Galilean Satellites and the Galileo Space Mission

1997 ◽  
pp. 13-20
Author(s):  
J. H. Lieske
Keyword(s):  
Space Mission ◽  
Galilean Satellites

scholarly journals Estimation of the Ephemerides and Gravity Fields of the Galilean Moons Through Orbit Determination of the JUICE Mission

2021 ◽  
Vol 100 (3) ◽  
pp. 195-206
Author(s):  
Andrea Magnanini
Keyword(s):  
Orbit Determination ◽  
Precise Orbit Determination ◽  
Orbital Evolution ◽  
Space Mission ◽  
Galilean Satellites ◽  
Great Opportunity ◽  
Tidal Interaction ◽  
Galilean Moons ◽  
Orbital Periods

AbstractJupiter and its moons are a complex dynamical system that include several phenomena like tides interactions, moon’s librations and resonances. One of the most interesting characteristics of the Jovian system is the presence of the Laplace resonance, where the orbital periods of Ganymede, Europa and Io maintain a 4:2:1 ratio, respectively. It is interesting to study the role of the Laplace resonance in the dynamic of the system, especially regarding the dissipative nature of the tidal interaction between Jupiter and its closest moon, Io. The secular orbital evolution of the Galilean satellites, and so the Laplace resonance, is strongly influenced by the tidal interaction between Jupiter and its moons, especially with Io. Numerous theories have been proposed regarding this topic, but they disagree about the amount of dissipation of the system, therefore about the magnitude and the direction of the evolution of the system, mainly because of the lack of experimental data. The future ESA JUICE space mission is a great opportunity to solve this dispute. The data that will be collect during the mission will have an exceptional accuracy, allowing to investigate several aspects of the dynamics the system and possibly the evolution of Laplace Resonance of the Galilean moons. This work will focus on the gravity estimation and orbit reconstruction of the Galilean satellites by precise orbit determination of the JUICE mission during the Jovian orbital phase using radiometric data.

scholarly journals Galilean Satellites and the Galileo Space Mission

1997 ◽  
Vol 165 ◽  
pp. 13-20
Author(s):  
J.H. Lieske
Keyword(s):  
Initial Period ◽  
Close Approach ◽  
Space Mission ◽  
Optical Navigation ◽  
Galilean Satellites ◽  
Navigation Data ◽  
Timing Data ◽  
Doppler Data ◽  
Jovian System ◽  
Astrometric Data

AbstractThe Galileo spacecraft arrived at Jupiter in December 1995 to start its two-year mission of exploring the Jovian system. The spacecraft will complete eleven orbits around Jupiter and have ten more close encounters with the outer three Galilean satellites, after the initial close approach to Io on December 7, 1995. Since the Io encounter occurred closer to Io than originally designed, the spacecraft energy change was greater than nominally planned and resulted in an initial spacecraft orbital period about 7 days less than that designed in the nominal tour. A 100-km change in the Io-encounter distance results in an 8-day change in initial period of the spacecraft. Hence the first Ganymede encounter was moved forward one week, and the aim points for the first two Ganymede encounters were altered, but all other encounters would occur on their nominal dates and at the nominal altitudes. This was accomplished without expending spacecraft fuel and resulted in the first Ganymede flyby occurring on June 27, 1996 rather than the nominally scheduled July 4.Earth- and spacecraft-based data were employed in developing ephemerides in support of the Galileo space mission. An analysis of CCD astrometric observations from 1992–1994, of photographic observations from 1967–1993, of mutual event astrometric data from 1973–1991, of Jovian eclipse timing data from 1652–1983, of Doppler data from 1987–1991, and of optical navigation data from the Voyager spacecraft encounter in 1979, produced the satellite ephemerides for the Galileo space mission.

Background particle detector for the solar x-ray photometer ChemiX of space mission “Interhelioprobe”: an adjustment of breadboard model modules

2015 ◽  
Vol 21 (2(93)) ◽  
pp. 3-14 ◽  
Author(s):  
O.V. Dudnik ◽  
◽  
E.V. Kurbatov ◽  
V.O. Tarasov ◽  
L.A. Andryushenko ◽  
...  
Keyword(s):  
Space Mission ◽  
Particle Detector ◽  
X Ray ◽  
Background Particle

CHARACTERISTICS OF POST-FLIGHT MUSCLE STRENGTH AND VELOCITY DYNAMICS IN COSMONAUTS AS A FUNCTION OF WEIGHT LOADING DURING LONG-TERM SPACE MISSIONS

2020 ◽  
Vol 54 (5) ◽  
pp. 23-28
Author(s):  
E.V. Fomina ◽  
◽  
T.B. Kukoba ◽  
Keyword(s):  
Muscle Strength ◽  
Body Mass ◽  
Flight Muscle ◽  
Space Mission ◽  
The Body ◽  
Maximum Strength ◽  
Training Device ◽  
Leg Muscle ◽  
Weight Loading

Testing of 25 cosmonauts showed that the amount of resistance training weight loading in long-term space mission influences dynamics of the leg-muscle strength and velocity recovery. On Earth, the loads equal from 70 to 130 % of the body mass is sufficient for keeping up endurance and maximum strength moments of shin and thigh muscles. In the group of cosmonauts who had not used the strength training device or chosen loads less than 30 % of the body mass the leg-muscle maximum strength and thigh endurance were decreased substantially on day 4 of return and all the more by day 15 back on Earth.

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