A report being released today by a committee of the National Research Council endorses Mars as a long-term “horizon” goal of NASA’s human spaceflight efforts, but suggests that more funding, and perhaps a human return to the Moon, are necessary to achieve that goal.
The report, by the Committee on Human Spaceflight, is being released today, with a webcast of a public briefing on the report available at 11 am EDT at the committee’s website. That report concludes the US needs to decide what its long-term goal should be in human spaceflight, and design a program to meet that goal with some flexibility in the steps along the way to achieve it.
“A sustainable program of human deep space exploration must have an ultimate, ‘horizon’ goal that provides a long-term focus that is less likely to be disrupted by major technological failures and accidents along the way and the vagaries of the political process and economic scene,” the report concludes. Of the destinations achievable in the foreseeable future by human missions—the Moon, near Earth asteroids, the moons of Mars, and Mars—only Mars fits the bill, the committee concluded.
“Among this small set of plausible goals, the most distant and difficult is putting human boots on the surface of Mars, thus that is the horizon goal for human space exploration,” said committee co-chairman Jonathan Lunine of Cornell University, in a statement accompanying the report. “All long-range space programs by our potential partners converge on this goal.”
A large section of the nearly 300-page report is devoted to examining mission architectures for future human space exploration, in particular those that lead to that horizon goal of humans on Mars. The report makes no specific recommendations about which pathway to pursue, but does suggest an “Enhanced Exploration” path, which includes missions to Earth-Moon L2, a near Earth asteroid in a “native” orbit, the suface of the Moon, and the moons of Mars before a landing on the surface of Mars would have a lower developmental risk than alternative scenarios, but would delay a human landing on Mars to perhaps as late as the 2050s.
The report was not as favorable towards the “ARM-to-Mars” approach, which follows the Asteroid Redirect Mission (ARM) that NASA is currently planning straight to missions to the Martian moons and then the surface. That architecture, the committee found, has an “exceedingly high” development risk and long gaps between missions. “[W]ithout a considerable increase in HSF funding for NASA, the ARM-to-Mars pathway presents the prospect of a long period of technology development where NASA’s stakeholders do not see actual human explorations missions taking place,” the report stated, adding that such long gaps between missions are among “the most serious challenges to program sustainability” identified in the report. (A third mission architecture, which included missions to the surface of the Moon before going on to the Martian surface, tended to lie between the ARM and Enhanced Exploration scenarios in terms of schedule and risk.)
Another key conclusion of the report is that any set of missions to send humans to Mars wil require funding above what NASA is getting today. “As long as flat NASA human spaceflight budgets are continued, NASA will be unable to conduct any human space exploration programs beyond cislunar space,” the report states. “The only pathways that successfully land humans on the surface of Mars require spending to rise above inflation for an extended period.” The report suggests funding increases of about twice the rate of inflation, or about 5% per year, would be needed to carry out the proposed exploration architectures.
Other parts of the report, on more general aspects of human spaceflight, are not too surprising. The committee found no single, compelling rationale for human space exploration, arguing instead for a nix of “pragmatic” and “aspirational” goals, from national prestige to scientific discovery to survival of the species. Public interest about human spaceflight, the committee concluded, is “modest” at best. “Space exploration fares relatively poorly among the public compared to other spending priorities,” the report notes.
In the statement accompanying the report, the committee’s other co-chairman, Purdue University president and former governor of Indiana Mitch Daniels, called on the government to provide long-term stability for the nation’s human space exploration program.
“Our committee concluded that any human exploration program will only succeed if it is appropriately funded and receives a sustained commitment on the part of those who govern our nation. That commitment cannot change direction election after election,” he said. “Our elected leaders are the critical enablers of the nation’s investment in human spaceflight, and only they can assure that the leadership, personnel, governance, and resources are in place in our human exploration program.”
However, given the history of changes in human spaceflight (documented in the report), along with relatively tepid public support, such long-term stability will be hard to come by.