Military Technology 05/2021

James Gervasi, Moog Propulsion and Fluids Control Business Unit Director, told MilTech that additional contracts are being awarded for on-orbit propulsion in three major areas: hypergolics, like hydrazine; green propulsion; and nuclear propulsion. (Photo: Moog) on large platform geosynchronous communication satellites, Earth ob- servation platforms, science and discovery missions, satellite naviga- tion systems, upper stage applications, and US Missile Defense Agency applications. Moog’s propulsion experience includes monopropellant, bipropellant, green propellant, cold gas, and Xenon propellant systems, all the way from component manufacturing to propulsion manifold as- sembly and test, to complete system fabrication, and to launch site processing, including propellant loading. Helping military departments achieve their overarching goal to ‘go green,’ Moog engineers have been actively developing and advancing the state of the art of green propellants for more than a decade. Gervasi recalled Moog worked with the US Air Force Research Laboratory and received the first monopropellant risk reduction contract to test a catalyst for green propellants in 2009. He concluded that heavyweight hot fire testing has been conducted on multiple self-heating monolithic foam ig- niters with the goal of reducing the power need for catalyst bed preheat. “Additional Moog activities being pursued in support of high performance green propellant thruster development include material compatibility re- search, thermal management, designing/assessing additive manufactured components and design/development of green propellant compatible rolling diaphragm tanks.” MilTech regularly reports on additive manufacturing’s (AM) expanding use across much of the defence enterprise. Bill Massaro, Moog Advanced Manufacturing Director, provided another datum point on AM’s increased use – in this instance, being developed for propulsion and complement- ing Moog’s strong heritage of providing thrusters and associated compo- nents to global satellite customers. To prepare for the ever-evolving space market, Moog has invested in a state-of-the-art metal AM facility and a new engine testing facility. Massaro first pointed out Moog engineers are developing technologies to support the next generation of monopropellant and bipropellant small thrusters, using AM and other advanced manufacturing methods. “AM of- fers unique geometries that increase propellant flow efficiencies and pro- vide unparalleled thermal management. Within 0.5in, a thruster could have a surface that will be greater than 2,500˚F and another feature that needs to be maintained [at] less than 100˚ F. The additive configuration allows for these temperatures to be accommodated where traditional manufacturing methods would not meet the expected package requirements.” When compared to conventional design methods, AM offers the ad- vantages of weight reduction, overall part-count reduction, reduced spe- cial processes such as welding and brazing, faster design iteration with shorter lead-times, and improved performance with a potential for lower cost products. Moog has recently manufactured and hot-fire tested AM rocket engine injectors made of titanium and INCONEL. Traditional or subtractive ma- chined parts have a lead-time of 12-15 months. Moog’s AM rapid product development reduced this to 4-6 months, with a replacement part lead- time of just four days. “Complex geometry due to injector complexity, envelope, and mass constraints made AM development the answer for a hardware design that had to meet strict customer performance specifica- tions,” Massaro concluded. Give Us More, Please The small selection of companies mentioned herein are on the bow- wave to provide more new technologies and capabilities to the broad space enterprise well beyond this decade. The insertion of innovation which offers sound returns on investment will be the norm, rather than the exception, in future space programmes. VirginOrbit’s LauncherOne rocket for the company’s Launch Demo 2 mission prepares for shipment. (Photo: VirginOrbit/Greg Robinson) [collaborative robot] testing support.” To further accelerate this technology thrust, in the last two years the company started a centralised working group on AR/VR, intended to rationalise the effort spent and evaluate benefits. Basso explained this working group was started concurrently with the company’s Digital Transformation and Industry 4.0 initiatives, with the goal of orienting and optimising experiences to adopt a product’s digital twin (intended as a physical, functional and perfor- mance representation of the spacecraft) in a digital secure lifecycle. “The final objective is a digital twin augmented with analysis results, operating in a digital target environment (eg radiations, planet surfaces - data and models available from scientific sources, and Thales Alenia Space lessons learned) […] This environment will support and speed up the project life- cycle, introducing a more modern approach based on virtual simulation rather than physical realisation of breadboarding models. In parallel, the standard deliverable documentation (ie, paper) will be rethought in favour of multimedia production and a more easily [managed] review of shared data.” The produced material can also be profitably used by non-technical disciplines (marketing, communications and others), in a space scenario that is becoming more and more commercial, and in which multimedia material can represent a more appealing and straightforward means to promote the industrial initiatives and products. James Gervasi, Moog Propulsion and Fluids Control Business Unit Director, believes the industry is also seeing growth in propulsion for de- fence and space, as additional contracts are being awarded for on-orbit propulsion in three major areas: hypergolics, like hydrazine; green pro- pulsion; and nuclear propulsion. “Each area will find specific capabilities required to perform the full gamut of missions, including DoD, civil and intelligence,” he stated. This market is another ‘sweet spot’ for the company, as Gervais ex- plained. “Moog has been a leader in on-orbit propulsion for more than 60 years, building components, subsystems and systems for nearly every spacecraft manufacturer in the world.” To that end, the company has designed, fabricated, tested, and delivered propulsion hardware used f f 46 · MT 5/2021 · Special Supplement Military Space