The recent debate on human space exploration, as highlighted most effectively by the report from a White House-chartered review panel led by Norm Augustine, has illustrated the fundamental issue. Such lofty goals have two features that make them very difficult to accomplish: They take a long time, and they cost a lot of money. But there is a mechanism that would work. No matter how we decide to implement such a program, it must be planned not for a year or two, or even for a decade or two, but for perhaps for a century. And trying to set its total cost before the technical issues have even been identified, much less resolved, is simply fiscally irresponsible. This is clearly evidenced by the wild fluctuations in NASA’s projected budget for human spaceflight through 2020: The latest indications are that it will be $28 billion less than the $80 billion approved four years ago.

The important financial metric is not the total cost of reaching whatever interim goals are set, such as setting up a base on the Moon or sending astronauts to Mars, but how much the nation can afford to spend each year on eventually attaining those goals. That is, it is NASA’s annual budget that must be employed to formulate any long-term program, not its total (and almost certainly indeterminable) cost. A very important corollary to that premise is that the final date on which these missions are accomplished should be a dependent variable, not a preselected one that has little or no real chance of being accurate.

It is of course necessary to set up a series of relatively short-term milestones against which both progress toward the ultimate goals and accountability for the funds expended can be measured. But there should be no panic if those milestones have to be extended; there is nothing wrong with changing directions as circumstances and progress dictate, as long as we maintain the long-term commitment instead of constantly starting and stopping. Note, too, that although delays in any project almost certainly lead to higher total program cost, it is really the annual cost that is most critical. Committing the nation to a relatively constant — and uninterrupted — annual investment in space will ensure that we will not be diverted by minor — and temporary — setbacks in our path toward what might be humanity’s ultimate salvation.

In short, sustainable and affordable exploration of the solar system cannot be done on a constrained schedule; moreover, there is no need to do so. The key consideration is not when we get humans to the Moon or Mars, but to avoid the stops and starts that doomed previous efforts by maintaining a steady, long-term commitment to building and validating the required capabilities and conducting the necessary missions efficiently and safely.

We must realize that this approach to space exploration should not be confused with the one espoused years ago by then-Sen. William Proxmire (D-Wis.), who said that since Mars isn’t going anywhere why should we commit hard-pressed budgets to get there? With that reasoning we would never get there, because budgets will always be tight.

There are of course some issues that will have to be resolved. Any multidecadal (or century-long) program must contend with the two-year, four-year and six-year terms of political tenure, and the even shorter quarterly return focus of industry executives. This will require a true commitment by congressional and administration leaders, and perhaps a new framework for government-industry cooperation.

Some concern has also been expressed about losing U.S. leadership in space to other nations who have expressed their intent to pursue human exploration of the Moon and even Mars, especially China. But this represents more of an opportunity than a problem — opening a viable path to the international cooperation that is widely recognized as the optimum mechanism for humanity’s expansion into space. Despite its flaws, the international space station (ISS) has shown that true cooperation is not only possible, but, in the case of the ISS, has proven to be indispensable in view of our reliance for the next five to seven years on Russian, European and Japanese transportation. Former NASA Administrator Mike Griffin had opened the path to international efforts in Moon exploration, both robotic and human, with Europe, Russia, China and India, and more recently to joint Mars exploration by robotic spacecraft with Europe. Extending the window for human exploration of the solar system in order to make it fiscally viable for the United States  also gives us the time needed to conduct the complex, intensive and lengthy negotiations that, as we learned from the ISS, are implicit in any major international undertaking.

Most importantly, NASA doesn’t really need more money (although it certainly would be helpful, if the administration and Congress are so inclined). A NASA budget of about $18 billion annually has appeared to be generally acceptable. That would be quite sufficient to carry on all of the important work being done by the agency, including not only reasonable progress toward developing the infrastructure for ambitious long-term space exploration goals but also robotic exploration projects, space and Earth science, aeronautics research, support of commercial programs and education, technology advancement and development, and maintenance of the NASA facilities. There is no need to emasculate any of these important NASA functions; the only change needed from the present doctrine would be to eliminate the deadlines, such as the mandate to land on the Moon by 2020 or any similar deadline for landing on Mars. It is the commitment to a continuous, ongoing space and aeronautics program and a consistent, affordable annual budget level that are needed, not bigger NASA budgets. We can pursue a vision for the next century in space. But we must recognize that it may take a century to realize and set up the plan accordingly.


Jerry Grey is a consultant to the American Institute of Aeronautics and Astronautics and the Universities Space Research Association, and a former professor of aerospace engineering at Princeton University.