Updates to the NASA human system risk management process for space exploration

Possible impacts of cosmic radiation on leukemia development during human deep space exploration

With the advent of deep space exploration and ambitious plans to return humans to the Moon and journey onward to Mars, humans will face exposure to ionizing radiation beyond Earth's atmosphere and magnetosphere. This is particularly concerning for the hematopoietic system that is sensitive to galactic cosmic rays (GCRs) during interplanetary missions. Epidemiological studies and animal studies implicate that exposure to ionizing radiation can cause leukemias, with recent consensus showing that almost all types of leukemias, even chronic lymphocytic leukemia, can be caused by ionizing radiation despite previous controversies. The possible deleterious effects of deep space travel on the formation, development, etiology, and pathophysiology of hematologic malignancies, specifically leukemias, remain largely unclear. The mechanism(s) by which ionizing radiations cause leukemia differs for different leukemia types and is poorly understood in the spaceflight environment, posing a serious health risk for future astronauts. This paper provides a comprehensive review of the various studies and evidence available on Earth and in space assessing the relationship between ionizing radiation and increased risk of leukemia. We also discuss the unique characteristics of leukemia in space, ethical considerations, risk assessments and potential challenges this may bring to astronauts and healthcare professionals as humanity continues to explore the cosmos.

Taking the 3Rs to a higher level: replacement and reduction of animal testing in life sciences in space research

Human settlements on the Moon, crewed missions to Mars and space tourism will become a reality in the next few decades. Human presence in space, especially for extended periods of time, will therefore steeply increase. However, despite more than 60 years of spaceflight, the mechanisms underlying the effects of the space environment on human physiology are still not fully understood. Animals, ranging in complexity from flies to monkeys, have played a pioneering role in understanding the (patho)physiological outcome of critical environmental factors in space, in particular altered gravity and cosmic radiation. The use of animals in biomedical research is increasingly being criticized because of ethical reasons and limited human relevance. Driven by the 3Rs concept, calling for replacement, reduction and refinement of animal experimentation, major efforts have been focused in the past decades on the development of alternative methods that fully bypass animal testing or so-called new approach methodologies. These new approach methodologies range from simple monolayer cultures of individual primary or stem cells all up to bioprinted 3D organoids and microfluidic chips that recapitulate the complex cellular architecture of organs. Other approaches applied in life sciences in space research contribute to the reduction of animal experimentation. These include methods to mimic space conditions on Earth, such as microgravity and radiation simulators, as well as tools to support the processing, analysis or application of testing results obtained in life sciences in space research, including systems biology, live-cell, high-content and real-time analysis, high-throughput analysis, artificial intelligence and digital twins. The present paper provides an in-depth overview of such methods to replace or reduce animal testing in life sciences in space research.

Medical Toxicology Considerations for Space Exploration

Spaceflight poses many risks to human health. Toxic exposures from inadvertent release of vehicle or payload chemicals and materials used in the operations of spaceflight are unique among them. There is a need for identification and development of clinical protocols for the management of toxic exposures before, during, and after spaceflight, particularly for acute exposures, because these events are likely to occur in austere environments with limited resources. The need for publicly available protocols is gaining importance as commercial spaceflight operations advance, and future spaceflight missions will require independence from Earth. This paper reviews the publicly available literature on toxic exposures in spaceflight to inform the development of relevant clinical practice guidelines. We performed a focused literature review and identified significant aerospace toxicologic incidents, including fatalities, injuries, and near-miss events. Sources included NASA-published literature, NASA safety reviews, published case reports, and published review articles. Searches were performed using the NASA Technical Reports Server, Google Scholar, and PubMed, and we included all cases involving exposure or potential exposure to an agent that could cause acute toxicity in spaceflight missions. Thirty-four cases were identified involving agents that can cause acute toxic effects. The two most common agents identified in acute toxicologic exposures in spaceflight operations were hydrazine and ammonia. These incidents can help us identify high-risk exposures so that we can develop protocols for the detection and management of future toxic exposures.

Technical Validation of a Spatial Tracking Configuration for Augmented and Co-Localized Medical Assistance Under Gravity Variations in Parabolic Flights

INTRODUCTION

Augmented reality is a promising technology for enhancing remote medical assistance. It assists users by directly projecting the relevant virtual assistance in the real world at the right moment and at the right location. This modality is called colocalization but has not been validated in parabolic flights. Our hypothesis was that this modality is technically feasible in weightlessness and is superior to a paper checklist in assisting a caregiver during a simulated medical emergency.

METHODS

During parabolic flight campaigns, we conducted an abdominal pain simulation scenario and sought to compare procedural assistances. Participants performed a basic medical examination using either classic cognitive aids (such as a paper checklist) or an augmented-reality device projecting visual co-localized (situated or embedded) assistance.

RESULTS

Gravity variations induced technical difficulties in the nominal functioning of augmented-reality headsets due to the native accelerometers in these devices. Clinical data were not interpretable due to small sample size secondary to the technical difficulties encountered. Finally, an efficient and stable spatial tracking configuration was found during the last flight, offering future research perspectives.

CONCLUSIONS

Our study validated the first achievement of a stable co-localized assistance under gravity variation. The augmented-reality headset required an external tracking system based on surrounding infrared cameras and an in-flight calibration to recreate the virtual environment (spatial mapping) independently of gravity conditions. Further studies are needed to clinically validate the potential benefits of co-localized augmented reality for space medicine.

Utilizing Martian samples for future planetary exploration-Characterizing hazards and resources

One of the most surprising and important findings of the first human landings on the Moon was the discovery of a very fine layer of lunar dust covering the entire surface of Moon along with the negative impacts of this dust on the well-being and operational effectiveness of the astronauts, their equipment, and instrumentation. The United States is now planning for human missions to Mars, a planet where dust can also be expected to be ubiquitous for many or most landing sites. For these missions, the design and operations of key hardware systems must take this dust into account, especially when related to crew health and safety. Improved understanding of Martian dust characteristics can inform its potential to also perform transport of microorganisms, both those inadvertently brought to Mars by the astronauts, or, if Martian microorganisms exist, the potential for their inadvertent return to Earth with the astronauts. Careful planning and design are needed to assure that future missions do not violate the United Nations Outer Space Treaty (1967) signed by all spacefaring nations. In this paper, we review the impact of lunar dust on the Apollo missions and identify several questions about dust in the atmosphere of Mars that may be answered by the curated samples that would be returned by the planned Mars Sample Return (MSR) Campaign. These answers would not only provide an opportunity to better understand the history of Mars but could also reduce uncertainty in charting the future of humanity's exploration of the planet.

Articular cartilage loss is an unmitigated risk of human spaceflight

Microgravity and space radiation are hazards of spaceflight that have deleterious effects on articular cartilage. Since it is not widely monitored or protected through dedicated countermeasures, articular cartilage loss is an unmitigated risk of human spaceflight. Spaceflight-induced cartilage loss will affect an astronaut's performance during a mission and long-term health after a mission. Addressing concerns for cartilage health will be critical to the continued safe and successful exploration of space.

Microgravity and Human Body: Unraveling the Potential Role of Heat-Shock Proteins in Spaceflight and Future Space Missions

In recent years, the increasing number of long-duration space missions has prompted the scientific community to undertake a more comprehensive examination of the impact of microgravity on the human body during spaceflight. This review aims to assess the current knowledge regarding the consequences of exposure to an extreme environment, like microgravity, on the human body, focusing on the role of heat-shock proteins (HSPs). Previous studies have demonstrated that long-term exposure to microgravity during spaceflight can cause various changes in the human body, such as muscle atrophy, changes in muscle fiber composition, cardiovascular function, bone density, and even immune system functions. It has been postulated that heat-shock proteins (HSPs) may play a role in mitigating the harmful effects of microgravity-induced stress. According to past studies, heat-shock proteins (HSPs) are upregulated under simulated microgravity conditions. This upregulation assists in the maintenance of the proper folding and function of other proteins during stressful conditions, thereby safeguarding the physiological systems of organisms from the detrimental effects of microgravity. HSPs could also be used as biomarkers to assess the level of cellular stress in tissues and cells exposed to microgravity. Therefore, modulation of HSPs by drugs and genetic or environmental techniques could prove to be a potential therapeutic strategy to reduce the negative physiological consequences of long-duration spaceflight in astronauts.

Spaceflight-associated pain

PURPOSE OF REVIEW

Consequences of the expanding commercial spaceflight industry include an increase in total number of spaceflight participants and an accompanying surge in the average number of medical comorbidities compared with government-based astronaut corps. A sequela of these developments is an anticipated rise in acute and chronic pain concerns associated with spaceflight. This review will summarize diagnostic and therapeutic areas of interest that can support the comfort of humans in spaceflight.

RECENT FINDINGS

Painful conditions that occur in space may be due to exposure to numerous stressors such as acceleration and vibration during launch, trauma associated with extravehicular activities, and morbidity resulting directly from weightlessness. Without normal gravitational forces and biomechanical stress, the hostile environment of space causes muscle atrophy, bone demineralization, joint stiffness, and spinal disc dysfunction, resulting in a myriad of pain generators. Repeated insults from abnormal environmental exposures are thought to contribute to the development of painful musculoskeletal and neuropathic conditions.

SUMMARY

As humanity invests in Lunar and Martian exploration, understanding the painful conditions that will impede crew productivity and mission outcomes is critical. Preexisting pain and new-onset acute or chronic pain resulting from spaceflight will require countermeasures and treatments to mitigate long-term health effects.

Levels of evidence for human system risk evaluation

NASA uses a continuous risk management process to seek out new knowledge of spaceflight-induced risk to human health and performance. The evidence base that informs the risk assessments in this domain is constantly changing as more information is gleaned from a continuous human presence in space and from ongoing research. However, the limitations of this evidence are difficult to characterize because fewer than 700 humans have ever flown in space, and information comes from a variety of sources that span disciplines, including engineering, medicine, food and nutrition, and many other life sciences. The Human System Risk Board (HSRB) at NASA is responsible for assessing risk to astronauts and communicating this risk to agency decision-makers. A critical part of that communication is conveying the uncertainty regarding the understanding of the changes that spaceflight induces in human processes and the complex interactions between humans and the spacecraft. Although the strength of evidence grades is common in the academic literature, these scores are often not useful for the problems of human spaceflight. The HSRB continues to update the processes used to report the levels of evidence. This paper describes recent updates to the methods used to assign the level of evidence scores to the official risk postures and to the causal diagrams used by the HSRB.

Long-term space missions' effects on the human organism: what we do know and what requires further research

Space has always fascinated people. Many years have passed since the first spaceflight, and in addition to the enormous technological progress, the level of understanding of human physiology in space is also increasing. The presented paper aims to summarize the recent research findings on the influence of the space environment (microgravity, pressure differences, cosmic radiation, etc.) on the human body systems during short-term and long-term space missions. The review also presents the biggest challenges and problems that must be solved in order to extend safely the time of human stay in space. In the era of increasing engineering capabilities, plans to colonize other planets, and the growing interest in commercial space flights, the most topical issues of modern medicine seems to be understanding the effects of long-term stay in space, and finding solutions to minimize the harmful effects of the space environment on the human body.