12 research outputs found
SPECTROModule: A modular in-situ spectroscopy platform for exobiology and space sciences
The evolution of the solar system and the origin of life remain some of the most intriguing questions for humankind. Addressing these questions experimentally is challenging due to the difficulty of mimicking environmental conditions representative for Early Earth and/or space conditions in general in ground-based laboratories. Performing experiments directly in space offers the great chance to overcome some of these obstacles and to possibly find answers to these questions. Exposure platforms in Low Earth Orbit (LEO) with the possibility for long-duration solar exposure are ideal for investigating the effects of solar and cosmic radiation on various biological and non-biological samples. Up to now, the Exobiology and space science research community has successfully made use of the International Space Station (ISS) via the EXPOSE facility to expose samples to the space environment with subsequent analyses after return to Earth. The emerging small and nanosatellite market represents another opportunity for astrobiology research as proven by the robotic O/OREOS mission, where samples were monitored in-situ, i.e. in Earth orbit. In this framework, the European Space Agency is developing a novel Exobiology facility outside the ISS. The new platform, which can host up to four different experiments, will combine the advantages of the ISS (long-term exposure, sample return capability) with near-real-time in-situ monitoring of the chemical/biological evolution in space. In particular, ultravioletâvisible (UVâVis) and infrared (IR) spectroscopy were considered as key non-invasive methods to analyse the samples in situ. Changes in the absorption spectra of the samples developing over time will reveal the chemical consequences of exposure to solar radiation. Simultaneously, spectroscopy provides information on the growth rate or metabolic activities of biological cultures. The first quartet of experiments to be performed on-board consists of IceCold, OREOcube and Exocube (dual payload consisting of ExocubeChem and ExocubeBio). To prepare for the development of the Exobiology facility, ground units of the UVâVis and IR spectrometers were studied, manufactured and tested as precursors of the flight units. The activity led to a modular in-situ spectroscopy platform able to perform different measurements (e.g. absorbance, optical density, fluorescence measurements) at the same time on different samples. We describe here the main features of the ground model platform, the verification steps, results and approach followed in the customization of commercialâoff-the-shelf (COTS) modules to make them suitable for the space environment. The environmental tests included random and shock vibration, thermal vacuum cycles in the range â20 °C to +40 °C and irradiation of the components with a total dose of 1800 rad (18 Gy). The results of the test campaign consolidated the selection of the optical devices for the Exobiology Facility. The spectroscopic performance of the optical layout was tested and benchmarked in comparison with state-of-the-art laboratory equipment and calibration standards showing good correlation. This includes spectra of samples sets relevant for the flight experiments and a performance comparison between the SPECTROModule ground model and state-of-the-art laboratory spectrometers. Considering the large number of samples and different types of optical measurements planned on-board the ISS, the main outcome was the implementation of an LED-photodiode layout for the optical density and fluorescence measurements of IceCold (42 samples) and ExocubeBio (111 samples); while the UVâVis spectrometer will be mainly focused on the change of the absorption spectra of the 48 samples of OREOcube.The ExocubeChem samples (in total 48) will be analysed by infrared spectroscopy. The ground platform supports the establishment of analogue research capabilities able to address the long-term objectives beyond the current application
Survival of lichens and bacteria exposed to outer space conditions - Results of the Lithopanspermia experiments
n the space experiments Lithopanspermia, experimental support was provided to the likelihood of the lithopanspermia concept that considers a viable transport of microorganisms between the terrestrial planets by means of meteorites. The rock colonising lichens Rhizocarpon geographicum and Xanthoria elegans, the vagrant lichen Aspicilia fruticulosa, and endolithic and endoevaporitic communities of cyanobacteria and bacteria with their natural rock substrate were exposed to space for 10 days onboard the Biopan facility of the European Space Agency (ESA). Biopan was closed during launch and re-entry. In addition, in the Stone facility, one sample of R. geographicum on its natural granitic substrate was attached at the outer surface of the re-entry capsule close to the stagnation point, only protected by a thin cover of glass textolite. Post-flight analysis, which included determination of the photosynthetic activity, LIVE/DEAD staining, and germination capacity of the ascospores, demonstrated that all three lichen were quite resistant to outer space conditions, which include the full spectrum of solar extraterrestrial electromagnetic radiation or selected wavelength ranges. This high resistance of the lichens to space appears to be due to their symbiotic nature and protection by their upper pigmented layer, the cortex. In contrast, the rock- or halite-inhabiting bacteria were severely damaged by the same exposure. After atmospheric re-entry, the granite of the Stone sample was transformed into a glassy, nearly homogenous material, with several friction striae. None of the lichen cells survived this re-entry process. The data suggest that lichens are suitable candidates for testing the concept of lithopanspermia, because they are extremely resistant to the harsh environment of outer space. The more critical event is the atmospheric re-entry after being captured by a planet. Experiments simulating the re-entry process of a microbe-carrying meteoroid did not show any survivors
Testing Laser-Structured Antimicrobial Surfaces Under Space Conditions: The Design of the ISS Experiment BIOFILMS
Maintaining crew health and safety are essential goals for long-term human missions to space.
Attaining these goals requires the development of methods and materials for sustaining the
crewâs health and safety. Paramount is microbiological monitoring and contamination
reduction. Microbial biofilms are of special concern, because they can cause damage to
spaceflight equipment and are difficult to eliminate due to their increased resistance to
antibiotics and disinfectants. The introduction of antimicrobial surfaces for medical,
pharmaceutical and industrial purposes has shown a unique potential for reducing and
preventing biofilm formation. This article describes the development process of ESAâs
BIOFILMS experiment, that will evaluate biofilm formation on various antimicrobial surfaces
under spaceflight conditions. These surfaces will be composed of different metals with and
without specified surface texture modifications. Staphylococcus capitis subsp. capitis,
Cupriavidus metallidurans and Acinetobacter radioresistens are biofilm forming organisms
that have been chosen as model organisms. The BIOFILMS experiment will study the biofilm
formation potential of these organisms in microgravity on the International Space Station on inert
surfaces (stainless steel AISI 304) as well as antimicrobial active copper (Cu) based metals that
have undergone specific surface modification by Ultrashort Pulsed Direct Laser Interference
Patterning (USP-DLIP). Data collected in 1 x g has shown that these surface modifications
enhance the antimicrobial activity of Cu based metals. In the scope of this, the interaction
between the surfaces and bacteria, which is highly determined by topography and surface
chemistry, will be investigated. The data generated will be indispensable for the future selection
of antimicrobial materials in support of human- and robotic-associated activities in space
exploration
3 versus 6 months of adjuvant oxaliplatin-fluoropyrimidine combination therapy for colorectal cancer (SCOT): an international, randomised, phase 3, non-inferiority trial.
BACKGROUND: 6 months of oxaliplatin-containing chemotherapy is usually given as adjuvant treatment for stage 3 colorectal cancer. We investigated whether 3 months of oxaliplatin-containing chemotherapy would be non-inferior to the usual 6 months of treatment. METHODS: The SCOT study was an international, randomised, phase 3, non-inferiority trial done at 244 centres. Patients aged 18 years or older with high-risk stage II and stage III colorectal cancer underwent central randomisation with minimisation for centre, choice of regimen, sex, disease site, N stage, T stage, and the starting dose of capecitabine. Patients were assigned (1:1) to receive 3 months or 6 months of adjuvant oxaliplatin-containing chemotherapy. The chemotherapy regimens could consist of CAPOX (capecitabine and oxaliplatin) or FOLFOX (bolus and infused fluorouracil with oxaliplatin). The regimen was selected before randomisation in accordance with choices of the patient and treating physician. The primary study endpoint was disease-free survival and the non-inferiority margin was a hazard ratio of 1·13. The primary analysis was done in the intention-to-treat population and safety was assessed in patients who started study treatment. This trial is registered with ISRCTN, number ISRCTN59757862, and follow-up is continuing. FINDINGS: 6088 patients underwent randomisation between March 27, 2008, and Nov 29, 2013. The intended treatment was FOLFOX in 1981 patients and CAPOX in 4107 patients. 3044 patients were assigned to 3 month group and 3044 were assigned to 6 month group. Nine patients in the 3 month group and 14 patients in the 6 month group did not consent for their data to be used, leaving 3035 patients in the 3 month group and 3030 patients in the 6 month group for the intention-to-treat analyses. At the cutoff date for analysis, there had been 1482 disease-free survival events, with 740 in the 3 month group and 742 in the 6 month group. 3 year disease-free survival was 76·7% (95% CI 75·1-78·2) for the 3 month group and 77·1% (75·6-78·6) for the 6 month group, giving a hazard ratio of 1·006 (0·909-1·114, test for non-inferiority p=0·012), significantly below the non-inferiority margin. Peripheral neuropathy of grade 2 or worse was more common in the 6 month group (237 [58%] of 409 patients for the subset with safety data) than in the 3 month group (103 [25%] of 420) and was long-lasting and associated with worse quality of life. 1098 serious adverse events were reported (492 reports in the 3 month group and 606 reports in the 6 month group) and 32 treatment-related deaths occurred (16 in each group). INTERPRETATION: In the whole study population, 3 months of oxaliplatin-containing adjuvant chemotherapy was non-inferior to 6 months of the same therapy for patients with high-risk stage II and stage III colorectal cancer and was associated with reduced toxicity and improved quality of life. Despite the fact the study was underpowered, these data suggest that a shorter duration leads to similar survival outcomes with better quality of life and thus might represent a new standard of care. FUNDING: Medical Research Council, Swedish Cancer Society, NETSCC, and Cancer Research UK
Time Profile of Cosmic Radiation Exposure During the EXPOSE-E Mission: The R3DE Instrument
The aim of this paper is to present the time profile of cosmic radiation exposure obtained by the Radiation Risk
Radiometer-Dosimeter during the EXPOSE-E mission in the European Technology Exposure Facility on the International
Space Stationâs Columbus module. Another aimis to make the obtained results available to other EXPOSE-E
teams for use in their data analysis. Radiation Risk Radiometer-Dosimeter is a low-mass and small-dimension
automatic device that measures solar radiation in four channels and cosmic ionizing radiation as well. The main
results of the present study include the following: (1) three different radiation sources were detected and quantifiedâ
galactic cosmic rays (GCR), energetic protons from the South Atlantic Anomaly (SAA) region of the inner
radiation belt, and energetic electrons from the outer radiation belt (ORB); (2) the highest daily averaged absorbed
dose rate of 426 ÎŒGy dâ»Âč came from SAA protons; (3) GCR delivered a much smaller daily absorbed dose rate of 91.1
ÎŒGy dâ»Âč, and the ORB source delivered only 8.6 ÎŒGy dâ»Âč. The analysis of the UV and temperature data is a subject of
another article (Schuster et al., 2012)
Multimicrobial Kombucha Culture Tolerates Mars-Like Conditions Simulated on Low-Earth Orbit
A kombucha multimicrobial culture (KMC) was exposed to simulated Mars-like conditions in low-Earth orbit (LEO). The study was part of the Biology and Mars Experiment (BIOMEX), which was accommodated in the European Space Agency's EXPOSE-R2 facility, outside the International Space Station. The aim of the study was to investigate the capability of a KMC microecosystem to survive simulated Mars-like conditions in LEO. During the 18-month exposure period, desiccated KMC samples, represented by living cellulose-based films, were subjected to simulated anoxic Mars-like conditions and ultraviolet (UV) radiation, as prevalent at the surface of present-day Mars. Postexposure analysis demonstrated that growth of both the bacterial and yeast members of the KMC community was observed after 60 days of incubation; whereas growth was detected after 2 days in the initial KMC. The KMC that was exposed to extraterrestrial UV radiation showed degradation of DNA, alteration in the composition and structure of the cellular membranes, and an inhibition of cellulose synthesis. In the âspace dark controlâ (exposed to LEO conditions without the UV radiation), the diversity of the microorganisms that survived in the biofilm was reduced compared with the ground-based controls. This was accompanied by structural dissimilarities in the extracellular membrane vesicles. After a series of subculturing, the revived communities restored partially their structure and associated activities
Copper kills microbes - the microbial struggle addressed in the upcoming ESA space experiment BIOFILMS
To achieve many of the Goals of ESAâs and NASAâs spaceprograms, an enduring human presence in space is
required. For those long-term missions, sustaining the crewsâ health and safety is essential. Here, the
development of improved spaceflight-suitable methods for microbiological monitoring and
decontamination are of great importance. The microflora of humans and habitat varies in response to
changes in environmental conditions aboard the International Space Station (ISS). Changes in the microflora
may result in an increased health risk for the crew. Furthermore, microbial biofilms are considered a risk in
space flight since they are known to cause damage to equipment from polymer deterioration, metal
corrosion and bio-fouling. Various studies have shown that certain metals reduce the number of contactmediated microbial contaminations. Antimicrobial surfaces are defined as materials that inhibit or reduce
microbial growth
The astrobiological mission EXPOSE-R on board of the International Space Station
EXPOSE-R flew as the second of the European Space Agency (ESA) EXPOSE multi-user facilities on the International Space Station. During the mission on the external URM-D platform of the Zvezda service module, samples of eight international astrobiology experiments selected by ESA and one Russian guest experiment were exposed to low Earth orbit space parameters from March 10th, 2009 to January 21st, 2011. EXPOSE-R accommodated a total of 1220 samples for exposure to selected space conditions and combinations, including space vacuum, temperature cycles through 273 K, cosmic radiation, solar electromagnetic radiation at >110, >170 or >200 nm at various fluences up to GJ mâ»ÂČ. Samples ranged from chemical compounds via unicellular organisms and multicellular mosquito larvae and seeds to passive radiation dosimeters. Additionally, one active radiation measurement instrument was accommodated on EXPOSE-R and commanded from ground in accordance with the facility itself. Data on ultraviolet radiation, cosmic radiation and temperature were measured every 10 s and downlinked by telemetry and data carrier every few months. The EXPOSE-R trays and samples returned to Earth on March 9th, 2011 with Shuttle flight, Space Transportation System (STS)-133/ULF 5, Discovery, after successful total mission duration of 27 months in space. The samples were analysed in the individual investigators laboratories. A parallel Mission Ground Reference experiment was performed on ground with a parallel set of hardware and samples under simulated space conditions following to the data transmitted from the flight mission
To other planets with upgraded millennial Kombucha in rhythms of sustainability and health support
Humankind has entered a new era of space exploration: settlements on other planetary
bodies are foreseen in the near future. Advanced technologies are being developed to
support the adaptation to extraterrestrial environments and, with a view on the longer term,
to support the viability of an independent economy. Biological processes will likely play a
key role and lead to the production of life-support consumables, and other commodities, in
a way that is cheaper and more sustainable than exclusively abiotic processes. Microbial
communities could be used to sustain the crewsâ health as well as for the production of
consumables, for waste recycling, and for biomining. They can self-renew with little
resources from Earth, be highly productive on a per-volume basis, and be highly
versatileâall of which will be critical in planetary outposts. Well-defined, semi-open,
and stress-resistant microecosystems are particularly promising. An instance of it is
kombucha, known worldwide as a microbial association that produces an eponymous,
widespread soft drink that could be valuable for sustaining crewsâ health or as a synbiotic
(i.e., probiotic and prebiotic) after a rational assemblage of defined probiotic bacteria and
yeasts with endemic or engineered cellulose producers. Bacterial cellulose products offer a
wide spectrum of possible functions, from leather-like to innovative smart materials during
long-term missions and future activities in extraterrestrial settlements. Cellulose production
by kombucha is zero-waste and could be linked to bioregenerative life support system (BLSS) loops. Another advantage of kombucha lies in its ability to mobilize inorganic ions
from rocks, which may help feed BLSS from local resources. Besides outlining those
applications and others, we discuss needs for knowledge and other obstacles, among
which is the biosafety of microbial producers.The National Academy of Sciences of Ukraine Space Research Program and the Alexander von Humboldt Foundation.Eat Easy (Kyiv, Ukraine) covered the publication fees of this manuscript.http://frontiersin.org/Astronomy_and_Space_Sciencesam2022BiochemistryGeneticsMicrobiology and Plant Patholog