Project Mercury Research Articles

Characterizing dehydration in short-term spaceflight using evidence from Project Mercury

Short-term spaceflight is commonly perceived as posing minimal risk to human health and performance. However, despite their duration, short-term flights potentially induce acute physiological changes that create risk to crews. One such change is dehydration (primarily body water loss) due to a heat-stressed environment. Such loss, if severe and prolonged, can lead to decrements in performance as well as increase the risk of more serious medical conditions. Though the general mechanisms of dehydration are broadly understood, the rate and extent of dehydration in short-term spaceflight has not been characterized. Combining data from the six spaceflights of the US Mercury program with a causal diagram illustrating the mechanisms of dehydration, we fit a path model to estimate the causal effects for all pathways in the causal model. Results demonstrate that Mercury astronauts experienced some degree of dehydration across the range of suited time and that the relationship between suited time and dehydration appears to be logarithmic. We discuss causal interpretations of the results and how the results from this and similar analyses can inform countermeasure development for short-term spaceflight.

Garden Hunter

Garden Hunter

Making Space for Women: Stories from Trailblazing Women of NASA’s Johnson Space Center ed. by Jennifer M. Ross-Nazzal

Reviewed by: Making Space for Women: Stories from Trailblazing Women of NASA’s Johnson Space Center ed. by Jennifer M. Ross-Nazzal Margaret A. Weitekamp Making Space for Women: Stories from Trailblazing Women of NASA’s Johnson Space Center. Edited by Jennifer M. Ross-Nazzal. (College Station: Texas A&M University Press, 2022. Pp. 443. Illustrations, notes index.) With this excellent compilation of oral history interviews, editor Jennifer Ross-Nazzal, the historian at the Johnson Space Center (JSC), the center for human spaceflight and mission control for the National Aeronautics and Space Administration (NASA), introduces readers to twenty-one women whose hard work and dedication helped build that center’s reputation for excellence. As a scholar, I have frequently searched for oral [End Page 393] history interviews in the deep collection that the JSC’s history office created and maintains. The individual experiences and personal recollections of contemporary actors—and the more than 1,400 oral history interviews compiled by the Johnson Space Center as of the book’s printing—deepen understanding of historical events and enliven their retelling. With this collection, Ross-Nazzal brings a selection of those resources to a broader readership. Ross-Nazzal’s introduction provides a well-researched and carefully footnoted summary of the history of women’s participation as NASA professionals. That progress was uneven, as such changes tend to be. She traces the broad outlines of the history beginning from the 1960s, when a woman behind a desk was assumed to be a secretary even if she was not, to the current day, which includes women in JSC’s leadership positions and an onsite childcare center. Ross-Nazzal self-consciously frames this volume as another possible aid to encourage that cultural shift toward women’s fuller participation in the professional work of spaceflight. Ross-Nazzal opens the volume with two oral history interviews from secretaries and administrative support, a fitting choice because for many years women’s participation at JSC was restricted to such roles. Nonetheless, reading these interviews reminds readers how vital such positions were for NASA’s work. The oral histories in this collection feature mathematicians and engineers, then flight controllers, spacesuit technicians, nurses and scientists, astronauts, trainers, senior management, and center management. Given how much the work at JSC focuses on human spaceflight, Ross-Nazzal makes a deliberate choice to illustrate through the book’s structure how much the work of astronauts is embedded in a network of other equally vital positions. The interview subjects go as far back in JSC’s history as Dee O’Hara, the nurse who worked closely with the original seven Project Mercury astronauts. She started at NASA in 1959, before the agency moved its human (then called “manned”) spaceflight operations to Houston. Peggy Whitson brings the story almost to the present as an astronaut who commanded the International Space Station and served as Chief of the Astronaut Office before retiring in 2018 to work for Axiom, a commercial spaceflight company. Throughout, the themes of mentorship and commitment to the mission illustrate how women gained professional footholds in fields that were not always completely welcoming. Often professional advancement decisions occurred because the right job, at the right level, opened at the right time. Readers should note that the chapters are edited versions of oral history interviews, not third-person accounts. As a result, in some instances there are references to federal government employment (such as pay-grade levels and NASA acronyms) that may not be immediately clear. Making Space for Women would be an excellent addition to history, women’s studies, or STEM (science, technology, engineering, and math) [End Page 394] classes to show students the range of careers that might be open to them thanks to these path-breaking women. Margaret A. Weitekamp Smithsonian’s National Air and Space Museum Copyright © 2022 The Texas State Historical Association

Extended Duration Orbiter Medical Project

Biomedical issues have presented a challenge to flight physicians, scientists, and engineers ever since the advent of high-speed, high-altitude airplane flight in the 1940s. In 1958, preparations began for the first manned space flights of Project Mercury. The medical data and flight experience gained through Mercury's six flights and the Gemini, Apollo, and Skylab projects, as well as subsequent space flights, comprised the knowledge base that was used to develop and implement the Extended Duration Orbiter Medical Project (EDOMP). The EDOMP yielded substantial amounts of data in six areas of space biomedical research. In addition, a significant amount of hardware was developed and tested under the EDOMP. This hardware was designed to improve data gathering capabilities and maintain crew physical fitness, while minimizing the overall impact to the microgravity environment. The biomedical findings as well as the hardware development results realized from the EDOMP have been important to the continuing success of extended Space Shuttle flights and have formed the basis for medical studies of crew members living for three to five months aboard the Russian space station, Mir. EDOMP data and hardware are also being used in preparation for the construction and habitation of International Space Station. All data sets were grouped to be non-attributable to individuals, and submitted to NASA s Life Sciences Data Archive.

Review: Beyond Blue Skies: The Rocket Plane Programs That Led to the Space Age, by Chris Petty

Review: <i>Beyond Blue Skies: The Rocket Plane Programs That Led to the Space Age</i>, by Chris Petty

KEY ENGINEERING SOLUTIONS IMPLEMENTED IN ROCKET AND SPACE SYSTEM VOSTOK TO ASSURE CREW SAFETY DURING ASCENT (towards 60th anniversary of the first man in space)

The paper analyzes engineering and operational solutions implemented in rocket and space system Vostok to assure crew safety during ascent in view of the need to complete the work on an extremely short notice. It reviews the results of flight tests of launch vehicles belonging to the R7 family and the status of work to develop a crew escape system by the time when the first manned mission of Vostok spacecraft took place. It provides an analysis of emergencies and measures to assure safety during prelaunch processing and ascent phase. The paper draws comparisons between our country’s project Vostok and US project Mercury. Key words: rocket and space system, spacecraft, descent vehicle, crew safety.

KEY ENGINEERING SOLUTIONS IMPLEMENTED IN ROCKET AND SPACE SYSTEM VOSTOK TO ASSURE CREW SAFETY DURING ASCENT (towards 60th anniversary of the first man in space)

The paper analyzes engineering and operational solutions implemented in rocket and space system Vostok to assure crew safety during ascent in view of the need to complete the work on an extremely short notice. It reviews the results of flight tests of launch vehicles belonging to the R7 family and the status of during prelaunch processing and ascent phase. The paper draws comparisons between work to develop a crew escape system by the time when the first manned mission of Vostok spacecraft took place. It provides an analysis of emergencies and measures to assure safety our country’s project Vostok and US project Mercury. Key words: rocket and space system, spacecraft, descent vehicle, crew safety.

Aloha Space Age: NASA and the Hawaiian Islands, 1957—1970

Aloha Space Age:NASA and the Hawaiian Islands, 1957—1970 David A. Smith (bio) I have been part of that generation so inspired by the space program. Nineteen sixty-one was the year of my birth, the year that Kennedy made his announcement. And one of my earliest memories is sitting on my grandfather's shoulders, waving a flag as astronauts arrived in Hawai'i. For me, the space program has always captured an essential part of what it means to be an American: reaching for new heights, stretching beyond what previously did not seem possible. And so as President, I believe that space exploration is ... an essential part of that quest. —US President Barack Obama, 2010 1 When scholars and the general public recall the early years of the National Aeronautics and Space Administration (NASA) space pro-gram, from Project Mercury through Project Apollo, the Cape and Kennedy Space Center in Florida and Manned Space Flight Center in Houston are the two earthbound locales that usually first come to mind. 2 Over the years, historians have also turned their attention to other sites outside of southeast Texas and Florida's space coast that played significant roles in space exploration. 3 One region that has [End Page 1] been almost universally overlooked by academic and popular authors alike, however, has been the State of Hawai'i, which became the fiftieth state just one year after NASA was established in November 1958. While the world's premier and perhaps most controversial astronomical site at Mauna Kea on the island of Hawai'i has been the subject of several studies (including one in this journal 4 ), the stories of the Hawaiian Islands' engagement with the movement of people to and from space and the Moon, including residents' responses to the Space Age, have not been told. From NASA's formative years through the early 1970s, the Hawaiian Islands played important and colorful roles in space exploration. On the island of Kaua'i, the Kōke'e tracking station was an integral part of the agency's tracking and communications network for the early human space flights that made up the Mercury, Gemini, and Apollo programs. O'ahu was the first port of call for astronauts returning from the Moon. The island of Hawai'i became the first choice for astronaut geology training and other lunar space-related activities. There were other significant, if less tangible, connections as well. From the aftermath of the Soviet Union's launch of Sputnik I through the dramatic return of the Apollo 13 astronauts in 1970, most, if not all, of Hawai'i's residents, local press, politicians, celebrities, schools, and cultural institutions consistently embraced space travel programs and related activities with a sense of enthusiasm and "great aloha" (especially in terms of greetings for returning astronauts) with a participation rate far out of proportion to Hawai'i's small population. A variety of schemes for space launch centers and facilities, related exhibition and educational programs, and spontaneous celebrations of NASA successes seemed to be everywhere in Hawai'i during the 1960s. Examining the Hawaiian Islands' engagement and welcome of these NASA initiatives fills an existing void in the literature and provides a window, from a mid-Pacific perspective, into understanding why the space program experienced the highest level of public approval of all major US federal initiatives during this era. 5 Rockets, Missiles, and Moonports Most scholars accept that the Space Age began when the Soviet Union launched the world's first man-made satellite, Sputnik, on October 4, 1957. [End Page 2] The United States quickly took notice and began focusing more attention on its own fledgling space initiatives. In the post-war period, the US Congress was alarmed by the perceived Soviet threat to America's security and to its now questionable lead in world technology. As historian Andreas Reichstein contends: "The reaction of the American people to the successful launch of Sputnik . . . has been compared to the one after Pearl Harbor." 6 Troubled O'ahu residents once again looked to the skies and, in November, reported spotting the companion rocket to the Soviet's "first artificial 'moon'" as it...

No Monkeying Around: An Anesthesiologist at the Heart of NASA and Project Mercury

No Monkeying Around: An Anesthesiologist at the Heart of NASA and Project Mercury

Need More Chimp Flights: Medical Drama and Presidential Decision-Making in Project Mercury.

Need More Chimp Flights: Medical Drama and Presidential Decision-Making in Project Mercury.

Global Networking and the Contrapuntal Node: The Project Mercury Earth Station in Zanzibar, 1959-64

In 1960, the US government and British protectorate of Zanzibar signed an agreement that allowed US contractors working for the National Aeronautics and Space Administration (NASA) to build an earth station that would support Project Mercury, the first manned US satellite mission. This article focuses on the development of the Project Mercury earth station in Zanzibar during 1959-1964. To historicize the earth station’s establishment, the focus lies on the geopolitical and sociotechnical relations that resulted in the Zanzibar station.

Global Networking and the Contrapuntal Node: The Project Mercury Earth Station in Zanzibar, 1959-64

Global Networking and the Contrapuntal Node: The Project Mercury Earth Station in Zanzibar, 1959-64

Incidence of an Astronaut Not Sealing the Pressure Garment Visor on Reentry

Audiovisual records of a Project Mercury pilot's activities during an orbital flight indicate that his visor was left open during reentry and descent to the sea surface, phases of flight during which cabin pressure loss was to be mitigated by suit pressurization; however the suit could not have been pressurized with the visor open. Thus, for a presentlyunknown reason, a critical safety step—sealing the visor and making a pressure suit integrity test before re-entry—was overlooked in this flight, a fact itself unreported in any flight review or historical documents known to the author. The lesson is clear: even a highly-motivated, federally-funded project remains at base a collaboration of individuals, the project only being as strong as the proverbial weakest link. Attention to development of thorough and unambiguous procedural checklists is reiterated.

Biomedical findings from NASA\u2019s Project Mercury: a case series

The United States first sent humans into space during six flights of Project Mercury from May 1961 to May 1963. These flights were brief, with durations ranging from about 15 min to just over 34 h. A primary purpose of the project was to determine if humans could perform meaningful tasks while in space. This was supported by a series of biomedical measurements on each astronaut before, during (when feasible), and after flight to document the effects of exposure to the spaceflight environment. While almost all of the data presented here have been published in technical reports, this is the first integrated summary of the main results. One unexpected finding emerges: the major physiological changes associated with these short-term spaceflights are correlated more strongly with time spent by the astronaut in a spacesuit than with time spent in space per se. Thus, exposure to the direct stressors of short-duration (up to 34 h) spaceflight was not the dominant factor influencing human health and performance. This is relevant to current spaceflight programs and especially to upcoming commercial flights in which time spent in space (as on a suborbital flight) will be minor compared to the time spent in associated preparation, ascent, and return.

The Other Space Race: Eisenhower and the Quest for Aerospace Security by Nicholas Michael Sambaluk

Reviewed by: The Other Space Race: Eisenhower and the Quest for Aerospace Securityby Nicholas Michael Sambaluk Alan D. Meyer (bio) The Other Space Race: Eisenhower and the Quest for Aerospace Security. by Nicholas Michael Sambaluk. Annapolis, MD: U.S. Naval Institute Press, 2015. Pp. 352. $44.95. Most accounts of the "space race" between the Soviet Union and the United States begin with the 1957 launch of the first artificial satellite, Sputnik 1, which panicked Americans into believing they had lost their technological (and thus military) edge over their cold war adversary. President Dwight Eisenhower's staid response failed to calm their fears; instead, it left many convinced that their avuncular but technologically naive commander in chief did not fully comprehend the strategic importance of outer space. Many authors treat Eisenhower's space policies of the late 1950s similarly, as little more than a reactive and reluctant prologue to the more ambitious and deliberate agenda pursued by Presidents Kennedy and Johnson in the 1960s: human spaceflight leading to the Apollo Moon landings. In The Other Space Race, historian Nicholas Michael Sambaluk argues that Eisenhower in fact created a coherent, long-term space policy that was firmly grounded in national defense. However, the president's low-key leadership style, which served him well throughout his first term, ultimately worked against him as public confidence eroded in the wake of Sputnik. Long before the Sputnik crisis, Eisenhower focused on developing unmanned (and unarmed) reconnaissance satellites to provide intelligence on Soviet military preparedness. To further this strategic goal, the White House announced plans to launch a scientific research satellite during the International Geophysical Year of 1957–58. Eisenhower's real goal for this non-military project was to create a precedent for international "freedom of space," which would make it legal for the United States to overfly the Soviet Union using top-secret spy satellites still under development. Ultimately he achieved both ends: Sputnik's orbit over the United States delivered the crucial "freedom of space" precedent, and by the time John Kennedy took office, photographs from the CIA's Corona spy satellites developed under Eisenhower proved the fiction of the so-called "missile gap" on which Kennedy had successfully campaigned. Ironically, because Eisenhower refused to even hint at Corona's existence, the American public, Congress, and even most top military leaders incorrectly concluded that he had no space policy. Although Eisenhower was mainly interested in reconnaissance satellites, Sputnik forced more visible action. In 1958 he replaced the National Advisory Committee for Aeronautics with another civilian agency, the National Aeronautics and Space Administration (NASA), in part to placate the public, but also to outmaneuver air force leaders who sought control of the nation's space program. And although he saw no practical function in [End Page 597]human spaceflight, Eisenhower subsequently approved NASA's Project Mercury for similar reasons. While he tolerated NASA's non-military agenda, the air force's planned hypersonic space plane, which promised to deliver nuclear warheads from outer space, flew directly in the face of Eisenhower's express policy to avoid weaponizing space (p. 47). Dubbed "Dyna-Soar" (for Dynamic Soarer), the piloted craft would be boosted into orbit atop a rocket, then conduct its mission while gliding back to Earth at speeds approaching 25,000 feet per second (17,000 mph) (p. 72). Sambaluk demonstrates how the postwar air force never doubted that it was the natural choice to lead the nation into manned spaceflight as an extension of its existing airpower doctrine, and shows how the program remained small enough to escape Eisenhower's notice until after Sputnik created considerable public outcry for decisive action to restore U.S. preeminence in space. By then, given Dyna-Soar's widespread popularity in military and political circles, coupled with Eisenhower's perceived weakness on space policy, the president felt that he could not cancel the program even though he clearly wanted to. Ultimately it was Kennedy (who initially favored the project as part of a massive defense spending program) who put the unfortunately named program on the path to extinction (p. 223). Although the title does not mention Dyna-Soar by name, the air force's abortive...

Spacefarers: Images of Astronauts and Cosmonauts in the Heroic Era of Spaceflight ed. by Michael J. Neufeld (review)

Reviewed by: Spacefarers: Images of Astronauts and Cosmonauts in the Heroic Era of Spaceflight ed. by Michael J. Neufeld De Witt Douglas Kilgore (bio) Spacefarers: Images of Astronauts and Cosmonauts in the Heroic Era of Spaceflight. Edited by Michael J. Neufeld. Washington, DC: Smithsonian Institution Press, 2013. Pp. 260. $29.95. The history of technology is interested in how machines and the systems on which they rely are made. It is also a field concerned with their role as socially embedded instruments of our culture. Spacefarers takes on the latter research agenda and applies it to one of the most visible technoscientific inventions of the space age: the astronaut. It is through this character that the space powers of the twentieth century sought a celestial renewal of national identity as well as narrative control over the powerful technologies that made spaceflight possible. The astronaut romanticized astronautic technology, making it conform to Earth-bound presuppositions about the qualities that make a hero: a stolid masculinity confirmed by investments of race, gender, family values, and national identity. But within this new man we also find the seeds of social change and, perhaps, the lesson that any successfully socialized technology will slip beyond its initial beneficiaries. This volume presents a story of hesitant social progress, as modeled by the heroes of space age technology. Spacefarers’s nine chapters extend and complicate the relatively new historical field of “astroculture.” Historian Alexander C. T. Geppert coined the term in Imagining Outer Space: European Astroculture in the Twentieth Century (2012). As defined by Michael Neufeld in this volume, it is “the whole complex of ideas and images related to space travel, astronomy, aliens, etc., that have now penetrated transnational popular and elite cultures” (p. 6). This collection’s remit is to recover the role that astronauts and cosmonauts played in astroculture, reestablishing its human dimension and thereby making sense of why humankind’s trespass into outer space either changed or, as importantly, did not change familiar social roles and political investments. The three sections of Spacefarers cover a tremendous amount of ground in a small space. The first three chapters provide a useful historical frame that takes us from the white, male, and Protestant archetype of Project Mercury to the race, gender, and professional diversity that characterized the space shuttle program. We are also given details of how television and motion pictures cast the astronaut in stories that valorized combat-tested pilots and denied active roles to women and professional scientists. In these stories the astronaut emerges as a romantic character whose dominant characteristic is cool control over spaceflight technology, which enables the transformation of outer space into an American frontier. The second three chapters recount the Soviet and French contribution to making cosmonauts into national heroes. We encounter Yuri Gagarin, [End Page 288] who becomes the ideal of a particular Soviet space future as well as an exemplar of the simple Russian peasant values valorized as fundamental to national identity. Also notable is how magazine coverage in France transformed American and Soviet spacemen into “spationauts” who adhered to conservative French domestic virtues. This section is rounded out with an interesting take on how American and Soviet magazines both presented astronauts as a new kind of human being because of their attachment to space technology and their conquest of space. These new men, however, also represent old national narratives as stabilized by race, gender, and ideology. The new is acceptable when it is also familiar. The final section brings us into the space shuttle era. Here “right stuff” heroism built around first-generation astronauts is recast by the inclusion of women, non-whites, and non-military professionals in the corps. This change is by turns promoted, celebrated, normalized, and resisted. We see how the image of the astronaut changes when women are inducted into the astronaut corps, through both the media response and the films created by NASA’s collaboration with the IMAX Corporation. The story changes when professional women are seen as an unremarkable part of the tight technological spaces of the space shuttle and its missions. The volume’s final essay, however, gives us a novel in which an astronaut’s space flight obsession...

Celebrating ASM's First 100 Years in Supporting Materials Innovation: 1954-1963

Abstract In recognition of ASM International's 100-year anniversary, AM&amp;P highlights historic events and technological advancements that occurred over the course of those years. This issue extends the timeline from 1954 to 1963, which includes the fatigue testing of a de Havilland Comet in a water tank, the discovery of the AOD process for stainless steel, the first commercial atomic power plant, the opening of ASM's geodesic dome, and the Project Mercury missions to orbit Earth.

Project Gemini online digital archive

An archive containing the first high‐resolution digital scans of the original flight films from Project Gemini, the second U.S. human spaceflight program, was unveiled by the NASA Johnson Space Center and Arizona State University's (ASU) School of Earth and Space Exploration on 6 January. The archive includes images from 10 flights. Project Gemini, which ran from 1964 to 1966, followed Project Mercury and preceded the Apollo spacecraft. Mercury and Apollo imagery are also available through ASU. For more information, see http://tothemoon.ser.asu.edu/gallery/gemini and http://apollo.sese.asu.edu/index.html.

Medical Policy Development for Human Spaceflight at NASA: An Evolution

Codification of medical policy for the National Aeronautics and Space Administration (NASA) did not occur until 1977. Policy development was based on NASA's human spaceflight efforts from 1958, and the need to support the operational aspects of the upcoming Space Shuttle Program as well as other future activities. In 1958, the Space Task Group (STG), a part of the National Advisory Committee on Aeronautics (NACA), became the focal point for astronaut selection, medical support, and instrumentation development in support of Project Mercury. NACA transitioned into NASA in 1958. The STG moved to Houston, TX, in 1961 and became the Manned Spacecraft Center. During these early years, medical support for astronaut selection and healthcare was provided through arrangements with the U.S. military, specifically the United States Air Force, which had the largest group of subject matter experts in aerospace medicine. Through most of the 1960s, the military worked very closely with NASA in developing the foundations of bioastronautics and space medicine. This work was complemented by select individuals from outside the government. From 1958 to 1977, there was no standard approach to medical policy formulation within NASA. During this time, it was individualized and subjected to political pressures. This manuscript documents the evolution of medical policy in the NASA, and provides a historical account of the individuals, processes, and needs to develop policy.

Reply: The Solar System Model for the Reconstructive Ladder

Sir: “Exploration, discovery, and creative scientific research are the keys to new knowledge, and essential toward understanding our origins and destiny.”1 This statement is guiding the future of the National Aeronautics and Space Administration. It also applies to our stimulating speciality perfectly. It is with great pleasure that we acknowledge the recent interest of ideas concerning the various reconstructive options that we can offer our patients in need today. The recent stimulating letter by Valentina Giordano et al. from Italy entitled “The Solar System Model for the Reconstructive Ladder” in the Journal again highlights the fundamental achievements of current plastic and reconstructive surgery.2 The current momentum in terms of conceptual thinking in reconstructive surgery appears to drift somehow into outer space, as reflected by the concept of the “reconstructive matrix” proposed by Erba et al. in 2010 in this Journal.3 Including the concept of reconstructive stages with maturation of the surgeon by Wong and Niranjan in 2008,4 and our “reconstructive clockwork” in 2010,5 it seems that with the evolving reconstructive techniques including acellular dermal matrices, composite tissue allotransplantation, tissue engineering and regeneration, and robotics, an increased complexity of procedures and surgical skills is mandatory. As far as the proposed reconstructive solar system is concerned, the surgeon in the center of the Milky Way has been assigned an extraordinary role; however, at least in our humble perception, the patient might better fit in the center of our common reconstructive efforts to obtain the best clinical result. Thus, we are in the midst of the discussion of who should be in the center of the universe, the surgeon or the patient. Likewise, Nicolaus Copernicus was involved in some discussion while proposing the heliocentric cosmology in his publication De Revolutionibus Orbium Coelestium in 1543. Giordano et al. state that “the planets, whose orbits are closer to the core, represent the most simple treatments, and often the most used ones, in medical practice.” We would like to question, for example, whether using acellular dermal matrices to represent the Earth in their concept is more often used than local flaps (Mars) or free flaps (Saturn). Considering our closest neighbors, Venus (skin grafting), being close in size to Earth but 400°C warmer because of greenhouse gases, or Mars (local flap) with its carbon dioxide atmosphere, skin grafting and local flaps are fundamental, long-standing techniques in plastic and reconstructive surgery. Mercury as a planet, representing direct closure, is the smallest and fastest moving planet in our solar system, with no natural satellites and almost no atmosphere. Besides, Project Mercury was the name of the first human spaceflight program of the United States from 1959 to 1963, followed by the Gemini and Apollo programs. Thus, direct closure as probably the fastest way to achieve defect closure is reiterated by the metaphor Mercury, the Roman symbol for speed. From an astronomical point of view, we have to correct the authors that Pluto is currently classified as a dwarf planet and no longer as a planet, which was changed in 2006 by the International Astronomical Union because it lacks the gravitational muscle to sweep up or scatter objects near its orbit. Karsten Knobloch, M.D., Ph.D. Peter M. Vogt, M.D., Ph.D. Plastic, Hand, and Reconstructive Surgery Hannover Medical School Hannover, Germany