is also no indication of any peak related to enhanced publication rates at around 12 months, or slightly longer, in the "GO author" data, as might be expected if authors were concerned about being "scooped." The concerns about a 6-month proprietary period (or even 0 months) versus 12 months appear not to be borne out by these publication timescales. The more than two-year publication timescale is similar on Spitzer and Chandra. These Hubble data were assembled by Jeff Valenti and Karen Levay.

Current status

Many of the agreements that formalized twelve months as the baseline proprietary period for JWST science were established about 10-15 years ago in the early-to-mid 2000s soon after JWST development began (e.g., the Memorandum of Understanding between the NASA and the JWST partner agencies, ESA and CSA). At that time, a proprietary period of 12 months was more widely accepted. Since that time there has been a consistent trend to more open datasets and shorter (zero in many cases) proprietary periods. The current discussion regarding the proprietary period has so far resulted in endorsements for six-months by the JWST Science Working Group (SWG) and the NASA Astrophysics Subcommittee (APS). Discussions within the Canadian astronomy community have indicated that there is broad support for a six-month proprietary period. A comprehensive presentation that summarized and updated the situation regarding proprietary time was given to the JSTAC at its December 2015 meeting. This was transmitted to the Institute Director in April 2016 and is available on the JSTAC website—see 2016 Proprietary Time Status. Currently, the proprietary period still remains at 12 months. For those wishing to get an overview of the current status and some of the issues, this is the place to go.

As always, I would like to express the appreciation of the JSTAC for the thoughtful and informative presentations from the JWST Project leadership and from the Institute leadership and team leads, and the willingness of all concerned to engage in extensive dialog. As the JSTAC Chair, I greatly appreciate the willingness of the members to express their views and to engage in very constructive dialog on complex issues where the optimal path forward is often not immediately obvious. We are embarking on a journey of exploration and discovery, and finding the path that "maximizes JWST's scientific productivity" is not an easy one, but it is so important for science, and for the public, and the policy makers who have supported this mission over the many years since its inception.


1 Note that NASA uses the phrase "exclusive access period" instead of the phrase "proprietary time." The latter terminology is the one most widely used in the general science community to describe closed datasets and so is the one generally used in this article.

2 This approximately two-month period was chosen as representative of the time it would minimally—and likely not optimally—take for a science team to process the newly available data, evaluate its scientific importance, devise a new approach or program, and actually write a credible proposal.

3 This is slightly less than expected for a GO cycle since the GTOs have a significant fraction of the time in Cycle 1 and their data has a 12-month proprietary period.