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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 523 records · Page 29
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Operating and Maintaining the JWST Cleanroom attached to JSC's Chamber A during preparations for the OTIS Cryogenic Thermal Vacuum Test

In order to maintain cleanliness during preparations for JWST’s OTIS (Optical Telescope Element-Integrated Science Instrument Module) Cryogenic Thermal Vacuum Test, a cleanroom was built that attached directly to the 60-year-old Chamber A. The cleanroom and chamber were outfitted with independent environmental control systems each providing ISO Class 71 air cleanliness. To maintain balanced, positive pressure in both the cleanroom and chamber volumes, a special control protocol was developed and successfully implemented. Dual back-up environmental control units (one each for the chamber and cleanroom) were installed just outside the building to provide environmental control redundancy due to a single source chilled water supply and weather threats. In addition, lack of a dedicated cleanroom airlock facilitating clean ingress and egress made it necessary to perform additional cleaning and packaging, as well as augment the uncontrolled truck lock space with small clean tents for pre-cleaning. Special procedures were developed to allow ingress of extra-large support equipment required for load testing of the cleanroom crane, installation of optical equipment in Chamber A and accommodation of the OTIS shipping container. A thorough bake-out and cleaning of Chamber A was also necessary to reduce volatiles from the shroud’s black thermal paint and to reduce particle fallout. Acrylic adhesive fracture discovered during early cryo-testing represented a significant challenge that was successfully mitigated prior to OTIS testing. A dedicated team of Contamination Control (CC) Technicians was specifically trained to clean support equipment and screen materials entering the cleanroom and chamber to ensure cleanliness and vacuum compatibility.

James Webb Space Telescope↗
NASA NTRS2022

Structures of the Nitrogenase Complex Prepared Under Catalytic Turnover Conditions

The enzyme nitrogenase couples adenosine triphosphate (ATP) hydrolysis to the multielectron reduction of atmospheric dinitrogen into ammonia. Despite extensive research, the mechanistic details of ATP-dependent energy transduction and dinitrogen reduction by nitrogenase are not well understood, requiring new strategies to monitor its structural dynamics during catalytic action. Here, we report cryo–electron microscopy structures of the nitrogenase complex prepared under enzymatic turnover conditions. We observe that asymmetry governs all aspects of the nitrogenase mechanism, including ATP hydrolysis, protein-protein interactions, and catalysis. Conformational changes near the catalytic iron-molybdenum cofactor are correlated with the nucleotide-hydrolysis state of the enzyme.

Hannah L. Rutledge↗
NASA NTRS2022

Preparations for the Launch, Cruise, and Orbital Operations Phases of the Psyche Mission

“Psyche: Journey to a Metal World” was selected in 2017 as the 14th mission in NASA’s Discovery program. The mission uses an electric propulsion (EP) system to rendezvous with and orbit the large metal asteroid (16) Psyche. Spacecraft development is a hybrid approach with deep-space avionics provided by the Jet Propulsion Laboratory (JPL) and a solar electric propulsion chassis based on Maxar’s 1300-series GEO communications satellites. The payload suite is comprised of a magnetometer, multispectral imager, and gamma ray & neutron spectrometer science instruments and the Deep Space Optical Communications advanced technology demonstration.The spacecraft is currently in the final integration and test phase to support a planned launch period open in August 2022. With under a year until liftoff, final pre-liftoff preparations are underway for the mission’s major in-flight Phases. The Launch Phase is the mission’s only critical event as the vehicle autonomously deploys the solar arrays and delivers the spacecraft to a safe state. Following a planned 70-day Initial Checkout Phase, the spacecraft thrusts with the EP system through the majority of a 3.5-year Cruise Phase, which includes a Mars gravity assist, to rendezvous with (16) Psyche. The Approach Phase uses optical navigation while continuing to thrust with the EP engines to deliver the spacecraft into orbit. Orbital Operations are baselined for 20 months as the spacecraft steps through four progressively lower orbital altitudes to study the largest M-type asteroid in the solar system.

Hart, William↗
NASA NTRS2022

Preparing the Mars Relay Network for the Arrival of the Perseverance Rover at Mars

The Perseverance rover represents NASA’s latest achievement in Mars exploration. Landing successfully on 18 Feb 2021, the rover’s transmitted data during its entry, descent, and landing (EDL) were captured by the Mars Reconnaissance Orbiter (MRO) and the Mars Atmosphere and Volatile Evolution (MAVEN) orbiter. This data, broadcast in near-realtime to the world, allowed everyone to share in the excitement (and “terror”) of the day. The images returned thereafter included the first images of the new landing site, video of the landing itself taken from a variety of vantage points, and eventually the historic images of the first powered flight on another planet. Behind the scenes, the return of that data to Earth was accomplished via Mars orbiters operated by NASA and ESA, using three different ground tracking networks. Considered together, this Mars Relay Network (MRN) enabled the successful, timely, and unobtrusive return of the rover’s data. This paper describes the preparations taken by the participants of the MRN in anticipation of the arrival of Perseverance at Mars. These were not only focused on successfully acquiring the rover’s critical event telemetry during its EDL, but also on readying the network to return the rover’s data on an ongoing basis as it pursued its mission objectives. Included is a brief description of the MRN, which represents a highly successful international collaboration and continues as critical infrastructure for NASA’s and ESA’s ongoing Mars exploration. Also summarized are the activities performed prior to EDL, including landing site reconnaissance and mission test and training activities; those activities performed on EDL day, especially the recording, return, and processing of the rover’s critical event telemetry; and those activities that are now being performed on an ongoing basis during the rover’s surface operations, including an outline of the planning processes that enable relay services. Finally, a description of the performance of the network to-date on behalf of the Perseverance rover is given, summarizing the success of the network to provide support to both it and other spacecraft on the surface of Mars.

Srnka, Evan↗
NASA NTRS2023

Preparing for Exploration from the Surface of Our Sister Planet

Earth’s sister planet, Venus, is teeming with questions and mysteries, yet is a critical planet to explore as we seek to learn more about Earth, our solar system, and exoplanets. This presentation will touch on the motivation for exploring Venus, some of the mysteries that exist, the challenges we face, and what NASA is doing to prepare for landing and operating on this inhospitable world.

Venus↗
NASA NTRSDate not supplied

RST Optical Telescope Integration and Test Preparation

The OTA for the Nancy Grace Roman Space Telescope includes the primary mirror, secondary mirror, and aft optics for guiding light into the Wide Field Instrument and the Coronagraph Instrument. The telescope is taking shape as the tested optical mirror assemblies are integrated. The assemblies have been thermal cycled to the cold temperatures for infrared operation, load tested to launch loads, vibration tested, and optically tested. Testing included launch-level vibration testing of the 2.4-meter light-weighted primary mirror assembly. In addition, the telescope control electronics (TCE) box has been fully assembled and the environmental testing of the TCE is progressing. Pictures and descriptions of the integration and test progress are provided, along with performance results measured at these levels of assemblies. Planning and test equipment preparation for the telescope thermal vacuum testing continues including plans to take advantage of the large dynamic range available with focus diversity phase retrieval and a Shack-Hartmann wavefront sensor for the gravity-sagged primary mirror.

Tony L Whitman↗
NASA NTRSDate not supplied

Dragonfly Preparation for Powered Flight: Lander Separation State Control to Ensure Successful Landing

NASA’s Dragonfly mission, led by The Johns Hopkins University Applied Physics Laboratory, is a relocatable octocopter lander to study Saturn’s largest moon Titan. The scientific goals of the mission include studying Titan’s prebiotic chemistry, geology, and atmosphere. Upon Titan arrival, the lander will enter the atmosphere, descend on a parachute to a ground-relative altitude of about 1000 m before being released, and then fly on internal power down to the surface. To guarantee desirable initial conditions for the lander release, the lander must meet certain angular rate conditions. These conditions include reducing the spin rate about the vertical axis to 4.9 deg/sec, using the rotors as actuators; and releasing with a negative pitch rate (rotating nose down) to ensure a successful transition to powered flight. This is achieved using a release trigger. Achieving these desired rates for lander release is part of the mission phase known as ‘preparation for powered flight’ (PPF). This paper proposes controls and logic to achieve the desired conditions for releasing the lander from the parachute.

Flight Mechanics↗
NASA NTRSDate not supplied

pyQuARC: Preparing for Full Release

Metadata holds the contextual information about data and is the underlying structure for many data search portals. High quality metadata optimizes search results, allowing users to quickly retrieve the data they need. With the abundant volume and diversity of Earth observation datasets, data discovery and metadata quality are critical for end users. The Common Metadata Repository (CMR), for example, currently hosts metadata for over 9,000 Earth observation data products archived across 12 NASA Distributed Active Archive Centers (DAACs). The Analysis and Review of CMR (ARC) Team, located at Marshall Space Flight Center, assesses the completeness, correctness, and consistency of these metadata records to ensure they are accessible, usable, and discoverable. In 2021, ARC began developing pyQuARC, an open source library for Earth Observation Metadata Quality Assessment to automate this effort. The tool uses ARC’s existing metadata quality framework to provide prioritized recommendations for metadata improvement. During initial testing, pyQuARC automatically identified 58% of metadata findings when compared with a sample of manually reviewed records. Using the results from initial testing, this presentation will focus on recent advancements and improvements of the tool as the ARC team prepares for pyQuARC’s full release. It will also demonstrate pyQuARC's enrichment value, not only for the ARC team, but the broader EOSDIS metadata community as well.

Essence Raphael↗
NASA NTRSDate not supplied

Dragonfly Preparation for Powered Flight: Lander Separation State Control to Ensure Successful Landing

NASA’s Dragonfly mission, led by The Johns Hopkins University Applied Physics Laboratory, is a relocatable octocopter lander to study Saturn’s largest moon Titan. The scientific goals of the mission include studying Titan’s prebiotic chemistry, geology, and atmosphere. Upon Titan arrival, the lander will enter the atmosphere, descend on a parachute to a ground-relative altitude of about 1000 m before being released, and then fly on internal power down to the surface. To guarantee desirable initial conditions for the lander release, the lander must meet certain angular rate conditions. These conditions include reducing the spin rate about the vertical axis to 4.9 deg/sec, using the rotors as actuators; and releasing with a negative pitch rate (rotating nose down) to ensure a successful transition to powered flight. This is achieved using a release trigger. Achieving these desired rates for lander release is part of the mission phase known as ‘preparation for powered flight’ (PPF). This paper proposes controls and logic to achieve the desired conditions for releasing the lander from the parachute.

Flight Mechanics↗
NASA NTRSDate not supplied

Preparations for Laser Rayleigh Scattering Flow Visualization of Inert Ethane Plumes in PSI Environments at the NASA Langley 60-ft Vacuum Sphere

Understanding of the interaction between the plume and the regolith during powered descent are critical for reliable landings and to avoid damaging the vehicle or nearby infrastructure. To further study this complex flowfield, preparations are underway to describe the interrogation of an impinging ethane plume in lunar-relevant conditions within the 60-ft vacuum sphere at LaRC using Rayleigh diagnostics.

Flow Visualization↗
NASA NTRSDate not supplied

2024 Nasa Lunabotics University Competition: Site Preparation With Bulk Regolith

Introduction: Lunabotics provides accredited institutions of higher learning students (vocational-technical, college, university) an opportunity to apply the NASA systems engineering process to design and build a prototype robot. This robot would be capable of performing the proposed operations on the Lunar surface in support of future Artemis mission goals. Lunabotics features a systems engineering design challenge to engage students in the next phase of hu-man space exploration supporting the Artemis missions. This two-semester event encourages students to design and build an autonomous or telerobotic robot designed to traverse the simulated Lunar surface and complete the assigned construction tasks. The number of teams accepted into this challenge is not predetermined but is based on the scores and overall quality of the Project Management Plans received and other factors. The culmination of the Lunabotics virtual challenge will be the design, build and operation of a functional prototype Lunar robot. Teams are required to submit the following: (1) Project Management Plan, (2) Systems Engineering Paper, a (3) STEM Engage-ment Report, and a (4) Proof of Life Video. This is an optional item, but to qualify for the grand prize a team must also submit a: (5) Presentation and Demonstration. Background: The NASA Lunabotics University Competition was first held in 2010 as a follow on to the NASA Regolith Excavation Challenge [1]. The high level of interest and participation from over 50 universities each year has led to a sustained annual competi-ion cadence: it has been held every May for the past 14 years [2,3]. Over 6,000 students have participated and been inspired to pursue Science, Technology, En-gineering and Mathematics careers (STEM). 2024 Competition: The necessary lunar surface tasks are evolving to meet the NASA Artemis Mission requirements. In the past Lunabotics challenges we gathered data to support Lunar mining for consuma-bles in the Lunar regolith. Now, in 2024, the task is to gather data on Lunar site preparation and construction by designing and building a robot that will traverse the chaotic Lunar terrain and construct a regolith-based berm. The goal is to build a berm structure which would be useful to the Artemis Mission for blast and ejecta protection during lunar landings and launches, shading cryogenic propellant tank farms, providing radiation protection around a nuclear power plant and other mission critical uses. Lunabotics will consist of three separate events this year. The first event is NASA’s Lunabotics Project Development Challenge, where teams submit various deliverables to be scored by judges. The second event will be the University of Central Florida (UCF) Lunabotics Qualification challenge, in the Exolith laboratory, where teams will put their de-signs to the test. The top ten scoring teams from the Qualification challenge are then invited to the third and final event, NASA’s Lunabotics On-Site Challenge at Kennedy Space Center in Florida. This presentation will summarize the results and lessons learned from the NASA Lunabotics University Competition held in May 2024.

Lunabotics↗
NASA NTRSDate not supplied

2024 Nasa Lunabotics University Competition: Site Preparation With Bulk Regolith

Lunabotics provides accredited in-stitutions of higher learning students (vocational-technical, college, university) an opportunity to apply the NASA systems engineering process to design and build a prototype robot. This robot would be capable of performing the proposed operations on the Lunar sur-face in support of future Artemis mission goals. Lunabotics features a systems engineering design challenge to engage students in the next phase of hu-man space exploration supporting the Artemis missions. This two-semester event encourages students to design and build an autonomous or telerobotic robot designed to traverse the simulated Lunar surface and complete the assigned construction tasks. The number of teams accepted into this challenge is not predetermined but is based on the scores and overall quality of the Project Management Plans received and other factors.

Lunabotics↗