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Nakazono, B.

Publications and source records attributed to Nakazono, B..

Mars Ascent Vehicle Hybrid Propulsion Development

Hybrid propulsion is being investigated as a propulsion method for a possible Mars Ascent Vehicle (MAV) application. MAV is part of a proposed larger Mars Sample Return (MSR) campaign plan to bring samples from Mars to earth for examination. The Mars Ascent Vehicle would launch Mars surface samples found and packaged by the Mars 2020 mission to orbit around Mars. This version of hybrid propulsion is based on a wax based solid fuel, called SP7A, and a Mixed Oxides of Nitrogen oxidizer, MON-25. SP7 is a new fuel formulation developed by Space Propulsion Group and was modified for this application to be resistant to Mars temperature extremes and modified again to lower the regression rate to become SP7A. MON-25 was chosen for its low freezing temperature. Due to cost constraints, MON-3 was the oxidizer used during testing through 2018. In 2019, full scale hybrid testing with MON-25 commenced in Mojave, CA by Whittinghill Aerospace. One flight motor will be subjected to thermal cycling in a vacuum and later fired in a vacuum to demonstrate the proposed Liquid Injection Thrust Vector Control system performance at White Sands Test Facility (WSTF). In addition, there will be MON-25 characterization work done at Purdue University and WSTF. Additional testing of subscale and full scale motors will be conducted with MON-3 with fuel grain stress, fuel grain support and case design test objectives by Space Propulsion Group Inc. of Butte, MT. This paper documents some of the testing, issues and accomplishments with the MAV hybrid propulsion option that is being considered (along with a two-stage solid propulsion option).

Story, G. T.↗

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.↗

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 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 to evaluate ISPP oxidizers (gaseous mixtures of O2 and CO2) and modify fuel type and chamber geometry. This work is the result of a continuing effort at JPL to characterize the burn characteristics and performance of different propellant combinations and motor configurations in order to refine 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 effort to determine the uncertainty associated with deriving a regression rate law and evaluating c* efficiency with the collected data.

Mechentel, F. S.↗

The ion propulsion system for Dawn

The Dawn Project's mission is to rendezvous and map the two heaviest main belt asteroids Vesta and Ceres. The Ion Propulsion System (IPS) for Dawn will be used for the heliocentric transfer from the Earth to Vesta, orbit capture at Vesta, transfer to a low Vesta orbit, departure and escape from Vesta, the heliocentric transfer from Vesta to Ceres, orbit capture at Ceres, and transfer to a low Ceres orbit.

ion propulsion asteroids spacecraft NSTAR↗