On Dec. 6, the Space Subcommittee of the House Science Committee held a hearing dedicated to four NASA astrophysics missions in pre-launch phases: the James Webb Space Telescope (JWST), the Transiting Exoplanet Survey Satellite (TESS), the Wide-Field Infrared Survey Telescope (WFIRST), and a future telescope mission that NASA expects to select in the early 2020s.
The discussion focused largely on how well NASA is managing its missions to ensure they produce valuable scientific results while keeping their costs and schedules under control. The agency’s use of the National Academies decadal surveys and other external review procedures drew particular attention.
Witnesses also aired concerns that JWST — currently NASA’s most expensive science mission — could breach its congressionally imposed cost cap of $8 billion before its launch, currently targeted for the first half of 2019.
A photograph from 2011 showing a membrane from the James Webb Space Telescope’s sunshield on a test fixture. The length of time needed to install and test sunshield release devices on the telescope contributed to a recent delay in the mission’s launch date.
(Image credit – NASA / Northrop Grumman Aerospace Systems)
On Sept. 28, NASA announced that it was delaying the launch of JWST from October 2018 until sometime between March and June 2019. In that announcement, Thomas Zurbuchen, the head of NASA’s Science Mission Directorate, said the delay was “not indicative of hardware or technical performance concerns,” but rather that “integration of the various spacecraft elements is taking longer than expected.” NASA reported that the project’s budget would accommodate the delay.
At the hearing, witnesses suggested that the situation might be somewhat more serious, given that the delay would nearly deplete remaining schedule and budget reserves. Cristina Chaplain, a Government Accountability Office official, said that integration is the “most risky phase” of mission development and that “more delays are possible given the risks associated with the work ahead and the level of schedule reserves that are now below what is recommended.” Her written testimony characterized the possibility of further delays as “likely” and indicated that, if that happens, it would cause the mission to breach the cost cap set in 2011.
Thomas Young, a former director of NASA’s Goddard Space Flight Center and a member of the National Academies Committee on Astronomy and Astrophysics (CAA), also suggested that JWST could experience further disruptions. He remarked, “In my opinion, the launch date and required funding cannot be determined until a new plan is thoroughly developed and verified by independent review.” He further argued that the temptation to take new risks to maintain cost and schedule targets should be resisted, remarking,
JWST is at a point in its development where the only criterion that is important is mission success. Every appropriate thing that can be done to maximize the probability of success should be done. At this stage of the project, a few extra days, or weeks, or even months of schedule delay or the expenditure of some additional dollars is a small price to pay to assure success of a mission as important as JWST.
Subcommittee Chair Brian Babin (R-TX) also asked Zurbuchen about why NASA chose to launch JWST from a launch site in French Guiana aboard a European Ariane 5 rocket. Zurbuchen replied the decision resulted from considerations relating to cost and NASA’s collaboration with international partners, adding, “We understand what the risks are [and] indeed are comfortable with it.”
Shifting the focus to TESS, Brooks asked Zurbuchen about how NASA would pay to launch the mission should it be delayed beyond its currently scheduled March 2018 launch date, given that it is already up against its cost cap. Zurbuchen replied that it would not prove problematic since any delay at this point would arise from outside the project. Brooks also asked him about the decision to make TESS the first NASA science mission to launch aboard a SpaceX Falcon 9 rocket and whether he has concerns about potential delays in certifying the rocket for the purpose. Zurbuchen replied he does not.
Another critical topic discussed at the hearing was whether expanding cost estimates for WFIRST indicate it is being poorly managed. NASA recently ordered an independent review of the mission, which recommended it be descoped to bring costs into alignment with earlier estimates.
In his opening statement, Science Committee Chair Lamar Smith (R-TX) called developments with WFIRST “troubling.” Referencing the cost growth of JWST prior to its 2011 rebaselining, he said, “Apparently NASA has not learned lessons from its past experiences.” He further suggested it may be necessary to place a cost cap on WFIRST as well.
The witnesses argued that NASA has handled WFIRST appropriately. Chaplain said that, in the years since the JWST rebaselining, NASA had made “significant improvements” to its methods for estimating and controlling cost.
Astrophysicist Christopher McKee, representing the National Academies, noted that the WFIRST review followed from the recommendations of the 2016 midterm assessment of the Academies’ 2010 astrophysics decadal survey.
Young testified that the review was conducted early in the mission planning process, and that the descoping decision would “mitigate” the issue. He further suggested, “The process being implemented for WFIRST should become standard for all major NASA projects.”
Asked by Babin whether a cost cap would help keep WFIRST on track, Young replied,
I’m not a fan of cost caps. I think the better solution is what NASA’s doing, and that is understand the requirements and the cost and risk and technical complexity of the requirements that exist now and adjust those to be what we collectively believe to be affordable and appropriate for WFIRST’s mission. And then to, in a rigorous fashion, control them as we implement the program.
While most of the hearing focused on NASA’s management of missions in its current portfolio, some of the discussion addressed the agency’s next large-scale telescope project after WFIRST. That choice is expected to follow from the recommendations of the next astrophysics decadal survey, targeted for release in 2020.
NASA has already begun to prepare the way for the survey by developing four mission concepts for the survey committee to consider. Matt Mountain, president of the Association of Universities for Research in Astronomy, testified about the potential of one of the concepts, the Large Ultraviolet/Optical/Infrared (LUVOIR) Telescope.
McKee, who, like Young, is a CAA member, approved of NASA’s decision to develop mission concepts, saying, “This methodical approach to preparing the community for the decadal is, in my personal opinion, vitally important.” He also reported that CAA is preparing to release a call for white papers that will provide “fresh community input” for the chair of the next decadal survey when he or she is appointed. McKee said the survey process is due to begin about one year from now.
