Planetary Airplane Extraction System Development and Subscale Testing

The Aerial Regional-scale Environmental Survey (ARES) project employs an airplane as the science platform from which to collect science data in the previously inaccessible, thin atmosphere of Mars. In order for the airplane to arrive safely in the Martian atmosphere a number of sequences must occur. A critical element in the entry sequence at Mars is an extraction maneuver to separate the airplane quickly (in less than a second) from its protective backshell to reduce the possibility of re-contact, potentially leading to mission failure. This paper describes the development, testing, and lessons learned from building a 1/3 scale model of this airplane extraction system. This design, based on the successful Mars Exploration Rover (MER) extraction mechanism, employs a series of trucks rolling along tracks located on the surface of the central parachute can. Numerous tests using high speed video were conducted at the Langley Research Center (LaRC) to validate this concept. One area of concern was that that although the airplane released cleanly, a pitching moment could be introduced. While targeted for a Mars mission, this concept will enable environmental surveys by aircraft in other planetary bodies with a sensible atmosphere such as Venus or Saturn s moon, Titan

Aircraft Configured for Flight in an Atmosphere Having Low Density

An aircraft is configured for flight in an atmosphere having a low density. The aircraft includes a fuselage, a pair of wings, and a rear stabilizer. The pair of wings extends from the fuselage in opposition to one another. The rear stabilizer extends from the fuselage in spaced relationship to the pair of wings. The fuselage, the wings, and the rear stabilizer each present an upper surface opposing a lower surface. The upper and lower surfaces have X, Y, and Z coordinates that are configured for flight in an atmosphere having low density

Design and evaluation of candidate pressure ports for the HYFLITE experiment

A concept for placing a pressure transducer directly in a shuttle type tile was developed at Langley Research Center. A 5 inch long quartz with a .020 inch inner diameter provides the thermal isolation necessary to allow 2800 F surface pressure measurements to be taken by pressure transducer rated at 250 F. The assembly is potted in place with RTV 560 in a piece of FRCI-12 thermal protection system insulation tile. The integrity of the thermal protection system is maintained even with the intrusion of the pressure port assembly and the pressure port does not disrupt the air flow across the lifting body. Approximately 200 of these pressure ports are to be used in each of the Hypersonic Flight Experiment (HYFLITE) flight tests. Initial vibroacoustic and aerothermal testing of the pressure port designs have been completed at Langley Research vibration laboratory and the 20 MWatt 2 x 9 turbulent duct facility at Ames Research Center. The performance of the pressure ports were found to be well within the required design limits for all cases. In addition, a failure mode in which the entire pressure port assembly was removed proved to be a begin case

Identification of host cell factors required for intoxication through use of modified cholera toxin

We describe a novel labeling strategy to site-specifically attach fluorophores, biotin, and proteins to the C terminus of the A1 subunit (CTA1) of cholera toxin (CTx) in an otherwise correctly assembled and active CTx complex. Using a biotinylated N-linked glycosylation reporter peptide attached to CTA1, we provide direct evidence that ∼12% of the internalized CTA1 pool reaches the ER. We also explored the sortase labeling method to attach the catalytic subunit of diphtheria toxin as a toxic warhead to CTA1, thus converting CTx into a cytolethal toxin. This new toxin conjugate enabled us to conduct a genetic screen in human cells, which identified ST3GAL5, SLC35A2, B3GALT4, UGCG, and ELF4 as genes essential for CTx intoxication. The first four encode proteins involved in the synthesis of gangliosides, which are known receptors for CTx. Identification and isolation of the ST3GAL5 and SLC35A2 mutant clonal cells uncover a previously unappreciated differential contribution of gangliosides to intoxication by CTx.Fundação para a Ciência e a Tecnologia (Fellowship

A Therapeutic Chemical Chaperone Inhibits Cholera Intoxication and Unfolding/Translocation of the Cholera Toxin A1 Subunit

Cholera toxin (CT) travels as an intact AB5 protein toxin from the cell surface to the endoplasmic reticulum (ER) of an intoxicated cell. In the ER, the catalytic A1 subunit dissociates from the rest of the toxin. Translocation of CTA1 from the ER to the cytosol is then facilitated by the quality control mechanism of ER-associated degradation (ERAD). Thermal instability in the isolated CTA1 subunit generates an unfolded toxin conformation that acts as the trigger for ERAD-mediated translocation to the cytosol. In this work, we show by circular dichroism and fluorescence spectroscopy that exposure to 4-phenylbutyric acid (PBA) inhibited the thermal unfolding of CTA1. This, in turn, blocked the ER-to-cytosol export of CTA1 and productive intoxication of either cultured cells or rat ileal loops. In cell culture studies PBA did not affect CT trafficking to the ER, CTA1 dissociation from the holotoxin, or functioning of the ERAD system. PBA is currently used as a therapeutic agent to treat urea cycle disorders. Our data suggest PBA could also be used in a new application to prevent or possibly treat cholera

Magnetostrictive Motor Development

AbstractThis paper reviews the history and present state of magnetostrictive devices capable of controlled motion over large linear distances. Magnetostriction imparts the most force perunit weight of any technology however, the successful development of practical devices requires a multi-disciplinary effort involving materials science, magnetics, innovative mechanical design, electrical power engineering, and system control engineering. Advances todate have included demonstrations linear motors capable of 115 Newtons of force at 2.54 centimeters/second.</jats:p

Persistent Assets in Zero-G and on Planetary Surfaces: Enabled by Modular Technology and Robotic Operations

Space operations are on the cusp of a revolutionary new operational paradigm that leverages modular systems and recurring robotic visits to Persistent Assets enabling asset maintenance, repair, and enhancement. A Persistent Asset is defined here as any zero-g or planetary surface system that benefits from in-space assembly (ISA) or multiple visits for servicing, repairs, and upgrades. This term is an extension of the term Persistent Platform used by Ms. Pam Melroy at the Defense Advanced Research Projects Agency to describe the vision of the Agency for a geosynchronous Earth orbiting platform. In this paper, the term Persistent Asset is introduced to encompass not only zero-g systems; such as telecommunication platforms, Earth observing science platform, Department of Defense platforms, and scientific telescope systems, but also planetary surface systems that support missions such as human outposts, science stations, and in-situ resource utilization systems. In contrast to the current state of the art, where space systems are typically launched as a single unit and operated without any further physical intervention after launch; future systems will be maintained, enhanced and reconfigured in-situ as new technology becomes available or mission needs change. Visits to the persistent asset can be regularly scheduled or dictated by funding constraints enabling a pay-as-you-go approach, which is largely independent of time-constraints and able to exploit launches of opportunity. In this paper, historical in-space assembly activities which relied heavily on astronaut extra-vehicular activity will be reviewed as well as early robotic assembly activities. These approaches will be contrasted with emerging modular approaches supporting realization of a new Persistent Asset operational paradigm. The paper will define attributes of the Persistent Asset paradigm and illustrate advantages by applying the paradigm to two relevant applications: 1) a large space telescope backing structure and 2) the backbone structure for a solar electric transport vehicle. Finally, recently developed unique Persistent Asset elements (modules, and interface approaches) will be described