Apollo Missions Research Articles

Investigation of the source region of the lunar-meteorite group with the remote sensing datasets: Implication for the origin of mare volcanism in Mare Imbrium

Lunar meteorites provide information about areas of the Moon not sampled by the Apollo and Luna missions, so they can be used as more-representative geochemical datasets for evaluating global lunar evolution. However, the launching craters remain unknown for many lunar meteorites. This paper, therefore, aims to identify the launching sites of lunar meteorites with remote-sensing datasets. This work focuses on one lunar-meteorite group, the Northwest Africa 773 (NWA 773) clan, which has the very-low-Ti basaltic composition and one of the youngest crystallization ages (~3 Ga) among the lunar basaltic meteorites. We investigated the source of the NWA 773 clan by comparing their geochemical compositions and geochronological information with the following remote-sensing datasets: 1) the Lunar Prospector gamma-ray elemental maps (FeO, TiO2, Th) and the SELENE gamma-ray elemental maps (CaO), 2) the surface ages determined from imaging data by using the crater-counting method, and 3) high-spatial-resolution maps of the FeO and TiO2 and spectral-ratio images made from the SELENE multi-band imager data. From these comparisons, the NWA 773 clan is most likely to have originated from the north part of Mare Imbrium inside the Procellarum KREEP Terrane (PKT). Furthermore, the eruption age of surface basalt surrounding the Le Verrier D crater in the north part of Mare Imbrium between 3.0 and 3.3 Ga, and the formation of the Le Verrier D crater, are consistent with the duration of igneous activity and timing of meteoroid impact of the NWA 773 clan. There is a fresh crater with bright ejecta on the edge of the Le Verrier D crater, and it is possibly the young launch crater of this meteorite group.

Nonlinear waveform distortion: Assessment and detection of clipping on speech data and systems

Speech, speaker, and language systems have traditionally relied on carefully collected speech material for training acoustic models. There is an enormous amount of freely accessible audio content. A major challenge, however, is that such data is not professionally recorded, and therefore may contain a wide diversity of background noise, nonlinear distortions, or other unknown environmental or technology-based contamination or mismatch. There is a crucial need for automatic analysis to screen such unknown datasets before acoustic model development training, or to perform input audio purity screening prior to classification. In this study, we propose a waveform based clipping detection algorithm for naturalistic audio streams and examine the impact of clipping at different severities on speech quality measurements and automatic speaker recognition systems. We use the TIMIT and NIST SRE08 corpora as case studies. The results show, as expected, that clipping introduces a nonlinear distortion into clean speech data, which reduces speech quality and performance for speaker recognition. We also investigate what degree of clipping can be present to sustain effective speech system performance. The proposed detection system, which will be released, could contribute to massive new audio collections for speech and language technology development (e.g. Google Audioset (Gemmeke et al., 2017), CRSS-UTDallas Apollo Fearless-Steps (Yu et al., 2014) (19,000 h naturalistic audio from NASA Apollo missions)).

Raman study of shock effects in lunar anorthite from the Apollo missions

AbstractEarth’s moon is a primary exploration target for space agencies around the world. The Moon records and preserves key information about fundamental processes that shape planetary crusts such as impact cratering. Understanding shock effects in lunar anorthite (Ca‐rich endmember of plagioclase feldspar), the principal component of anorthosite and the most common crustal mineral on the Moon, is key to the early evolution of the Moon and terrestrial planets in the solar system. However, there has not been a systematic study of shock effects in lunar anorthite using modern analytical techniques that could be used in future lunar surface exploration, such as Raman spectroscopy. This study examined 23 polished thin sections from all six Apollo missions using optical and Raman spectroscopy. We documented a variety of shock features recording low to moderate shock levels, including fractures, deformed twins, undulatory extinction, planar features, and partially isotropic plagioclase. A notable nonobservation was the absence of planar deformation features (PDFs) or completely isotropic (i.e., diaplectic glass) in this suite of samples. Raman spectroscopy results of the observed shock features show similar progressive changes in terrestrial samples: As shock level increases, band broadening, reduction of intensities, and peak loss were observed. Our Raman data are efficient in identifying shock levels and distinguishing planar features from PDFs and deformed twins, and differentiating amorphous areas from crystalline plagioclase, suggesting Raman spectroscopy as a useful tool for purposely selecting moderately to strongly shocked samples to return in future lunar missions. Our study can also help the interpretation of Raman data of impact materials from the past and future exploration missions and demonstrate the utility of Raman spectroscopy for documenting and selecting samples for future lunar missions.

Lunar trans-Earth trajectory design and practice for the Chang’e-5 mission

<p indent=0mm>The Chang’e-5 mission is the first automatic robot Lunar sampling return mission in China. Compared with the previous Chinese Lunar exploration missions, the Lunar trans-Earth flight is a new phase and facing many challenges. Limited by the capability of launch vehicle and the high latitude of the domestic touchdown region, the flight scheme adopted in the Chang’e-5 spacecraft is quite the different from those of American Apollo mission and Soviet Union’s Luna mission. The Lunar trans-Earth scheme of Chang’e-5 mission is to escape Lunar orbit using the optimal injection time and return to the Earth with skip-entry. The design constraints, models, algorithms and practical engineering considerations of the Lunar trans-Earth trajectory design of the Chang’e-5 mission are systematically introduced in this paper. A novel optimal trans-Earth injection (TEI) guidance algorithm, which can obtain the optimal escape impulsive and accurately target the entry interface (EI) from elliptical Lunar parking orbit, is proposed. The all-target aiming guidance algorithm with separation disturbance compensation is desinged to improve the accuracy and rapidity of convergence. The results of Chang’e-5 on-orbit flight show that the Lunar trans-Earth trajectory design and corresponding guidance algorithm can acheive the mission requirements. Besides, the aiming accuracy of entry corridor is very high.

From the Apollo Programme to the EM Algorithm and Beyond

Abstract Nan Laird is the Harvey V. Fineberg professor of biostatistics (emerita) at the Harvard T. H. Chan School of Public Health, and the winner of the 2021 International Prize in Statistics. In this interview with Ed Hirschland, she discusses her career and contributions

Decentralized project management concept for schedule-critical space projects

The Apollo moon missions of the 1960s pioneered the classic phased approach to space mission management. While successful at the time, this rigid and inflexible management philosophy has become synonymous with cost and schedule overruns of most high-profile space missions. The software industry has recently adopted modern, more flexible project management techniques based on “lean-agile” methods that enable team collaboration and communication through distributed task and schedule management, online document sharing and rolling-wave planning. However, due to the inherent schedule complexities of hardware development and the firm constraints of design review and launch timelines, flexible project management frameworks have not been widely adopted for space mission management. This paper presents a modified version of the traditional agile management philosophy, adapted to the unique needs of the space industry. A recent satellite development project was managed using the new modified-agile approach, while collecting project hours and task durations. Comparisons were made between this new style of space project management and a recently completed satellite development project using traditional space project management techniques. Results show that the new management approach reduced strain on the project team, improved overall productivity, and maintained a more level task loading when compared to the traditional management approach. This paper also illustrates how the new management approach can enable project resilience to change by analyzing its response to the labor disruptions caused by the COVID-19 pandemic.

Endless Novelties of Extraordinary Interest: The Voyage of H.M.S. Challenger and the Birth of Modern Oceanography, by Doug Macdougall

Reviewed by: Endless Novelties of Extraordinary Interest: The Voyage of H.M.S. Challenger and the Birth of Modern Oceanography by Doug Macdougall Stewart Weaver (bio) Endless Novelties of Extraordinary Interest: The Voyage of H.M.S. Challenger and the Birth of Modern Oceanography, by Doug Macdougall; pp. xvii + 257. New Haven and London: Yale University Press, 2019, $30.00. Doug Macdougall's Endless Novelties of Extraordinary Interest: The Voyage of H.M.S. Challenger and the Birth of Modern Oceanography tells the story of H.M.S. Challenger, a steam-assisted, 2,300 ton, Pearl-class corvette warship of the British Royal Navy. Laid down at Woolwich in 1858, she saw limited service during the Franco-Mexican War in 1862 and was flagship of Australia Station between 1866 and 1870. But her fame derives from her scientific, not military, service. Converted to the work of oceanographic research in 1872, she then set out from Portsmouth on a three-and-a-half-year voyage of discovery that would take her on a meandering course of almost 70,000 miles around the world and through its several seas. The Challenger Expedition (as it is usually called) was history's first major oceanographic undertaking. The brainchild of Charles Wyville Thomson, professor of natural history at Edinburgh University, and jointly sponsored by the Royal Society and the Admiralty, it undertook the first systematic investigations of the physical, chemical, and [End Page 286] biological properties of the deep seas and led to many astonishing discoveries, including that of the existence of the Mid-Atlantic Ridge. The official expedition report, edited by Wyville Thomson and the naturalist John Murray, ran to fifty sumptuous volumes that in total effectively established the modern science of oceanography and remain touchstones for its study even today. Reflecting on the expedition as he neared the end of the final volume in 1895—some nineteen years after the Challenger had returned to England—Murray felt confident in claiming that it marked "the greatest advance in the knowledge of our planet since the celebrated discoveries of the fifteenth and sixteenth centuries" (qtd. in Macdougall 241). Macdougall is a retired professor of earth sciences at the Scripps Institution of Oceanography and the author of several previous books about the earth's history, geological time, ice ages, and the like. He first learned of the Challenger Expedition while studying deep-sea sediments as a graduate student, and over his years as a working earth scientist his interest in the ship's voyage grew, not just on account of its findings—many of which, as Macdougall tells us, have been superseded—but also for its "iconic place in the annals of ocean exploration" (x). The expedition was, he says, the Apollo project of its day, an ambitious, government-funded, "big science" leap into the unknown that captured and then lingered in the public imagination (xii). Many have written about it, starting with some veterans of the expedition itself and, more recently, several historians of ocean science and exploration. But Macdougall is an actual ocean scientist as well as a popular writer; he thus brings both a high level of professional understanding of his subject and a talent for making it accessible. Rather than give us a complete chronological account of the expedition as others have done, he chooses to proceed topically through its various discoveries and particular points of inquiry. We therefore get chapters focusing on extraterrestrial particles, sea-floor sediments, remote island geology, marine shore life (chiefly penguins and crabs), icebergs and glaciers, corals and coral reefs, tropical bird life, and, finally, marine bioluminescence. In each case, Macdougall tends to look forward from the expedition: that is, he takes us from the expedition's discovery or understanding of something—coral reef formation, for example—to how scientists understand it now. Historians might wish for a few more backward glances of the sort in which Macdougall indulges in his discussion of Charles Darwin and coral reefs. But the merit of the forward-looking approach is that it allows Macdougall to educate his readers in marine science and give some context to such contemporary concerns as coral bleaching, polar melt, and ocean acidification. In a quite...

From Cybernetics to Systems Theory in the First Space Age: Observations on the Pilot Problem

The first space age offers a remarkable context to scrutinise the inverse fates of cybernetics and systems theory in the 1960–70s, the latter taking the place of the former thanks to its operational effectiveness. Both fields appeared to tackle the pilot problem head-on, either to shoot a pilot down (cybernetics in World War II) – or to send some to the moon and back (systems engineering and management in the Apollo programme). The study of three US institutions (TRW, SDC and NASA) demonstrates an intense alliance between them, with a persistent focus on the issues of automation and systems thinking. A selection of written documents produced by each entity shows with utmost clarity their high degree of involvement in a post-cybernetics systemic approach. Incidentally, those analyses also show how the differences and similarities between old space and new space reveal themselves in light of the pilot problem. Overall, the pilot’s role reconfigured the man/machine assemblage as much as the pilot was reconfigured by that assemblage, with the critical assistance of computation.

Public debt and intergenerational ethics: how to fund a clean technology ‘Apollo program’?

ABSTRACT If the present generation refuses to bear the burden of mitigating global heating, could we motivate sufficient action by shifting that burden to our descendants? Several writers have proposed breaking the political impasse by funding mitigation through public debt. Critics attack such proposals as both unjust and infeasible. In fact, there is reason to think that some debt financing may be more equitable than placing the whole burden of mitigation on the present generation. While it might not be viable for all countries to take this route simultaneously, a vanguard state, or group of states, could use public debt to fund an ambitious programme to develop inexpensive forms of clean low- or no-emission technology. This would ensure that vanguard actor or set of actors a leading role in those sectors while at the same time benefiting future generations around the world. Key policy insights Debt-financed clean technology research can shift part of the burden of greenhouse gas mitigation to our descendants, breaking the political impasse of inaction or delayed action. Far from being an injustice to future generations, this could actually be fairer than expecting the present generation to bear the full burden of mitigation. Such an initiative may be most feasible if pursued by a vanguard actor.

The helium bubble: Prospects for 3He-fuelled nuclear fusion

The helium bubble: Prospects for 3He-fuelled nuclear fusion

Retracing the Footprints

Abstract NASA is engaged in a new program to send astronauts back to the lunar surface. Some elements of the new program, called Artemis, will seem like carbon copies of the 1960s roadmap to the Moon. Bu the effort will take advantage of computers, design tools, and materials that are radically more advanced than they were for the Apollo program.

The geologic map of the Cassini quadrangle on the Moon: planetary cartography between science, efficacy and cartographic aesthetics

Before humans set foot on the Lunar surface in 1969 during the US Apollo program, the Moon had been investigated in great detail through telescopic observations, and a number of spacecraft sent by ...

Interview: Kate Greene

Second-in-command on Nasa's first simulated Mars mission, HI-SEAS, Kate Greene discusses what it takes to be a modern astronaut, and why today's 'right stuff' is different from what was required on the Apollo missions of the 20th century.

Modeling Lunar Pyroclasts to Probe the Volatile Content of the Lunar Interior

AbstractConstraining the volatile budget of the lunar interior has important ramifications for models of Moon formation. While many early and previous measurements of samples acquired from the Luna and Apollo missions suggested the lunar interior is depleted in highly volatile elements like H, a number of high‐precision analytical studies over the past decade have argued that it may be more enriched in water than previously thought. Here, we integrate recent remotely sensed near‐infrared reflectance measurements of small Dark‐Mantle‐Deposits (DMDs) Birt E and Grimaldi, interpreted to represent pyroclastic deposits, and physics‐based eruption models to better constrain the preeruptive water content of the magmas that resulted in these deposits. We model the trajectory and water loss of pyroclasts from eruption to deposition, coupling eruption dynamics with a volatile diffusion model for each pyroclast. Modeled pyroclast sizes and final water contents are then used to predict spectral reflectance properties for comparison with the observed orbital near‐infrared data. We develop an inversion scheme based on the Markov‐Chain Monte‐Carlo (MCMC) method to retrieve constraints between governing parameters such as the initial volatile content of the melt and the pyroclast size distribution (which influences the remotely measured water absorption strengths). The MCMC inversion allows us to estimate the primordial (preeruption) water content for different DMDs and therefore explore whether their source is volatile‐rich. Our results suggest that the preeruptive water content of the magmas sampled by Birt E and Grimaldi can be constrained within a range 400–800 ppm, while the pyroclast size in diameter corresponding to the 50th percentile of a given deposit likely ranges from ∼400 to 600 μm in diameter. Finally, we determine the evaporation and cooling rates are likely low, ∼10−6 m/s and 6°C/s, respectively.

What makes space activities commercial?

Between the 1950s and 1980s, U.S. space sector activities were government-driven, government-sponsored, government-managed, and assisted by the industry-sector. Awareness of non-governmental space activities originated in the 1980s and gained prominence in the early 2000s with the founding of well-funded private companies. This paper takes an organizational evolution perspective to refine what is meant by “commercial” space markets and activities and compares the results to previous discussions offered by space community authors. From an organization theory perspective, the three primary forces of the evolution change model (variation, selection, and retention) provide a framework for renewed commercial space activity discussions. Together, the strength of these three forces can indicate how “commercial” a market is. Two case examples are presented to illustrate application of this framework: the U.S. space race era activities during the 1960s, and the current space tourism market. Despite competitions for various contracts awarded to industry-sector firms, the Apollo program was clearly government-driven, and was not “commercial” to any significant extent. The current space tourism market is clearly considered “commercial,” but with qualifications. Conclusions from this review include the appropriate levels of analysis to discuss space market characteristics, a comparative analysis of the “commercial” activities of the U.S. space race era and the current space tourism, the inference of proxies for estimating the strength of the three evolution model forces, and a caution about the accuracy of “commercial” market forecasts.

Seamless maps of major elements of the Moon: Results from high-resolution geostationary satellite

Major elements such as Fe, Ti, Mg, Al, Ca and Si play very important roles in understanding the origin and evolution of the Moon. Previous maps of these major elements derived from orbital data are based on mosaic images or low-resolution gamma-ray data. The hue variations and gaps among orbital boundaries in the mosaic images are not conducive to geological studies. This paper aims to produce seamless and homogenous distribution maps of major elements using the single-exposure image of the whole lunar disk obtained by China’s high-resolution geostationary satellite, Gaofen-4, with a spatial resolution of ∼ 500 m. The elemental contents of soil samples returned by Apollo and Luna missions are regarded as ground truth, and are correlated with the reflectance of the sampling sites extracted from Gaofen-4 data. The final distribution maps of these major oxides are generated with the statistical regression model. With these products, the average contents and proportions of the major elements for maria and highlands were estimated and compared. The results showed that SiO2 and TiO2 have the highest and lowest fractions in mare and highland areas, respectively. Moreover, the relative concentrations of these elements could serve as indicators of geologic processes, e.g., the obviously asymmetric distributions of Al2O3, CaO and SiO2 around Tycho crater may suggest that Tycho crater was formed by an oblique impact from the southwest direction.

Giant Impact: The Leading Scenario of the Origin of the Moon

Moon, an astronomical body hanging in the sky, has been recorded and studied by mankind for thousands of years, even before the invention of the word “moon”. There are numerous varying theories about its origin. The aim of this article is to compare and further analyze the common theories of the origin of Moon. First, we provide basic information about the moon, the moon’s soil, and the basic elements of the moon and offer an introduction to solar and lunar eclipses and why they exist, as well as human efforts to explore the moon, including the Apollo program and the Chang’E program. Finally, we analyze and compare the four most common theories about the origin of the Moon: the split theory, homologation theory, capture theory and impact theory. Among all, the more accepted theory is the big collision theory though there is still no scientific basis for it. This article introduces the origins of the Moon by analyzing the pros and cons and describing possible future directions.

RETRACTED: Interpreting Locked Photographic Data: The Case of Apollo 17 Photo GPN-2000-00113

Photography can be used for pleasure and art but can also be used in many disciplines of science, because it captures the details of the moment and can serve as a proving tool due to the information it preserves. During the period of the Apollo program (1969 to 1972), the National Aeronautics and Space Administration (NASA) successfully landed humans on the Moon and showed hundreds of photos to the world presenting the travel and landings. This paper uses computer simulations and geometry to examine the authenticity of one such photo, namely Apollo 17 photo GPN-2000-00113. In addition, a novel approach is employed by creating an experimental scene to illustrate details and provide measurements. The crucial factors on which the geometrical analysis relies are locked in the photograph and are: (a) the apparent position of the Earth relative to the illustrated flag and (b) the point to which the shadow of the astronaut taking the photo reaches, in relation to the flagpole. The analysis and experimental data show geometrical and time mismatches, proving that the photo is a composite.

Super High Frequency Events: A New Class of Events Recorded by the InSight Seismometers on Mars

AbstractWe present a new class of seismic signals that are recorded by the seismometer placed on the surface of Mars as part of the NASA InSight mission. The signals, termed super high frequency (SF) events, are of short duration (∼20 s), are often similar in amplitude, and feature high‐frequency energy between ∼5 and 30 Hz that is dominant on the horizontal components. For detection and characterization of SF events, we employ the available continuous 20 samples per second (sps) data from the Very Broadband instrument. Due to bandwidth limitations, 100 sps data from the short‐period sensor are only partially obtainable, but they aid in analysis of the frequency content above 10 Hz and in distinguishing the events from high‐frequency noise. From June 2019 to May 2020, 780 SF events have been detected. The events observed occur in repeatable patterns that last for weeks. Initially, the SF events were clustered in the hours before sunset, but more recently, they have been distributed across the evening period. Based on template matching techniques, we have identified 16 distinct families that generally follow the temporal clusters. A thermal origin of these events is suggested, since the majority of the events fall within a ±2 h time window around sunset with extreme temperature changes. The SF events have similarities with thermal events observed on the lunar surface from data collected during the Apollo missions.

ARIA - NASA’S Apollo Airborne Fire Brigade

As the Non-Commissioned Officer-In-Charge of ARIA Control, 1968–71, MSgt Anderson relates his experience of the little-known history of the United States Air Forces’ fleet of eight Apollo Range Instrumentation Aircraft (ARIA – a-RYE-a) that supported Project Apollo 4 through Apollo 17 and more than 50 other military, commercial and scientific space projects for some 33 years. At the conclusion, readers should be able to articulate the history, purpose, function, operations and control of the ARIA fleet.