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The numerically integrated planetary ephemerides by JPL, IMCCE, and IPA are largely based on the same observation set and dynamical models. The differences between ephemerides are expected to be consistent within uncertainties. Uncertainties in the orbits of the major planets and the dwarf planet Pluto based on recent analysis at JPL are described.

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... Without new observations, DE421 accuracy rapidly decreases. According to Folkner (2010), Mars ephemeris uncertainty declines to about 10 km by the end of 2015, and ephemeris uncertainties of other planets (except the Earth) are even larger by then. ...
... The ephemerides of planetary bodies, the natural satellite and the star used JPL DE421 (Folkner, 2010), SPICE ephemeris (Acton, 1996), and Tycho-2 star catalogue, respectively (Høg et al., 2000). The optical characteristics of Mars, Phobos, and Deimos sensors are shown in Table 3. ...
To obtain accurate navigation results with respect to Earth simultaneously with those with respect to the target for an interplanetary probe to approach the target planet, this paper proposes a Radio/Optical integrated navigation method based on ephemeris correction, which deeply affects the fusion accuracy. In this paper, the model of the ephemeris error is established, and taking the analytical solution of the ephemeris uncertainty as measurement, the target ephemeris error and its covariance are estimated by Kalman filter and fed back to modify the force models. By correcting the target ephemeris and using information fusion, the Radio/Optical integrated navigation prevents the ephemeris uncertainty polluting the fusion accuracy, and efficiently combines the radio and optical navigation results. The results show the influence of the ephemeris error can be removed, and the Radio/Optical integrated navigation is capable of providing accurate navigation results with respect to Earth and the target. The results demonstrate the proposed method yields an accuracy superior to the conventional method, which proves its effectiveness.
... Jacobson et al. (1999) showed that results from the Galileo mission indicate that the ephemeris error of the positions of the Galilean moons with respect to Jupiter is 5 km (1σ) in each direction. However, the ephemeris error of Jupiter's position with respect to the Earth is about 5 km in the radial direction, 20 km in the cross-track direction, and 20 km in the out-of-plane direction (Folkner 2010). However, the Juno mission that will arrive at Jupiter in 2016 is expected to significantly decrease these errors in Jupiter's ephemeris using radiometric ranging data (Folkner 2010). ...
... However, the ephemeris error of Jupiter's position with respect to the Earth is about 5 km in the radial direction, 20 km in the cross-track direction, and 20 km in the out-of-plane direction (Folkner 2010). However, the Juno mission that will arrive at Jupiter in 2016 is expected to significantly decrease these errors in Jupiter's ephemeris using radiometric ranging data (Folkner 2010). With these improvements in the ephemeris, it is plausible that a CGJ capture could be navigated with only ground-based radiometric navigation. ...
Employing multiple gravity-assist flybys of Jupiter’s Galilean moons can save a substantial amount of (Formula presented.) when capturing into orbit about Jupiter. Using Callisto and Ganymede, the most massive and distant of the Galilean moons, as gravity-assist bodies reduces the Jupiter orbit insertion (Formula presented.) cost, while allowing the spacecraft to remain above the worst of Jupiter’s radiation belts. A phase-angle approach is used to find initial guesses for a Lambert targeter to find patched-conic Callisto–Ganymede transfers. A B-plane targeter using grid search methodology is used to backward target Earth to find launch conditions. Twenty-nine distinct patched-conic trajectories were found from Earth to Callisto–Ganymede–JOI capture throughout the search space from 2020–2060. Five promising trajectories were found that launch from Earth between July 11, 2023 and July 20, 2023, and arrive at Jupiter between February and September 2026. These trajectories were numerically integrated using GMAT and, in the author’s opinion, are excellent candidates for use on NASA’s planned Europa Clipper mission.
... If two bodies m 1 , m 2 , are falling toward a third body, m 3, and both violate the EP, their separation oscillates at a frequency ω 2ω 1 with an amplitude [2,3] We use uncertainties in δr, r, ω 1 and ω 2 to constrain where P 1 is 29.5 yrs, P 2 is 11.9 yrs, r 1 is 9.5 AU and we take δr to be five times the range uncertainty to Jupiter or 50 km [8]. We then find ε 2 =3×10 -8 which is thirty times better than the Trojan limit. ...
... For the Sun-Jupiter system (a=5.2 AU, P=12 yrs, m 1 /m 2 =1047) we take δa to be twice the current range uncertainty of 10 km [8], δω=0.2 arcsec/century [9] and δ(m 1 /m 2 )= 1.7×10 -5 [7], giving ε 1 = 9×10 -5 . Results are summarized in Table 1. ...
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Most extensions of the standard model of particle physics predict composition-dependent violations of the universality of free fall (equivalence principle). We test this idea using observational uncertainties in mass, range and mean motion for the Moon and planets, as well as orbit uncertainties for Trojan asteroids and Saturnian satellites. For suitable pairs of solar-system bodies, we derive linearly independent constraints on relative difference in gravitational and inertial mass from modifications to Kepler’s third law, the migration of stable Lagrange points, and orbital polarization (the Nordtvedt effect). These constraints can be combined with data on bulk composition to extract limits on violations of the equivalence principle for individual elements relative to one another. These limits are weaker than those from laboratory experiments, but span a much larger volume in composition space.
... We use an uncertainty in the ephemeri- des of the minor moons of 300 km ( Christou et al., 2010;Emelyanov and Arlot, 2008). The uncertainty of the Jupiter ephemeris is estimated at about 10- 40 km in right ascension α and declination δ, and about 1-5 km in range (Folkner, 2011;Fienga et al., 2014). However, these estimates are based on the inter-comparison between different ephemerides, and may very well be too optimistic an estimate for the true error: we use an uncertainty of 10 km in range and 100 km in α and δ. ...
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Radio tracking and astrometric data obtained by the JUICE mission, using the PRIDE, 3GM and JANUS instruments, will allow the dynamics of the Galilean moons to be measured to unprecedented accuracy. As a result, the dynamical models used for creating ephemerides from these data will most likely require the inclusion of various heretofore neglected physical effects.
... The more direct way to elucidate this issue is the analysis of ephemerides; however, several more years of measurements are required. The main difficulties are the complex treatment of measured values (see Pitjeva, 2013), the limited accuracy of measurements, especially for the determination of the variation of orbits (Folkner, 2010), the complexity of the model (more than 260 parameters, as mentioned by Pitjeva, 2011) and the absence of an acceptable theory supporting orbits' expansion. The calculations are performed to fit the only available model, where orbits are invariant; as the number of parameters is huge, the possibility of adjustment to invariant orbits is large within the present accuracy of data. ...
The barycentric dynamical reference system (BDRS) is a space–time reference system whose origin agrees with the solar system barycenter. Note that the BDRS is not yet an IAU-adopted name, in contrast to BCRS and GCRS; often, it is called conventional dynamical realization of the ICRS, a name that however lacks the reference to the barycenter.
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We present the second realization of the International Celestial Reference Frame (ICRF2) at radio wavelengths using nearly 30 years of Very Long Baseline Interferometry observations. ICRF2 contains precise positions of 3414 compact radio astronomical objects and has a positional noise floor of ~40 μas and a directional stability of the frame axes of ~10 μas. A set of 295 new "defining" sources was selected on the basis of positional stability and the lack of extensive intrinsic source structure. The positional stability of these 295 defining sources and their more uniform sky distribution eliminates the two greatest weaknesses of the first realization of the International Celestial Reference Frame (ICRF1). Alignment of ICRF2 with the International Celestial Reference System was made using 138 positionally stable sources common to both ICRF2 and ICRF1. The resulting ICRF2 was adopted by the International Astronomical Union as the new fundamental celestial reference frame, replacing ICRF1 as of 2010 January 1.
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The planetary and lunar ephemeris DE 421 represents updated estimates of the orbits of the Moon and planets. The lunar orbit is known to submeter accuracy through fitting lunar laser ranging data. The orbits of Venus, Earth, and Mars are known to subkilometer accuracy. Because of perturbations of the orbit of Mars by asteroids, frequent updates are needed to maintain the current accuracy into the future decade. Mercury's orbit is determined to an accuracy of several kilometers by radar ranging. The orbits of Jupiter and Saturn are determined to accuracies of tens of kilometers as a result of spacecraft tracking and modern ground-based astrometry. The orbits of Uranus, Neptune, and Pluto are not as well determined. Reprocessing of historical observations is expected to lead to improvements in their orbits in the next several years.
With 2 years of tracking data collection from the MRO spacecraft, there is noticeable improvement in the high frequency portion of the spherical harmonic Mars gravity field. The new JPL Mars gravity fields, MRO110B and MRO110B2, show resolution near degree 90. Additional years of MGS and Mars Odyssey tracking data result in improvement for the seasonal J gravity changes which compares well to global circulation models and Odyssey neutron data and Mars rotation and precession (psi&dot;=-7594±10mas/year). Once atmospheric dust is accounted for in the spacecraft solar pressure model, solutions for Mars solar tide are consistent between data sets and show slightly larger values (k2 = 0.164 ± 0.009, after correction for atmospheric tide) compared to previous results, further constraining core models. An additional 4 years of Mars range data improves the Mars ephemeris, determines 21 asteroid masses and bounds solar mass loss (dGMSun/dt < 1.6 × 10-13 GMSun year-1).
The planetary ephemeris is an essential tool for interplanetary spacecraft navigation, studies of solar system dynamics (including, for example, barycenter corrections for pulsar timing ephemeredes), the prediction of occultations, and tests of general relativity. We are carrying out a series of astrometric VLBI observations of the Cassini spacecraft currently in orbit around Saturn, using the Very Long Baseline Array (VLBA). These observations provide positions for the center of mass of Saturn in the International Celestial Reference Frame (ICRF) with accuracies ~0.3 milli-arcsecond (1.5 nrad), or about 2 km at the average distance of Saturn. This paper reports results from eight observing epochs between 2006 October and 2009 April. These data are combined with two VLBA observations by other investigators in 2004 and a Cassini-based gravitational deflection measurement by Fomalont et al. in 2009 to constrain a new ephemeris (DE 422). The DE 422 post-fit residuals for Saturn with respect to the VLBA data are generally 0.2 mas, but additional observations are needed to improve the positions of all of our phase reference sources to this level. Over time we expect to be able to improve the accuracy of all three coordinates in the Saturn ephemeris (latitude, longitude, and range) by a factor of at least three. This will represent a significant improvement not just in the Saturn ephemeris but also in the link between the inner and outer solar system ephemeredes and in the link to the inertial ICRF. Comment: Accepted for publication in the Astronomical Journal
California Institute of Technology. 1.0 0.0
  • P R Peabody
  • J F Scott
  • E G Orozco
Peabody, P. R., Scott, J. F., and Orozco, E. G., 1964, "JPL Ephemeris Tapes E9510, E9511, and E9512", Technical Memorandum 33-167, Jet Propulsion Laboratory, California Institute of Technology. 1.0 0.0 1960 1970 1980 1990 2000 2020 2040 1950 2010 2030 2050 1960 1970 1980 1990 2000 2020 2040 1950 2010 2030 2050 1960 1970 1980 1990 2000 2020 2040 1950 2010 2030 2050 0 1960 1970 1980 1990 2000 2020 2040 1950 2010 2030 2050 1960 1970 1980 1990 2000 2020 2040 1950 2010 2030 2050 1960 1970 1980 1990 2000 2020 2040 1950 2010 2030 2050