Search Our Scientific Publications & Authors

Acta Astronaut 2022 Aug 13;197:323-335. Epub 2022 May 13.

Department of Aerospace and Mechanical Engineering, Sapienza University of Rome, Via Eudossiana, 18 - 00184, Rome, Italy.

The pandemic emergency caused by the spread of COVID-19 has stressed the importance of promptly identifying new epidemic clusters and patterns, to ensure the implementation of local risk containment measures and provide the needed healthcare to the population. In this framework, artificial intelligence, GIS, geospatial analysis and space assets can play a crucial role. Social media analytics can be used to trigger Earth Observation (EO) satellite acquisitions over potential new areas of human aggregation. Read More

Acta Astronaut 2022 Jul 29;196:282-289. Epub 2022 Apr 29.

Ann and H. J. Smead Department of Aerospace Engineering Sciences, University of Colorado Boulder, United States.

Background: Astronauts live and work in isolated, confined, extreme (ICE) environments that create both high stress and the need for high performance. The COVID-19 pandemic created ICE-like conditions across the globe by confining people to their homes under the ever-present threat of disease. Our goal is to understand the impact of prior experience in ICE on coping, using the pandemic as a pseudo space analog environment. Read More

Acta Astronaut 2021 Mar 3;180:545-559. Epub 2021 Jan 3.

Shinshu University, Tokida, Ueda, Nagano, Japan.

One way to improve our model of Mars is through aerial sampling and surveillance, which could provide information to augment the observations made by ground-based exploration and satellite imagery. Flight in the challenging ultra-low-density Martian environment can be achieved with properly scaled bioinspired flapping wing vehicle configurations that utilize the same high lift producing mechanisms that are employed by insects on Earth. Through dynamic scaling of wings and kinematics, we investigate the ability to generate solutions for a broad range of flapping wing flight vehicles masses ranging from insects (10) kg to the Mars helicopter (10) kg. Read More

Acta Astronaut 2022 Jan 24;190:14-23. Epub 2021 Sep 24.

Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.

Background: Sustained high levels of astronaut cognitive performance are a prerequisite for mission success. A neuropsychological battery of 10 brief cognitive tests (Cognition) covering a range of cognitive domains was specifically developed for high performing astronauts to objectively assess cognitive performance. Extended mission durations require repeated cognitive testing and thus high acceptability of the Cognition software to the astronaut population. Read More

Acta Astronaut 2021 Apr 2;181:516-529. Epub 2020 Oct 2.

NASA Space Science Mission Operations, NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA.

Debris strikes on operational spacecraft are becoming more common due to increasing numbers of space objects. Sample return missions indicate hundreds of minor strikes, but rigorous analysis is often only performed when a strike causes an anomaly in spacecraft performance. Developing techniques to identify and assess minor strikes that do not immediately cause anomalous behavior can help to validate models for debris populations, perform risk assessments, and aid in the attribution of future anomalies. Read More

Acta Astronaut 2020 Jul 18. Epub 2020 Jul 18.

University of Alabama in Huntsville, USA.

This article will compare the collection of materials for the Saturn V documentation project under NAS8-21321 in 1968 to standard processes for collecting space history today. A case study of The Saturn V grant outlines the benefits of collecting research material in real time. This case study is compared to the findings compiled at the 2018 conference "To Boldly Preserve: Archiving for the Next Half-Century of Spaceflight. Read More

Acta Astronaut 2020 Dec 28;177:351-372. Epub 2020 Jul 28.

NASA Johnson Space Center, 2101 NASA Parkway, Houston, Tx, 77598, USA.

The Flexible Lunar Architecture for Exploration (FLARE) is a concept to deliver four crew to the lunar surface for a minimum of seven days and then return them safely to Earth. FLARE can be implemented whenever the component vehicles are operational. FLARE was developed as an alternative to NASA's Human Landing System (HLS) reference architecture from the Design Analysis Cycle (DAC) #2 created in 2019. Read More

Acta Astronaut 2020 Oct 3;175:290-299. Epub 2020 Jun 3.

Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA.

Human spaceflight and the characteristics of people who become astronauts have changed over time. Here we present an analysis of n=1,265 manned spaceflights by n=562 astronauts from 1961-2020 to investigate historical trends over time and between space agencies in terms of astronaut demographics and spaceflight duration. Generalized linear models and generalized linear mixed models were implemented with adjustments for all available demographic data as covariates. Read More

Acta Astronaut 2019 Jul 28;160:433-441. Epub 2018 Oct 28.

Battelle Center for Science and Technology Policy, The Ohio State University, Columbus, OH, United States.

is an emerging concept in the health sciences that approaches human, animal and environmental health from a single framework. This policy approach is grounded in the knowledge that approximately 70 percent of emerging diseases in humans originate from other species, and that this species crossover is precipitated by stresses to environmental systems such as habitat change and biodiversity loss. Remote sensing tools apply well to this approach due to the multitude of variables that can be measured across borders in real-time. Read More

Acta Astronaut 2019 Jun 6;159:499-507. Epub 2019 Feb 6.

NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX, 77058, USA.

The modal response of a liquid-filled tank to external acoustic excitation can be used to infer with high resolution the mass of contained liquid, the mass flow rate of liquids into and out of the tank, and changes in tank pressure. Both contained liquid mass and internal ullage pressure affect the modal response of the tank walls through fluid mass-loading of the tank walls and pressure-induced wall stiffening, respectively. Modal Propellant Gauging refers to the technology that exploits these shifts in modal frequencies to infer the mass of propellant in a tank. Read More

Acta Astronaut 2018 Jul 23;148:294-300. Epub 2018 Apr 23.

BioServe Space Technologies, Aerospace Engineering Sciences Department, University of Colorado, Boulder, 80309, USA.

Biofilm growth has been observed in Soviet/Russian (Salyuts and Mir), American (Skylab), and International (ISS) Space Stations, sometimes jeopardizing key equipment like spacesuits, water recycling units, radiators, and navigation windows. Biofilm formation also increases the risk of human illnesses and therefore needs to be well understood to enable safe, long-duration, human space missions. Here, the design of a NASA-supported biofilm in space project is reported. Read More

Acta Astronaut 2017 03 18;132:268-281. Epub 2016 Dec 18.

Dept. of Earth Sciences, Brock University, St. Catharines, ON, Canada L2S 3A1.

We tested science operations strategies developed for use in remote mobile spacecraft missions, to determine whether reconnoitering a site of potential habitability prior to in-depth study (a walkabout-first strategy) can be a more efficient use of time and resources than the linear approach commonly used by planetary rover missions. Two field teams studied a sedimentary sequence in Utah to assess habitability potential. At each site one team commanded a human "rover" to execute observations and conducted data analysis and made follow-on decisions based solely on those observations. Read More

Acta Astronaut 2016 Jun;123:16-25

NASA, Ames Research Center, Moffett Field, CA 94035, Bldg. N-245, MS-245-3.

Mars Sample Return is the highest priority science mission for the next decade as recommended by the 2011 Decadal Survey of Planetary Science [1]. This article presents the results of a feasibility study for a Mars Sample Return mission that efficiently uses emerging commercial capabilities expected to be available in the near future. The motivation of our study was the recognition that emerging commercial capabilities might be used to perform Mars Sample Return with an Earth-direct architecture, and that this may offer a desirable simpler and lower cost approach. Read More

Acta Astronaut 2016 09 10;126:411-423. Epub 2016 May 10.

SGT/NASA Ames Research Center, United States.

This work provides an efficiency analysis of the LightForce space debris collision avoidance scheme in the current debris environment and describes a simulation approach to assess its impact on the long-term evolution of the space debris environment. LightForce aims to provide just-in-time collision avoidance by utilizing photon pressure from ground-based industrial lasers. These ground stations impart minimal accelerations to increase the miss distance for a predicted conjunction between two objects. Read More

Acta Astronaut 2014 Feb;94(2):807-812

Department of Radiation Oncology, 3620 Hamilton Walk, 183 John Morgan Building, University of Pennsylvania, Philadelphia, PA, 19104, USA.

Changes in intracranial pressure (ICP) during space flight have stimulated an area of research in space medicine. It is widely speculated that elevations in ICP contribute to structural and functional ocular changes, including deterioration in vision, which is also observed during space flight. The aim of this study was to investigate changes in OP occurring as a result of ionizing radiation exposure (at doses and dose-rates relevant to solar particle event radiation). Read More

Acta Astronaut 2013 Nov;92(1):89-96

Integrative Skeletal Adaptation & Genetics Laboratory, Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA.

A single exposure to hindlimb unloading leads to changes in body mass, body composition and bone, but the consequences of multiple exposures are not yet understood. Within a 18wk period, adult C57BL/6 male mice were exposed to one (1x-HLU), two (2x-HLU) or three (3x-HLU) cycles of 2 wk of hindlimb unloading (HLU) followed by 4 wk of reambulation (RA), or served as ambulatory age-matched controls. µCT longitudinally tracked changes in abdominal adipose and lean tissues, lumbar vertebral apparent volumetric bone mineral density (vBMD) and upper hindlimb muscle cross-sectional area before and after the final HLU and RA cycle. Read More

Acta Astronaut 2013 Nov;92(1):79-88

Stony Brook University, Department of Biomedical Engineering, Bioengineering Building, Rm 215, Stony Brook, NY 11794-5281, United States.

Microgravity induced bone loss represents a critical health problem in astronauts, particularly occurred in weight-supporting skeleton, which leads to osteopenia and increase of fracture risk. Lack of suitable evaluation modality makes it difficult for monitoring skeletal status in long term space mission and increases potential risk of complication. Such disuse osteopenia and osteoporosis compromise trabecular bone density, and architectural and mechanical properties. Read More

Acta Astronaut 2013 Nov;92(1):73-78

Department of Medicine, University of California San Francisco and Endocrine Research Unit, San Francisco Veterans Affairs Medical Center, 4150 Clement St, 111N, San Francisco, CA 94121, USA.

Skeletal loading and unloading has a pronounced impact on bone remodeling, a process also regulated by insulin-like growth factor 1 (IGF-1) signaling. Skeletal unloading leads to resistance to the anabolic effect of IGF-1, while reloading after unloading restores responsiveness to IGF-1. However, a direct study of the importance of IGF-1 signaling in the skeletal response to mechanical loading remains to be tested. Read More

Acta Astronaut 2013 Nov;92(1):15-20

Dept. of Medicine, UCSD, La Jolla, CA, USA ; Dept. of Radiology, UCSD, La Jolla, CA, USA.

Rationale: Exposure to extraterrestrial dusts is an almost inevitable consequence of any proposed planetary exploration. Previous studies in humans showed reduced deposition in low-gravity compared with normal gravity (1G). However, the reduced sedimentation means that fewer particles deposit in the airways, increasing the number of particles transported to the lung periphery where they eventually deposit albeit at a smaller rate than in 1G. Read More

Acta Astronaut 2012 Aug;77:207-213

Division of Sleep and Chronobiology, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.

Several laboratories have found large, highly reliable individual differences in the magnitude of cognitive performance, fatigue and sleepiness, and sleep homeostatic vulnerability to acute total sleep deprivation and to chronic sleep restriction in healthy adults. Such individual differences in neurobehavioral performance are also observed in space flight as a result of sleep loss. The reasons for these stable phenotypic differential vulnerabilities are unknown: such differences are not yet accounted for by demographic factors, IQ or sleep need, and moreover, psychometric scales do not predict those individuals cognitively vulnerable to sleep loss. Read More

Acta Astronaut 2012 ;79:61-66

Medical Student, McGill University. Montreal, Quebec.

In the coming decades, as we continue our path of space exploration beyond Earth's orbit, we will be required to provide sound medical and surgical care for the safety of space travellers and space flight participants. A few investigations have taken place in the field of surgery in space. In this paper, the authors review the present literature in order to identify possible limitations that currently exist and that could impair our ability to provide surgical care during spaceflight, from the pre-operative to the post-operative period. Read More

Acta Astronaut 2011 Dec;69(11-12):949-959

Unit of Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania.

The Psychomotor Vigilance Test (PVT) objectively assesses fatigue-related changes in alertness associated with sleep loss, extended wakefulness, circadian misalignment, and time on task. The standard 10-min PVT is often considered impractical in applied contexts. To address this limitation, we developed a modified brief 3-min version of the PVT (PVT-B). Read More

Acta Astronaut 2008 Sep;63(5-6):594-602

Department Of Biomedical Engineering, The Johns Hopkins University School Of Medicine, Baltimore, MD.

Flying a parabolic trajectory in an aircraft is one of the few ways to create freefall on Earth, which is important for astronaut training and scientific research. Here we review the physics underlying parabolic flight, explain the resulting flight dynamics, and describe several counterintuitive findings, which we corroborate using experimental data. Typically, the aircraft flies parabolic arcs that produce approximately 25 seconds of freefall (0 g) followed by 40 seconds of enhanced force (1. Read More

Acta Astronaut 2008 ;63(7-10):833-840

Division of Sleep and Chronobiology, Department of Psychiatry, and Center for Sleep and Respiratory Neurobiology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.

The demands of sustaining high levels of neurobehavioral performance during space operations necessitate precise scheduling of sleep opportunities in order to best preserve optimal performance. We report here the results of the first split-sleep, dose-response experiment involving a range of sleep/wake scenarios with chronically reduced nocturnal sleep, augmented with a diurnal nap. To characterize performance over all combinations of split sleep in the range studied, we used response surface mapping methodology. Read More

Acta Astronaut 2005 Nov;57(9):713-21

Department of Kinesiology, University of Minnesota, Minneapolis, MN 55455, USA.

The designation of a simple, non-invasive, and highly precise method to monitor the thermal status of astronauts is important to enhance safety during extravehicular activities (EVA) and onboard emergencies. Finger temperature (Tfing), finger heat flux, and indices of core temperature (Tc) [rectal (Tre), ear canal (Tec)] were assessed in 3 studies involving different patterns of heat removal/insertion from/to the body by a multi-compartment liquid cooling/warming garment (LCWG). Under both uniform and nonuniform temperature conditions on the body surface, Tfing and finger heat flux were highly correlated with garment heat flux, and also highly correlated with each other. Read More

Acta Astronaut 2005 Jul-Oct;57(2-8):676-83

NASA Johnson Space Center, Houston, TX, 77058, USA.

The Vision for Space Exploration invokes activities on the Moon in preparation for exploration of Mars and also directs International Space Station (ISS) research toward the same goal. Lunar missions will emphasize development of capability and concomitant reduction of risk for future exploration of Mars. Earlier papers identified three critical issues related to the so-called NASA Mars Design Reference Mission (MDRM) to be addressed in the lunar context: (a) safety, health, and performance of the human crew; (b) various modalities of mission operations ranging surface activities to logistics, planning, and navigation; and (c) reliability and maintainability of systems in the planetary environment. Read More

Acta Astronaut 2005 Jul-Oct;57(2-8):661-75

International Space University, France.

The paper addresses the evolution of the Canadian Space Station Program between 1981 and 2003. Discussions with potential international partners, aimed at jointly developing the current International Space Station program, were initiated by NASA in 1982. Canada chose, through the further development of the technologies of Canadarm on the space shuttle, to provide and operate an advanced and comprehensive external robotics system for space station, and to use the space station for scientific and commercial purposes. Read More

Acta Astronaut 2005 Jul-Oct;57(2-8):649-60

NASA Ames Research Center, Moffett Field, CA 94035-1000, USA.

As we move boldly forward into the 21st century, there has rarely been a more exciting time in which to contemplate the future of space exploration. The President of the United States has made a new and ambitious commitment to exploration of the solar system and beyond. Robotic partners will play a vital role in ensuring that the Vision is truly "sustainable and affordable". Read More

Acta Astronaut 2005 Jul-Oct;57(2-8):634-41

Department of Psychosocial Science, University of Bergen, Norway.

The assessment of personality is recognized by space agencies as an approach to identify candidates likely to perform optimally during spaceflights. In the use of personality scales for selection, the impact of social desirability (SD) has been cited as a concern. Study 1 addressed the impact of SD on responses to the Personality Characteristic Inventory(PCI) and NEO-FFI. Read More

Acta Astronaut 2005 Jul-Oct;57(2-8):630-3

University of California, San Francisco, USA.

Being in space is a powerful experience that can have an enduring, positive impact on the psychological well-being of astronauts and cosmonauts. We sought to examine the frequency, intensity and distribution of such salutogenic experiences among persons who have flown in space, using a questionnaire we developed based on the scientific literature and first person accounts. All participants reported positive effects of being in space, but the degree of change varied widely, and some experiences were particularly common. Read More