Geodynamic evolution of the orogen : the West Carpathian and Ouachitas case study

Twelve time interval maps have been presented which depict the plate tectonic configuration, paleogeography and lithofacies for the circum-arpathian area from the Late Carboniferous through Neogene and for the circum-Ouachita region from Late Cambrian through Early Permian. The following geodynamic evolutionary stages can be distinguished in these two orogens: Stage I - rifting of terranes off the major continent, forming oceanic basins (Triassic-Early Cretaceous in the Carpathian region, Cambrian-Devonian in the Ouachita region); Stage II - formation of subduction zones along the active margin, partial closing of oceanic basin, development of deep-water flysch basin associate with this rifting on the platform (passive margin) with the attenuated continental crust (Late Cretaceous-Paleocene in the Carpathian region, Early Carboniferous in the Ouachitas); Stage III - collision, perhaps terrane-continent, with the accompanying conver- gence of two large continents, development of accretionary prisms, Eocene-Early Miocene time in the Carpathian region, Late Carboniferous in the Ouachitas; and Stage IV - postcollisional, (Miocene-Present-future? in the Carpathians, Permian-Triassic in the Ouachitas). Both, Carpathians and Ouachitas are accretionary prisms formed in response to terrane-continent and continent-continent collision. The paleogeographic approach we have taken shows how these mountain belts were constructed through the orogenic cycle, which reflects complex plate tectonic processes. Carpathians and Ouachitas record complete and homologous Wilson cycle

The Journey Of The Lunar Flashlight Propulsion System From Launch Through End Of Mission

The Lunar Flashlight Propulsion System (LFPS) was developed as a technology demonstration to enable the Lunar Flashlight spacecraft to reach Lunar orbit and to desaturate onboard reaction wheels. While the system produced over 16 m/s of delta-v and successfully managed momentum, variable thrust performance, most likely due to debris in the propellant flow path, kept the spacecraft from reaching the Moon. This paper details the in-flight journey of the LFPS, highlighting both successes and challenges met throughout the mission, and provides lessons learned applicable to future CubeSat missions and additively manufactured propulsion systems

Overview of the Development of the Advanced Electric Propulsion System (AEPS)

NASA is committed to the demonstration and application of high-power solar electric propulsion to meet its future mission needs. It is continuing to develop the 14 kW Advanced Electric Propulsion System (AEPS) under a project that recently completed an Early Integrated System Test (EIST) and System Preliminary Design Review (PDR). In addition, NASA is pursuing external partnerships in order to demonstrate Solar Electric Propulsion (SEP) technology and the advantages of high-power electric propulsion-based spacecraft. The recent announcement of a Power and Propulsion Element (PPE) as the first major piece of an evolvable human architecture to Mars has replaced the Asteroid Redirect Robotic Mission (ARRM) as the most likely first application of the AEPS Hall thruster system. This high-power SEP capability, or an extensible derivative of it, has been recognized as a critical part of a new, affordable human exploration architecture for missions beyond-low-Earth-orbit. This paper presents the status of AEPS development activities, and describes how AEPS hardware will be integrated into the PPE ion propulsion system

Overview of the Development and Mission Application of the Advanced Electric Propulsion System (AEPS)

NASA remains committed to the development and demonstration of a high-power solar electric propulsion capability for the Agency. NASA is continuing to develop the 14 kilowatt Advanced Electric Propulsion System (AEPS), which has recently completed an Early Integrated System Test and System Preliminary Design Review. NASA continues to pursue Solar Electric Propulsion (SEP) Technology Demonstration Mission partners and mature high-power SEP mission concepts. The recent announcement of the development of a Power and Propulsion Element (PPE) as the first element of an evolvable human architecture to Mars has replaced the Asteroid Redirect Robotic Mission as the most probable first application of the AEPS Hall thruster system. This high-power SEP capability, or an extensible derivative of it, has been identified as a critical part of an affordable, beyond-low-Earth-orbit, manned-exploration architecture. This paper presents the status of the combined NASA and Aerojet AEPS development activities and updated mission concept for implementation of the AEPS hardware as part of the ion propulsion system for a PPE

Lessons Learned During the Implementation of a Cold Gas Propulsion System for the SunRISE Mission

The SunRISE mission utilizes a two-phase cold gas propulsion system, which provides several advantages over other cold gas systems but experienced challenges during assembly and testing. Since 2020, Georgia Tech Research Corporation (GTRC), Utah State University Space Dynamics Laboratory (SDL), and the Jet Propulsion Laboratory (FPL) have implemented several improvements to the SunRISE propulsion system. The SunRISE propulsion system leverages an additively manufactured monolithic structure, commercial off-the-shelf (COTS) valves and transducers, and the benign working fluid R-236fa to provide a suitable propulsion system for the SunRise mission. While the GTRC propulsion system had been developed for other missions, the multi-organizational team found and corrected several previously undetected design issues, including filters with highly variable flow performance, solenoid valve drive circuit issues, and inconsistencies in the tank additive manufacturing process that impacted manufacturing yield, thrust consistency, and quality of seals. Leaks in metallic fittings were also identified, and process improvements were put in place to mitigate them. Solenoid valve stiction was the last issue which was mitigated through valve screening and drive circuit adjustments. In this paper, we present lessons learned from the SunRISE propulsion system effort to aid future teams in identifying and addressing similar issues

In-flight propulsion system characterization for both Mars Exploration Rover Spacecraft

Two Mars Exploration Rover spacecraft were dispensed to red planet in 2003, culminating in a phenomenally successful prime science mission. Twin cruise stage propulsion systems were developed in record time, largely through heritage with Mars Pathfinder. As expected, consumable usage was minimal during the short seven-month cruise for both spacecraft. Propellant usage models based on pressure and temperature agreed with throughput models with in a few percent. Trajectory correction maneuver performance was nominal, allowing the cancellation of near-Mars maneuvers. Spin thruster delivered impulse was 10-12% high vs. ground based models for the intial spin-down maneuvers, while turn performance was XX-XX% high/low vs. expectations. No clear indications for pressure transducer drift were noted during the brief MER missions

Interactions between Macroparticles and High-Energy Proton Beams

A known threat to the availability of the LHC is the interaction of macroparticles (dust particles) with the LHC proton beam. At the foreseen beam energy of 6.5 TeV during Run 2, quench margins in the superconducting magnets will be 2-3 times lower, and beam losses due such interactions may result in magnet quenches. The study introduce an improved numerical model of such interactions, as well as Monte-Carlo simulations that give the probability that such events will result in a beam-dump during Run 2

Domain-Specific Languages and Diagram Customization for a Concurrent Engineering Environment

A major open question for advocates of Model-Based Systems Engineering (MBSE) is the question of how system and subsystem engineers will work together. The Systems Modeling Language (SysML), like any language intended for a large audience, is in tension between the desires for simplicity and for expressiveness. In order to be more expressive, many specialized language elements may be introduced, which will unfortunately make a complete understanding of the language a more daunting task. While this may be acceptable for systems modelers, it will increase the challenge of including subsystem engineers in the modeling effort. One possible answer to this situation is the use of Domain-Specific Languages (DSL), which are fully supported by the Unified Modeling Language (UML). SysML is in fact a DSL for systems engineering. The expressive power of a DSL can be enhanced through the use of diagram customization. Various domains have already developed their own schematic vocabularies. Within the space engineering community, two excellent examples are the propulsion and telecommunication subsystems. A return to simple box-and-line diagrams (e.g., the SysML Internal Block Diagram) are in many ways a step backward. In order allow subsystem engineers to contribute directly to the model, it is necessary to make a system modeling tool at least approximate in accessibility to drawing tools like Microsoft PowerPoint and Visio. The challenge is made more extreme in a concurrent engineering environment, where designs must often be drafted in an hour or two. In the case of the Jet Propulsion Laboratory's Team X concurrent design team, a subsystem is specified using a combination of PowerPoint for drawing and Excel for calculation. A pilot has been undertaken in order to meld the drawing portion and the production of master equipment lists (MELs) via a SysML authoring tool, MagicDraw. Team X currently interacts with its customers in a process of sharing presentations. There are several inefficiencies that arise from this situation. The first is that a customer team must wait two weeks to a month (which is 2-4 times the duration of most Team X studies themselves) for a finalized, detailed design description. Another is that this information must be re-entered by hand into the set of engineering artifacts and design tools that the mission concept team uses after a study is complete. Further, there is no persistent connection to Team X or institutionally shared formulation design tools and data after a given study, again reducing the direct reuse of designs created in a Team X study. This paper presents the underpinnings of subsystem DSLs as they were developed for this pilot. This includes specialized semantics for different domains as well as the process by which major categories of objects were derived in support of defining the DSLs. The feedback given to us by the domain experts on usability, along with a pilot study with the partial inclusion of these tools is also discussed