On Aug. 24, the National Academies released a study report on the value of NASA’s large strategic science missions, also known as “flagship” missions.
Missions such as the Hubble Space Telescope, Mars Curiosity rover, and Cassini Saturn probe have ranked among NASA’s greatest successes, yielding both outstanding scientific breakthroughs and glowing media coverage. However, such complex and expensive projects have sometimes suffered cost overruns and schedule delays that are serious enough to impede other NASA activities and damage the agency’s reputation. Moreover, even when they go smoothly, resources expended on large missions could be used on a greater number of smaller missions instead.
In view of large missions’ liabilities, in late 2014 John Grunsfeld, then head of NASA’s Science Mission Directorate (SMD), began advocating an Academies study as a way to draw attention to the unique functions they play within NASA’s science mission portfolio and to clarify how they should be balanced with smaller missions. The study began last year and was co-chaired by Johns Hopkins University Applied Physics Laboratory physicist Ralph McNutt and by former astronaut and University of Virginia engineering professor Kathryn Thornton.
NASA’s Terra satellite is a large strategic mission that cost $1.3 billion and launched in 1999 as part of the Earth Observing System, and it is still operating. However, NASA’s Earth Science Division is no longer planning such expensive spacecraft, preferring instead to develop smaller satellites to conduct Earth-focused observations.
(Image credit – NASA)
At their kickoff meeting in October, committee members heard from Grunsfeld, his successor Thomas Zurbuchen, and from other NASA officials, who outlined many of the considerations underlying large strategic mission planning and management.
The speakers observed that the missions are “strategic” in several ways. In many cases only large missions can accomplish certain pressing scientific goals. Often, they are also well equipped to address a wide variety of scientific questions, even ones not anticipated at the time of launch. The speakers further explained that large missions can play a pivotal role in developing and sustaining the scientific communities that participate in the missions and rely on their data, and the missions serve as focal points for the development of new scientific and space technologies.
Having completed its study, the committee affirms the value of large strategic missions, detailing in its report the scientific role they play and the special challenges endemic to their planning and management. The committee declines, though, to recommend any “figure of merit” that could help NASA weigh tradeoffs in striking a balance between large missions and smaller ones. It notes that the goals of large missions, and even the concept of “balance,” vary too widely among the scientific fields represented in SMD’s four divisions — Astrophysics, Heliophysics, Planetary Science, and Earth Science — for any such measure to be useful.
Instead, the committee recommends that NASA continue to follow the National Academies-organized decadal surveys, which engage the relevant scientific communities to set priorities for each SMD division. Where additional advice is needed, the committee advises NASA to turn to its own recently restructured science advisory committees.
Some of the strongest recommendations in the committee’s report relate to how the decadal surveys should handle large strategic missions. Noting that the surveys currently set priorities among scientific goals, the committee urges both NASA and the survey committees to also explore the practical tradeoffs that may need to be made during the mission formulation process.
The committee suggests that, before a decadal survey begins, mission proposal teams should outline “ranges of scientific scope … such as minimum science goals and maximum budgets, as well as [identify] what science goals are most desirable at different budget levels.” In turn, the survey committees should take possible budgetary constraints into account and provide flexible “decision rules” and “mission concept variants” that can inform decisions about de-scoping and “up-scoping” spacecraft capabilities and mission profiles as circumstances evolve.
Because of large strategic missions’ scale, a key concern the committee investigated is the effect that cost overruns and schedule delays can have on the rest of NASA’s mission portfolio.
NASA directly manages missions that it deems “strategic,” which includes all of its most expensive missions. All other missions that NASA oversees are competed, meaning that the agency selects them from a set of mission proposals submitted by outside teams led by principal investigators (PI) responsible for project management. Unlike many NASA-directed missions, PI-led missions are subject to strict cost caps.
Whether NASA-directed missions should be subject to similar controls is a critical question. In recent history, increasing costs and launch delays became major problems for the James Webb Space Telescope (JWST) and Curiosity rover, both NASA-directed large strategic missions. Congress ultimately separated JWST’s funding from the rest of the Astrophysics Division and subjected the project to intensive oversight, and it has remained on budget and on schedule since then.
However, the committee argues that experiences such as the cost growth of JWST should not be taken as typical of large strategic mission management, citing findings by the Aerospace Corporation that, in aggregate, NASA-directed missions’ record of cost growth is similar to that of PI-led missions. The committee also affirms that budgeting and management reforms implemented under the NASA Authorization Act of 2005 and in the wake of the JWST situation have been effective, noting the Government Accountability Office’s increasing satisfaction with NASA’s management of large projects.
The committee reports no concerns about impending imbalances in NASA’s mission portfolio. It stresses that the most critical factor in keeping missions on budget and on schedule is “providing sufficient funds up front to retire risks definitively prior to mission confirmation,” particularly by developing all mission technologies to a high maturity level prior to the mission’s preliminary design review (PDR). It urges, though, that NASA continue to adapt its cost estimation tools as management and technology evolves, for example with the increasing use of CubeSats.
The committee also notes that “low-fidelity cost estimates” circulated prior to NASA’s post-PDR decision to implement a mission cannot be considered authoritative, and that reference to such early figures has often created a misleading public impression of cost overruns.
As an aid in its own investigations, the committee reports that it benefited from access to NASA’s in-house data relating to mission management and outputs, even if the information was sometimes “uneven and, in some cases, entirely missing.” Recognizing, though, that NASA has done increasingly well in collecting such data, the committee urges the agency to make it available through a publicly accessible database, elaborating,
These data should include development costs; publication numbers and other bibliographic data; outreach data (number of press releases and so on should be tracked); science, engineering, and other full-time equivalents; and other routine data typically sought in senior review proposal submittals once prime missions have been completed.
