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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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881 records · Page 49
All sourcesNASA NTRSDOE OSTI
NASA NTRS2021

Ground-based Automated Scheduling for Operations of the Mars 2020 Rover Mission

The National Aeronautics and Space Administration’s (NASA) Mars 2020 Rover, named Perseverance, landed on the surface of Mars in Jezero Crater on February 18, 2021. Since the landing, the rover’s activities have been planned with the aid of a ground-based automated scheduling system called Copilot. Automated scheduling is very rare for planetary rover missions. Historically humans have created a schedule manually and ensured that the schedule satisfied all constraints. Higher levels of automation in the system allows science planners to produce schedules for the rover more quickly. In addition to scheduling user-provided activities, Copilot generates and schedules two types of support activities: sleep activities and heating activities. Some activities require the CPU to be on as they execute, so Copilot schedules wakeups and shutdowns of the CPU at the appropriate times. Some activities require areas of the rover to be heated before they can execute, and that heating must be maintained throughout the duration of the activity. Copilot schedules the preheat and maintenance heating activities for the user-provided activities that require them. To facilitate Copilot usage, the Crosscheck tool shows the science planners how Copilot constructed a schedule. For activities that fail to be scheduled, Crosscheck gives information on the constraints that the activity would have violated. This gives the users insight into how to change the input activities and constraints in order to achieve a schedule that satisfies their goals.

Towey, Shannon↗
NASA NTRSDate not supplied

Investigation of Prophage Regions of Bacterial Strains Isolated from the International Space Station (ISS)

Space flight agencies are planning missions back to the Moon and to Mars. When sending humans into space, it is impossible to separate them from microorganisms, either in their associated microbiome or in the spacecraft environment, which are modified through the movement of genetic material. Bacteriophages, small viruses that invade and replicate within bacterial cells, play a central role in the genetic composition and evolution of microorganisms. Lysogenic bacteriophages can insert themselves into the DNA of their bacterial hosts, forming prophage regions, which can also transfer genes from previous hosts. Thus, we aimed to identify and classify all prophages from twelve bacterial species cultured from the International Space Station (ISS) from 2017 to 2018. We determined representative bacterial strains for each species, whose genomes were analyzed to identify prophage regions. Complete prophages were identified through database searches and the number of prophage regions were compared to terrestrial analogs. Additionally, prophage region and genome sizes were compared for each species, identifying the percentage of bacteriophage DNA in each genome. We determined that the prophage-susceptible bacterial species isolated from the ISS had a higher number of prophage regions when compared to terrestrial analogs, as well as having a larger percentage of their genomes made up of prophage material. Of the eighteen complete prophages identified, 72.2% were of family Siphoviridae and 27.8% were of family Myoviridae. Only one of the prophages had a BLAST similarity over 80%, suggesting that the remainder of prophages are novel species. These results imply that there is a higher rate of prophage transduction and lysogeny during spaceflight, and that the prophages present are novel.

Phage↗
NASA NTRS2021

Ground and Onboard Automated Scheduling for the Mars 2020 Rover Mission

The Mars 2020 Rover mission is using automated scheduling in two capacities. As of March 2021 a ground-based scheduler automatically schedules rover wake/sleep and preheats to support Mars 2020 daily operations. Included in the ground system is an explainable scheduling tool that allows users in-sight into the schedule developed by the automated scheduler. An onboard scheduler that will allow the rover autonomously better account for variations in execution is in development for use later in the mission.

Towey, Shannon↗
NASA NTRS2024

Flight Dynamics and Navigation Performance of the BioSentinel Mission

BioSentinel was one of ten CubeSats launched by the Space Launch System (SLS) as part of the Artemis I campaign on 16 November 2022. A lunar flyby gave BioSentinel the needed energy to escape the Earth-Moon system into heliocentric space. The biological payload contains yeast cells designed to measure radiation in deep space beyond the reach of Earth’s magnetosphere. This paper discusses in detail the BioSentinel flight performance, as well as challenges and lessons learned prior to, and during the mission.

BioSentinel↗
NASA NTRS2023

Microbial Adaptation to Spaceflight Is Correlated With Bacteriophage-Encoded Functions

Evidence from the International Space Station suggests microbial populations are rapidly adapting to the spacecraft environment; however, the mechanism of this adaptation is not understood. Bacteriophages are prolific mediators of bacterial adaptation on Earth. Here we survey 245 genomes sequenced from bacterial strains isolated on the International Space Station for dormant (lysogenic) bacteriophages. Our analysis indicates phage-associated genes are significantly different between spaceflight strains and their terrestrial counterparts. Additionally, we identify 283 complete prophages, those that could initiate bacterial lysis and infect additional hosts, of which 21% are novel. These prophage regions encode functions that correlate with increased persistence in extreme environments, such as spaceflight, to include antimicrobial resistance and virulence, DNA damage repair, and dormancy. Our results correlate microbial adaptation in spaceflight to bacteriophage-encoded functions that may impact human health in spaceflight.

Space Biology↗
DOE OSTI2021

Electrodes with silicon oxide active materials for lithium ion cells achieving high capacity, high energy density and long cycle life performance

Improved negative electrodes can comprise a silicon based active material blended with graphite to provide more stable cycling at high energy densities. In some embodiments, the negative electrodes comprise a blend of polyimide binder mixed with a more elastic polymer binder with a nanoscale carbon conductive additive. The silicon-based blended graphite negative electrodes can be matched with positive electrodes comprising nickel rich lithium nickel manganese cobalt oxides to form high energy density cells with good cycling properties.

Venkatachalam, Subramanian↗
DOE OSTI2022

Update of Radiation References: Results from the WMO Expert Team on Radiation References

Primary metrological references for solar (shortwave) & terrestrial (longwave) radiation are instrument-based, managed by PMOD/WRC. New references (new instruments) have been proposed with improved traceability to SI. However, comparisons show bias between the old and new references. ET-RR should advise WMO whether and how to proceed with the change in radiation references without disrupting climate (and meteorological) science.

ACP↗
DOE OSTI2023

Electrodes with silicon oxide active materials for lithium ion cells achieving high capacity, high energy density and long cycle life performance

Improved negative electrodes can comprise a silicon based active material blended with graphite to provide more stable cycling at high energy densities. In some embodiments, the negative electrodes comprise a blend of polyimide binder mixed with a more elastic polymer binder with a nanoscale carbon conductive additive. The silicon-based blended graphite negative electrodes can be matched with positive electrodes comprising nickel rich lithium nickel manganese cobalt oxides to form high energy density cells with good cycling properties.

Venkatachalam, Subramanian↗