A NASA illustration of its proposed Asteroid Redirect Mission. The lackluster support for that mission suggests it may be time to borrow an approach from the scientific community on how to select human exploration missions. (credit: NASA)

A decadal survey for human scientific exploration of space: a focus on discovery

by Matt Greenhouse
Monday, February 10, 2014

The role of science in the nation’s human spaceflight program has been controversial since the inception of the Apollo program. That controversy continues to this day. It is the root cause of NASA’s failure to achieve national consensus on defining the first deep space mission objective for human spaceflight, and is an aspect that has most limited the nation’s progress on planning for human exploration of deep space. Despite nearly 50 years of advocacy that the focus of NASA’s human spaceflight program should be to enable scientific discovery, this program remains adrift as a result of a national space policy that fails to head this long-standing advice.

The omnibus spending bill that funds NASA and the rest of the federal government through the remainder of this fiscal year leaves the agency fully on-track to continue development of enabling assets for deep space exploration. However, no progress has been achieved on selection of an initial deep space mission objective since the National Academy of Sciences reported that no consensus exists within the nation’s science community in support of the Obama Administration’s direction to land an astronaut on an asteroid by 2025, as laid out in the 2010 National Space Policy.

Recognizing that this requirement could not be achieved within foreseen cost constraints, NASA proposed, in its 2014 budget request, a novel deviation to the this requirement first described in an obscure unpublished study, in which an asteroid would be transferred into lunar orbit to enable its exploration in not-so-deep space closer to home. The above spending bill appropriates funding to further flesh out this idea. However, the report language makes clear that Congressional support for implementation of this mission has not yet been achieved, and there is no evidence that significant support for it exists within the nation’s science community. If NASA’s “rocket scientists” are so smart, why have they seemingly fumbled the ball on selecting a first deep space mission for the astronauts? The science community of the United States consists primarily of very smart people. Unfortunately, they are held at arm’s length from the mission selection process for human exploration of deep space.

NASA’s Science Mission Directorate (SMD) has had unblemished success in implementing high consensus mission selections for the past 40 years. So why has building a consensus for the first human deep space mission become an intractable problem for NASA? The root cause is the unintended consequence of segregating science and human spaceflight management into separate organizations without specifying which should be supporting the other. NASA’s Human Exploration and Operations Mission Directorate (HEOMD) and SMD operate independently to such a degree that they have evolved immiscible internal cultures. For example, most Americans would take for granted that a modern effort by their government to explore the unknown would be a program of scientific exploration. History has shown that the alternative—non-scientific exploration—is much less efficient in terms of realized return on investment in the form of discovery. Yet, within the culture of HEOMD, the relationship between an exploration mission and the science motivation for it is ambiguous at best. In the organization of today’s NASA, when astronauts are added to the tool set of a spaceflight mission architecture, the mission becomes magically exempt from the norms of science mission selection that have served the nation well for the past 40 years. What are those norms?

The process of science depends entirely on transparency. Its practitioners are, by nature, driven by curiosity and skepticism. In the culture of the science community, discoveries, conclusions, and results are only accepted if they are achieved by fully transparent means. In the culture of science, the free exchange of ideas and the maintenance of a public arena in which ideas are competed, in a free and open way, are critical enabling aspects of scientific exploration. The culture of science is the culture of SMD, and the mission selection process utilized by SMD respects the above boundary conditions. As a consequence, its missions enjoy broad consensus across the nation’s science community at inception. How do they do it?

Under the direction of Congress, three agencies—NASA, the National Science Foundation, and, more recently, the Department of Energy—jointly fund the National Research Council (an organization of the National Academy of Sciences) to conduct a Decadal Survey of major science research areas, and to report on that community’s prioritized objectives for space science during each decade. SMD respects this prioritization in its allocation of funds and implementation of major projects. For smaller initiatives, such as Explorer-class missions, SMD competitively selects community-proposed missions through a unique solicitation vehicle in which the relative quality of scientific ideas, and their alignment with Decadal Survey priorities, is a selection factor along with the traditional factors of cost and risk.

In astrophysics, this process has been running in its current form since 1970 (with prior evolutions stemming from the 1960s). It has yielded the world’s most productive programs of exploration resulting in discovery, producing much of what we know about the universe and the history and fate of the Earth, resulting in multiple Nobel Prizes. The national consensus behind missions selected via this process results from the high transparency and broad community involvement in each step of it. For example, the set of ideas that were submitted to the most recent astrophysics decadal survey are readily available to anyone and they represent the best ideas that the whole science community can muster. Approximately 3,900 authors representing 3,000 institutions penned more than 300 white papers that the National Academy vetted to set SMD priorities for this decade. Five panels appointed by the National Research Council (NRC), consisting of more than 60 of the Nation’s leading experts on the relevant subject matter, did this vetting.

Congress recently directed the NRC to conduct a smaller-scale study of human space flight objectives. This NRC report is expected later this year. Although this one-time effort is a welcome first step in the right direction, it is not a substitute for the depth of public engagement that is achieved by an ongoing Decadal Survey process. Its impact on the nation’s space policy remains to be seen.

In sharp contrast to the transparency, direct public involvement, and strategic coherence embodied by decadal surveys, the process by which HEOMD’s current selection for its first deep space mission catapulted from a short unpublished study to the central objective of the nation’s human spaceflight program in less than a year’s time is entirely opaque to most stakeholders. Even if the in situ resource utilization goals of the asteroid program could be achieved within practical spending limits, lack of transparency in the process by which it achieved top national priority precludes any hope of building consensus acceptance by the nation’s science community. In this community, it is not enough to get “the right answer” to a problem: one has to show the work to get that answer as well. It must be clear what alternatives were considered, what rationale was employed in the prioritization of them, and the alternatives must be solicited in a free and open process to which anyone can respond with confidence that the playing field is a level one.

It is unlikely that the organizational ambiguity between SMD and HEOMD— the supported-vs.-supporting nature of the relationship between them—will be fixed internally. Although it is clear that humanity’s greatest scientific exploration productivity in space was achieved by the Hubble mission architecture in which SMD was supported by HEOMD (see “A values-based approach toward national space policy”, The Space Review, June 10, 2013), this model has not been embraced by the agency in its planning for HEOMD’s first deep space exploration mission.

The current appropriations bill leaves NASA on track to build the tools for human exploration of deep space. However, building a national consensus on the purpose to which these tools should be put will not be achieved until Congress directs NASA to implement a decadal survey process for prioritization of human exploration mission objectives. The SMD model can be readily and directly applied. Doing so is not rocket science. With near-term Congressional action, implementation of a decadal survey for human spaceflight can be achieved in time to yield a high consensus mission selection by the end of this decade, when the Space Launch System and Crew Exploration Vehicle will be ready. It is time to put the science community into the game to run this ball down the field via a decadal survey process for prioritization of the first and every subsequent human mission of scientific exploration.

Matt Greenhouse has served on the James Webb Space Telescope senior staff as Project Scientist for the JWST science instrument payload since 1997. He specializes in infrared imaging spectroscopy, development of related instrumentation and technologies, flight project science, and technical management.

Home