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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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101 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Recovery from Missed Thrust During Gateway's NRHO Insertion Using Auxiliary Propulsion

Various strategies are assessed by which the first two elements of Gateway could recover from missed thrust events during insertion into a Near Rectilinear Halo Orbit (NRHO). Recovery strategies are assessed in terms of their ability to maintain the desired NRHO insertion epoch ad well as their cost in terms of additional time and ∆v required to reach the NRHO. Strategies utilize a 50 kW Solar Electric Propulsion (SEP) system onboard the Power and Propulsion Element (PPE). Recovery solutions are found that, in the event of a missed thrust arc during the Insertion Phase of the Gateway Lunar Transit, deliver the space-craft into the NRHO within three additional revolutions (roughly 21 days) and 80 m/s ∆v.

missed thrust↗
NASA NTRSDate not supplied

SR-1 Freedom Thermal Architecture Challenges

The SR-1 Freedom mission aims to demonstrate nuclear electric propulsion (NEP) and deliver the Skyfall helicopter payload to Mars. Repurposing the existing Gateway Power and Propulsion Element (PPE) spacecraft and combining it with a 20 kWe-class nuclear power module (NPM) presents a variety of thermal architecture challenges. These include unprecedented waste heat rejection requirements, integration with a spacecraft bus originally designed for a different mission profile, and novel packaging constraints. This presentation will describe the simplified concept of operations as it relates to on-orbit thermal environments, early-phase architecture trades and supporting analyses, and planned forward work. We will also discuss our strategy for integrated thermal modeling of the complete spacecraft and examples of interface challenges necessitated by this ambitious effort.

Thermal↗
NASA NTRSDate not supplied

Analysis of Cislunar Transfers Departing from a Near Rectilinear Halo Orbit Using Solar Electric Propulsion

An analysis is completed to support the design of optimized trajectories of a massive spacecraft from an L2 Southern NRHO to a Distant Retrograde Orbit and a L2 Northern NRHO using a Solar Electric Propulsion System (SEP). An optimized trajectory is developed for each transfer for a 54t spacecraft utilizing a 26.6kW SEP system. A parameterization is developed for each reference transfer to allow analysis of the sensitivity of the trajectory to changes in vehicle mass, SEP power, and Ion Propulsion System (IPS) performance. Required Dv for each transfer is characterized by the initial acceleration of the spacecraft, thus allowing trajectories to be assessed over a wide range of vehicle mass and SEP power inputs. This approach is shown to be useful in identifying optimal IPS configurations for minimizing propellant requirements for the reference transfers. Additionally, the analysis identifies regions where increases in SEP power do not immediately result in a corresponding decrease in required propellant as well as highlights the relative sensitivities of propellant requirements to changes in IPS thrust and specific impulse.

low thrust↗
NASA NTRS2022

Constraining Clouds and Convective Parameterizations in A Climate Model Using Paleoclimate Data

Cloud and convective parameterizations strongly influence uncertainties in equilibrium climate sensitivity. We provide a proof-of-concept study to constrain these parameterizations in a perturbed parameter ensemble of the atmosphere-only version of the Goddard Institute for Space Studies Model E2.1 simulations by evaluating model biases in the present-day runs using multiple satellite climatologies and by comparing simulated δ 18 O of precipitation (δ 18 O p ), known to be sensitive to parameterization schemes, with a global database of speleothem δ 18 O records covering the Last Glacial Maximum (LGM), mid-Holocene (MH) and pre-industrial (PI) periods. Relative to modern interannual variability, paleoclimate simulations show greater sensitivity to parameter changes, allowing for an evaluation of model uncertainties over a broader range of climate forcing and the identification of parts of the world that are parameter sensitive. Certain simulations reproduced absolute δ 18 O p values across all time periods, along with LGM and MH δ 18 O p anomalies relative to the PI, better than the default parameterization. No single set of parameterizations worked well in all climate states, likely due to the non-stationarity of cloud feedbacks under varying boundary conditions. Future work that involves varying multiple parameter sets simultaneously with coupled ocean feedbacks will likely provide improved constraints on cloud and convective parameterizations.

cloud and convective parameterization↗
NASA NTRSDate not supplied

NASA Progress on the Development and Qualification of a 12-kW Hall-Effect, Solar Electric Propulsion Thruster

The National Aeronautics and Space Administration (NASA) continues to evolve the human exploration approach for beyond low-Earth orbit and in a manner involving international, academic, and industry partners. The center of this approach is NASA’s Gateway program that will establish a permanent human presence in lunar orbit for human cislunar science, operations, and lunar surface access to eventually land the next American astronauts on the south pole of the Moon. In support of the effort, NASA’s Space Technology Mission Directorate (STMD) began a project to increase the state of the art for the Hall-Effect Solar Electric Propulsion (SEP) technology. The resulting Advanced Electric Propulsion System (AEPS) project has developed a 12 kW Hall-effect thruster in support of the Gateway program. The project is managed by the NASA Glenn Research Center (GRC), supported by the NASA Jet Propulsion Laboratory (JPL) with development, qualification & flight hardware all supplied by L3 Harris Aerojet Rocketdyne (AR). Development of the 12-kW Hall thruster electric propulsion system began with maturation of the Hall Effect Rocket with Magnetic Shielding (HERMeS) Technology Demonstration Units (TDUs). The technology development was then transitioned to AR via the AEPS contract, which built and tested two Engineering Test Unit (ETU) thrusters and multiple critical components. The project transitioned to the production of the three flight thrusters and entered qualification testing at the component and thruster levels.

Electric Propulsion↗
NASA NTRSDate not supplied

NASA Progress on the Development and Qualification of a 12-kW Hall-Effect, Solar Electric Propulsion Thruster

The National Aeronautics and Space Administration (NASA) continues to evolve the human exploration approach for beyond low-Earth orbit and in a manner involving international, academic, and industry partners. The center of this approach is NASA’s Gateway program that will establish a permanent human presence in lunar orbit for human cislunar science, operations, and lunar surface access to eventually land the next American astronauts on the south pole of the Moon. In support of the effort, NASA’s Space Technology Mission Directorate (STMD) began a project to increase the state of the art for the Hall-Effect Solar Electric Propulsion (SEP) technology. The resulting Advanced Electric Propulsion System (AEPS) project has developed a 12 kW Hall-effect thruster in support of the Gateway program. The project is managed by the NASA Glenn Research Center (GRC), supported by the NASA Jet Propulsion Laboratory (JPL) with development, qualification & flight hardware all supplied by L3 Harris Aerojet Rocketdyne (AR). Development of the 12-kW Hall thruster electric propulsion system began with maturation of the Hall Effect Rocket with Magnetic Shielding (HERMeS) Technology Demonstration Units (TDUs). The technology development was then transitioned to AR via the AEPS contract, which built and tested two Engineering Test Unit (ETU) thrusters and multiple critical components. The project transitioned to the production of the three flight thrusters and entered qualification testing at the component and thruster levels.

Electric Propulsion↗
NASA NTRS2026

A Missed Thrust Framework for Low-Thrust Spiral Trajectories to the NRHO

A framework is developed by which end-to-end optimization of many-revolution low-thrust spiral trajectories can be completed in the presence of missed thrust events. This framework is applied to the Lunar Transit trajectory by which the initial capability of NASA’s Gateway lunar space station will be delivered to a Near Rectilinear Halo Orbit. This low-thrust mission consists of three subphases, each designed according to the specific objectives and dynamical regimes encountered as the mission progresses from a medium Earth insertion orbit to cislunar space. The presented framework accounts for the unique considerations demanded by each mission phase and incorporates appropriate capabilities into a novel mission analysis tool. This methodology enables large scale and reliable analyses of missed thrust events across the end-to-end Lunar Transit to verify the robustness of flight trajectories across the full range of considered launch dates.

missed thrust↗
NASA NTRSDate not supplied

Mission Design Considerations for a Low-Thrust Spacecraft

Developing an executable low-thrust trajectory for use in a spaceflight mission requires the design and optimization of a deterministic trajectory as well as the validation that the selected architecture is robust to some set of uncertainties, execution errors, and potential contingencies. Uncertainty in the ability of the spacecraft and its launch vehicle to execute a trajectory as well as potential deviations such as in-flight anomalies combine with design-to constraints and requirements to complicate the optimization problem. The approach by which robust mission design was accomplished for the initial capability of NASA’s Gateway is presented as well as associated results.

NRHO↗
NASA NTRSDate not supplied

Mission Design Considerations for a Low-Thrust Spacecraft

Developing an executable low-thrust trajectory for use in a spaceflight mission requires the design and optimization of a deterministic trajectory as well as the validation that the selected architecture is robust to some set of uncertainties, execution errors, and potential contingencies. Uncertainty in the ability of the spacecraft and its launch vehicle to execute a trajectory as well as potential deviations such as in-flight anomalies combine with design-to constraints and requirements to complicate the optimization problem. The approach by which robust mission design was accomplished for the initial capability of NASA’s Gateway is presented as well as associated results.

mission design↗