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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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At least 361 records · Page 20
All sourcesNASA NTRSDOE OSTI
NASA NTRS2008

A Human Espophageal Epithelial Cell Model for Study of Radiation Induced Cancer and DNA Damage Repair

For cancer risk assessment in astronauts and for countermeasure development, it is essential to understand the molecular mechanisms of radiation carcinogenesis and how these mechanisms are influenced by exposure to the types of radiation found in space. We are developing an in vitro model system for the study of radiation-induced initiation and progression of esophageal carcinoma, a type of cancer found to have a significant enhancement in incidence in the survivors of the atomic bomb detonations in Japan. Here we present the results of our preliminary characterization of both normal and hTERT immortalized esophageal epithelial cells grown in 2-dimensional culture. We analyzed DNA repair capacity by measuring the kinetics of formation and loss of - H2AX foci following radiation exposure. Additionally, we analyzed induction of chromosomal aberrations using 3-color fluorescence in situ hybridization (FISH). Data were generated using both low LET (gamma rays) and high LET ions (1000 MeV/nucleon iron).

Huff, Janice L.↗
NASA NTRS2008

Technical Aspects of the Space Telescope Imaging Spectrograph Repair (STIS-R)

In August 2004, the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) ceased operation, due to a failure in the Side 2 Low Voltage Power Supply (LVPS2). LVPS2 provided power to the entire instrument, including all detectors and mechanisms. Following the LVPS2 failure, a team was assembled to analyze the fault and to determine if STIS repair (STIS-R) was feasible. The team concluded that by replacing a power supply board within LVPS2, STIS could be brought back to full functionality. STIS-R will be conducted during Servicing Mission 4 (SM4), and will consist of replacing the power supply board and a new passive cooling system. STIS-R will restore full function of the instrument with one of the two redundant sides of the instrument. In this presentation, we focus on the technical aspects associated with STISR.

Rinehart, Stephen↗
NASA NTRS2008

Technical Aspects of the Advanced Camera For Surveys Repair (ACS-R)

The ACS Repair (ACS-R) team includes contributors from NASA's Goddard Space Flight Center, Ball Aerospace, and Teledyne Imaging Sensors; It determined that all of the capabilities of the ACS could be restored and created a concept for the ACS-R component of SN4. ACSR will restore the WFC of ACS by replacing the existing CCD Electronics Box (CEB) with the CEB-Replacement (CEB-R) and providing power from a new Low Voltage Power Supply Replacement (LVPS-8). The new LVPS-R will also attempt to restore the HRC function by providing power through the original power bus. In this presentation, we faeus on the concept and technical aspects of the ACS-R.

Rinehart, Stephen↗
NASA NTRS2009

Damage Detection and Self-Repair in Inflatable/Deployable Structures

Inflatable/deployable structures are under consideration for applications as varied as expansion modules for the International Space Station to destinations for space tourism to habitats for the lunar surface. Monitoring and maintaining the integrity of the physical structure is critical, particularly since these structures rely on non-traditional engineering materials such as fabrics, foams, and elastomeric polymers to provide the primary protection for the human crew. The closely related prior concept of monitoring structural integrity by use of built-in or permanently attached sensors has been applied to structures made of such standard engineering materials as metals, alloys, and rigid composites. To effect monitoring of flexible structures comprised mainly of soft goods, however, it will be necessary to solve a different set of problems - especially those of integrating power and data-transfer cabling that can withstand, and not unduly interfere with, stowage and subsequent deployment of the structures. By incorporating capabilities for self-repair along with capabilities for structural health monitoring, successful implementation of these technologies would be a significant step toward semi-autonomous structures, which need little human intervention to maintain. This would not only increase the safety of these structures, but also reduce the inspection and maintenance costs associated with more conventional structures.

Brandon, Erik↗
NASA NTRS2010

Test Validation of the Repair to the Space Station Solar Alpha Rotary Joint (SARJ)

The SARJ LITE (Lubrication Interval Test) test rig was built as a method to evaluate the performance of the grease repair on the Starboard SARJ of the International Space Station(ISS). The on-orbit SARJ was temporarily parked after receiving significant degradation on one of its race ring nitrided surfaces as a result of inadequate lubrication ( high dry contact friction) and unaccounted for roller traction kinematics. In a scaled down rig, flight like roller bearings were preloaded and cycled on a nitrided 15-5 race surface. Grease was added to the track and with instrumentation monitoring performance, trending data will be extracted and used to determine lubrication intervals for both Port and Starboard ISS SARJ's. The grease lubrication was found to be effective in eliminating the high friction that contributed to the on-orbit race degradation.

Allmon, Curtis↗
NASA NTRS2009

Apparatus and method for enhancing tissue repair in mammals

An apparatus is introduced for the use of enhancing tissue repair in mammals. The apparatus includes a sleeve; an electrically conductive coil; a sleeve support; an electrical circuit configured to supply the coil with a square wave time varying electrical current sufficient to create approximately 0.05 gauss to 0.5 gauss. When in use, the sleeve of the apparatus is placed on a mammalian body part and the time varying electromagnetic force of from approximately 0.05 gauss to 0.5 gauss is generated on the mammalian body for an extended period of time so that the tissue is encouraged to be regenerated in the mammalian body part at a rate in excess of the normal tissue regeneration rate relative to regeneration without application of the time varying electromagnetic force.

Goodwin, Thomas J.↗
NASA NTRS2010

Mission Reliability Estimation for Repairable Robot Teams

A mission reliability estimation method has been designed to translate mission requirements into choices of robot modules in order to configure a multi-robot team to have high reliability at minimal cost. In order to build cost-effective robot teams for long-term missions, one must be able to compare alternative design paradigms in a principled way by comparing the reliability of different robot models and robot team configurations. Core modules have been created including: a probabilistic module with reliability-cost characteristics, a method for combining the characteristics of multiple modules to determine an overall reliability-cost characteristic, and a method for the generation of legitimate module combinations based on mission specifications and the selection of the best of the resulting combinations from a cost-reliability standpoint. The developed methodology can be used to predict the probability of a mission being completed, given information about the components used to build the robots, as well as information about the mission tasks. In the research for this innovation, sample robot missions were examined and compared to the performance of robot teams with different numbers of robots and different numbers of spare components. Data that a mission designer would need was factored in, such as whether it would be better to have a spare robot versus an equivalent number of spare parts, or if mission cost can be reduced while maintaining reliability using spares. This analytical model was applied to an example robot mission, examining the cost-reliability tradeoffs among different team configurations. Particularly scrutinized were teams using either redundancy (spare robots) or repairability (spare components). Using conservative estimates of the cost-reliability relationship, results show that it is possible to significantly reduce the cost of a robotic mission by using cheaper, lower-reliability components and providing spares. This suggests that the current design paradigm of building a minimal number of highly robust robots may not be the best way to design robots for extended missions.

Trebi-Ollennu, Ashitey↗
NASA NTRS2010

Test Validation of the Repair to the Space Station Solar Alpha Rotary Joint

The Solar Array Alpha Joint Lubrication Interval Test (SARJ LITE) test rig was built as a method to evaluate the performance of the grease repair on the Starboard SARJ of the International Space Station (ISS) . The on-orbit SARJ was temporarily parked after receiving significant damage on one of its race ring surfaces as a result of inadequate lu brication (high dry contact friction) and unaccounted for roller traction kinematics. In a scaled down rig, flight-like roller bearings wer e preloaded and cycled on a nitrided 15-5 race surface. Grease was ad ded to the track and with instrumentation monitoring performance, trending data will be extracted and used to determine lubrication interva ls for both Port and Starboard ISS SARJ?s. The grease lubrication was found to be effective in eliminating the high friction that contributed to the onorbit race damage.

Allmon, Curtis↗
NASA NTRS2010

Adaptable Holders for Arc-Jet Screening Candidate Thermal Protection System Repair Materials

Reusable holders have been devised for evaluating high-temperature, plasma-resistant re-entry materials, especially fabrics. Typical material samples tested support thermal-protection-system damage repair requiring evaluation prior to re-entry into terrestrial atmosphere. These tests allow evaluation of each material to withstand the most severe predicted re-entry conditions.

Riccio, Joe↗
NASA NTRS2011

Component-Level Electronic-Assembly Repair (CLEAR) Synthetic Instrument Capabilities Assessment and Test Report

The role of synthetic instruments (SIs) for Component-Level Electronic-Assembly Repair (CLEAR) is to provide an external lower-level diagnostic and functional test capability beyond the built-in-test capabilities of spacecraft electronics. Built-in diagnostics can report faults and symptoms, but isolating the root cause and performing corrective action requires specialized instruments. Often a fault can be revealed by emulating the operation of external hardware. This implies complex hardware that is too massive to be accommodated in spacecraft. The SI strategy is aimed at minimizing complexity and mass by employing highly reconfigurable instruments that perform diagnostics and emulate external functions. In effect, SI can synthesize an instrument on demand. The SI architecture section of this document summarizes the result of a recent program diagnostic and test needs assessment based on the International Space Station. The SI architecture addresses operational issues such as minimizing crew time and crew skill level, and the SI data transactions between the crew and supporting ground engineering searching for the root cause and formulating corrective actions. SI technology is described within a teleoperations framework. The remaining sections describe a lab demonstration intended to show that a single SI circuit could synthesize an instrument in hardware and subsequently clear the hardware and synthesize a completely different instrument on demand. An analysis of the capabilities and limitations of commercially available SI hardware and programming tools is included. Future work in SI technology is also described.

Oeftering, Richard C.↗
NASA NTRS2008

The Repair and Return to Flight of Solid Rocket Booster Forward Skirt Serial Number 20022

On April 5, 1991, a solid rocket booster (SRB) forward skirt serial number (S/N) 20022 sustained buckling damage during water impact after the launch of Space Transportation System Flight 37 (STS-37). As of that date, five forward skirts had been lost during water impact. Repair attempts began with the least damaged skirt available (S/N 20022). Sp ecial hydraulic tooling was used to remove buckled areas of the skirt. Afterwards, its aft clevis pinholes were found to be out of alignment with the redesigned solid rocket motor (RSRM) check gauge, but weld passes were used to correct this condition. Meanwhile, USA Analytics generated mechanical property data for buckled and subsequently debuckled material. Their analysis suggested that structural integrity might be improved by adding stringer reinforcements, stiffeners, to the aft bay section of the skirt. This improvement was recommended as a fleet modification to be implemented on a case-by-case basis.

Malone, T. W.↗
NASA NTRS2012

TPS Inspection and Repair

Dr. Scott Parazynski provided a retrospective on the EVA tools and procedures efforts NASA went through in the aftermath of Columbia for the Shuttle Thermal Protection System (TPS) inspection and repair. He describes his role as the lead astronaut on this effort, and covered all of the Neutral Buoyancy Lab (NBL), KC 135 (reduced gravity aircraft), Precision Air Bearing Floor (PABF), vacuum chamber and 1 G testing that was done in order to develop the tools and techniques that were flown. Parazynski also discusses how the EVA community worked together to resolve a huge safety issue, and how his work in the spacesuit was critical to overcoming a design limitation of the Space Shuttle.

Parazynski, Scott↗
NASA NTRS2015

Space Station Solar Array Joint Repair

In Oct 2007 the International Space Station (ISS) crew noticed a vibrating camera in the vicinity of Starboard Solar Alpha Rotary Joint (SARJ). It had less than 5 months of run time when the anomaly was observed. This approximately 3.2 meter diameter bearing joint supports solar arrays that power the station critical to its operation. The crew performed an EVA to identify what was causing the vibration. It was discovered that one of the 3 bearing tracks of this unconventional bearing had significant spalling damage. This paper discusses the SARJ's unique bearing design and the vulnerability in its design leading to the observed anomaly. The design of a SARJ vacuum test rig is also described along with the results of a life test that validated the proposed repair should extend the life of the SARJ a minimum of 18 years on-orbit.

Loewenthal, Stuart↗
NASA NTRS2015

The Microwave Assisted Composite Manufacturing and Repair (MACMAR) Project

The inherent microwave property of carbon nanotubes (CNTs) generates the thermal energy required to induce reversible polymerization of the matrix in these self-healing composites. Microwaves will be used to demonstrate advanced composite manufacturing and repair using self-healing composites.

Falker, John↗
NASA NTRS2018

Composite Bonded Joint: Repair Development

This report documents the details of my work as a NASA KSC intern for the Fall Session from August 27th to December 14th, 2018. My efforts and contributions were with the Materials Science Branch, a staffed organization within the Laboratories, Development, & Testing (NE-L) Division of the Engineering Directorate. The principle responsibilities of the Materials Science group are to support the design, development, and operations activities for materials and processes with the purpose of providing unique solutions for flight hardware, ground support equipment, and customer requests. My role as an intern focused on assisting engineers in developing repair processes to mature bonded joint technology in support of SLS ? scale hardware. My primary goals for this internship were to become more familiar with composite materials and learn more about processes I was unfamiliar with, such as prepregs and out-of-autoclave processing. This project allowed me to learn new skills such as scarfing and curing composites. Additional goals I had were to learn more about NASA's laboratories and projects under development. This internship not only provided me with those experiences, but also allowed me to build relationships with inspiring engineers; a takeaway I will never forget.

Composite Materials↗
NASA NTRS2020

A Bi-Exponential Repair Algorithm for Radiation-Induced Double-Strand Breaks: Application to Chromosome Aberrations

Chromosome aberrations (CAs) are one of the effects of radiation exposure and are used as a biomarker. A new simulation program, named RITCARD (Radiation induced tracks, chromosome aberrations, repair, and damage) was developed to simulate radiation-induced CA. RITCARD is used with the program RITRACKS (Relativistic Ion Tracks), which simulates the radiation tracks. The restitution kinetics algorithm presented here is a significant improvement over the one used in the first version. Simulations of radiation-induced CA were performed for several ion types and mixed irradiation fields. These simulations will be useful to help interpreting experiments of galactic cosmic rays (GCR) simulator.

Plante, Ianik↗