Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “FY19”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

15 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2019

Mars Ascent Vehicle Hybrid Propulsion Development

Mars Ascent Vehicle Study Agenda: Potential Mars Sample Return (MSR); Potential Hybrid Design; 2019 Preliminary Architecture Assessment; Propellant Combination - Fuel; Propellant Combination - Oxidizer; Full Scale Testing thru 2018; Hypergolic Ignition; TEA/TEB (triethylaluminum/triethylborane) Ignition; Solid Hypergolic Additives; 2018 test - longest duration test; 2019 test; Liquid Injection Thrust Vector Control; White Sands Test Facility; FY19 and Future Work; Summary.

Story, George↗
NASA NTRS2019

High Velocity Impact Performance of a Dual Layer Thermal Protection System for the Mars Sample Return Earth Entry Vehicle

The Mars Sample Return (MSR) Earth Entry Vehicle (EEV) is currently planned on being released from its Micro-Meteorite/Orbital Debri (MM/OD) shielding housing about two days before the Earth entry phase. This leaves the EEV exposed to incoming MM/OD impacts, potentially damaging the heat shield and compromising its Entry, Decent, and Landing (EDL) integrity. Currently, two materials are proposed to comprise the MSR-EEV heat shield, a dual layer material Heat-shield for Extreme Entry Environment Technology (HEEET) and Phenolic Impregnated Carbon Ablator (PICA). PICA has been well characterized for OD class impacts, ~7km/s high mass impacts, from previous testing done in the Orion program, but hasn't under-gone extensive MM impact testing. HEEET is a rela-tively new material with minimal prior testing in re-gards to High Velocity Impacts (HVI). In order to in-form selectability of a material, it is crucial to under-stand the material performance when faced with an HVI, directly affecting mission success probability.The current measure of a Thermal Protection Sys-tem's (TPS) performance against an HVI is evaluating a thermally sized material against its derived Balistic Limit Equation (BLE). A BLE is generated empirically from multiple shots of HVI testing, and is used as a first order method in evaluating TPS's performance against the expected MM/OD environment. This method has proved useful for previous uniform densi-ty TPS materials, but has never been validated against a dual layer recession material such as HEEET. Testing in the MSR program for FY19 has a re-quirement to assess the effects of a dual layer TPS by testing various thicknesses of HEEET's Recession Layer, seen in Figure 1. From this data, BLE's will be derived for the individual thickness ratio samples, as well as the material as a whole to evaluate if a heritage form of the BLE can capture the complex physics associated with a dual layer system. Crater morpholo-gy will also be assessed with post-test Non-Destructive Evaluation (NDE) methods such as CT scanning to visualize if a BLE can well predict the associated pene-tration depths, since a BLE assumes full disinigration of the impacting particle and is generally only used to size a spherical crater ? disregarding any shrapenel effects from a high density impactor.To inform this analysis, expected MM environ-ments from the Meteoroid Engineering Model (MEM) and analytical equations for mass flux of incoming MM were evaluated against the notional MSR-EEV trajectory [1]. Using those dispersions, a monte-carlo was run to determine the most probable particle pa-rameters, as well as the riskiest in terms of full bondline penetration. From these probabilities, a test matrix was designed to test against bounding cases for the various parameters of the BLE: projectile density, projectile mass, projectile velocity, and the impact angle.This presentation will discuss the performance of the dual layer TPS material HEEET against a wide range of impact kinetic energies and densitites, as well as the comparison of HEEET to PICA in terms of MM/OD performance and selectability criteria.

Libben, B. J.↗
NASA NTRS2019

A Single Stage to Orbit Design for a Hybrid Mars Ascent

A Single Stage to Orbit (SSTO) hybrid propulsion system has been previously studied as an option for a conceptual Mars Ascent Vehicle (MAV). The hybrid motor uses a wax-based fuel developed specifically for this application, so it can take advantage of a single port design. The oxidizer is Mixed Oxides of Nitrogen (MON-25). Higher Nitric Oxide concentrations have been discussed in the past, however, the lower temperature capability is no longer needed. The MAV Payload Assembly (MPA), which would house the Orbiting Sample (OS) has changed substantially from previous iterations and has become more compact. Benefits of the hybrid option include its predicted low temperature behavior, high performance and ability to restart (enabling the SSTO). However, the hybrid technology remained at a relatively low Technology Readiness Level (TRL). In an attempt to increase the TRL, a technology development program has been underway for the past four years. The results of the technology development program are now being incorporated to an updated concept for a hybrid Mars Ascent Vehicle, with the eventual goal of informing a hybrid propulsion design that closes under the guidelines currently envisioned for a potential Mars Sample Return campaign. This paper focuses on the hybrid propulsion system design and the preliminary results from the first part of the FY19 technology development program (October 2018 to July 2019) and includes some results from a Preliminary Architecture Assessment (PAA) study. In the PAA, experts from all relevant subsystems (propulsion, avionics, GN&C, structures, thermal, etc.) are brought together to determine an updated vehicle design. The PAA is being run out of Marshall Space Flight Center (MSFC) in coordination with the Mars Sample Return study lead by the Jet Propulsion Laboratory (JPL). Currently, it is thought that the Mars Ascent Vehicle would be housed in a Sample Retrieval Lander (SRL), along with a fetch rover. The SRL would be responsible for several crucial functions on the MAV including heating, erection and providing the ignition signal. This paper will also outline the future testing and path forward through the rest of the fiscal year. This includes full scale testing at Whittinghill Aerospace, hypergolic additive testing at Purdue, evaluation of adding hypergolic additives to a full-scale grain. A hybrid fuel formulation has been updated with a reduced regression rate, which again was developed by Space Propulsion Group. This design will be used to determine the benefits of a hybrid versus solid propulsion system for a MAV, as they fit into the larger vision for a potential Mars Sample Return campaign.

Story, George↗
NASA NTRS2021

Hydrocarbon Cold-Flow Simulation of LOX/LH2 Rocket Aerodynamics

In FY19, this project developed a test method which employed heated ethane in the physical simulation of rocket plume aerodynamics. Based on this work, EUS partnered with significant leveraged funding. A portable, self-contained test bed was also fabricated to support validation of the new method. In FY20, this project focused on the formal validation of ethane’s performance as an aerodynamic simulant as well as the development of the analytical and hardware infrastructure required to carry out that task. The test bed was activated, a series of heated-ethane tests on one or more rocket/diffuser configurations were conducted, and characterizations of the performance of the ethane simulation compared to hot-fire were performed. A series of 127 tests were conducted on 13 aerodynamic configurations to evaluate ethane’s performance as a simulant. It was found that the new methodology can reproduce rocket plume flow fields with +/- 0.5% pressure error at ~3% physical scale. The result is a cost-per-test reduction of ~99% compared to the hot-fire subscale testing typically used to obtain equivalent data. Some initial efforts have taken place, and future efforts are being planned with LaRC supersonic retro propulsion and MSFC SLS aerodynamics teams, which are interested in using the ethane system to wind-tunnel test human-rated Mars lander retrorockets and SLS Booster. Details of the prototypical experiments were published as NASA TM 2020-5009122,and have been presented in JANNAF Virtual Conference paper, "New Developments in Retro propulsion Testing for Mars Entry, Descent and Landing".

Daniel Jones↗
NASA NTRS2021

Multi-Physics Based Thermo-Well Fatigue Design Tool

In this study, mathematical-based models for fatigue life were developed for Resistance Temperature Detectors (RTDs)/thermo-wells in high-pressure, cryogenic flow environments. A literature review that identified bench-scale stainless steel fatigue data at cryogenic temperatures that can be used to validate fatigue life mathematical models was pursued. Developing the ability to predict the fatigue life of RTDs/thermo-wells in high-pressure, cryogenic flow environments, especially liquid oxygen (LOX), will lead to a lower incidence of RTD damage and failure during propulsion test activities. During this performance period, the project was transitioned to a computational RTD/thermos-well fatigue modeling effort rather than the previously proposed experimental fatigue testing in FY19 since the computational modeling approach will provide a better fundamental understanding of fatigue behavior at cryogenic temperatures prior to pursuing potentially costly experimental tests. Due to COVID-19 issues impairing access to some needed university partnerships, tools and lab facilities, FY20efforts are continuing into FY21 and will be reported upon in greater detail in the FY21 report

Harry Ryan↗
NASA NTRS2021

Logistics Reduction: RFID Enabled Autonomous Logistics Management (REALM) (LR-REALM)

The Advanced Exploration Systems (AES) Logistics Reduction (LR) project Radio-frequency identification (RFID) Enabled Autonomous Logistics Management (REALM) task focuses on the subset of autonomous logistics management functions pertaining to automated localization and inventory of all physical assets pertaining to, or within, a vehicle utilizing RFID technologies. REALM technology can provide detailed data to enable autonomous operations such as automated crew procedure generation and robotic interaction with logistics and deep space habitats; this is especially of value where communication delays with Earth drive the need for self-reliance. The REALM project will conduct a series of ISS technology demonstrations. The first ISS demonstration, REALM-1, started in February 2017 and was completed at the end of FY19 when it was transitioned to the ISS program for sustaining operations. The second ISS demonstration, REALM-2, started late2019 and will continue for at least one year.

NASA TechPort↗
NASA NTRS2022

Characterization of Lunar Polar Volatiles for Curation and ISRU - Executive Summary

The goal of this project is to support lunar exploration by simulating and characterizing ice and volatile-rich materials expected to be found at the lunar poles. These materials are highly sensitive to heating, which could significantly alter their composition and prevent scientific studies on lunar samples. During FY19, we obtained materials for and designed a simulated lunar environment, within which volatile-rich simulant could be made. We also refined the procedure for moderate-fidelity lunar simulants at cryogenic temperatures. In FY20, we completed our test setup, and we can now reach cryogenic temperatures and near-lunar pressures with active compositional monitoring of volatiles in the vapor phase. For FY21, we: 1) progressed towards developing sample storage temperature requirements for volatile-rich samples by completing storage testing, along with materials testing for Artemis geologic sampling, 2) obtained instrumentation for solid sample monitoring to characterize solid species, and 3) progressed towards water extraction testing for ISRU. Our test results will directly feed into Artemis science requirements, hardware designs for sample return, vehicle requirements (HLS, Gateway, Orion), and operations planning for lunar exploration activities.

Julie L Mitchell↗
NASA NTRS2022

Exploring the Clouds of Venus: Science Driven Aerobot Missions to Our Sister Planet

Venus is essential to our understanding of the evolution and habitability of Earth-size planets throughout the galaxy. The selection of the VERITAS, EnVision, and DAVINCI missions by NASA and ESA in June 2021 is an important step in advancing the science. However, addressing many of the most challenging questions will require in situ platforms that can operate in the Venus environment for extended periods in order to capture the full complexity of our sister planet. Aerobots are aerial vehicles that exploit buoyancy to achieve long-duration operation in the Venus cloud layer where environmental conditions are comparatively benign. Buoyancy control, explained in more detail in a companion paper at this conference, allows aerobots to change altitude with little energy expenditure enabling new scientific measurement opportunities. These include atmospheric chemistry, dynamics, geophysical measurements of the crust and interior and geological investigations enabled by high resolution surface imaging. One aspect to our approach to defining missions that fit within the resource constraints of competitive missions is keeping the scale small. Today’s science-driven appetite for sophisticated measurements and large volumes of data is driving size upwards but advances in technology can enable aerobots that can be delivered to Venus at manageable costs. The other aspect is supporting the aerobot at Venus with orbiters providing data relay, localization and synergistic science. The recently selected orbiters, equipped with low-cost proximity relay systems routinely used at Mars may obviate the need for dedicated orbiters thereby enabling Discovery mission candidates. Four aerobot mission concepts have been defined which fit comfortably within the current New Frontiers (NF) cost cap ($900M in $FY22). One of these concepts would also be a candidate for a Discovery mission if that cost cap ($500M in $FY19) were raised. Raising the NF cost cap would enable more capable aerobot missions combining both altitude control with synergistic orbital observations. Investigations of surface geology at high resolution with subcloud NIR nightside imaging and dropsondes on the dayside of Venus could also benefit from collaborations with foreign contributions.

"O'Rourke, Joseph"↗