Conceptual design of a closed loop nutrient solution delivery system for CELSS implementation in a micro-gravity environment

Described here are the results of a study to develop a conceptual design for an experimental closed loop fluid handling system capable of monitoring, controlling, and supplying nutrient solution to higher plants. The Plant Feeder Experiment (PFE) is designed to be flight tested in a microgravity environment. When flown, the PFX will provide information on both the generic problems of microgravity fluid handling and the specific problems associated with the delivery of the nutrient solution in a microgravity environment. The experimental hardware is designed to fit into two middeck lockers on the Space Shuttle, and incorporates several components that have previously been flight tested

Neurogenic Fever after Acute Traumatic Spinal Cord Injury: A Qualitative Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVE: To determine the incidence, pathogenesis, and clinical outcomes related to neurogenic fevers following traumatic spinal cord injury (SCI). METHODS: A systematic review of the literature was performed on thermodysregulation secondary to acute traumatic SCI in adult patients. A literature search was performed using PubMed (MEDLINE), Cochrane Central Register of Controlled Trials, and Scopus. Using strict inclusion and exclusion criteria, seven relevant articles were obtained. RESULTS: The incidence of fever of all origins (both known and unknown) after SCI ranged from 22.5 to 71.7% with a mean incidence of 50.6% and a median incidence of 50.0%. The incidence of fever of unknown origin (neurogenic fever) ranged from 2.6 to 27.8% with a mean incidence of 8.0% and a median incidence of 4.7%. Cervical and thoracic spinal injuries were more commonly associated with fever than lumbar injuries. In addition, complete injuries had a higher incidence of fever than incomplete injuries. The pathogenesis of neurogenic fever after acute SCI is not thoroughly understood. CONCLUSION: Neurogenic fevers are relatively common following an acute SCI; however, there is little in the scientific literature to help physicians prevent or treat this condition. The paucity of research underscored by this review demonstrates the need for further studies with larger sample sizes, focusing on incidence rate, clinical outcomes, and pathogenesis of neurogenic fever following acute traumatic SCI

Mission Design for the Exploration of Ice Giants, Kuiper Belt Objects and Their Moons Using Kilopower Electric Propulsion

The exploration of Ice Giants, Kuiper Belt Objects (KBOs) and their moons pose unique challenges from a mission design standpoint. NASA is currently developing a scalable 1-10 kilowatt electric class in-space fission reactor, known as Kilopower. The focus of this paper is to investigate the applicability of Kilopower Electric Propulsion to orbiting missions to Uranus, Neptune, and Pluto. This effort is broken into two pieces for each destination. First, a broad search of interplanetary trajectories with multiple gravity assists is completed to identify a range of mission opportunities from 2025 to 2045. Second, preliminary analysis is completed to understand the accessibility of various destination orbits, including elliptical orbits around the primary body and circular orbits around the largest moons. Results suggest that orbital missions to Uranus and Neptune are feasible with reasonable time of flight. Further work is necessary to achieve similar success with Pluto missions, but preliminary results are promising

Electron density stratification in two-dimensional structures tuned by electric field

A new kinetic instability which results in formation of charge density waves is proposed. The instability is of a purely classical nature. A spatial period of arising space-charge and field configuration is inversely proportional to electric field and can be tuned by applied voltage. The instability has no interpretation in the framework of traditional hydrodynamic approach, since it arises from modulation of an electron distribution function both in coordinate and energy spaces. The phenomenon can be observed in thin 2D nanostructures at relatively low electron density.Comment: 4 pages, 2 figure

Innovative interstellar explorer

An interstellar "precursor" mission has been under discussion in the scientific community for at least 30 years. Fundamental scientific questions about the interaction of the Sun with the interstellar medium can only be answered with in situ measurements that such a mission can provide. The Innovative Interstellar Explorer (IIE) and its use of Radioisotope Electric Propulsion (REP) is being studied under a NASA "Vision Mission" grant. Speed is provided by a combination of a high-energy launch, using current launch vehicle technology, a Jupiter gravity assist, and long-term, low-thrust, continuous acceleration provided by an ion thruster running off electricity provided by advanced radioisotope electric generators. A payload of ten instruments with an aggregate mass of ~35 kg and requiring ~30 W has been carefully chosen to address the compelling science questions. The nominal 20-day launch window opens on 22 October 2014 followed by a Jupiter gravity assist on 5 February 2016. The REP system accelerates the spacecraft to a "burnout" speed of 7.8 AU per year at 104 AU on 13 October 2032 (Voyager 1's current speed is ~3.6 AU/yr). The spacecraft will return at least 500 bits per second from at least 200 AU ~30 years after launch. Additional (backup) launch opportunities occur every 13 months to early 2018. In addition to addressing basic heliospheric science, the mission will ensure continued information on the far-heliospheric galactic cosmic ray population after the Voyagers have fallen silent and as the era of human Mars exploration begins

Physical Acoustics

Contains reports on eight research projects.Office of Naval Research (Contract Nonr-1841(42)United States Air Force, Air Force Cambridge Research Center, Air Research and Development Command (Contract AF19(604)-2051

Carbon stable isotope analysis of cereal remains as a way to reconstruct water availability: preliminary results

Reconstructing past water availability, both as rainfall and irrigation, is important to answer questions about the way society reacts to climate and its changes and the role of irrigation in the development of social complexity. Carbon stable isotope analysis of archaeobotanical remains is a potentially valuable method for reconstructing water availability. To further define the relationship between water availability and plant carbon isotope composition and to set up baseline values for the Southern Levant, grains of experimentally grown barley and sorghum were studied. The cereal crops were grown at three stations under five different irrigation regimes in Jordan. Results indicate that a positive but weak relationship exists between irrigation regime and total water input of barley grains, but no relationship was found for sorghum. The relationship for barley is site-specific and inter-annual variation was present at Deir ‘Alla, but not at Ramtha and Khirbet as-Samra

LEO to GEO (and Beyond) Transfers Using High Power Solar Electric Propulsion (HP-SEP)

Rideshare, or Multi-Payload launch configurations, are becoming more and more commonplace but access to space is only one part of the overall mission needs. The ability for payloads to achieve their target orbits or destinations can still be difficult and potentially not feasible with on-board propulsion limitations. The High Power Solar Electric Propulsion (HP-SEP) Orbital Maneuvering Vehicle (OMV) provides transfer capabilities for both large and small payload in excess of what is possible with chemical propulsion. Leveraging existing secondary payload adapter technology like the ESPA provides a platform to support Multi-Payload launch and missions. When coupled with HP-SEP, meaning greater than 30 kW system power, very large delta-V maneuvers can be accomplished. The HP-SEP OMV concept is designed to perform a Low Earth Orbit to Geosynchronous Orbit (LEO-GEO) transfer of up to six payloads each with 300kg mass. The OMV has enough capability to perform this 6 kms maneuver and have residual capacity to extend an additional transfer from GEO to Lunar orbit. This high deltaV capability is achieved using state of the art 12.5kW Hall Effect Thrusters (HET) coupled with high power roll up solar arrays. The HP-SEP OMV also provides a demonstration platform for other SEP technologies such as advanced Power Processing Units (PPU), Xenon Feed Systems (XFS), and other HET technologies. The HP-SEP OMV platform can be leveraged for other missions as well such as interplanetary science missions and applications for resilient space architectures