Lessons Learned From the Clementine Mission

Executive Summary

Clementine was a relatively low-cost, technology-demonstration mission that, as a secondary objective, was designed to survey the Moon and to fly past an asteroid. After a 22-month development phase, the spacecraft was launched in late January 1994. Operated by the Ballistic Missile Defense Organization within the U.S. Department of Defense (DOD), Clementine was the first U.S. space mission to leave Earth's vicinity that was not run by NASA. Because of Clementine's many similarities to NASA's current drive to carry out space missions that are "smaller, cheaper, and faster," this document describes some of the mission's operational features that differ from traditional NASA practice and that might be profitably brought into scientific spaceflights. This report first presents a preliminary assessment of Clementine's scientific return to date. Although much of the data reduction, calibration, and analysis is yet to be completed, Clementine already appears to have returned interesting and valuable scientific results, especially its identification of the lunar topography, which shows much more relief than anticipated. However, the spacecraft's limited instrument complement prevented the mission from accomplishing the highest-priority objective for lunar science, namely determination of the Moon's global geochemistry. This should not be regarded as a failure, because the mission was not motivated by the achievement of any particular scientific objective. Answers to most of the fundamental scientific questions, listed previously by COMPLEX,* will come only after further exploration of the Moon by orbiters and landers.

Clementine carried several new-technology devices and utilized lightweight spacecraft components. These elements are likely to have considerable application aboard small space science missions. Clementine was operated unlike most of the major space science missions of the past two decades: a small, highly dedicated team was given full responsibility for virtually all phases of the mission from design and construction of the spacecraft through to its launch and subsequent operation. The project stayed close within its budget and the spacecraft was delivered on time. Several aspects of Clementine—its cost, its incorporation of new technology, technological cooperation between NASA and DOD, and the scheme for software development—should be studied by groups more appropriately constituted than COMPLEX.

The mission's success rested to a considerable degree on the operational team's substantial freedom to make decisions and on the easy access to technology already developed. The tight time schedule forced swift decisions and lowered costs, but also took a human toll. The stringent budget and the firm limitations on reserves guaranteed that the mission would be relatively inexpensive, but surely reduced the mission's capability, may have made it less cost-effective, and perhaps ultimately led to the loss of the spacecraft before the completion of the asteroid flyby component of the mission.

For the most part, within its constrained lunar science objectives, Clementine was successful. Because of various factors, Clementine's costs were significantly less than most comparable space science missions might be. Since Clementine was not planned originally as a science mission and did not have science as a primary objective, funds were not allocated for instrument development and scientific calibration, or for data reduction and analysis. Nevertheless, Clementine validated the concept that, with proper operational profiles, small missions (such as those in the Discovery and MidEx programs) are capable of accomplishing significant research in space science.

Clementine also demonstrated the usefulness to space science of missions emphasizing the testing of innovative technologies, fresh management styles, and new approaches to spacecraft operations. Future missions of this type should be initiated provided that they are capable of achieving first-class science and that the scientific community is actively involved in them as early as possible.

The extent to which traditional NASA programs could or should follow this model is unclear at present. What is clear is that Clementine provides an existence proof that a small team of non-NASA researchers can successfully assume the overall responsibility for a deep-space mission.

* See, for example, Space Studies Board, National Research Council, An Integrated Strategy for the Planetary Science: 1995-2010, National Academy Press, Washington, D.C., 1994.


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