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Found 5 entries in the Bibliography.
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Spectroscopic Measurements of the Ion Velocity Distribution at the Base of the Fast Solar Wind
In situ measurements of the fast solar wind reveal non-thermal distributions of electrons, protons, and minor ions extending from 0.3 au to the heliopause. The physical mechanisms responsible for these non-thermal properties and the location where these properties originate remain open questions. Here, we present spectroscopic evidence, from extreme ultraviolet spectroscopy, that the velocity distribution functions (VDFs) of minor ions are already non-Gaussian at the base of the fast solar wind in a coronal hole, at altit ...
Jeffrey, Natasha; Hahn, Michael; Savin, Daniel; Fletcher, Lyndsay;
Published by: The Astrophysical Journal Published on: 03/2018
YEAR: 2018   DOI: 10.3847/2041-8213/aab08c
Astrophysics - Solar and Stellar Astrophysics; line: profiles; parker solar probe; Solar Probe Plus; Solar wind; Sun: corona; Sun: heliosphere; Sun: UV radiation; techniques: spectroscopic
Risk reduction of integration and testing operations using augmented reality on Parker solar probe
Flying a spacecraft involves significant risks, but building and testing should not have to. At the Johns Hopkins University Applied Physics Laboratory (JHU APL), the Parker Solar Probe (PSP) program has leveraged Augmented Reality (AR) to reduce risks involved with mechanical integration and testing (I&T) operations of the spacecraft. Three major contexts benefitted using AR tools: 1) design and rehearsal of integration sequences and procedures, 2) planning and preparing for flight system level testing, and 3) communication ...
Hahne, Devin; Ruiz, Felipe; DeMatt, Nicholas; Fagan, Adam;
Published by: 30th Space Simulation Conference: Mission Success Through Testing of Critical Challenges Published on:
The radio frequency telecommunications system for the NASA Europa clipper mission
The NASA Europa Clipper mission, a partnership between the California Institute of Technology Jet Propulsion Laboratory (JPL) and the Johns Hopkins University Applied Physics Laboratory (APL), is currently in Phase B and scheduled for launch in 2022. A Jupiter orbiter, it will perform repeated flybys of the moon, Europa, to assess the icy moon’s structure and habitability. The spacecraft’s dual X/Ka-band radio frequency telecommunications subsystem has five primary functions: Provide spacecraft command capability ...
Srinivasan, Dipak; Angert, Matthew; Ballarotto, Mihaela; Berman, Simmie; Bray, Matthew; Garvey, Robert; Hahne, Devin; Haskins, Chris; Porter, Jamie; Schulze, Ron; Scott, Chris; Sharma, Avinash; Sheldon, Colin;
Published by: Proceedings of the International Astronautical Congress, IAC Published on:
Data handling; Earth (planet); Microwave antennas; NASA; Orbits; Propulsion; Radio navigation; Radio waves; Space flight; Telecommunication; Traveling wave tubes; Parker Engineering
Antenna scattering measurements using a scaled 3-D printed spacecraft model
A method to measure an antenna s performance when mounted to an electrically large and complex-shaped spacecraft is described. In the past, either time-intensive numerical simulations or antenna range measurements of an expensive full-scale model of the spacecraft were used to determine the antenna s performance. An alternative method fabricated a reduced-size scaled spacecraft model using 3-D printing processes. The antenna is also reduced in size by the same scale factor as the spacecraft, but the frequency of operation is ...
Sharma, Avinash; Hahne, Devin; Stilwell, Robert; Malouf, Perry;
Published by: 2016 IEEE Antennas and Propagation Society International Symposium, APSURSI 2016 - Proceedings Published on:
Ceramic coatings for the solar probe plus mission
A study was conducted to develop the coatings needed to protect the Solar Probe Plus Thermal Protection System (TPS) from the harsh environment. The TPS encountered harsh environment during its mission close to the sun, facing significant solar fluxes. The first part of the study addressed the way a coating s microstructure affected its optical properties and the way coatings were designed to maintain the right microstructure over temperature. The study was led by a researcher from the Advanced Technology Laboratory of the W ...
Mehoke, D.; Congdon, E.; , Drewry; Eddins, C.; Deacon, R.; Wolf, T.; Hahn, D.; King, D.; Nagle, D.; Buchta, M.; Zhang, D.; Hemker, K.; Spicer, J.; Jones, J.; Ryan, S.; Schlichter, G.;
Published by: Johns Hopkins APL Technical Digest (Applied Physics Laboratory) Published on:
Grain growth; Microstructure; Optical properties; Probes; Parker Engineering