The Scorpius Expendable Launch Vehicle Family and Status of the Sprite Mini-Lift

Conger, Robert E.; Chakroborty, Shyama; Wertz, James R.; Kulpa, Jack

doi:10.2514/6.2002-2004

Cited by 5 publications

(2 citation statements)

References 1 publication

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“…This solution is often proposed as a mean to reduce development costs and try to establish a sort of limited "serial production" 25,26 . A famous (and perhaps extreme) example of this approach is the OTRAG project 27 .…”

Section: Final Commentsmentioning

confidence: 99%

Hybrid rocket fuel residuals - an overlooked topic

Barato¹,

Grosse²,

Bettella³

2014

50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

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Rocket propulsion performance is characterized by parameters as thrust, specific impulse, and propellant mass ratio. The propellant mass ratio is affected by propellant residuals, which is often overlooked in hybrid rocket design. Such residual is the mass of propellant which cannot be used for propulsion purposes and is left in the vehicle after performing its mission objective. In case of liquid and solid rocket design it is state-of-the art that propellant residuals are small so that they do not affect the usage of both propulsion types for high performance missions with high ideal velocity changes. In authors' view the residual topic is not recognized by its importance and impact on performance in published hybrid rocket studies, which motivates this work. When hybrid rockets are concerned, due to their specific working characteristics the propellant residual size may have implications on their usability for missions with high ideal velocity requirements. For this reason, residual minimization might be another important design challenge for this rocket propulsion type, beside enhancement of fuel regression rate and combustion efficiency. An overview of the different origins and types of hybrid residuals is presented and reviewed for its relevance. Three different types of residuals are identified: the first part is related to the oxidizer that remains in the tank and in the feed lines. The second part can be mainly attributed to fuel grain design and spatial regression behaviour. The third part of residuals results from uncertainties in important design parameters of the hybrid rocket propulsion system, which determine thrust, pressure and O/F-mixture (and therefore this part of residuals). These design parameters, which are used to model oxidizer injection and fuel regression behaviour as well as nozzle mass flow are identified and introduced in the governing equations of hybrid motor operation to investigate the effect of uncertainties on the rocket velocity change bandwidth, which can be delivered by the specific hybrid rocket propulsion unit. This investigation is done by numerical simulations and in addition by existing analytical solutions. NomenclatureA = area a, b, d, e = characteristic velocity equation constants a, α, n = regression rate law coefficients c* = characteristic velocity = thrust coefficient Cd = discharge coefficient D = diameter Propulsion and Energy Forum 2 = throat erosion rate g = gravity value G = mass flux H 2 O 2 = Hydrogen Peroxide I = impulse k = structural index K = mass flow (oxidizer or fuel) parameter L = length = mass flow m = mass LOX = Liquid Oxygen N 2 O = Nitrous Oxide O/F = oxidizer to fuel ratio (text) p = pressure r = port radius = regression rate R = diameter ratio Re = reliability SSTO = Single Stage To Orbit t = time T = thrust = injection parameter = expansion ratio = oxidizer to fuel ratio (equations) = efficiency ΔV = velocity increment Δp = pressure drop = density subscripts 0 = initial or reference b = burning c = combustion chamber exit = nozzle exit f = fu...

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Section: Final Commentsmentioning

confidence: 99%

Hybrid rocket fuel residuals - an overlooked topic

Barato¹,

Grosse²,

Bettella³

2014

50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

View full text Add to dashboard Cite

show abstract

“…In this context, the use of ablative materials based on graphite shows a feasible solution to increase reliability and reduce costs. Regarding ablative materials for chambers, the work of Kim, Conger and Fisher [3][4][5] are very similar, referring to materials and technologies already employed in 1968 during the development of the propulsion unit of North American manned lunar landing module. Essentially, that technology was based on an internal layer of silica fibers with phenolic resin and an overwrapped outer layer of carbon fiber and epoxy resin [5].…”

Section: Introductionmentioning

confidence: 99%

Microstructural and ablative properties of graphite nozzles with SiC coating deposited by CVD technique

Loureda

Caliari

Regiani

et al. 2020

Mater. Res. Express

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The development of efficient, reliable and affordable propulsion units is one of the main objectives in the development of aerospace technology. Typically the final cost of the vehicle is deeply affected by this subsystem. In this study, a hybrid combination of the ablative chamber is presented where graphite nozzles coated with chemical vapor deposited Silicon Carbide (CVD-SiC) is submitted to the ablative environment, generated by a DC plasma torch operating at a power of 35 kW and homogeneous heat flow of 0.75 MW m −2 . The ablative properties of the samples were evaluated by measuring the weight loss as a function of the exposure time, weight loss of 0.11% after 70 s of exposition due to the formation of SiO gas was observed. The microstructure characteristics of SiC coating before and after ablation tests were carried out by SEM and XRD showing that it goes to scale oxidation to forming of SiO 2 (β-quartz) and SiC (β to α) phase transformation. Whereas the ablation mechanism showed to be dependent on the initial coating thickness and exposure time.

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MEMS Technology Demonstration on Traveler-1

D’Souza¹,

Jamison²,

Young³

et al. 2002

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Public reporting burden (or this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY) AbstractTrave!er-I is a flight test platform for advanced micro-electro-mechanical systems (MEMS) devices that is being built at the University of Southern California (USC) and is to be flown aboard the next Scorpius® sub-orbital launch vehicle. Microcosm, Inc. and Scorpius Space Launch Company have initiated a program that currently provides sub-orbital launch opportunities, with the possibility of orbital flights in the future. Flight opportunities such as these allow for short duration missions where new technologies can be rapidly developed and tested in a launch and space environment. Traveler-I allows for low cost flight demonstration and testing of new and innovative MEMS devices such as a Free-Molecule Micro-Resistojet (FMMR) and a Knudsen Compressor. The FMMR is a MEMSbased propulsion system for low impulse bit delivery, which is designed to perform attitude control and primary maneuvers for nanosatellites. The Knudsen Compressor is a MEMS-based vacuum pump that employs the physical principle of thermal transpiration to drive a flow across an aerogel substance. Advances in MEMS capabilities have allowed the construction of micro-scale versions of space sensors such as mass spectrometers, optical spectrometers, and gas chromatographs. These devices require vacuum pumps to provide the necessary environment for their operation. Inexpensive and rapid access to space may eventually lead to low-cost testing, which supports rapid development and redesign so that more mature and reliable technologies can be used in future satellite systems, without the expense of designing, building and operating an entire satellite. In addition, the size of MEMS devices allows for the testing of multiple systems simultaneously. Traveler-I is a good example of how advanced technologies may be tested for low cost while reducing risk and development time for future programs.

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The Scorpius Expendable Launch Vehicle Family and Status of the Sprite Mini-Lift

Cited by 5 publications

References 1 publication

Hybrid rocket fuel residuals - an overlooked topic

Hybrid rocket fuel residuals - an overlooked topic

Microstructural and ablative properties of graphite nozzles with SiC coating deposited by CVD technique

MEMS Technology Demonstration on Traveler-1

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