The National Academy of Sciences was chartered by Congress in 1863. The mandates of the original charter led to the creation of a Space Science Board (SSB) in 1958, following a joint request for assistance from the National Science Foundation, the National Advisory Committee for Aeronautics (now NASA), and the Defense Advanced Research Projects Agency. When it was created, the SSB was charged "to stimulate needed research; to promote necessary coordination of scientific effort; and to provide such advice and recommendations to appropriate individuals and agencies with regard to space science as may be. . . desirable."

Within a year of its creation, the SSB had, at NASA's request, launched studies into, among other topics, "the problems of interplanetary probes and space stations, [and] their objectives, Venus and Mars. . . ." Throughout the 1960s, the SSB issued a series of reports (see bibliography) outlining major issues in the planetary sciences that were later explored, in part, by NASA's Pioneer and Mariner series of spacecraft.

In the early 1970s, the SSB created a standing body dedicated exclusively to the planetary sciences, the Committee on Planetary and Lunar Exploration (COMPLEX). COMPLEX's first four chairs, Gerald Wasserburg (Caltech), Michael McElroy (Harvard University), Eugene Levy (University of Arizona), and Donald Hunten (University of Arizona), set the standard for the committee's future activities by completing individual research strategies for the inner planets, outer planets, and primitive solar system bodies.

COMPLEX acquired new responsibilities during the tenure of its fifth chair, Robert Pepin (University of Minnesota), in the late 1980s. In 1988, the Space Science Board was reorganized into today's Space Studies Board: The Committee on Planetary Biology and Chemical Evolution was disbanded and its responsibilities were assigned to COMPLEX. Besides acquiring responsibility for exobiology, the committee extended its purview outward to encompass the discovery and study of planetary systems around other stars with the publication of the report, Strategy for the Detection and Study of Other Planetary Systems and Extrasolar Planetary Materials: 1990-2000.

Updating and integrating the existing strategies for the solar system's various "geographical" regions has been COMPLEX's most important accomplishment in recent years. This task was conceived during Larry Esposito's (University of Colorado) tenure as COMPLEX's sixth chair and carried out during that of Joseph A. Burns (Cornell University). The resulting report, An Integrated Strategy for the Planetary Sciences: 1995-2010, was completed in 1994 and became one of the first NRC reports accessible via the Internet. Closely related to the Integrated Strategy was the report, The Role of Small Missions in Planetary and Lunar Exploration, which was issued in 1995 toward the end of Burns' tenure as chair.


COMPLEX's eighth chair, Ronald Greeley (Arizona State University), was appointed in 1995. Under his direction, the committee is currently finishing two reports -- assessments of the Clementine mission and NASA's Mars exploration program. -- and is midway through a study on the trans-Neptunian solar system.

Although Mars has been a primary target for space science missions over the last three decades, the record of success in the last few years has been poor. Indeed there has not been a completely successful Mars mission since Viking in the mid 1970s. The failure of NASA's most recent Mars mission, Mars Observer, was a particularly hard blow for the planetary science community because this spacecraft was scheduled to carry out many of the highest-priority investigations of the Red Planet. The imminent flights of Mars Pathfinder and Mars Global Surveyor (the inaugural mission of the Mars Surveyor program) have the potential to recover the science lost with the destruction of Mars Observer and to greatly expand our knowledge of the most Earthlike planet in the solar system.

Since the intensive study of Mars was a high priority in COMPLEX's Integrated Strategy, the SSB charged COMPLEX to assess the Mars Pathfinder mission and the Mars Surveyor program to see if they are responsive to the priorities outlined in the committee's past reports. This study is now in the final stages of review.

The Clementine mission was designed to space-qualify advanced, lightweight imaging sensors and component technologies and to demonstrate autonomous operation for use in the next generation of Department of Defense spacecraft. A secondary objective was to perform a two-month global mapping survey of the Moon and a flyby of a near-Earth asteroid. Given the trend toward smaller, focused planetary science missions, the SSB asked COMPLEX to evaluate the preliminary scientific return from Clementine and to determine the lessons the scientific community can learn from Clementine on a variety of issues including schedule, budget, management approach, mission operations, and data processing. This study is currently in final review.

The trans-Neptunian study involves a review of the current state of scientific understanding of the distant outer solar system. Its goal is to identify the most important scientific questions about this region that can be addressed by ground- and spacebased telescopic observations and spacecraft missions in the near future.


COMPLEX's most recent meeting took place at the National Academy of Sciences' Arnold and Mabel Beckman Center on the campus of the University of California, Irvine, February 5-7, 1996. The main purpose of this meeting was to continue work on the trans-Neptunian study and to hear presentations on some of NASA's ongoing solar system exploration missions. In addition, COMPLEX chair Ronald Greeley reviewed NASA's Planetary Exploration "Road Map" development and the activities of two new SSB task groups _ the Task Group on Issues in Mars Sample Return (concerned with planetary protection and, in particular, forward contamination by extraterrestrial samples returned to Earth) and the Task Group on Space Astronomy and Astrophysics (concerned with opportunities and priorities in the post-SIRTF era).

COMPLEX member Gene Shoemaker reported to the committee on the latest developments in the study of near-Earth asteroids. This presentation was complemented by a presentation by Steward Nozette (Phillips Laboratory) on the USAF's plans for the Clementine 2 multi-asteroid flyby mission scheduled for launch in May 1998.

Additional presentations were made by Andrew Ingersoll (Caltech), Christopher McKay (NASA Ames), and Michael Carr (USGS) on various aspects of the scientific rationale for mobility on and in planetary surfaces and atmospheres. This topic may become the subject of a formal COMPLEX study (subject to NRC approval) once some of the committee's current projects are completed.

Presentations on current NASA planetary missions were given by Arden Albee, Matthew Golombek, and Torrence Johnson, the project scientists for Mars Global Surveyor, Mars Pathfinder, and Galileo respectively. Presentations related to the trans-Neptunian study included one by Dale Cruikshank (NASA Ames) on groundbased observations of the Kuiper disk. Another was given by Michael A'Hearn (University of Maryland), who reviewed his experiences chairing a recent NRC study and the relevance of the resulting report, A Scientific Assessment of a New Technology Orbital Telescope, to studies of the outer solar system.

Shortly after the Irvine meeting, COMPLEX received a formal request from NASA to perform a fast turnaround assessment of the planetary exploration "Road Map" currently under development. This will occur at the committee's next meeting, which will take place in Irvine, California, on June 24-28, 1996.


Ronald Greeley, Chair (Arizona State University)
James Arnold (University of California, San Diego)
Fran Bagenal (University of Colorado)
Jeffrey Barnes (Oregon State University)
Philip Christensen (Arizona State University)
Russell Doolittle (University of California, San Diego)
Heidi Hammel (MIT)
George McGill (University of Massachussets, Amherst)
Harry McSween (University of Tennessee)
Ted Roush (San Francisco State University)
John Rummel (Marine Biological Laboratory)
Gerald Schubert (University of California, Los Angeles)
Eugene Shoemaker (Lowell Observatory)
Darrell Strobel (Johns Hopkins University)
Alan Tokunaga (University of Hawaii)
Roger Yelle (Boston University)
Maria Zuber (MIT)

Additional information about COMPLEX and its activities can be found on the COMPLEX Home Page ( or by contacting its executive secretary, David H. Smith, The Space Studies Board, HA-584, National Academy of Sciences, 2101 Constitution Avenue NW, Washington DC 20418.