NASA Life Research Articles

Celebrating 30 years of access to NASA Space Life Sciences data.

NASA's space life sciences research programs established a decades-long legacy of enhancing our ability to safely explore the cosmos. From Skylab and the Space Shuttle Program to the NASA Balloon Program and the International Space Station National Lab, these programs generated priceless data that continue to paint a vibrant picture of life in space. These data are available to the scientific community in various data repositories, including the NASA Ames Life Sciences Data Archive (ALSDA) and NASA GeneLab. Here we recognize the 30-year anniversary of data access through ALSDA and the 10-year anniversary of GeneLab.

:Life in Space: NASA Life Sciences Research during the Late Twentieth Century

Previous articleNext article No AccessRecentMaura Phillips Mackowski. Life in Space: NASA Life Sciences Research during the Late Twentieth Century. 346 pp., notes, bibl., index. Gainesville: University of Florida Press, 2022. $35 (cloth); ISBN 9781683402602. E-book available.Elizabeth A. KesslerElizabeth A. Kessler Search for more articles by this author PDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Isis Volume 114, Number 2June 2023 Publication of the History of Science Society Article DOIhttps://doi.org/10.1086/724878 For permission to reuse, please contact [email protected]PDF download Crossref reports no articles citing this article.

Life in Space: NASA Life Sciences Research during the Late Twentieth Century by Maura Phillips Mackowski

Reviewed by: Life in Space: NASA Life Sciences Research during the Late Twentieth Century by Maura Phillips Mackowski Alwin J. Cubasch (bio) Life in Space: NASA Life Sciences Research during the Late Twentieth Century By Maura Phillips Mackowski. Gainesville: University of Florida Press, 2022. Pp. 392. Several recent publications have shown an interest in the science and technology that is necessary to live in space. Early astronaut training has become a focus of historical research, as well as the conflicting roles of astronauts as both scientific field workers and test subjects in space (Hersch, "Spacework"; Bimm and Kilian, "The Well-Tempered Astronaut"; Fendley, "First Contact"). Other publications have delved into the history of closed-loop ecologies for long-term space flight (Höhler, Spaceship Earth in the Environmental Age; Munns and Nickelsen, Far Beyond the Moon) and the psychology of living in space (Karafantis, "Sealab II and Skylab"; Grevsmühl, "Laboratory Metaphors in Antarctic History"). Questions of scientific cooperation across the Iron Curtain during the Apollo-Soyuz Test Project have also received scholarly attention (A. Jenks, Collaboration in Space and the Search for Peace on Earth). Against this backdrop, Maura Phillips Mackowski's second book on the history of NASA's life science research is a welcome addition that addresses the life science funding "bubble" (p. 6) at NASA from 1980 to 2004. Mackowski employs a wide definition of what counts as life science, allowing her to cover a broad range of NASA's endeavors from research on lab animals and artificial gravity centrifuges to crew safety systems and escape vehicles. This wide range illustrates NASA's own indecisiveness on what topics should be covered by its life science research programs. It also supports Mackowski's main argument that even in the heyday of life science during the space shuttle and early International Space Station era (p. 74), outside scientists were reluctant to engage with NASA, an agency they considered an unreliable source of funding because of its ever-shifting agenda. Drawing from a wide range of sources and interviews, Mackowski's study especially shines when it locates NASA's life sciences in broader societal and [End Page 627] political trends, from the early enthusiasm of the space shuttle era to the end and aftermath of the Cold War, which restricted funding levels and forced NASA into sometimes uneasy international cooperations. She convincingly shows how cultural influences, political currents, and actors like animal welfare organizations shaped the possibilities the life science community had to conduct research in space. Looking the other direction, the book also discusses NASA's efforts to persuade outside actors and agencies to cooperate on life science projects like radiation research. Her book gives valuable insights into questions of collaboration and competition in late twentieth-century institutionalized science, especially when it deals with NASA's strategies for and difficulties in distributing its main resources to scientists, namely funding and space flight opportunities, fairly between its own centers and extramural researchers. Equally important, the book touches on questions of participation in research settings on Earth and in space and discusses the dynamics of long-distance teamwork between astronauts and scientists. But most of all this is a book about how (not) to manage research in large techno-scientific organizations. Mackowski argues that NASA's constantly shifting priorities discouraged researchers who spent years developing research proposals that underwent peer review and long ground preparation only to be denied flight because of altered mission schedules, new research priorities, or funding cuts. NASA's life science programs often were the first items that fell victim to the reallocation of resources and reorganizations after congressional hearings or the new space policies of incoming presidents. Unfortunately, the actual developments and achievements of NASA's life science sometimes take a backseat in Mackowski's study. While NASA's indecisiveness is mirrored in the interwoven threads of the book, its thematic organization makes following the narrative difficult, as actors and key decisions seem to vanish at points only to reappear a few subchapters later. The book's reliance on NASA's acronyms sometimes conveys the feeling that readers must be intimately familiar with organigrams of NASA headquarters and NASA centers to grasp every detail. Mackowski...

Accurate Prediction Approach of SOH for Lithium-Ion Batteries Based on LSTM Method

The deterioration of the health state of lithium-ion batteries will lead to the degradation of the battery performance, the reduction of the maximum available capacity, the continuous shortening of the service life, the reduction of the driving range of electric vehicles, and even the occurrence of safety accidents in electric vehicles driving. To solve the problem that the traditional battery management system is difficult to accurately manage and predict its health condition, this paper proposes the mechanism and influencing factors of battery degradation. The battery capacity is selected as the characterization of the state of health (SOH), and the long short-term memory (LSTM) model of battery capacity is constructed. The intrinsic pattern of capacity degradation is detected and extracted from the perspective of time series. Experimental results from NASA and CALCE battery life datasets show that the prediction approach based on the LSTM model can accurately predict the available capacity and the remaining useful life (RUL) of the lithium-ion battery.

Far Beyond the Moon: A History of Life Support Systems in the Space Age by David P. D. Munns and Kärin Nickelsen (review).

Reviewed by: Far Beyond the Moon: A History of Life Support Systems in the Space Age by David P. D. Munns and Kärin Nickelsen Jordan Bimm (bio) Far Beyond the Moon: A History of Life Support Systems in the Space Age By David P. D. Munns and Kärin Nickelsen. Pittsburgh: University of Pittsburgh Press, 2021. Pp. 206. Make no mistake, this is a book about shit in space. The sanitized title and cover design don't do justice to what's inside this important and far-ranging history of human waste's various roles in sealed artificial environments designed for space travel. The problem of what to do with astronaut poo has been there since the start of human spaceflight, and coauthors David Munns and Kärin Nickelsen note that sixty-plus years later, a long-term sustainable solution remains elusive. From stick-on poop collection bags to vacuum-assisted commodes to aquarium-like algae habitats converting solid waste into (theoretically) edible food, the array of [End Page 302] engineering and life sciences approaches examined ranges from simple and pragmatic to complex and far-future directed. The first book-length historical treatment of the topic, this frank, unflinching look at an unglamorous, sometimes embarrassing, yet absolutely essential aspect of space technology aims to remove what the authors convincingly argue has been a limiting stigma. We need to talk about shit in space, and Far Beyond the Moon is a thought-provoking conversation starter. The book moves mostly chronologically through a selection of little-known but fascinating American and Soviet projects from the 1960s to the 1990s, emblematic of the work trajectories on this issue, and evocative of themes the authors want to highlight. These include how waste is conceptualized; talked about (or not); incorporated into ecological and technological schemata; collected, stored, or processed; and finally centered in totalizing visions of environment and environmentalism extending far beyond tiny space cabins to experimental megastructures and the entire Earth. The result is an illuminating history of the space race and its aftermath from the new perspective of sanitary engineering. First, the authors dispel the notion that NASA only began work on the problems of long-term living in space in the 1970s, with Skylab extending post-Apollo missions from days to months (ch. 1). Munns and Nickelsen delve into the lesser-known history of NASA's life science research in the 1960s, and of work managing closed systems carried out between the Agency's Ames and Langley centers, as well as in the U.S. Air Force, and at private defense contractors Lockheed, Boeing, and General Electric. Next, the book focuses on fecal bags and the Algatron, two technologies developed in the 1960s representing vastly different approaches to dealing with astronaut poop (ch. 2). The stowable fecal bag used on NASA's famed Apollo missions was straightforward but also messy, smelly, and not reusable. In contrast, the Algatron—an experimental system developed at Berkeley with USAF funding but never flown in space—used algae cultures to endlessly recycle human waste into purified water and food. The book then pivots to the Soviet 1960s space program and ambitious human experiments at the Krasnoyarsk Institute, where scientists sealed test-subjects inside prototype closed ecological systems called "planet-ships" (ch. 3). Started in 1962, these culminated in a year-long experiment in 1967, when three subjects attempted to live and work in close quarters, growing hydroponic crops and recycling their waste with a system similar to the Algatron. Next, the authors take readers into the 1970s and waste-centric critiques of Gerard K. O'Neill's utopian plans for massive cylindrical space settlements, and then into the 1980s to real-life problems with space shuttle toilets and important links between astronaut psychology and hygiene in orbit (ch. 4). Their final chapter focuses on the best-known episode covered in the book, the infamous Biosphere 2 experiments in the early 1990s. Small groups attempted to live inside a giant sealed ecosystem [End Page 303] constructed in Arizona, with controversial results. Munns and Nickelsen place this project—often understood in terms of ecology—squarely within their history of spaceflight and sanitation. Historians of technology will find...

Translating Basic Research to Astronaut Health in Space: NASA Ames Rodent Specimen Biobanking for the Human Research Program

Abstract As an extension of NASA Ames’ long history and sustaining international collaboration for sharing tissues acquired from one-off spaceflight experiments, we have recently established a new mobile operation for acquiring small animal biospecimens from ongoing ground-based studies supported by the NASA Human Research Program (HRP) organized at Johnson Space Center (JSC). Goals of Ames’ Biospecimen Sharing Programs (BSPs) are to: (1) advance understanding of physiological responses and adaptations to the space environment utilizing animal models in support of fundamental space and gravitational biology research, and to promote human health in space and on Earth, (2) provide a repository of high-quality, well-preserved, and carefully archived and maintained biospecimens by applying modern approaches and established best practices in the biobanking field, and (3) establish a database for gathering broad and comprehensive scientific information corresponding to these samples, including cutting edge techniques for tracking and archiving of structural, descriptive, and administrative metadata. This program, modeled after contemporary human and animal biobanking initiatives, is yielding a rich archive of quality specimens that can be used to address a broad range of current and future scientific questions relevant to NASA Life Sciences, Exploration Medicine, and beyond.

Mousetronaut by M. Kelly

Kelly, Mark. Mousetronaut. New York: Simon & Schuster, 2012.Several mice are training hard in the hope of being chosen to take part in a NASA space flight. Meteor the Mouse is much smaller than the others, but his hard work is recognized by the Shuttle Commander who chooses him as one of the six lucky mice to board the shuttle! Only Meteor adapts well to zero-gravity. He saves the mission when, because of his small size, he is able to rescue the key to the control panel when it gets stuck between two monitors.While kind of cute, especially when you learn the story is loosely based on a real mouse, I was left underwhelmed. It is a picture book, so the story is very short and more suited to the younger children in the recommended age range of 4-8. There’s no mention of why the mice were taken to space in the first place. While the story has a somewhat positive message in that sometimes the underdog can save the day, it wasn’t the fact that Meteor was a hard worker that led to his success but merely the fact that he was small.The illustrations by C.F. Payne vary in their appeal. The images of the space shuttle at lift-off and the astronauts floating in their spacesuits have an authentic feel, and the facial expressions of the mice in space are priceless. The human faces, however, are more like caricatures for an older audience with their sometimes oddly shaped faces and exaggerated noses. It was great to see a female among the astronauts, but the use of shading made her look as though she had as much five o’clock shadow as the men.The best part of the work is the afterword where the author, a retired astronaut, shares facts about the NASA program and life in space. Kids will learn some fun details, like that astronauts have to swallow their toothpaste! There is a list of recommended reading for further information, as well as a list of websites with videos or interactive games. This was the first installment of what might become a series of adventures (Mousetronaut Goes to Mars was released October 2013) so one hopes for more riveting plots in the further stories.Recommended with Reservations - 2 out of 4 starsReviewer: Trish ChatterleyTrish is a Public Services Librarian for the John W. Scott Health Sciences Library at the University of Alberta. In her free time she enjoys dancing, gardening, and reading books of all types.

Origins and development of NASA's exobiology program, 1958–1976

Following NASA's founding in 1958, the American space agency was quick to embrace exobiology as an important goal. In July 1959 NASA's first administrator, T. Keith Glennan, appointed a Bioscience Advisory Committee, which reported in January 1960 that NASA should not only be involved in space medicine, but also should undertake the search for extraterrestrial life. In the spring of 1960 NASA set up an Office of Life Sciences. By August it had authorized the Jet Propulsion Laboratory (JPL) to study the type of spacecraft needed to land on Mars and search for life. In order to study chemical evolution, the conditions under which life might survive, and a variety of related issues, NASA's first life sciences lab was set up at its Ames Research Center in California in 1960. In 1962 the Space Science Board of the National Academy of Sciences set the search for extraterrestrial life as “the prime goal of space biology”. The search for life beyond Earth in many ways became a driver of the American space program, and these early events were the essential underpinnings that led to the landings of two Viking spacecraft on Mars in 1976. Despite the failure to find life unambiguously, research in exobiology continued and was transformed two decades later as astrobiology.

The Price of Exploration

NASA is in the final throes of implementing the most powerful surface reconnaissance mission ever undertaken to Mars. Dubbed the Mars Science Laboratory (MSL), it represents NASA's first life inference mission equipped with instruments capable of detecting the chemical building blocks of life more than an order of magnitude more sensitive than those used by the Viking mission of the 1970s. MSL will also demonstrate multiple technical capabilities needed to enable a future robotic Mars sample return mission. In his 31 October Letter (“Viewing NASA's Mars budget with resignation,” p. [672][1]), former NASA Associate Administrator S. A. Stern suggested that excessive cost growth of MSL is deeply damaging NASA's overall planetary exploration agenda and destroying the opportunity for a future Mars sample return mission. He blames senior NASA leaders for disbanding his MSL independent technical review team, which he claims forced his resignation. ![Figure][2] Let's roll. Wheels have been fitted to NASA's Mars Science Laboratory (MSL) rover, which is being assembled at NASA's Jet Propulsion Laboratory, Pasadena, California. The rover has a ground clearance of about 60 cm, or 2 feet, and is about the size of a small automobile. CREDIT: NASA/JPL Now is the time to set the record straight. NASA consolidated its independent standing review boards to streamline the process for all major flight programs in 2007. The MSL Standing Review Board remains in effect and was never disbanded. Stern also claims that MSL was “assigned” a cost level of $650 million. He fails to mention when and by whom. The $650 million cost was a placeholder assigned to a medium-class Mars rover mission by the National Research Council Solar System Decadal Survey committee in 2002, before NASA had developed a basis of cost estimate for MSL. This served as input to NASA studies from 2000 to 2004 to fully define the MSL mission and culminated in the competitive selection of its science payload in late 2004. At that time, the overall mission was baselined at a cost of $1.4 billion, not including several costs associated with the radioisotope power system. Given the experience with the cost of the Mars Exploration Rovers and the increased scientific and technical scope of the MSL mission, the so-called assigned value of $650 million is not credible. Stern's own New Horizons flyby mission to Pluto cost NASA more than $650 million; it is unrealistic to expect that a 700-kg analytical laboratory that must soft-land on Mars and drive around with 100 kg of scientific instruments could possibly cost less than a planetary flyby mission. Indeed, MSL's 2 years of intensive surface science operations are difficult to compare to any missions in the $650 million price class given typical science-per-dollar metrics. The established NASA cost to implement MSL as of the time of its confirmation review was $1.55 billion (August 2006), which grew due to NASA-wide issues with thermal protection system materials in 2007 to approximately $1.7 billion. The total cost growth of the MSL mission development since NASA confirmed the mission is typical of other Mars exploration missions successfully flown over the past decade. The cost to fly MSL in 2009 will be less than the cost (in today's dollars) of flying a nonmobile Viking Lander laboratory to Mars, and MSL includes a whole new generation of instruments and mobility. NASA has an exemplary record of honoring its commitments to implement flagship-class missions that frequently “rewrite the textbooks” as they discover how the universe operates. To abandon MSL at this time would represent an unprecedented break with this guiding philosophy. As President John F. Kennedy once stated, we choose to do these things not because they are easy, but because they are hard. NASA succeeded with Apollo to the Moon, Hubble to the universe, and Cassini to Saturn. The agency is ready now to assault the martian frontier with MSL. [1]: /lookup/doi/10.1126/science.322.5902.672b [2]: pending:yes

Data archiving in animal experimentation: Merits, challenges, and a case study

Electronic data archives may supplement the traditional peer-reviewed journal article. The merits of data archiving include public service, a more complete research project, overcoming barriers to limited-access research resources, and increasing the impact of a scientific project. A case study of chimpanzee timing performance in space is derived from the NASA Life Sciences Data Archive (http://lsdajsc. nasagov). An analysis of the archived data suggests that the scalar property (a form of Weber's law) applies to timed performance of a chimpanzee in orbit of the earth. Challenges associated with data archives are discussed. Although significant challenges are associated with archiving electronic data, these difficulties are outweighed by its merits.

AAA award winners.

AAA award winners.

Measuring the economic returns from successful NASA life sciences technology transfers.

Since 1958 NASA has invested approximately $3.7 billion in life sciences R&D in the support of the successful human space flight program. There are numerous studies documenting the spin-off technologies that can be traced to NASA research and development activities. Most of these studies describe the technologies and their uses; however only a few measure the economic impact of the spin-offs and most of these are benefit/cost studies that tend to overstate benefits or underestimate costs. This study takes a different approach, measuring only economic impacts to the companies that developed successful spin-off products from NASA life sciences investments. A personal interview was conducted with each company and the benefits are conservatively estimated as the value-added by the NASA technology to the company's output and the amount of additional private R&D stimulated by the NASA R&D. This pilot study of fifteen companies, using a very conservative measurement technique, found a large return to companies that have successfully commercialized NASA life sciences spin-off products. Value-added benefits totaled over $1.5 billion and a NASA R&D total investment in these 15 technologies of $64 million was found to stimulate an additional $200 million in private R&D. The study also found that the largest benefits were from products developed and marketed by large companies, primarily because these companies had the financial and marketing resources to work on a scale unavailable to smaller companies. Many of the small companies reported very profitable product-lines as well as documented evidence of benefits extending to the commercial users of their products. However, the smaller companies often lacked either the ability or the desire to expand into much larger scale production. NASA and other government technology transfer programs may be overlooking an opportunity to enlarge the economic benefits from their spin-off technologies. When a federal R&D grant or contract ends, the formal relationship between the agency and the company also usually ends. However, the companies continue to use the prior connection to NASA for advertising and for developing new business partners. One recommendation of this study is for NASA to be more proactive with "alumni" companies and to help open additional financial and marketing doors for these companies.

Space Station Research: Details Please

The comments in the News of the Week article “An improvement in vital signs” (by A. Lawler, 4 Aug., p. [707][1]) by Julie Swain, deputy chief of NASA's life and microgravity sciences office, about the NASA life science research program to be mounted on the space station are notably vague. When

Contributions to the U.S. Space Program

The News of the Week article “Goldin shakes up NASA's life sciences program” (Andrew Lawler, 12 May, p. [938][1]) does not include mention of the many contributions that Arnauld Nicogossian, former chief of NASA's Office of Life and Microgravity Sciences and Applications (OLMSA), has made to our nation's space program. Despite flat budgets for OLMSA over the past 6 years, Nicogossian's leadership has increased the office's extramural research community from about 650 to more than 900 researchers from nationally recognized institutions. Working with the National Institutes of Health and the National Science Foundation, Nicogossian has been instrumental in establishing the Life Sciences competitive peer review process, which requires all NASA scientific research to undergo vigorous peer review by independent external panels. Nicogossian should also be credited with spearheading an interdisciplinary research program in biology, physics, and chemistry, which uses biologically inspired technology as the basis for integration. This effort is attracting a new generation of scientists to NASA, as well as several Nobel laureates. Whether serving as the associate administrator for OLMSA or as chief health and medical officer, Arnauld Nicogossian will continue to do an outstanding job providing NASA with world-class leadership and expertise. [1]: /lookup/doi/10.1126/science.288.5468.938

Microgravity processing of immiscible aluminum-indium alloys

This paper addresses the Coupled Growth in Hypermonotectics experiment carried out aboard NASA's Life and Microgravity Spacelab Mission which took place from June 10 to July 7, 1996. The experiment involved the directional solidification of hypermonotectic (immiscible) alloys in an attempt to obtain steady-state, coupled growth conditions by processing under microgravity conditions. Processing was carried out utilizing the Advanced Gradient Heating Facility directional solidification furnace in order to obtain the high thermal gradients and controlled growth rates required for stability. Solidification under the proper growth conditions was expected to lead to interface stability and the production of a desired aligned fibrous microstructure even for hypermonotectic alloys. The paper covers the objectives of the experiment and a discussion of the anticipated results. While microstructural information is not yet available at the time of writing, results will be presented on the thermal gradients and growth rates obtained and how these compared with predictions.

FORCE-VELOCITY AND FORCE-POWER PROPERTIES OF HUMAN MUSCLE FIBERS AFTER SPACEFLIGHT 1081

The purpose of this study was to investigate the effects of 17 days of spaceflight (SF) on the force-velocity-power properties of human muscle fibers. Pre- and post-SF soleus (SOL) and gastrocnemius (GAST) muscle biopsies were obtained from 4 male crew members of the 17 day NASA Life Microgravity Sciences Spacelab mission (STS-78). 384 single fiber segments were subjected to a series of isotonic force clamps at maximal Ca2+ -activation and subsequently run on 5% SDS polyacrylamide gels to determine myosin heavy chain(MHC) composition. After SF, shortening velocity at peak power output increased for the SOL type I (+29%) and GAST type 1 (+30%) fibers and was unchanged for the GAST-IIa fibers. In contrast, the force produced at peak power declined for SOL-I (-28%), GAST-I (-11%), and GAST-IIa fibers (-17%) due to decreases in peak force (Po) and a/Po for the SOL-I fibers, a/Po only for the GAST-I fibers, and Po only for the GAST-IIa fibers. Absolute peak power was affected by these changes as indicated intable (FL, fiber length; * P < 0.05, † P = 0.06). The increased peak power of the post-SF GAST-I fibers may be due to their preferential recruitment during the exercise countermeasures used on this flight.

Animal Activists Target NASA Mission

A lobbying campaign by animal activists could jeopardize the scheduled launch this fall of a multinational space project to examine the effects of weightlessness on rhesus monkeys. The controversy pits the political muscle of animal-rights activists and their allies—who have called the experiments “one giant leap backward for mankind”—against NASA life scientists eager to conduct the first comprehensive examination of the effects of weightlessness on muscles, bones, the immune system, and coordination. The Bion project is a joint effort involving U.S., French, and Russian scientists.

Educational opportunities within the NASA specialized center of research and training in gravitational biology

The NASA Specialized Center of Research and Training (NSCORT) in Gravitational Biology was established at Kansas State University, supported through NASA's Life Science Division, Office of Space Science and Applications. Educational opportunities, associated with each of the research projects which form the nucleus of the Center, are complemented by program enrichments such as scholar exchanges and linkages to other NASA and commercial programs. The focus of this training program, and a preliminary assessment of its successes, are described.

Dynamics of a dual‐driver acoustic resonator and control system used in a thermoacoustic refrigerator

Until the development of the Thermoacoustic life sciences refrigerator (TALSR) [S. L. Garrett et al., J. Acoust. Soc. Am. 93, 2364 (1993)], all previous thermoacoustic refrigerators employed only a single electrodynamic driver. Due to the acoustic power requirements for TALSR, a dual‐driver, half‐wavelength engine was designed. This introduces additional complications for the resonance frequency control and tracking circuitry since each driver constitutes a driven simple harmonic oscillator and the two drivers, both of which have an associated microphone and accelerometer, are coupled by an acoustically resonant system. A computer model of the three strongly interacting resonant systems will be described along with a series of experimental measurements that explored a variety of operating conditions. [Work supported by NASA—Life Sciences Division and the Naval Postgraduate School Direct Funded Research Program.]

Thermoacoustic life sciences refrigerator

This thermoacoustic refrigerator is being built to preserve biological samples (blood, urine, etc.) during Space Shuttle operations. It employs two high-power electrodynamic drivers capable of generating 60 W of acoustic power each, two ‘‘stacks,’’ and four internal heat exchangers in order to produce 700 BTU/h (205 W) of cooling in the refrigerator mode at 4 °C and 400 BTU/h (117 W) of cooling in the freezer mode at −22 °C. The working fluid is a 2-MPa mixture of He and Xe gas. Both hot and cold heat exchangers use circulating fluids to remove heat from the insulated sample enclosure and exhaust enthalpy from the engine. This talk will describe the acoustical design and electronic control systems that permit long-term autonomous operation while on orbit. Except for the fact that the entire systems operates from a 28-Vdc power supply, it is not unlike a typical small household refrigerator. [Work supported by NASA—Life Sciences Division and managed by General Electric Government Systems.]