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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 91 records · Page 5

Analysis of quasi-hybrid solid rocket booster concepts for advanced earth-to-orbit vehicles

A study was conducted to assess the feasibility of quasi-hybrid solid rocket boosters for advanced Earth-to-orbit vehicles. Thermochemical calculations were conducted to determine the effect of liquid hydrogen addition, solids composition change plus liquid hydrogen addition, and the addition of an aluminum/liquid hydrogen slurry on the theoretical performance of a PBAN solid propellant rocket. The space shuttle solid rocket booster was used as a reference point. All three quasi-hybrid systems theoretically offer higher specific impulse when compared with the space shuttle solid rocket boosters. However, based on operational and safety considerations, the quasi-hybrid rocket is not a practical choice for near-term Earth-to-orbit booster applications. Safety and technology issues pertinent to quasi-hybrid rocket systems are discussed.

Zurawski, Robert L.↗

Analysis of quasi-hybrid solid rocket booster concepts for advanced earth-to-orbit vehicles

A study was conducted to assess the feasibility of quasi-hybrid solid rocket boosters for advanced earth-to-orbit vehicles. Thermochemical calculations were conducted to determine the effect of liquid hydrogen addition, solids composition change plus liquid hydrogen addition, and the addition of an aluminum/liquid hydrogen slurry on the theoretical performance of a PBAN solid propellant rocket. The Space Shuttle solid rocket booster was used as a reference point. All three quasi-hybrid systems theoretically offer higher specific impulse when compared with the Space Shuttle solid rocket boosters. However, based on operational and safety considerations, the quasi-hybrid rocket is not a practical choice for near-term earth-to-orbit booster applications. Safety and technology issues pertinent to quasi-hybrid rocket systems are discussed.

Zurawski, Robert L.↗

Plasma Rocket With Hybrid Exhaust Plume

Proposed plasma rocket, described in report, generates hybrid exhaust plume comprising annular layer of relatively cool neutral gas around plasma core. Plasma and gas intermix, providing gradual radial transition between the two. Amount of gas injected adjusted to control propulsive efficiency; relatively cool gas boundary layer at surface of nozzle insulates nozzle from high plasma temperature.

Chang, Franklin R.↗

A 6U Hybrid Propulsion Module for CUBESATS

A 6U hybrid propulsion module is presented. It is designed to be used as a stage for a 6U CubeSat with a combined wet mass up to 25 kg. Hybrid rocket propulsion is utilized because it is responsive, high performance, capable of multiple burns and safe/non-toxic. Hybrid rockets employ a solid fuel and liquid or gaseous oxidizer. In this case, the fuel is PolyMethyl MethAcrylate and the oxidizer is gaseous oxygen. This propellant combination produces an Isp of greater than 300 seconds. The gaseous oxidizer simplifies the design and is used in dual mode with cold gas thrusters for attitude control. In general, hybrid propulsion is higher performance and higher thrust than conventional options considered for CubeSats (e.g. monopropellants), making it ideal for larger manuevers such as plane changes. The Attitude Control System has been sized to ensure that the CubeSat can be controlled under the thrust loads of the propulsion system. A hybrid rocket motor of this size is currently being tested at the Jet Propulsion Laboratory. Thirty-four successful tests have been completed at JPL with this propellant combination during the last 2.5 years. Current tests include long duration tests (> 95 seconds) and multiple starts (five). These tests and applicability to potential mission requirements will be discussed. Future test plans to move the motor into a vacuum facility to achieve a Technology Readiness Level of 5 by the end of September 2018 will be discussed, and an overview of the proposed TRL 5 to 6 maturity plan will also be presented.

Nakazono, B.↗

Large-Scale Hybrid Motor Testing

Hybrid rocket motors can be successfully demonstrated at a small scale virtually anywhere. There have been many suitcase sized portable test stands assembled for demonstration of hybrids. They show the safety of hybrid rockets to the audiences. These small show motors and small laboratory scale motors can give comparative burn rate data for development of different fuel/oxidizer combinations, however questions that are always asked when hybrids are mentioned for large scale applications are - how do they scale and has it been shown in a large motor? To answer those questions, large scale motor testing is required to verify the hybrid motor at its true size. The necessity to conduct large-scale hybrid rocket motor tests to validate the burn rate from the small motors to application size has been documented in several place^'^^.^. Comparison of small scale hybrid data to that of larger scale data indicates that the fuel burn rate goes down with increasing port size, even with the same oxidizer flux. This trend holds for conventional hybrid motors with forward oxidizer injection and HTPB based fuels. While the reason this is occurring would make a great paper or study or thesis, it is not thoroughly understood at this time. Potential causes include the fact that since hybrid combustion is boundary layer driven, the larger port sizes reduce the interaction (radiation, mixing and heat transfer) from the core region of the port. This chapter focuses on some of the large, prototype sized testing of hybrid motors. The largest motors tested have been AMROC s 250K-lbf thrust motor at Edwards Air Force Base and the Hybrid Propulsion Demonstration Program s 250K-lbf thrust motor at Stennis Space Center. Numerous smaller tests were performed to support the burn rate, stability and scaling concepts that went into the development of those large motors.

Story, George↗

Peregrine 100-km Sounding Rocket Project

The Peregrine Sounding Rocket Program is a joint basic research program of NASA Ames Research Center, NASA Wallops, Stanford University, and the Space Propulsion Group, Inc. (SPG). The goal is to determine the applicability of this technology to a small launch system. The approach is to design, build, and fly a stable, efficient liquefying fuel hybrid rocket vehicle to an altitude of 100 km. The program was kicked off in October of 2006 and has seen considerable progress in the subsequent 18 months. This research group began studying liquifying hybrid rocket fuel technology more than a decade ago. The overall goal of the research was to gain a better understanding of the fundamental physics of the liquid layer entrainment process responsible for the large increase in regression rate observed in these fuels, and to demonstrate the effect of increased regression rate on hybrid rocket motor performance. At the time of this reporting, more than 400 motor tests were conducted with a variety of oxidizers (N2O, GOx, LOx) at ever increasing scales with thrust levels from 5 to over 15,000 pounds (22 N to over 66 kN) in order to move this technology from the laboratory to practical applications. The Peregrine program is the natural next step in this development. A number of small sounding rockets with diameters of 3, 4, and 6 in. (7.6, 10.2, and 15.2 cm) have been flown, but Peregrine at a diameter of 15 in. (38.1 cm) and 14,000-lb (62.3-kN) thrust is by far the largest system ever attempted and will be one of the largest hybrids ever flown. Successful Peregrine flights will set the stage for a wide range of applications of this technology.

Zilliac, Gregory↗

Development Concepts for Mars Ascent Vehicle (MAV) Solid and Hybrid Vehicle Systems

Mars Ascent Vehicle (MAV) Study Introduction: Previous Studies -Solid, liquid and hybrid rocket propulsion feasibility studies since 2011 -Focus on hybrid rocket propulsion since 2016; Reassessing Propulsion Systems for Risk Reduction - Liquid propulsion vehicle found to not be feasible; Challenges -An autonomous return mission has never been done -Mars surface environments -Platform packaging limitations -Performance and trajectory requirements; Study Team -MSFC’s Advanced Concepts Office (ACO) -MSFC propulsion and vehicle design engineering expertise -JPL MAV team.

McCollum, Lisa Tunstill↗

Experimental investigation of a solid rocket combustion simulator

The response of solid rocket motor materials to high-temperature corrosive gases is usually accomplished by testing the materials in a subscale solid rocket motor. While this imposes the proper thermal and chemical environment, a solid rocket motor does not provide practical features that would enhance systematic evaluations such as: the ability to throttle for margin testing, on/off capability, low test cost, and a low-hazards test article. Solid Rocket Combustion Simulators (SRCS) are being evaluated by NASA to test solid rocket nozzle materials and incorporate these essential practical features into the testing of rocket materials. The SRCS is designed to generate the thermochemical environment of a solid rocket. It uses hybrid rocket motor technology in which gaseous oxygen (Gox) is injected into a chamber containing a solid fuel grain. Specific chemicals are injected in the aft mixing chamber so that the gases entering the test section match the temperature and a non-dimensional erosion factor B' to insure similarity with a solid motor. Because the oxygen flow can be controlled, this approach allows margin testing, the ability to throttle, and an on/off capability. The fuel grains are inert which makes the test article very safe to handle. The objective of this work was to establish the baseline operating characteristics of a Labscale Solid Rocket Combustion Simulator (LSRCS). This included establishing the baseline burning rates of plexiglass fuels and the evaluation of a combustion instability for hydroxy-terminated polybutadyene (HTPB) propellants. The scope of the project included: (1) activation of MSFC Labscale Hybrid Combustion Simulator; (2) testing of plexiglass fuel at Gox ranges from 0.025 to 0.200 lb/s; (3) burning HTPB fuels at a Gox rate of 0.200 lb/s using four different mixing chamber configurations; and (4) evaluating the fuel regression and chamber pressure responses of each firing.

Frederick, Robert A., Jr.↗

Hybrids - Best of both worlds

An overview is presented of hybrid rocket propulsion systems whereby combining solids and liquids for launch vehicles could produce a safe, reliable, and low-cost product. The primary subsystems of a hybrid system consist of the oxidizer tank and feed system, an injector system, a solid fuel grain enclosed in a pressure vessel case, a mixing chamber, and a nozzle. The hybrid rocket has an inert grain, which reduces costs of development, transportation, manufacturing, and launch by avoiding many safety measures that must be taken when operating with solids. Other than their use in launch vehicles, hybrids are excellent for simulating the exhaust of solid rocket motors for material development.

Goldberg, Ben E.↗

Hybrids for heavy-lift propulsion - Unsolved problems

The basic unsolved problems of hybrid rockets are examined with the aim of facilitating solutions which could enable the attainment of the full potentials of the hybrid as a heavy-lift propulsion system. The advantages of safety, cost-effectiveness, stop-restart capability, and simplicity of the manufacturing process are reviewed. Attention is given to a comprehensive turbulent hybrid rocket combustion model.

Ramohalli, Kumar↗

Mars Ascent Vehicle Hybrid PropulsionEffort

A technology development program was undertaken to determine if the benefits of hybrid rocket propulsion could be realized for a Mars Ascent Vehicle (MAV) application. Specifically, the goal of this program was to increase the Technology Readiness Level (TRL) of a hybrid propulsion system such that it could be considered for a potential Mars Sample Return Campaign. Over the course of approximately five years, a new, wax-based fuel was developed, characterized and tested with Mixed Oxides of Nitrogen (from MON-3 to MON-25). Various ignition mechanisms were tested and solid hypergolic additives were evaluated for their potential to ignite the hybrid motor. Several hot-fire test campaigns were completed at both sub- and full-scale. The technology development program was born out of a JPL study documented by Shotwell and Karp that identified the Single Stage to Orbit (SSTO) hybrid propulsion system for a potential Mars Ascent Vehicle to be the lowest Gross Lift Off Mass option from the ten configurations evaluated. Benefits of the hybrid option included its predicted favorable low temperature storage and operation behavior, high performance and ability to restart (enabling the SSTO). The main disadvantage of the hybrid option was its low TRL,as it essentially started as a blank sheet design with a new fuel development. Near the end of the technology development program, a Preliminary Architecture Assessment (PAA) was completed to evaluate a single-stage hybrid propulsion system and a two-stage solid propulsion system for a potential MAV. The solid propulsion system was selected for further study in 2019, primarily because of its flight heritage. While the hybrid technology development program made many strides, there was still a list of challenges to overcome. This paper will discuss the substantial progress and remaining challenges from the technology development effort from 2015 through 2019. This includes fuel development and reformulation, sub- and full-scale testing at Space Propulsion Group, full scale testing at Parabilis, full scale testing at Whittinghill Aerospace, hypergolic additive testing at Purdue and Penn State and the evaluation of adding hypergolic additives to a full-scale grain. It also includes a discussion of the design that resulted from the Preliminary Architecture Assessment.

hybrid rocket↗

Hybrid Propulsion In-Situ Resource Utilization Test Facility Results for Performance Characterization

Hybrid propulsion presents a promising alternative to conventional systems for in-space propulsion applications using In-Situ Propellant Production (ISPP). A hybrid propulsion test facility has been built at the NASA Jet Propulsion Laboratory (JPL) with the capability of evaluating ISPP oxidizers (gaseous mixtures of O2 and CO2) and modifying fuel type and chamber geometry. This work is the result of a continuing e ort at JPL to characterize the burn characteristics and performance of different propellant combinations and motor configurations in order to re ne and support preliminary designs. Twelve tests using gaseous oxygen and two paraffin based fuels (Black Paraffin and SP1X) from the 2015 campaign are presented. Different reduction techniques are compared in an e ort to determine the uncertainty associated with deriving a regression rate law and evaluating c* efficiency with the collected data.Hybrid motors are mechanically and chemically simple propulsion systems that have the potential forlong-term storability with low gross mass. The oxidizer (such as gaseous O2) can be produced in-situ,signicantly reducing the landed mass. The solid, inert fuel is stored in the combustion chamber in its most dense state, further reducing the total structural mass and volume. Considerable eorts have been focusedon ISPP for Environmental Control and Life Support Systems (ECLSS) and human exploration of Mars.At optimum oxidizer to fuel ratio (O/F), about 70% of the total propellant mass could be produced in-situ.Paran based fuels exhibit a fast regression rate behavior due to the formation of a thin liquid layer on thefuel surface.1 A high burn rate is necessary in order to reach a medium to high thrust range. In order toachieve an O/F ratio close to optimum performance (between 2.1 and 2.7 for the O2/Paran combination),the fuel mass ow needs to be suciently large compared to the oxidizer ow. The slow regression rateof classical hybrid rocket fuels leads to long fuel grain designs or complicated multi-port structures. Singleport, high regression rate fuels have the potential to reduce residual propellant mass and have a grainlength to diameter ratio (L/D) more favorable for packaging. However, hybrid motors remain at a fairly lowTechnology Readiness Level (TRL), and solutions to accurately measure and increase performance are stilllacking, especially for small-scale motors that are constrained to tight packaging.A total of 12 hotres were performed and analyzed in this campaign. All of these tests were conductedat pressures above the critical pressure of paran wax, approximately 6.7 bar (97 psi).2 Three dierentmotor congurations were explored while conserving a single cylindrical port fuel grain. Additionally, sincethrottling is a crucial advantage of hybrid rocket propulsion systems, low oxidizer mass ows (60 - 100 g/s)and uxes (5 - 30 g/cm2/s) were investigated to determine the performance impact in this regime.

Mechentel, F. S.↗

Hybrid Propulsion In-Situ Resource Utilization Test Facility Results

Hybrid rockets present a promising alternative to conventional chemical propulsion systems for In-Situ Resource Utilization (ISRU) and in-space applications. While they have many benefits for these applications, there are still many small details that require research before they can be adopted into flight systems. A flexible test facility was developed at JPL to test operation of hybrid motors at small scale (5 cm outer diameter fuel grains) over a range of conditions. Specifically, this paper studies two of the major advantages: low temperature performance and throttling. Paraffin-based hybrid rockets are predicted to have good performance at low temperatures. This could significantly decrease the overall system mass by minimizing the thermal conditioning required for Mars or outer planet applications. Therefore, the coefficient of thermal expansion and glass transition of paraffin are discussed. Additionally, deep throttling has been considered for several applications. This was a natural starting point for hotfire testing using the hybrid propulsion ISRU test facility. Additionally, short length to diameter ratio (L/D) fuel grains are tested to determine if these systems can be packaged into geometrically constrained spaces.

Karp, Ashley Chandler↗

Effects of 1980 technology on weight of a recovery system for a one million pound booster

The effects were evaluated of 1980 technology on the weight of recovery systems capable of decelerating a one-million-pound booster to vertical velocities of 60 or 30 ft/sec at sea level impact. A nominal set of booster staging conditions were assumed and there were no constraints on parachute size, number or type. The effects of new materials that would be available by 1980, the effects of booster attitude during entry, various parachute staging methods, parachute reefing schemes, parachute-retro rocket hybrid systems, and the effects of dividing the booster into separate pieces for recovery were evaluated. It was determined that for the systems considered, a hybrid parachute-retro-rocket recovery system would have the minimum weight. New materials now becoming available for parachute fabrication should result in a 37-percent reduction in hybrid recovery system weight for an impact velocity of 30 fps.

Eckstrom, C. V.↗

Mars Ascent Vehicle Hybrid Propulsion Effort

A technology development program was undertaken to determine if the benefits of hybrid rocket propulsion could be realized for a Mars Ascent Vehicle (MAV) application. Specifically, the goal of this program was to increase the Technology Readiness Level (TRL) of a hybrid propulsion system such that it could be considered for a potential Mars Sample Return Campaign. Over the course of approximately five years, a new, wax-based fuel was developed, characterized and tested with Mixed Oxides of Nitrogen (from MON-3 to MON-25). Various ignition mechanisms were tested and solid hypergolic additives were evaluated for their potential to ignite the hybrid motor. Several hot-fire test campaigns were completed at both sub- and full-scale. The technology development program was born out of a JPL study documented by Shotwell and Karp that identified the Single Stage to Orbit (SSTO) hybrid propulsion system for a potential Mars Ascent Vehicle to be the lowest Gross Lift Off Mass option from the ten configurations evaluated. Benefits of the hybrid option included its predicted favorable low temperature storage and operation behavior, high performance and ability to restart (enabling the SSTO). The main disadvantage of the hybrid option was its low TRL, as it essentially started as a blank sheet design with a new fuel development. Near the end of the technology development program, a Preliminary Architecture Assessment (PAA) was completed to evaluate a single-stage hybrid propulsion system and a two-stage solid propulsion system for a potential MAV. The solid propulsion system was selected for further study in 2019, primarily because of its flight heritage. While the hybrid technology development program made many strides, there was still a list of challenges to overcome. This paper will discuss the substantial progress and remaining challenges from the technology development effort from 2015 through 2019. This includes fuel development and reformulation, sub- and full-scale testing at Space Propulsion Group, full scale testing at Parabilis, full scale testing at Whittinghill Aerospace, hypergolic additive testing at Purdue and Penn State and the evaluation of adding hypergolic additives to a fullscale grain. It also includes a discussion of the design that resulted from the Preliminary Architecture Assessment.

hybrid rocket↗