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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS2020

Psyche Magnetometer Engineering Model Test and Thermal Model Correlation to Validate Operational Thermal Requirement

Psyche Fluxgate Magnetometer candidate fabricated by UCLA has a critical temperature gradient requirement inside the magnetometer sensor head. Since the temperature gradient requirement is a driving factor for the magnetometer operation and science data collection at 16 Psyche, it is critical to validate and verify this requirement via modeling and test. In this work, a thermal vacuum test was completed for Psyche flight-like magnetometer engineering model. Flight-like environments were simulated for a hot operational case (after launch), a cold survival case (cruise), and two cold operational cases to characterize thermal performance of the instrument. An additional, non-flight, steady-state test case was completed to better correlate the magnetometer thermal model. During the test, sensitive Cernox temperature sensors with accuracy of ±0.1°C were used to precisely characterize the temperature gradient and correlate the model to the best accuracy. Collected test data indicated power consumption of 28% lower than predicted. The temperature gradient measured met the expected value and the requirement. Test data indicated the magnetometer also met the AFTs in relevant hot and cold environments. Test Results were used to correlate the thermal model. The correlated thermal model will be integrated to the spacecraft thermal model to predict magnetometer thermal performance while collecting science data in Psyche orbits.

Caron, Ryan↗
NASA NTRS2020

Solar Array Pointing Requirements Development for the Psyche Spacecraft

Pointing the solar array to the Sun is critical for the power management in all so-lar-powered space missions. This is particularly true for NASA’s Psyche mis-sion, which will explore the large asteroid (16) Psyche orbiting the Sun at around 3 AU. Due to the large distance to the Sun, use of electric propulsion, and sophisticated scientific orbits at Psyche, the definition of this pointing accu-racy became a challenging task for the spacecraft design, which involves the GNC, Power, and Thermal subsystems as well as Mission Design. This paper describes the story of how this complicated requirement development evolved for Psyche mission.

Madni, Ashley↗
NASA NTRS2020

Missed Thrust Requirements for Psyche Mission

The Psyche Mission, part of NASA’s Discovery Mission Program, will explore the metal asteroid (16) Psyche which orbits the sun at ~3 AU. The spacecraft uses solar electric propulsion (SEP) as its primary propulsion system during the ~3.5 year trajectory to (16) Psyche and 21 month orbital operations period around the asteroid. As the first NASA mission to use Hall thrusters for deep space exploration, unique challenges have been identified and resolved in how we plan to accommodate unplanned coast (missed thrust time) during the trajectory and orbital operations and still meet the mission objectives. This paper describes the projects missed thrust requirements in detail, along with the accompanying rationale and analysis plan for the Psyche mission.

Snyder, John Steven↗
NASA NTRS2020

Electric Propulsion for the Psyche Mission: Development Activities and Status

NASA’s Psyche mission will launch in 2022 and begin a 3.6-year cruise to the metallic asteroid Psyche, where it will examine this unique body. The baseline spacecraft design is a hybrid of JPL’s deep-space heritage subsystems with commercial partner Maxar’s electric propulsion, power, and structure subsystems. All primary propulsion will be done with SPT-140 thrusters, which will be the first use of Hall thrusters for a NASA mission. The electric propulsion subsystem and its implementation for the Psyche mission are described here. Major testing activities have included the successful completion of subsystem integrated testing with the design modifications required for Psyche, and a series of low-power thrust repeatability tests that were performed in support of navigation analyses. Thruster performance models have been further validated with new SPT-140 flight data, and new analyses of thruster swirl torque have been performed that result in much higher values than previously estimated. Analysis of recent Maxar flight data has also provided a new understanding of in-flight propellant usage uncertainties. Subsystem integration and test activities are now underway and the status and plans are discussed.

Johnson, Ian↗
NASA NTRS2021

Electric Propulsion for the Psyche Mission: One Year to Launch

NASA’s Psyche mission will launch in 2022 and begin a 3.6-year cruise to the metallic asteroid Psyche, the largest metal asteroid in the solar system. The baseline spacecraft design is a hybrid of JPL’s deep-space heritage subsystems with commercial partner Maxar’s electric propulsion, power, and structure subsystems. The Psyche mission will feature the first use of Hall thrusters for a NASA mission, and the first use of Hall thrusters beyond cis-lunar space. This paper will provide an overview of the electric propulsion subsystem and details of the flight system implementation for the Psyche mission. The concept of operations is discussed including subsystem-level operations, the initial checkout after launch, and cruise and orbital operations. Command and control interfaces with the spacecraft and fault protection design are presented. Finally, the status of subsystem assembly and test is described.

Li, Julie↗
DOE OSTI2025

Ground calibration and in-flight commissioning of the Gamma-Ray and Neutron Spectrometer (GRNS) for NASA’s Psyche mission

NASA's Psyche spacecraft is currently enroute to the asteroid 16 Psyche, where it will perform an orbital investigation focused on determining the nature of the asteroid. A key part of this investigation is measurements of elemental composition to determine if the asteroid is rich in iron-nickel metal. To that end, the Psyche spacecraft payload includes a Gamma-Ray and Neutron Spectrometer (GRNS). GRNS is composed of two subsystems; a Gamma-Ray Spectrometer (GRS) with a high-purity germanium γ-ray sensor surrounded by a borated plastic scintillator Anti-Coincidence Shield (ACS), and a Neutron Spectrometer (NS) with three 3 He-filled gas proportional counters that are sensitive to different neutron energy regimes. We describe results from the pre-launch calibration campaign, along with early in-flight results from post-launch instrument commissioning. The information detailed here is focused on providing future users of GRNS data with the information needed to properly interpret the observations from the instrument.

Peplowski, Patrick N. [Johns Hopkins Univ., Baltim↗
NASA NTRS2019

Numerical investigations of background pressure effects and channel erosion in the SPT-140 Hall thruster for the Psyche mission

Four SPT-140 Hall thrusters are the main components of the electric propulsion system for the Psyche mission. We employ the 2-D (r-z) code Hall2De to conduct numerical simulations of the SPT-140 with the goal of estimating erosion of the acceleration channel rings for the Psyche mission profile. The simulations are informed by direct measurements of the plasma conditions in the acceleration channel that were obtained using laser-induced fluorescence. We validate our simulation results with additional plasma measurements, wear test erosion rates, and performance data as a function of background pressure. We then make use of a series of numerical simulations to compute the progressive erosion of the channel walls, using as input parameters a profile for the Psyche mission that includes operation at 4.5, 2.5 and 1.0 kW with duration of all segments increased by a 50% margin. We find that the channel walls are not completely eroded at the end of the mission (plus 50% margin). We also observe a progressive decrease in thrust as the channel walls erode that is consistent with the wear test and flight data, with a rate of ~4.5 mN/kh for the first 2,500 h and constant thrust after that. The reasons for these thrust trends are explained.

Lenguito, Giovanni↗
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 NTRS2019

Sun search desgin for the Psyche spacecraft

Psyche is a scientific mission to explore the large asteroid (16) Psyche that orbits the Sun at ~3 AU. Managed by JPL, it is the first instance of Maxar’s product line of geosynchronous communication satellites being repurposed for deep space. This paper presents the design of a unique sun sensor configuration for Safe Mode of the spacecraft. It enables quick, robust, and propellant-efficient safing while leveraging sensors, avionics, and algorithms that have extensive, flight-proven heritages

Turner, Eric↗
NASA NTRS2019

Mechanism behind the dependence of thrust on facility backpressure and implications on the operation of the SPT-140 onboard the Psyche mission

The Psyche mission will employ Stationary Plasma Thrusters (SPT-140) for primary propulsion in space and will be the first to use Hall thrusters beyond lunar orbit. One of the longest standing risks in the implementation of this EP technology on missions like Psyche is our limited understanding of the effects of ground test facilities on the performance and wear of the thruster.

Lenguito, Giovanni↗
NASA NTRS2021

Psyche Science Planning with the Science Opportunity Analyzer

Psyche is a NASA Discovery mission intent on solving mysteries surrounding early planetary formation. The mission spacecraft will journey to (16) Psyche: a metallic asteroid believed to be the exposed core of an early planetesimal. Despite the unique nature of the target asteroid and the mission’s novel science goals, a significant portion of the project’s science planning needs may be met through the use of legacy tools. In particular, the adoption of the Jet Propulsion Laboratory’s (JPL) Science Opportunity Analyzer (SOA) promises to satisfy mission requirements with minimal development effort. Originally developed as a multi-mission science planning tool, SOA can design and visualize observations, perform geometric flight rule checking, model physical phenomena, and much more. The software has been used by the mission since its proposal phase and is expected to continue providing valuable capabilities throughout operations.

Elkins-Tanton, Linda T.↗
DOE OSTI2022

A compact light shield for the Psyche gamma-ray spectrometer

A compact, low-mass light shield has been designed for the Psyche space mission high-purity germanium gamma-ray spectrometer. The spectrometer will be vented to space, which can allow solar photons to enter the cryostat and cause charge-induced noise. The light shield was designed to block more than 99.9% of solar photons while maintaining high molecular conductance to space vacuum. COMSOL simulations and experiments were performed to characterize light shield photon attenuation and molecular conductance. Finally, the light shield was integrated onto the gamma-ray spectrometer and photon suppression and vacuum performance were demonstrated.

(16) Psyche↗
NASA NTRS1985

Pole orientation of 16 Psyche by two independent methods

Nineteen new lightcurves of 16 Psyche are presented along with a pole orientation derived using two independent methods, namely, photometric astrometry and magnitude-amplitude-shape-aspect. The pole orientations found using these two methods agree to within 4 deg. The results from applying photometric astrometry were prograde rotation, a sidereal period of 0.1748143 days + or - 0.0000003 days, and a pole at longitude 223 deg and latitude +37 deg, with an uncertainty of 10 deg, and, from applying magnitude-amplitude-shape-aspect a pole at 220 + or - 1 deg, +40 + or - 4 deg, and a modeled triaxial ellipsoid shape (a greater than b greater than c) and a/b = 1.33 + or - 0.07. The discrepancy between the high-pole latitude found here and the low latitudes reported by Lupishko et al. (1982) and Zhou and Yang (1982) is discussed.

Tedesco, E. F.↗
NASA NTRSDate not supplied

Psyche Hardware Abstraction Simulation Environment (PHASE): Development of High-Fidelity Downlink Model for Flight Software Performance Testing

NASA’s Katherine Johnson Independent Verification and Validation (IV&V) Independent Test Capability (ITC) Team develops high fidelity software-only simulations (or “digital-twins”) of NASA’s most critical missions that are then used for software verification and validation (V&V). One such digital-twin simulator nearing maturity is the Psyche Hardware Abstraction Simulation Environment (PHASE). PHASE utilizes an instruction set simulator along with ITC-developed avionics models. PHASE includes a newly-developed model of the telecom hardware with a high-fidelity downlink interface, capable of supporting reconfigurable downlink data rates and transmission modes. The different downlink transmission modes allow more processing to be ceded from software onto the telecom hardware. Thus, we are able to monitor the performance of the downlink software module in the time-partitioned OS and perform more realistic dynamic testing based on software’s resource utilization. This presentation will cover PHASE, avionics modeling, the downlink model, and its usage for flight software performance testing.

modeling↗
NASA NTRS2020

An Approach to Magnetic Cleanliness for the Psyche Mission

In this paper we describe the derivation of these requirements, test and analyses methods, and more generally the processes and procedures that govern the magnetics program for Psyche. The paper concludes with a discussion of the challenges and work to go and a comparison with the magnetic control processes of other missions with similar magnetic cleanliness constraints.

de Soria-Santacruz Pich, Maria↗