{"id":54037,"date":"2024-12-18T08:20:44","date_gmt":"2024-12-18T08:20:44","guid":{"rendered":"https:\/\/www.innovationnewsnetwork.com\/?p=54037"},"modified":"2024-12-18T08:20:44","modified_gmt":"2024-12-18T08:20:44","slug":"insights-into-nasas-small-spacecraft-electric-propulsion-ssep","status":"publish","type":"post","link":"https:\/\/www.innovationnewsnetwork.com\/insights-into-nasas-small-spacecraft-electric-propulsion-ssep\/54037\/","title":{"rendered":"Insights into NASA\u2019s Small Spacecraft Electric Propulsion (SSEP)"},"content":{"rendered":"

The NASA Glenn Research Center<\/a> provides fascinating insights into its groundbreaking propulsion solution for small spacecraft.<\/h2>\n

Developed by NASA\u2019s Glenn Research Center, the Small Spacecraft Electric Propulsion (SSEP) Technology Suite, LEW-TOPS-162, enables a compact, high-performance, long-lasting and scalable primary propulsion system for small spacecraft. The SSEP belongs to a class of in-space propulsion known as solar electric propulsion (SEP), where thrust is derived from solar energy and solar panels rather than heavy, combustible stored chemicals.<\/p>\n

Combining electric and magnetic fields, the SSEP converts solar energy to thrust by trapping electrons ejected from a cathode in a doughnut-like ring created by an annular magnetic field contained within its thruster. This creates a Hall current, a circulating swirl of electrons, confined in the thruster\u2019s annulus, and enables Hall Effect Thrusters (HETs). Thrust is generated when a neutral gas is released at one end of the annular thruster, which then diffuses into the Hall current, where electrons can collide with it and ionize it. Now charged, this gas is abruptly accelerated out of the other end of the annular thruster due to an electric field, imparting thrust.<\/p>\n

The SSEP solves a technology gap for NASA<\/a>, specifically, the lack of a highly capable SEP system optimized for small spacecraft on the order of 200 to 500 kilograms. This scale of spacecraft makes the SSEP ideal for rideshare. This is the practice of purchasing secondary payload volume on a rocket whose orbital trajectory is mostly paid for by another. By maximizing capacity with rideshares, more hardware is lifted to space, which creates more opportunities for small spacecraft.<\/p>\n

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Fig 1: Applications for hall effect thrusters based on Relative Delta-V<\/figcaption><\/figure>\n

Leveraging heritage, the SSEP increases the operating life of sub-kilowatt HETs. Compared to state-of-the-art sub-kilowatt HETs, the SSEP operates five to seven times longer, making it ideal for high maneuver applications in low-Earth orbit (LEO), geostationary orbit (GEO), lunar missions, and beyond. (See Figure 1\u2019s Advanced Sub-kilowatt SEP applications).<\/p>\n

Heritage is a term of art. As the name suggests, it is demonstrated technology success passed from one space-flown mission to another. Since the cost of flying spacecraft is so expensive, mission designers value space-tested and proven technology. Heritage helps newer spacecraft avoid costly failures because designers select proven technology. Knowing this, NASA Glenn\u2019s SSEP team engineered with heritage in mind. Unlike other technology solutions, the SSEP\u2019s focus on heritage design practices, materials, processes, and components facilitates market adoption, while also implementing creative and focused design advancements, pushing sub-kilowatt HET capability beyond the state-of-the-art.<\/p>\n

To promote market adoption and American in-space competitiveness, Glenn provides these technologies individually, or in aggregate, to U.S. companies through a no-cost, nonexclusive license agreement with a companion Space Act Agreement (SAA). SAAs are legal instruments for NASA to collaborate. Under this framework, licensees receive a comprehensive technical package that NASA Glenn built and curates in a consortia-like environment. This is a service NASA provides with the aim of eventually buying U.S.-made high-quality and high-performance SEP systems.<\/p>\n

An advantage of HETs over other high-performance SEPs, such as gridded-ion thrusters, is their higher thrust-to-power ratio. High thrust-to-power ratios make HETs attractive for time-sensitive missions requiring large impulse maneuvers. Since most SEPs flown today utilize HETs, their advancement has immediate space industry implications. Indeed, economic projections suggest that commercial space revenue in 2040 could exceed $1 trillion U.S. dollars; as of 2020, it was $350 billion. Driving this growth is the reduced cost to access space and increased demand for satellite-based services.<\/p>\n

Impacting this growing market, the SSEP can revolutionize small spacecraft capabilities while minimizing launch costs. Epitomized by the \u201cTyranny of the Rocket Equation,\u201d lifting more payload on a rocket means packing that rocket with more propellant mass. More mass means more propellant; more propellant begets more mass, leading to more propellant. And the tyranny repeats. The SSEP breaks this cycle.<\/p>\n

Today, with regular flights to LEO, the space industry resembles the aviation industry. Increased launch cadence means increased rideshare. To maximize rideshares, more small spacecraft equipped with SSEP can tag along as secondary payload and depart after orbital insertion.<\/p>\n