Efficient Computation of Current Collection in Bare Electrodynamic Tethers in and beyond OML Regime

Sanjurjo-Rivo, Manuel; Sánchez‐Arriaga, G.; Peláez, Jesús

doi:10.1061/(asce)as.1943-5525.0000479

Cited by 9 publications

(13 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Following a similar procedure to the one presented in Ref. [38] for bare tethers in passive modes, Eq. ( 22) can be written in a form that is more convenient for fast numerical calculations.…”

Section: Appendix a The Anodic Segmentmentioning

confidence: 99%

Electrical model and optimal design scheme for low work-function tethers in thrust mode

Sánchez‐Arriaga

Sanmartin

2020

Aerospace Science and Technology

Self Cite

View full text Add to dashboard Cite

A low work-function tether (LWT), a subclass of bare electrodynamic tether made of a conductor partially coated with a low work function material, can exchange momentum and energy with planetary magnetospheres without any consumable. If fed by an onboard power source to reverse the natural direction of the current given by the motional electric field, a LWT can produce an useful thrust in drag compensation and re-boost scenarios. In the considered scheme, the LWT has an anodic bare segment for passive electron collection, followed by an insulated segment, a power source, and a cathodic segment that emits electrons passively through thermionic and photoelectric effects. Current and voltage profiles along the LWT are obtained and used to compute the system efficiency, i.e. the electrical power to mechanical power conversion rate, and the minimum electrical power to avoid space-charge effects in the cathodic segment. The design conditions to reach a high-efficiency regime are presented. For a given orbit and required thrust, optimal values for the tether geometry, including the fractional lengths of all three tether segments, are found. The results are applied to the preliminary design of a LWT system that would compensate the aerodynamic drag on the International Space Station. The analysis shows that the mission can be performed by a LWT fed with a power source of 4.7 kW, length, width and thickness equal to 5.1 km, 2 cm and 30 um, work function 1.5 eV, and temperature 600 K.

show abstract

Section: Appendix a The Anodic Segmentmentioning

confidence: 99%

Electrical model and optimal design scheme for low work-function tethers in thrust mode

Sánchez‐Arriaga

Sanmartin

2020

Aerospace Science and Technology

Self Cite

View full text Add to dashboard Cite

show abstract

“…(15) and (16) as a function of tether geometry for a given mission. Once tether geometry is known, BETsMA computes tether deorbiting with more accurate models 21,22 . Table 1 shows optimal tether geometry and performance for deorbiting missions from initial orbit altitude H 0 =850 km and three different inclinations and spacecraft masses.…”

Section: Electrodynamic Tethersmentioning

confidence: 99%

Comparison of technologies for deorbiting spacecraft from low-earth-orbit at end of mission

2017

Self Cite

View full text Add to dashboard Cite

An analytical comparison of four technologies for deorbiting spacecraft from Low-Earth-Orbit at end of mission is presented. Basic formulas based on simple physical models of key figures of merit for each device are found. Active devices-rockets and electrical thrustersand passive technologies-drag augmentation devices and electrodynamic tethers-are considered. A basic figure of merit is the deorbit device-to-spacecraft mass ratio, which is, in general, a function of environmental variables, technology development parameters and deorbit time. For typical state-of-the-art values, equal deorbit time, middle inclination and initial altitude of 850 km, the analysis indicates that tethers are about one and two orders of magnitude lighter than active technologies and drag augmentation devices, respectively; a tether needs a few percent mass-ratio for a deorbit time of a couple of weeks. For high inclination, the performance drop of the tether system is moderate: mass ratio and deorbit time increase by factors of 2 and 4, respectively. Besides collision risk with other spacecraft and system mass considerations, such as main driving factors for deorbit space technologies, the analysis addresses other important constraints, like deorbit time, system scalability, manoeuver capability, reliability, simplicity, attitude control requirement, and re-entry and multi-mission capability (deorbit and re-boost) issues. The requirements and constraints are used to make a critical assessment of the four technologies as functions of spacecraft mass and initial orbit (altitude and inclination). Emphasis is placed on electrodynamic tethers, including the latest advances attained in the FP7/Space project BETs. The superiority of tape tethers as compared to round and multi-line tethers in terms of deorbit mission performance is highlighted, as well as the importance of an optimal geometry selection, i.e. tape length, width, and thickness, as function of spacecraft mass and initial orbit. Tether system configuration, deployment and dynamical issues, including a simple passive way to mitigate the well-known dynamical instability of electrodynamic tethers, are also discussed. Nomenclature B Magnetic field E m Motional electric field h Tether thickness H Spacecraft altitude H 0 Initial Altitude H F Final Altitude i Orbit inclination

show abstract

“…the numerical algorithm in charge of computing the current and voltage profiles throughout the tether. Being necessary at every time step to evaluate the Lorentz force and torque, these algorithms received an important attention in past works [29,30,31,18] and severely affect the computational cost, robustness, and fidelity of the simulators. This work presents a comprehensive description of the second version of the Bare Electrodynamic Tether Mission Analysis Software (BETsMA v2.0).…”

Section: Introductionmentioning

confidence: 99%

A code for the analysis of missions with electrodynamic tethers

2022

View full text Add to dashboard Cite

Efficient Computation of Current Collection in Bare Electrodynamic Tethers in and beyond OML Regime

Cited by 9 publications

References 17 publications

Electrical model and optimal design scheme for low work-function tethers in thrust mode

Electrical model and optimal design scheme for low work-function tethers in thrust mode

Comparison of technologies for deorbiting spacecraft from low-earth-orbit at end of mission

A code for the analysis of missions with electrodynamic tethers

Contact Info

Product

Resources

About