The American Astronomical Society (AAS) recently released a statement expressing concern over budget actions taken by NASA’s Science Mission Directorate. However, the purpose of my comments here is not the AAS statement, so much as the underlying issues that led to NASA taking the actions that it did, and the potential effect those actions will have on the nation’s future economy and security.

NASA’s actions were the result of a very real budget crunch, one that put NASA managers in a difficult position. There are several reasons for that crunch in my view, but two deserve special mention; congressionally directed funding, also known as earmarks ; and the cost and pace of NASA science missions.

Congressional earmarks for NASA in the 2005 budget totaled $426 million, the bulk of which was shared by NASA’s Exploration Mission and Science Mission d irectorates. By way of comparison, the numbers for the previous two fiscal years were $388 million and $500 million. The concern here is that congressional earmarks made without an offsetting increase in NASA’s budget now represent a significant problem for planning and execution of missions and long-term agency planning.

If earmarking continues at this level, the ability of the scientific community and NASA to plan an orderly and responsible use of taxpayers’ money to gain knowledge will be eroded.

Congressional earmarks are like the black sheep of the family. Everyone whispers that they are bad, but nobody wants to talk about them too loudly for fear of upsetting members of Congress. I do not see congressional earmarks as being bad in principle; they are part of the grease that makes government work. What is bad is that the vast majority of these earmarks are unfunded mandates , and the timescale for their insertion in the budget process is far shorter than for strategically planned programs.

It is this inability of the agencies to put together an orderly plan that has become the problem. When the level of earmarks is modest, most agencies can cope without inflicting serious damage on their own programs. When the level of earmarks reaches the levels we see today, planning becomes difficult or even impossible, forcing the agencies to cut key programs.

The budget situation is further encumbered by the fact that few, if any, of the major science missions are able to remain within the budget and schedule that was used to sell those missions. This is due to several factors. One is that the science missions of today push the envelope of technical capability. As such, there is often an underestimate of how long and how complicated development will be.

This leads to cost growth and to schedule slippage, which is an implicit growth in cost. Also, buoyed by the remarkable successes in NASA’s and the National Science Foundation’s science activities, scientists see exciting and even more challenging horizons, leading to new missions. The funding agencies, wanting to accomplish as much as they can, respond to community pressure and initiate these programs. This leads to a situation not unlike that faced by commuters in major urban areas. As long as cars are reasonably spaced and there are no disturbances, traffic at peak times moves well. But, the slightest disturbance, a few slowly moving vehicles, debris falling from a pickup, and there is an instant traffic jam. These often persist long after the causing event has been removed.

The same happens with NASA science missions. Their orderly progression relies on an all-too-narrow margin of fiscal and schedule fidelity to avoid the equivalent of a rush-hour traffic jam. In the case of missions, however, the resolution of the problem may be cancellation. As noted in the recent AAS statement, the situation this year for NASA’s science program was so severe that for the first time in recent memory cuts were made in the smaller programs that serve as the lifeblood for the next generation of scientists, the basic research programs.

Budget forecasts paint a bleak picture for the foreseeable future, so these trends can be expected to continue. Congress must realize how severely its actions are hurting the very programs that most members support, and either reduce the level of earmarks or provide the money to go with their directed activities, or simply declare that it will take some fraction of the budget each year for this activity and work within that budget.

The latter approach would at least allow the agencies to plan. The agencies and the scientific community also need to be more realistic in terms of the rate of missions that can be accomplished under these circumstances, and to make sure that they control the cost and schedule of those missions that they do undertake.

If these trends continue, we will see fewer and fewer students moving into the very fields that provide the creative energy to fuel the nation’s economic and technology engines. This will put our country at risk, and that should not be an acceptable outcome to our leaders in Congress or the agencies that fund our research programs.

David Black is the current chair of the American Astronomical Society’s Committee on Astronomy and Public Policy.