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At least 19 recordsLinked to original sources
PubMed1999

Estimating the mass of asteroid 433 eros during the NEAR spacecraft flyby

The Near Earth Asteroid Rendezvous (NEAR) spacecraft flew within 3830 kilometers of asteroid 433 Eros on 23 December 1998. The gravitational perturbation on NEAR was evident in the spacecraft tracking data. Ground-based Doppler and range tracking of the spacecraft as well as spacecraft images of the asteroid's center of figure and surface features were used to determine the mass and rotation pole of Eros. The mass of Eros is (7.2 +/- 1.8) x 10(18) grams and, coupled with a volume estimate provided by the NEAR imaging team, this mass suggests a bulk density of 2.5 +/- 0.8 grams per cubic centimeter. The rotation pole position is 15.6 (+/-3.7) degrees in right ascension and 16.4 (+/-1.8) degrees in declination, which is consistent with ground-based and NEAR imaging team observations.

Journal Article↗
PubMed1973

Microbiological profiles of four Apollo spacecraft.

Selected surfaces from the Command Module, Lunar Module (ascent and descent stages), Instrument Unit, Saturn S-4B engine, and Spacecraft Lunar Module Adapter comprised the various components of four Apollo spacecraft which were assayed quantitatively and qualitatively for microorganisms. In addition, the first Lunar Roving Vehicle was assayed. Average levels of microbial contamination (10(4) per square foot of surface) on the Command Module, Instrument Unit, and Saturn S-4B engine were relatively consistent among spacecraft. The first postflight sampling of interior surfaces of the Command Module was possible due to elimination of the 21-day back-contamination quarantine period. Results of the pre- and postflight samples revealed increases in the postflight samples of 3 logs/inch(2). A total of 5,862 microbial isolates was identified; 183 and 327 were obtained from the Command Module at preflight and postflight sampling periods, respectively. Although the results showed that the majority of microorganisms isolated were those considered to be indigenous to humans, an increase in organisms associated with soil and dust was noted with each successive Apollo spacecraft.

Actinomycetales↗
PubMed1998

A methodology to select a wire insulation for use in habitable spacecraft.

This paper investigates electrical overheating events aboard a habitable spacecraft. The wire insulation involved in these failures plays a major role in the entire event scenario from threat development to detection and damage assessment. Ideally, if models of wire overheating events in microgravity existed, the various wire insulations under consideration could be quantitatively compared. However, these models do not exist. In this paper, a methodology is developed that can be used to select a wire insulation that is best suited for use in a habitable spacecraft. The results of this study show that, based upon the Analytic Hierarchy Process and simplifying assumptions, the criteria selected, and data used in the analysis, Tefzel is better than Teflon for use in a habitable spacecraft.

Chemical Phenomena↗
PubMed1997

Carcinogens in spacecraft air.

The health effects of long-term exposure to ionizing radiation during spaceflight are a major concern to NASA, especially for missions beyond low-Earth orbit. Experiments involving astronauts will be conducted during the next few years to improve the risk assessment for exposures to ionizing radiation during flights; however, concomitant exposure to certain airborne chemical carcinogens during these experiments could confound the results of radiation experiments. Carcinogens can reach the spacecraft atmosphere from leaking thrusters, from off-gassing materials, from chemical experiments and from human metabolism. The Johnson Space Center Toxicology Group routinely analyzes atmospheric samples collected aboard spacecraft. The exposure limits for radiomimetic compounds such as benzene are reduced because of the potential interaction between radiation and chemical exposures. Analysis of recent spacecraft air samples indicates that the following carcinogens are often present in measurable concentrations: acetaldehyde, dichloromethane, formaldehyde and isoprene. Occasionally, the carcinogens 1,2-dichloroethane, acrolein, benzene and furan are found in atmospheric samples. During normal operating conditions, the low concentrations of and limited periods of exposure to airborne carcinogens are thought to pose minimal health risks to crew members, and should not confound experiments involving sensitive methods to detect biological effects of ionizing radiation.

Acetaldehyde↗
PubMed1977

Microbiological profiles of the Viking spacecraft.

Planetary quarantine requirements associated with the launch of two Viking spacecraft necessitated microbiological assessment during assembly and testing at Cape Canaveral and the Kennedy Space Center. Samples were collected from selected surface of the Viking Lander Capsules (VLC), Orbiters, (VO), and Shrouds at predetermined intervals during assembly and testing. Approximately 7,000 samples were assayed. Levels of bacterial spores per square meter on the VLC-1 and VLC-2 were 1.6 x 10(2) and 9.7 x 10(1), respectively, prior to dry-heat sterilization. The ranges of aerobic mesophilic microorganisms detected on the VO-1 and VO-2 at various sampling events were 4.2 x 10(2) to 4.3 x 10(3) and 2.3 x 10(2) to 8.9 x 10(3)/m2, respectively. Approximately 1,300 colonies were picked from culture plates, identified, lypholipized, and stored for future reference. About 75% of all isolates were microorganisms considered indigenous to humans; the remaining isolates were associated with soil and dust in the environment. The percentage of microorganisms of human origin was consistent with results obtained with previous automated spacecraft but slightly lower than those observed for manned (Apollo) spacecraft.

Actinomycetales↗
PubMed1974

Comparison of media for detection of fungi on spacecraft.

Five media, including Trypticase soy agar (TSA; BBL) pour plates, spread plates of TSA, Mycophil agar with chloromycetin, Mycophil agar with chloromycetin and Actidione, and cornmeal agar with chloromycetin were quantitatively and qualitatively compared for the detection of fungi on spacecraft. Cornmeal agar with chloromycetin yielded the highest number of fungal colonies, although not always significantly higher than Mycophil agar with chloromycetin or TSA spread plates. Cornmeal agar with chloromycetin also gave the best qualitative representation of fungi on the spacecraft, recovering 68% of the genera found from all media. This medium yielded 10 times the number of fungal colonies and 3 times the number of genera found on TSA pour plates as currently used for spacecraft assay.

Agar↗
PubMed1996

Plasma observations at Io with the Galileo spacecraft.

Plasma measurements made during the flyby of Io on 7 December 1995 with the Galileo spacecraft plasma analyzers reveal that the spacecraft unexpectedly passed directly through the ionosphere of Io. The ionosphere is identified by a dense plasma that is at rest with respect to Io. This plasma is cool relative to those encountered outside the ionosphere. The composition of the ionospheric plasmas includes O++, O+ and S++, S+, and SO2+ ions. The plasma conditions at Io appear to account for the decrease in the magnetic field, without the need to assume that Io has a magnetized interior.

Extraterrestrial Environment↗
PubMed1967

Microbiological burden on the surfaces of Explorer 33 spacecraft.

The Explorer XXXIII Spacecraft (Anchored Interplanetary Monitoring Platform, or AIMP) was decontaminated to prevent gross contamination of the moon with terrestrial microorganisms. Assay of the total spacecraft surface before and after decontamination showed that the decontamination procedure reduced the viable microbiological burden from 1.40 x 10(6) to 3.60 x 10(4). However, assembly of parts which were not decontaminated for engineering reasons or were not assembled under cleanroom conditions increased the viable microbial burden at the time of launch to 2.62 x 10(5).

Humans↗
PubMed1970

Quantitative and qualitative microbiological profiles of the Apollo 10 and 11 spacecraft.

Microbiological profiles were determined for surfaces of the command module, lunar module (ascent and descent stages), instrument unit, Saturn S-4B stage, and the spacecraft lunar module adapter of the Apollo 10 and 11 spacecraft. Average levels of contamination of the command module were 2.1 x 10(4) and 2.7 x 10(4) microorganisms per ft(2) for Apollo 10 and 11, respectively. With the exception of the exterior surfaces of the ascent stage of the lunar module and the interior surfaces of the command module, average levels of microbial contamination on all components of the Apollo 11 were found to be lower than those observed on Apollo 10. For each Apollo mission, approximately 2,000 colonies were picked from a variety of media and identified. The results showed that approximately 95% of all isolates were those considered indigenous to humans; the remaining were associated with soil and dust in the environment. However, the ratio of these two general groups varied depending on the degrees of personnel density and environmental control associated with each module.

Bacteria↗
PubMed1975

Volatile organic components in the Skylab 4 spacecraft atmosphere.

The volatile organic components in the spacecraft cabin atmosphere of Skylab 4 were trapped on a solid adsorbent at various times during the mission. In post-flight analyses, more than 300 compounds in concentrations from less than 1 ppb up to 8000 ppb could be detected by high-resolution gas chromatography. In the samples of the 11th, 47th, and 77th day of the mission, approximately 100 components in the molecular weight range of 58 to 592 were identified by mass spectrometry. Besides components known from other environments, such as alkanes, alkenes, and alkylated aromatic hydrocarbons, components typical for the human metabolism such as ketones and alcohols were found. Other typical components in the spacecraft atmosphere are fluorocarbons (freons) and various silicone compounds, mostly normal and cyclic methylsiloxanes.

Air Pollutants↗
PubMed1985

[Suprathreshold alternating vestibular stimuli in orbiting spacecrafts].

The actual knowledge of the thresholds of stimulation of the otolith organ is reviewed. A vestibular stimulus unknown until now with a value transgressing the threshold has been found. This gravitational force is due to the gravitation of the sun and is caused by the fact that the spacecraft is moving at a different speed with respect to the sun on one side of the orbit than on the other. The problems of vestibular experiments in space and the connection with space motion sickness due to a field of microgravitation in orbiting spacecrafts is discussed.

Gravitation↗
PubMed1996

External ocular hyperemia: a quantifiable indicator of spacecraft air quality.

BACKGROUND: Eye irritation consistently ranks as a top astronaut complaint but is difficult to measure. Exposure to internal air pollution hypothetically disrupts the eye's tear film, thereby exposing the crewmembers' conjunctivae to the irritating effects of the recirculated, contaminant-laden atmosphere of the space vehicle. Causes elude engineers and toxicologists, who report that measured irritants remain below established Spacecraft Maximum Allowable Concentrations. Lack of objective ocular endpoints stymies efforts to identify etiologies. HYPOTHESIS: Computers offer a practical means of analyzing ocular hyperemia in space. METHODS: We use computer analysis to quantify redness and blood vessels of digitized images of bulbar conjunctivae in near real time. Custom software masks artifacts, lids and lashes for each photographic or telemedicine ocular image, Algorithms then generate semi-independent measurements of hyperemia. Computed difference scores between 34 pairs of images were compared with subjective difference scores as voted on by a panel of ophthalmology residents. RESULTS: Objective data were reliably extracted from ocular images and significantly correlated (r = 0.583, p < 0.05) with subjective scores. CONCLUSIONS: This ground-based methodology generates accurate and reliable ocular endpoint data without mass, volume, or power penalty. To assist in identifying and eliminating onboard ocular irritants, these objective data can be regressed against independent variables such as mission elapsed time, subjective astronaut complaints, levels of chemical and electromagnetic contaminants, nephthelometric and barothermal data. As missions lengthen, sensitive tools such as hyperemia quantification will become increasingly important for assessing and optimizing spacecraft environments.

Adult↗
PubMed2024

Neobacillus driksii sp. nov. isolated from a Mars 2020 spacecraft assembly facility and genomic potential for lasso peptide production in Neobacillus.

UNLABELLED: During microbial surveillance of the Mars 2020 spacecraft assembly facility, two novel bacterial strains, potentially capable of producing lasso peptides, were identified. Characterization using a polyphasic taxonomic approach, whole-genome sequencing and phylogenomic analyses revealed a close genetic relationship among two strains from Mars 2020 cleanroom floors (179-C4-2-HS, 179-J1A1-HS), one strain from the Agave plant (AT2.8), and another strain from wheat-associated soil (V4I25). All four strains exhibited high 16S rRNA gene sequence similarity (>99.2%) and low average nucleotide identity (ANI) with Neobacillus niacini NBRC 15566T, delineating new phylogenetic branches within the genus. Detailed molecular analyses, including gyrB (90.2%), ANI (86.4%), average amino acid identity (87.8%) phylogenies, digital DNA-DNA hybridization (32.6%), and percentage of conserved proteins (77.7%) indicated significant divergence from N. niacini NBRC 15566T. Consequently, these strains have been designated Neobacillus driksii sp. nov., with the type strain 179-C4-2-HST (DSM 115941T = NRRL B-65665T). N. driksii grew at 4&#xb0;C to 45&#xb0;C, pH range of 6.0 to 9.5, and 0.5% to 5% NaCl. The major cellular fatty acids are iso-C15:0 and anteiso-C15:0. The dominant polar lipids include diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and an unidentified aminolipid. Metagenomic analysis within NASA cleanrooms revealed that N. driksii is scarce (17 out of 236 samples). Genes encoding the biosynthesis pathway for lasso peptides were identified in all N. driksii strains and are not commonly found in other Neobacillus species, except in 7 out of 26 recognized species. This study highlights the unique metabolic capabilities of N. driksii, underscoring their potential in antimicrobial research and biotechnology. IMPORTANCE: The microbial surveillance of the Mars 2020 assembly cleanroom led to the isolation of novel N. driksii with potential applications in cleanroom environments, such as hospitals, pharmaceuticals, semiconductors, and aeronautical industries. N. driksii genomes were found to possess genes responsible for producing lasso peptides, which are crucial for antimicrobial defense, communication, and enzyme inhibition. Isolation of N. driksii from cleanrooms, Agave plants, and dryland wheat soils, suggested niche-specific ecology and resilience under various environmentally challenging conditions. The discovery of potent antimicrobial agents from novel N. driksii underscores the importance of genome mining and the isolation of rare microorganisms. Bioactive gene clusters potentially producing nicotianamine-like siderophores were found in N. driksii genomes. These siderophores can be used for bioremediation to remove heavy metals from contaminated environments, promote plant growth by aiding iron uptake in agriculture, and treat iron overload conditions in medical applications.

Phylogeny↗
PubMed1995

[An approach to formalized description of the spacecraft radiation safety task].

Relationships correlating the damage expected from radiation exposure in space mission with radiobiological reactions of the body, parameters of radiation environment along the trajectory, and shielding properties of spacecraft structures were established with the use of mathematical tools of the set theory and the theory of chances. To this end, appropriate mathematical formulas were introduced which aided formalization of the space crew radiation safety task in the form of two inequalities.

Aerospace Medicine↗
PubMed1996

[Optimal isotope composition of biogenic chemical elements on board of manned spacecrafts].

Isotope composition of biogenic chemical elements (BCE) is discussed. A hypothesis is offered that biochemical and biomedical processes must be influenced as by the isotope composition of hydrogen and oxygen, so by the composition of stable isotopes of all the BCE constituting plants, animals, and humans. Biochemical, toxicological and other biomedical analyses should be performed to determine the best BCE isotope composition. These must be followed by development of methods, technologies, and life support systems to form and maintain the best isotope composition inside spacecraft habitable modules.

Humans↗
PubMed1974

Mathematical estimation on the level of microbial contamination on spacecraft surfaces by volumetric air sampling.

Microbiological sampling methods presently used for enumeration of microorganisms on spacecraft surfaces require contact with easily damaged components. Estimation of viable particles on surfaces using air sampling methods in conjunction with a mathematical model would be desirable. Parameters necessary for the mathematical model are the effect of angled surfaces on viable particle collection and the number of viable cells per viable particle. Deposition of viable particles on angled surfaces closely followed a cosine function, and the number of viable cells per viable particle was consistent with a Poisson distribution. Other parameters considered by the mathematical model included deposition rate and fractional removal per unit time. A close nonlinear correlation between volumetric air sampling and airborne fallout on surfaces was established with all fallout data points falling within the 95% confidence limits as determined by the mathematical model.

Actinomycetales↗
PubMed1975

Psychrophilic microorganisms from areas associated with the Viking spacecraft.

Microorganisms capable of growth at 7 C were enumerated and isolated from soil samples from the manufacture and assembly areas of the Viking spacecraft. Populations ranging from 4.2 X 10(3) to 7.7 X 10(6)/g of soil were isolated from the 15 soil samples examined. Temperature requirements were determined, and those growing at 3 C, but not at 32 C, were designated as obligate psychrophiles in this investigation. Populations of soil bacteria, including aerobic sporeformers, ranging from 1.5 X 10(2) to 9.8 X 10(5)/g were capable of growth at 3 C, but not at 32 C. Bacterial isolates were identified to major generic groups. No psychrophilic sporeformers were isolated from soil from the manufacture area, but psychrophilic sporeformers ranged from 0 to 6.1 X 10(3)/g from soil from the assembly area.

Aerobiosis↗