Book Review: NASA's Discovery Program

book cover Review: NASA’s Discovery Program by Jeff Foust Monday, February 5, 2024 Bookmark and Share NASA’s Discovery Program: The First Twenty Years of Competitive Planetary Exploration by Susan M. Niebur with David W. Brown, Editor NASA, 2023 ebook, 444 pp., illus. ISBN 978-1-62683-076-9 Free At last week’s meeting of NASA’s Small Bodies Assessment Group, a group devoted to issues of exploration of asteroids, comets, and other small solar system bodies, a question came up: when will NASA issue its next call for proposals for missions in the Discovery program? The answer from NASA officials was the same as they have given in other recent meetings: not any time soon. Uncertainty about overall spending levels along with budget pressures specific to planetary programs, including Mars Sample Return, meant that NASA was holding off, for now, the next competition to select the next mission or missions, which would likely not fly until the early 2030s. Goldin wanted to start a line of low-cost planetary science missions, only to be told that there already was one, Discovery. Goldin’s eyes “got real big” upon hearing about it. The Discovery program has evolved significantly since its creation more than three decades ago. What started out as a program for missions flown at low cost and a higher acceptance of risk has turned into one with missions that are more expensive and risk-averse, but very productive. Discovery has included Mars landers, a Mercury orbiter and expeditions to asteroids and comets, nearly every one of which has been a success. The idea of competitively selected missions led by a principal investigator (PI) has become widely accepted and adopted for both larger (New Frontiers) and smaller (SIMPLEx) planetary missions. The evolution of the Discovery program over its first decades is the subject of a NASA history, NASA’s Discovery Program. (Susan Niebur, a former NASA Discovery program scientist, won a NASA history grant to write the book; after her untimely death in 2012, science writer David Brown came in to complete the book.) It illustrates, by following missions from NEAR and Mars Pathfinder to Dawn and Kepler, how the program and its balancing of cost, risk, and science changed over that time. The origins of Discovery can be traced back to a 1989 meeting of a committee looking at the future of planetary exploration, when Stamatios “Tom” Krimigis of the Applied Physics Lab discussed the success of PI-led space science missions in NASA’s Explorer program. Despite considerable initial skepticism that low-cost planetary missions were feasible, it set the wheels in motion for what would become the Discovery program and its first two missions, NEAR and Mars Pathfinder. Competition for missions soon followed, with an initial cost cap of $150 million in 1992 dollars, excluding launch. Discovery happened to align with the arrival at NASA of Dan Goldin and his desire for faster, better, cheaper (FBC) missions. Goldin, the book notes, instructed the agency’s associate administrator for space science, Wes Huntress, shortly after becoming administrator to start a line of low-cost planetary science missions, only to be told that there already was one, Discovery. Goldin’s eyes “got real big” upon hearing about it, Huntress recalled. Discovery rode the wave of FBC in the ’90s but was also affected by its problems, notably the failure of the Mars Climate Orbiter and Mars Polar Lander missions in 1999. There was a retrenchment that followed, with far less tolerance for risk across the board. “Arguably, no single act would have further-reaching and more devastating budgetary and cultural implications for the Discovery Program,” the book states. “For NASA, risk aversion would become paramount in a program where risk was intrinsic.” That risk aversion was further enhanced by the only complete Discovery mission failure, the CONTOUR comet mission, which broke apart during a burn of a solid-fuel kick stage shortly after its launch in 2002. (The Genesis mission suffered a failure of the parachute of its solar wind sample return capsule, but the mission was still able to salvage much of the science from the crashed capsule.) While mission failures were to be expected as part of the FBC approach, acceptance of risk and failures was never that high in reality. Later Discovery missions would have more reviews and requirements, which would lead to higher costs. The program now is very different from the one conceived nearly 35 years ago. The 1992 cost cap of $150 million would, in today’s dollars, be about $350 million. The most recent Discovery mission to launch, Psyche, cost $1.2 billion. The book follows the Discovery missions through Dawn and Kepler, which launched in the late 2000s, along with discussing the 2007 selection of GRAIL, the lunar gravity mapping mission that launched in 2011. (Lunar Prospector, the first competitively selected Discovery mission, curiously gets only a handful of pages, far less than other missions, despite being remarkably inexpensive.) Each had unique problems but with similar themes: management challenges, particularly in the relationships among the PI, project manager, and major contractors; cost overruns that led to threats of cancellation; and technical problems. Some of the issues were predictable, while others bordered on the bizarre: the deputy project manager for the MESSENGER Mercury orbiter, groomed to succeed the project manager upon his impending retirement, instead abruptly left the program after what the book described as “a particularly taxing trip to a West Coast supplier.” The Discovery program, from a scientific standpoint, has been a success: its missions have returned a wealth of data from Mercury to the main asteroid belt. But the program now is very different from the one conceived nearly 35 years ago. The 1992 cost cap of $150 million would, in today’s dollars, be about $350 million. The most recent Discovery mission to launch, Psyche, cost $1.2 billion, an increase that is only partially explained by accounting changes like the inclusion of launch costs. Psyche and other recent Discovery missions aren’t included in the book, but the trends in costs and risk involving earlier missions have clearly continued. NASA’s Discovery Program is a fascinating examination of the evolution of the Discovery program specifically and, more broadly, how acceptance of risk and cost changes as a program matures. It should be required reading for anyone contemplating a proposal for the next round of the Discovery program—whenever that takes place. Jeff Foust (jeff@thespacereview.com) is the editor and publisher of The Space Review, and a senior staff writer with SpaceNews. He also operates the Spacetoday.net web site. Views and opinions expressed in this article are those of the author alone.