SMART-1 Electric Propulsion: An Operational Perspective

Milligan, David; Gestal, D.; Camino, O.

doi:10.2514/6.2006-5767

Cited by 16 publications

(4 citation statements)

References 9 publications

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“…10 The first spacecraft to use Hall thrusters for primary propulsion outside of Earth's orbit was the ESA's SMART-1 spacecraft. 11 Several trends in electric propulsion in general and Hall thruster technology in particular are requiring that the traditional notion of the Hall thruster as a 1600-s specific impulse device be reexamined. These include, at least, new materials and fabrication technologies, advanced computer simulations, the rapid rise in spacecraft power, and new missions requiring propulsion systems with larger operating envelopes, longer lifetimes, and greater efficiencies.…”

Section: Introduction Mmentioning

confidence: 99%

High-Specific Impulse Hall Thrusters, Part 2: Efficiency Analysis

Hofer¹,

Gallimore

2006

Journal of Propulsion and Power

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A laboratory-model Hall thruster with a magnetic circuit designed for high-specific impulse (2000-3000 s) was evaluated to determine how current density and magnetic field affect thruster operation. Results have shown for the first time that a minimum current density and optimum magnetic field shape exist at which efficiency will monotonically increase with specific impulse. At the nominal mass flow rate of 10 mg/s and between discharge voltages of 300 and 1000 V, total specific impulse and total efficiency ranged from 1600 to 3400 s and 51 to 61%, respectively. Comparison with a similar thruster showed how efficiency can be optimized for specific impulse by varying the shape of the magnetic field. Plume divergence decreased from a maximum of 48 deg at 400 V to a minimum of 35 deg at 1000 V, but increased between 300 and 400 V as the likely result of a large increase in discharge current oscillations. The breathing-mode frequency continuously increased with voltage, from 14.5 kHz at 300 V to 22 kHz at 1000 V, in contrast to other Hall thrusters where a sharp decrease of the breathing-mode frequency was found to coincide with increasing electron current and decreasing efficiency. These findings suggest that efficient, high-specific impulse operation was enabled through the regulation of the electron current with the applied magnetic field. η t = total efficiency θ = azimuthal coordinate direction ∇ z B r = axial gradient of the centerline radial magnetic field Nomenclature

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Section: Introduction Mmentioning

confidence: 99%

High-Specific Impulse Hall Thrusters, Part 2: Efficiency Analysis

Hofer¹,

Gallimore

2006

Journal of Propulsion and Power

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“…Electric propulsion technologies, such as ion thrusters and Hall thrusters, are efficient in accelerating particles of the propellant by electric and magnetic field, resulting in a high I sp . The first demonstration of electric propulsion system to achieve large-scale orbit transfer is European Space Agency's (ESA) Small Missions for Advanced Research in Technology-(SMART-) 1 [14][15][16]. The 370 kg satellite was equipped with a 1.5 kW Hall thruster providing 90 mN thrust at the I sp of 1600 s. SMART-1 was launched in September 2006, and it took about 2 months to enter the Moon's orbit.…”

Section: Propulsion Systems For Lunar Explorationmentioning

confidence: 99%

The View of Micropropulsion Technology for China’s Advanced Small Platforms in Deep Space

Wei¹,

Yan²,

Liu³

et al. 2022

Space Sci Technol

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In this paper, micropropulsion systems are analyzed in conjunction with the various mission requirements of China’s deep space exploration. As a great challenge facing the world, deep space exploration can be enabled only in a few countries with a success rate of around 50%. With the advancement of spacecraft and scientific instruments, it is now feasible to build small and low-cost spacecraft for a variety of deep space missions. As spacecraft become smaller, there is a need for proper micropropulsion systems. Examples of propulsion system selections for deep space exploration are discussed with a focus on products developed by Beijing Institute of Control Engineering (BICE). The requirements for propulsion systems are different in lunar/interplanetary exploration and gravitational wave detection. Chemical propulsion is selected for fast orbit transfer and electric propulsion for increasing scientific payloads. Cold gas propulsion and microelectric propulsion are good choices for space-based gravitational wave detection due to the capability of variable thrust output at the micro-Newton level. The paper also introduces the sub-1-U micropropulsion modules developed by BICE with satisfactory performance in flight tests, which are promising propulsion systems for small deep space platforms. A small probe with an electric sail propulsion system has been proposed for the future solar system boundary exploration of China. The electric sail serves as not only a propellant-free thruster but also a detector probing the properties of the space medium.

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“…Parameters denoted with * are not explicitly used in this paper but are shown here for reference. The spacecraft mass-to-power ratio, β is originally adopted from the SMART-1 mission (Milligan et. al., 2006).…”

Section: Introductionmentioning

confidence: 99%

Electric Sailing under Observed Solar Wind Conditions

Toivanen

Janhunen

2009

Astrophys. Space Sci. Trans.

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In this paper, sailing and navigation in the solar wind with a spacecraft powered by an electric sail is addressed. The electric sail is a novel propellantless spacecraft propulsion concept based on positively charged tethers that are centrifugally uncoiled and stabilised to extract the solar wind momentum by repelling the solar wind protons. Steering of such a sail ship is realised either by changing the tether voltage or the sail spin plane. To model the solar wind, we use spacecraft observations for the density and wind speed at 1 AU and assume that the speed is constant and density decreases in square of the distance from the Sun. Using the electric sail thrust formula, we describe the sail response to the solar wind variations, especially, the self-reefing effect leading to a smooth spacecraft acceleration even during periods of large densities or fast winds. As a result, the variations of the acceleration are statistically small relative to the density and wind speed variations. Considering the navigation, we adopt an optimal transfer orbit to Mars originally obtained for constant solar wind speed and density. The orbit and associated sail operations including a coasting phase are then used as the navigation plan to Mars. We show that passive navigation based only on the statistical results is far too inaccurate for planetary missions and active navigation is required. We assume a simple active navigation system that monitors only the actual orbital speed with an onboard accelerometer and matches it with the optimal orbital speed by altering the tether voltage independently from the future solar wind conditions. We launch 100 test spacecraft with a random launch date and show that with the active navigation 85% (100%) of the spacecraft reach a distance relative to Mars less than about 10 (70) Mars radii with a residual speed less than 20 m/s (80 m/s). As a conclusion, the electric sail is highly navigable and it suits for targeting planets and asteroids, in addition to broad targets such as the heliopause.

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SMART-1 Electric Propulsion: An Operational Perspective

Cited by 16 publications

References 9 publications

High-Specific Impulse Hall Thrusters, Part 2: Efficiency Analysis

High-Specific Impulse Hall Thrusters, Part 2: Efficiency Analysis

The View of Micropropulsion Technology for China’s Advanced Small Platforms in Deep Space

Electric Sailing under Observed Solar Wind Conditions

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