Electrodynamic tether at Jupiter II:Fast moon tour after capture

An electrodynamic bare-tether mission to Jupiter,following the capture of a spacecraft (SC) into an equatorial highly elliptical orbit with perijove at about 1.3 times the Jovian radius, is discussed. Repeated applications of the propellantless Lorentz drag on a spinning tether, at the perijove vicinity, can progressively lower the apojove at constant perijove, for a tour of Galilean moons. Electrical energy is generated and stored as the SC moves from an orbit at 1 : 1 resonance with a moon, down to resonance with the next moon; switching tether current off, stored power is then used as the SC makes a number of flybys of each moon. Radiation dose is calculated throughout the mission,during capture, flybys and moves between moons. The tour mission is limited by both power needs and accumulated dose. The three-stage apojove lowering down to Ganymede, Io, and Europa resonances would total less than 14 weeks, while 4 Ganymede, 20 Europa, and 16 Io flybys would add up to 18 weeks, with the entire mission taking just over seven months and the accumulated radiation dose keeping under 3 Mrad (Si) at 10-mm Al shield thickness.

A proposed two-stage two-tether scientific mission at Jupiter

A two-stage mission to place a spacecraft (SC) below the Jovian radiation belts, using a spinning bare tether with plasma contactors at both ends to provide propulsion and power,is proposed. Capture by Lorentz drag on the tether, at the periapsis of a barely hyperbolic equatorial orbit, is followed by a sequence of orbits at near-constant periapsis, drag finally bringing the SC down to a circular orbit below the halo ring. Although increasing both tether heating and bowing, retrograde motion can substantially reduce accumulated dose as compared with prograde motion, at equal tether-to-SC mass ratio. In the second stage,the tether is cut to a segment one order of magnitude smaller, with a single plasma contactor, making the SC to slowly spiral inward over severalmonths while generating large onboard power, which would allow multiple scientific applications, including in situ study of Jovian grains, auroral sounding of upper atmosphere, and space- and time-resolved observations of surface and subsurface.

Electrodynamic tether at Jupiter 2. Tour missions after capture

Three separate scenarios of an electrodynamic tether mission at Jupiter following capture of a spacecraft (SC) into an equatorial, highly elliptical orbit around the planet, with perijove at about 1.5 times the Jovian radius, are discussed. Repeated application of Lorentz drag on the spinning tether, at the perijove vicinity, can progressively lower the apojove. One mission involves the tethered-SC rapidly and frequently visiting Galilean moons; elliptical orbits with apojove down at the Ganymede, Europa, and Io orbits are in 2:5, 4:9, and 1:2 resonances with the respective moons. About 20 slow flybys of Io would take place before the accumulated radiation dose exceeds 3 Mrad (Si) at 10 mm Al shield thickness, with a total duration of 5 months after capture (4 months for lowering the apojove to Io and one month for the flybys). The respective number of flybys for Ganymede would be 10 with a total duration of about 9 months. An alternative mission would have the SC acquire a low circular orbit around Jupiter, below the radiation belts, and manoeuvre to get an optimal altitude, with no major radiation effects, in less than 5 months after capture. In a third mission, repeated thrusting at the apojove vicinity, once down at the Io torus, would raise the perijove itself to the torus to acquire a low circular orbit around Io in about 4 months, for a total of 8 months after capture; this corresponds, however, to over 100 apojove passes with an accumulated dose, of about 8.5 Mrad (Si), that poses a critical issue.

Jupiter power generation with electrodynamic tethers at constant orbital energy

An electrodynamic tether system for power generation at Jupiter is presented that allows extracting energy from Jupiter's corotating plasmasphere while leaving the system orbital energy unaltered to first order. The spacecraft is placed in a polar orbit with the tether spinning in the orbital plane so that the resulting Lorentz force, neglecting Jupiter's magnetic dipole tilt, is orthogonal to the instantaneous velocity vector and orbital radius, hence affecting orbital inclination rather than orbital energy. In addition, the electrodynamic tether subsystem, which consists of two radial tether arms deployed from the main central spacecraft, is designed in such a way as to extract maximum power while keeping the resulting Lorentz torque constantly null. The power-generation performance of the system and the effect on the orbit inclination is evaluated analytically for different orbital conditions and verified numerically. Finally, a thruster-based inclination-compensation maneuver at apoapsis is added, resulting in an efficient scheme to extract energy from the plasmasphere of the planet with minimum propellant consumption and no inclination change. A tradeoff analysis is conducted showing that, depending on tether size and orbit characteristics, the system performance can be considerably higher than conventional power-generation methods.

El mas sagrado y altitonante jupiter San Antonio de Padua, lustre decoroso del cielo de la Religion Serafica... que con los... rayos de su ardiente caridad exita los devotos à su mas plausible exercicio de los nueve Martes [Texto impreso]

Serrano Morales data la actividad de Cabrera entre 1672 y 1732

Status of the Mariner Jupiter/Saturn 1977 project : National Aeronautics and Space Administration : report to the Congress /

"B-183134."

The planet Jupiter (1970).

Mode of access: Internet.

Tables écliptiques des satellites de Jupiter : d'apres la théorie de M. le Marquis de Laplace, et la totalité des observations faites depuis 1662 jusqu'à l'an 1802 /

Mode of access: Internet.

Astronomy of the satellites of the Earth, Jupiter and Saturn : grounded upon Sir Isaac Newton's theory of the Earth's satellite ... Also new tables of the motions of the satellites of Jupiter and Saturn ... by which their places and position ... may be exactly determined at any given time. Adapted to the meridian of London. To which is added a problem to find the latitude of the place by the altitude of the sun, moon, or star, upon any azimuth ... /

Mode of access: Internet.

Tables astronomiques du Soleil, de la Lune, des planetes, des etoiles fixes et des satellites de Jupiter et de Saturne ... /

Mode of access: Internet.

De inaequalitabus quas Saturnus et Jupiter sibi mutuo videntur inducere praesertim circa tempus conjunctionis : opusculum ad Parisiensem Academiam transmissum et nunc primum editum /

Mode of access: Internet.

Piece qui a remporté le prix de l'Académie Royale des Sciences, en M. DCC.XLVIII sur les inégalités du mouvement de Saturne & de Jupiter : selon la fondation faite par feu M. Rouillé de Meslay ...

Recherches sur la question des inégalités du mouvement de Saturne et de Jupiter ... / par M. Euler, 123 p.

Ephemerides des mouvemens celestes pour les années 1725, jusqu'en 1735 : Où l'on trouve les mouvemens diurnes des planetes en longitudes, leurs latitudes, aspects & mediations, celles des etoiles, leurs lever, coucher, apparitions & occultations, les immersions & emersions du premier satellite de Jupiter pour les mêmes années ... /

Mode of access: Internet.

Ephemerides des mouvemens celestes pour les années 1715, jusqu'en 1725 : Où l'on trouve les mouvemens diurnes des planetes en longitudes, leurs latitudes, aspects & mediations, celles des etoiles, leurs lever, coucher, apparitions & occultations, les immersions & emersions du premier satellite de Jupiter pour les mêmes années ... /

Mode of access: Internet.