During the course of the study, the committee heard that more than 2 years after the President announced the interim goal of sending humans to an asteroid by 2025 there has been little effort to initiate such a mission. There are still no good asteroid targets for such a mission, a necessary prerequisite for determining mission length and details such as the astronauts’ exposure to radiation and the consumables required. There is also no indication that NASA is undertaking the sort of comprehensive search necessary to identify asteroid targets. In addition, no hardware, such as a habitation module, is under development. The committee also heard from NASA officials that an asteroid mission is more difficult to accomplish and has less utility for developing equipment and operations for an eventual Mars landing mission than they initially believed. For example, unlike a lunar surface mission, an asteroid mission does not result in the development of equipment or operations necessary for eventual Mars missions. While the committee did not undertake a technical assessment of the feasibility of an asteroid mission, it was informed by several briefers and sources that the current planned asteroid mission has significant shortcomings. Despite isolated pockets of support for a human asteroid mission, the committee did not detect broad support for an asteroid mission inside NASA, in the nation as a whole, or from the international community. In contrast, as noted in Chapter 1 (see Box 1.1), three of the last four U.S. presidents (dating back to 1989) have endorsed a mission to Mars as a long-term goal for the human exploration of space.
Finding. Human exploration. The committee has seen little evidence that the current stated interim goal for NASA’s human spaceflight program—namely, to visit an asteroid by 2025—has been widely accepted as a compelling destination by NASA’s own workforce, by the nation as a whole, or by the international community. Although asteroids remain important subjects for both U.S. and international robotic exploration and study, on the international front there appears to be continued enthusiasm for a mission to the Moon but not for an asteroid mission. This lack of national and international consensus on the asteroid-first mission scenario undermines NASA’s ability to establish a comprehensive, consistent strategic direction that can guide program planning and budget allocation. The current program has significant shortcomings in the pursuit of the stated goal of the asteroid mission. There has been a long-standing general agreement that a human mission to Mars should be the long-term goal of the human spaceflight program, even though a near-term commitment to such a program is still pending.
In the area of Earth and space science, NASA has clearly demonstrated the success of the strategic planning process that is founded on the National Research Council’s (NRC’s) decadal surveys. The decadal survey process has matured into a robust method of developing a set of goals and objectives for the Science Mission Directorate’s various programs that are based on a scientific community consensus on an achievable suite of science programs in pursuit of high-priority, compelling science questions. However, even the best strategic plan is vulnerable to severe changes in the assumptions that underlie its development, whether those changes are applied internally or externally. As an example, the recent set of surveys on astronomy and astrophysics and on planetary science were based on budget projections provided to the relevant decadal committees, and now these projections exceed the current budget as well as current budget projections. In addition, poor cost control in major missions under development has further strained the budget, with consequences described in Chapter 1.
Finding. Earth and space science. Key decadal survey priorities in astronomy and astrophysics, planetary science, and Earth science now will not be pursued for many years, or not at all. The carefully crafted strategic planning process, with its priority setting and consensus building, that has led in the past to the United States leading the world, with science missions such as the Curiosity rover on the surface of Mars and the Hubble Space Telescope, is now in jeopardy because it no longer may lead to a tangible program outcome.