Lessons Learned From the Clementine Mission


According to BMDO, the Clementine mission achieved many of its technology objectives during its flight to the Moon in early 1994 but, because of a software error, was unable to test the autonomous tracking of a cold target. The preliminary analyses of the returned lunar data suggest that valuable scientific measurements were made on several important topics but that COMPLEX's highest-priority objectives for lunar science were not achieved. This is not surprising given that the rationale for Clementine was technological rather than scientific. COMPLEX lists below a few of the lessons that may be learned from Clementine.

Although the Clementine mission was not conceived as a NASA science mission exactly like those planned for the Discovery program, many operational aspects of the two are similar. It is therefore worthwhile to understand the strengths and faults of the Clementine approach. Some elements of the Clementine operation that led to the mission's success include the following:

1. The mission's achievements were the responsibility of a single organization and its manager, which made that organization and that individual accountable for the final outcome.

2. The sponsor adopted a hands-off approach and set a minimum number of reviews (three).

3. The sponsor accepted a reasonable amount of risk and allowed the project team to make the trade-offs necessary to minimize the mission's risks while still accomplishing all its primary objectives.

4. The development schedule was brief and the agreed-on funding (and funding profile) was adhered to.

COMPLEX recommends that these attributes should be incorporated into future small-scale NASA missions such as Discovery (similar recommendations were made in a recent COMPLEX report1) and MidEx.

Among the operational shortcomings of Clementine were the following:

1. An overly ambitious schedule and a slightly lean budget (meaning insufficient time for software development and testing, and leading ultimately to human exhaustion); and

2. No support for data calibration, reduction, and analysis.

The principal lesson to be learned in this category is that any benefits from the constructive application of higher risk for lower cost and faster schedule will be lost if the schedule does not allow adequate time for the development of all essential systems or makes no allowance for human frailties.

Another lesson to be drawn is that despite its limitations, if judged strictly as a science mission, Clementine attested that significant scientific information can be gathered during a technology-demonstration mission. In the current era of limited funds, when science missions will be infrequent, the opportunity to fly scientific instruments aboard missions whose objectives might be other than science must be seized and, indeed, encouraged. During such opportunities it would be inexcusable to do second-class science. Thus the scientific community must be actively involved in such projects from their initiation.

In terms of budget and schedule, Clementine was undertaken in an even more challenging environment than might be expected for most programs within the Discovery and MidEx designations, according to current guidelines for these programs. Thus, the substantial accomplishment of Clementine provides a measure of confidence that NASA's Discovery program can be successful provided that the same degrees of team independence and risk acceptance are granted. Clementine's performance allows clear identification of many of the essential ingredients for success in carrying out low-cost, deep-space missions. Therefore, COMPLEX is encouraged to believe that the Discovery program has a significant opportunity to underpin NASA's program of solar system exploration in the years ahead. It is also likely that "smaller, faster, cheaper" programs—if properly designed and operated—can accomplish much in other areas of space research such as astronomy/astrophysics and space physics.

Many of the apparent innovations of Clementine, compared to practices on recent scientific missions, lay in areas where COMPLEX had some experience but not full expertise. Areas where more appropriately constituted groups may be able to draw additional lessons from the Clementine mission include the following:

An accurate comparison of the cost of Clementine compared to that of a typical science mission;

The use of new technology on Clementine;

The pros and cons of a technological alliance between military and civilian space organizations; and

Clementine's software development practices.

In conclusion, perhaps the most basic lesson from the Clementine mission is that the ability to carry out end-to-end planning and implementation of a (U.S.) planetary mission has evolved beyond NASA's domain. Thus an underlying assumption of the Discovery program—that a non-NASA principal investigator can be successful when assuming overall responsibility for a deep-space mission—has, in effect, been validated.


1. Space Studies Board, National Research Council, The Role of Small Missions in Planetary and Lunar Exploration, National Academy Press, Washington, D.C., 1995.


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