DOCSLIB.ORG

The Flyby Anomaly and the Effect of a Topological Torsion Current

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Flyby Anomaly and the Effect of a Topological Torsion Current The Flyby Anomaly and the Effect of a Topological Torsion Current Mario J. Pinheiro1 aDepartment of Physics, Instituto Superior T´ecnico - IST, Universidade de Lisboa - UL, Av. Rovisco Pais, 1049-001 Lisboa, Portugal Abstract A new variational technique determines the general condition of equilibrium of a rotating gravitational or electromagnetic system (or both) and provides a modified dynamical equation of motion from where it emerges a so-far un- forseen topological torsion current (TTC) [Mario J. Pinheiro (2013) 'A Varia- tional Method in Out-of-Equilibrium Physical Systems', Scientific Reports 3, Article number: 3454]. We suggest that the TTC may explain, in a simple and direct way, the anomalous acceleration detected in spacecrafts during close planetary flybys. In addition, we theorize that TTC may represent a novel rela- tionship between linear momentum and angular motion through the agency of a vector potential. Keywords: Variational Methods in Classical Mechanics; Statistical physics, thermodynamics, and nonlinear dynamical systems; Celestial mechanics (including n-body problems); Relativity and gravitation 1. Introduction Flyby (or swing-by, gravitational slingshot, or gravity assist maneuver) is a well-known method in interplanetary spaceflight to alter the path and the speed of a spacecraft using the gravity of a planet or other astronomical object IRevised manuscript URL: http://mjpinheiro.weebly.com/ (Mario J. Pinheiro) [email protected] Preprint submitted to Physics Letters a March 20, 2016 5 (see, e.g., Ref. [1]). The rescue of the Apollo crew in 1970 was the first flyby maneuver ever did, using the Lunar flyby [2]. But the flyby anomaly is one among other, possibly related, several astro- metric anomalies that are referred in the technical literature, such as the change of the solar mass over time M_ (changes that result from a balance between the 10 mass loss due to radiation and solar wind compensated by falling materials con- tained in comets, rocks and asteroids) leading to the observation of a decrease of −14 the heliocentric gravitation constant per year GM_ =GM = (−5:0 ± 4:1):10 per year and a variation of the astronomical unit by approximately 10 m per century [3]. Quite surprisingly, dark matter does not have a gravitational in- 15 fluence in the solar system because its density is very low [4]. The angular 41 momentum of the Sun seems to be smaller than expected (S ≤ 0:95 × 10 kg m2 s−1) unless the Sun's gravitomagnetic force is included [5, 6]. The anoma- lous behavior of the Saturnian perihelion cannot be explained in the framework of the standard Newtonian and Einsteinian General Theory of Relativity [7], 20 also suggesting the need of new physics or the effect of an external tidal poten- tial acting on the Solar System possibly due to a new hypothetical huge body, Tyche [8, 9]. The phenomenological modification of Newtonian dynamics pro- posed by MOND doesn't offer a satisfying explanation for Cassini spacecraft anomaly [8]. The Faint Young Sun Paradox [10, 11, 12] can possibly be accom- 25 modated within a certain general class of gravitational theories with nonminimal coupling between metric and matter predicting a secular variation of the Earth heliocentric distance [13, 14]. Recent analysis of a Lunar Laser Ranging data record revealed an anomalous increase of the eccentricity rate of the lunar orbit [15, 16, 14, 17]. This effect 30 is not related to a possible change of the speed of light [16] or some dissipation at the lunar core and mantle [15], but possibly non-tidal explanations can be viable [17]. Astrometric data points to the existence of at least four unexplained anoma- lies, from the small and constant Doppler frequency drift shown by the radio- 35 metric data from Pioneer 10 and 11, which can be interpreted as a uniform 2 −8 2 acceleration of aP = (8:74±1:33)10 cm=s towards the Sun found in the data of both spacecraft when they were at a distance of 20 au from the Sun [18, 19, 20, 21, 22, 23] to the disturbing observation that a number of satellites in Earth flyby have undergone mysterious energy changes [22]. This effect is essentially a 40 slight departure from Newtonian acceleration (see also Ref. [24] for an overview of unexplained phenomena within our Solar System and in the universe). As already shown in several ways [18, 20], the effect is not a real gravitational phenomenon that certainly would have affected other major bodies of the Solar System. The possibility that this uniform Sunward acceleration, such as the one 45 experienced by the Pioneer spacecraft, might have a gravitational nature was shown to be erroneous [25, 26, 27, 28], and could not even affect the motion of the outer planets of the Solar System [29, 30]. Rindler-type extra-acceleration on test particles was ruled out altogether because it would affect the main features of the Oort cloud [31]. Furthermore, exotic physics is probably not affecting 50 Pioneer spacecraft trajectories [32]. Also proposed was the possibility the Pioneer anomaly might have a different non-gravitational origin, such as a recoil force associated with an anisotropic emission of thermal radiation off the spacecraft [33, 34, 35, 36, 37, 38, 39]. As discussed earlier, a secular change in the astronomical unit (au) d(au)dt = −1 55 7 ± 2 m cy [40] was reported [41, 40, 42] and several explanations were pro- posed, among them, the change in the moment of inertia of the Sun due to radiative mass loss [43] but the possible variation of the dark matter density was ruled out [44]. The huge importance of the problem and the uncertainties related to the causes of its variation lead to the proposal of fixing the value of 60 au [45, 46, 47]. Other proposed explanations for this effect include an adiabatic acceleration of light due to an adiabatic decreasing of the permeability and per- mittivity of empty space [48]; the dilaton-like Jordan-Brans-Dicke scalar field as the source of dark energy, which introduces a new term of force with mag- 2 nitude aP = Fr=m = −c =RH (RH is the Hubble scale), (see Ref. [49]); light 65 speed anisotropy [50] based on Lorentz space-time interpretation and resorting from the earlier measurement of D. C. Miller (see also Ref. [51] which gives an 3 interesting reformulation of the special theory of relativity); and a computer modeling technique called the Phong reflection model [52], which explains the effect as due to the heat reflected from the main compartment, though this 70 explanation still needs confirmation. The flyby anomaly appears as a shift in the Doppler data of Earth-flybys of several spacecrafts and it is currently interpreted as anomalous velocity jumps, positive and negative, of the order of a few mm s−1 observed near the closest approach during the Earth flybys [53, 54]. Several attempts to explain the flyby 75 anomaly have been put forth so far. For example, as far as standard physics is concerned, it was shown that the Rosetta flyby is unlikely due to thermal recoil pressure [55] or to Lorentz forces [56], but might be due to gravitoelectric (contributing up to 10−2 mm s−1)and gravitomagnetic forces (up to 10−5 mm s−1) [57]. Moreover, it was shown that neither the general relativistic Lense- 80 Thirring effect nor a Rindler-type radial uniform acceleration were the cause of the flyby anomaly [23]. Unusual explanations were advanced based on a possible modification of inertia at very low acceleration when Unruh wavelengths exceed the Hubble distance [58]; the elastic and inelastic scattering of ordinary matter with dark matter, although submitted to highly constraints [59, 60]; how 85 Conformal Gravity affects the trajectories of geodesic motion around a rotating spherical object, but are not expected to cause the flyby anomaly [61]. In this paper, we suggest a possible theoretical explanation of the physical process underlying the unexpected orbital-energy change observed during close planetary flybys [22, 62] based on the topological torsion current (TTC) found 90 in a previous work [63]. Anderson et al. [64] proposed a helicity-rotation coupling that is akin to our proposal. However, the anomalous acceleration cannot be explained by means of the helicity-rotation mechanism due to its small magnitude. The TTC was obtained in the framework of a new variational principle based on the fundamental equation of thermodynamics treated as a 95 differential form. That formulation gives a set of two first order differential equations that have the same symplectic structure as classical mechanics, fluid dynamics, and thermodynamics. The procedure can be applied to investigate 4 out-of-equilibrium dynamic systems. From that approach emerges a TTC of the form ijkAj!k, where Aj and !k denote the components of the vector 100 potential (here, the gravitational) and where ! denotes the angular velocity of the accelerated frame. 2. Outlines of the method A standard technique for treating thermodynamical systems on the basis of information-theoretic framework has been developed previously [65, 66, 67, 63]. 105 We can find in technical literature several textbooks that give an overview over the subject, see e.g., Ref. [68, 69, 70, 71, 72, 73]. This work may be applied to a self-gravitating plasma system. The extended mathematical formalism devel- oped to investigate out-of-equilibrium systems in the framework of information theory can be applied to the analysis of the equilibrium and stability of a grav- 110 itational and electromagnetic system (e.g., rotating plasma, or spacecraft in a gravitationally-assisted maneuver). Our method is based on applying Lagrange multipliers to the total entropy of an ensemble of particles.
Load more

Recommended publications
  • Document Downloaded From: This Paper Must Be Cited As: the Final
    Document downloaded from: http://hdl.handle.net/10251/122856 This paper must be cited as: Acedo Rodríguez, L.; Piqueras, P.; Moraño Fernández, JA. (2018). A possible flyby anomaly for Juno at Jupiter. Advances in Space Research. 61(10):2697-2706. https://doi.org/10.1016/j.asr.2018.02.037 The final publication is available at http://doi.org/10.1016/j.asr.2018.02.037 Copyright Elsevier Additional Information See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/321306820 A possible flyby anomaly for Juno at Jupiter Article in Advances in Space Research · November 2017 DOI: 10.1016/j.asr.2018.02.037 CITATION READS 1 149 3 authors, including: Luis Acedo José Antonio Moraño Universitat Politècnica de València Universitat Politècnica de València 93 PUBLICATIONS 1,145 CITATIONS 55 PUBLICATIONS 162 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Call for Papers Complexity: Discrete Models in Epidemiology, Social Sciences, and Population Dynamics View project Call for Papers: Journal "Symmetry" (MDPI) Special Issue "Mathematical Epidemiology in Medicine & Social Sciences" View project All content following this page was uploaded by Luis Acedo on 28 February 2018. The user has requested enhancement of the downloaded file. A possible flyby anomaly for Juno at Jupiter L. Acedo,∗ P. Piqueras and J. A. Mora˜no Instituto Universitario de Matem´atica Multidisciplinar, Building 8G, 2o Floor, Camino de Vera, Universitat Polit`ecnica de Val`encia, Valencia, Spain December 14, 2017 Abstract In the last decades there have been an increasing interest in im- proving the accuracy of spacecraft navigation and trajectory data.
    [Show full text]
  • Arxiv:0907.4184V1 [Gr-Qc] 23 Jul 2009 Keywords Anomalous Puzzle
    Space Science Reviews manuscript No. (will be inserted by the editor) The Puzzle of the Flyby Anomaly Slava G. Turyshev · Viktor T. Toth Received: date / Accepted: date Abstract Close planetary flybys are frequently employed as a technique to place space- craft on extreme solar system trajectories that would otherwise require much larger booster vehicles or may not even be feasible when relying solely on chemical propulsion. The theo- retical description of the flybys, referred to as gravity assists, is well established. However, there seems to be a lack of understanding of the physical processes occurring during these dynamical events. Radio-metric tracking data received from a number of spacecraft that experienced an Earth gravity assist indicate the presence of an unexpected energy change that happened during the flyby and cannot be explained by the standard methods of mod- ern astrodynamics. This puzzling behavior of several spacecraft has become known as the flyby anomaly. We present the summary of the recent anomalous observations and discuss possible ways to resolve this puzzle. Keywords Flyby anomaly · gravitational experiments · spacecraft navigation. 1 Introduction Significant changes to a spacecraft’s trajectory require a substantial mass of propellant. In particular, placing a spacecraft on a highly elliptical or hyperbolic orbit, such as the orbit required for an encounter with another planet, requires the use of a large booster vehicle, substantially increasing mission costs. An alternative approach is to utilize a gravitational assist from an intermediate planet that can change the direction of the velocity vector. Al- arXiv:0907.4184v1 [gr-qc] 23 Jul 2009 though such an indirect trajectory can increase the duration of the cruise phase of a mission, the technique nevertheless allowed several interplanetary spacecraft to reach their target destinations economically (Anderson 1997; Van Allen 2003).
    [Show full text]
  • High Precision Modelling of Thermal Perturbations with Application to Pioneer 10 and Rosetta
    High precision modelling of thermal perturbations with application to Pioneer 10 and Rosetta Vom Fachbereich Produktionstechnik der UNIVERSITAT¨ BREMEN zur Erlangung des Grades Doktor-Ingenieur genehmigte Dissertation von Dipl.-Ing. Benny Rievers Gutachter: Prof. Dr.-Ing. Hans J. Rath Prof. Dr. rer. nat. Hansj¨org Dittus Fachbereich Produktionstechnik Fachbereich Produktionstechnik Universit¨at Bremen Universit¨at Bremen Tag der m¨undlichen Pr¨ufung: 13. Januar 2012 i Kurzzusammenfassung in Deutscher Sprache Das Hauptthema dieser Doktorarbeit ist die pr¨azise numerische Bestimmung von Thermaldruck (TRP) und Solardruck (SRP) f¨ur Satelliten mit komplexer Geome- trie. F¨ur beide Effekte werden analytische Modelle entwickelt und als generischen numerischen Methoden zur Anwendung auf komplexe Modellgeometrien umgesetzt. Die Analysemethode f¨ur TRP wird zur Untersuchung des Thermaldrucks f¨ur den Pio- neer 10 Satelliten f¨ur den kompletten Zeitraum seiner 30-j¨ahrigen Mission verwendet. Hierf¨ur wird ein komplexes dreidimensionales Finite-Elemente Modell des Satelliten einschließlich detaillierter Materialmodelle sowie dem detailliertem ¨außerem und in- nerem Aufbau entwickelt. Durch die Spezifizierung von gemessenen Temperaturen, der beobachteten Trajektorie sowie detaillierten Modellen f¨ur die W¨armeabgabe der verschiedenen Komponenten, wird eine genaue Verteilung der Temperaturen auf der Oberfl¨ache von Pioneer 10 f¨ur jeden Zeitpunkt der Mission bestimmt. Basierend auf den Ergebnissen der Temperaturberechnung wird der resultierende Thermaldruck mit Hilfe einer Raytracing-Methode unter Ber¨ucksichtigung des Strahlungsaustauschs zwischen den verschiedenen Oberf¨achen sowie der Mehrfachreflexion, berechnet. Der Verlauf des berechneten TRPs wird mit den von der NASA ver¨offentlichten Pioneer 10 Residuen verglichen, und es wird aufgezeigt, dass TRP die so genannte Pioneer Anomalie inner- halb einer Modellierungsgenauigkeit von 11.5 % vollst¨andig erkl¨aren kann.
    [Show full text]
  • Conclusive Analysis & Cause of the Flyby Anomaly
    Introduction Theory Analysis Conclusion Conclusive analysis & cause of the flyby anomaly Range proportional spectral shifts for general communication V. Guruprasad Inspired Research, New York http://www.inspiredresearch.com 2019-07-17 c 2019 V. Guruprasad IEEE NAECON 2019 1/20 Introduction Theory Analysis Conclusion Summary • Popular context: Astrometric solar-system anomalies[1] Pioneer: ∆V r_ H r at r 5 AU (blueshift) { SOLVED[2] • 0 Flyby: ∆V trajectory∼ ≈ − discontinuity≥ at satellite range • [3] Lunar orbit eccentricity growth: also H0 • ∼ Earth orbit radius growth: also H0 • ∼ • Present work: conclusive solution of the flyby anomaly All NASA-tracked flybys checked, fit to 1%, more issues found • Fit presence and absence, correlated to transponder • • Real motivation and result: wave theory+practice correction Rewrite communication and radar: source range in all signals • Rewrites physics and astrophysics since Kepler • Computation overlooked since Euler and d'Alembert • Needed extremely robust empirical validation • [1] Anderson and Nieto 2009. [2] Turyshev et al. 2012. [3] The terrestrial reference frame is uncertain to about same order..Altamimi et al. 2016 c 2019 V. Guruprasad IEEE NAECON 2019 2/20 Introduction Theory Analysis Conclusion Faithful led by the blind • Fourier transform presumes clock rate stability Clock rate stability requires design and procedures • But even HST calibration cycles only correct cumulative errors • No awareness of range proportional or scale drift rate errors • Best Allan deviations in any observations
    [Show full text]
  • Working at the Jet Propulsion Laboratory (JPL)
    Working at the Jet Propulsion Laboratory (JPL), Anderson, Campbell, Ekelund, Ellis, and Jordan reported on and characterized orbital‐energy changes during six Earth flybys by the Galileo, NEAR, Cassini, Rosetta, and MESSENGER spacecraft; the JPL researchers found an empirical prediction formula consistent with the anomalous energy changes. http://virgo.lal.in2p3.fr/NPAC/relativite_fichiers/anderson_2.pdf “Anomalous Orbital‐Energy Changes Observed during Spacecraft Flybys of Earth” (2008) According to Wikipedia, “The flyby anomaly is an unexpected energy increase during Earth‐flybys of spacecraft. This anomaly has been observed as a shift in the S‐ Band and X‐Band Doppler and ranging telemetry. Taken together it causes a significant unaccounted velocity increase of over 13 mm/sec during flybys.” http://en.wikipedia.org/wiki/Flyby_anomaly What might the flyby anomaly have to do with the Pioneer anomaly and Milgrom’s Modified Newtonian Dynamics (MOND)? Define modified general relativity theory (GRT) with the Rañada‐Milgrom effect to be the heuristic model obtained by replacing the ‐1/2 in the standard form of Einstein’s field equations by ‐1/2 + dark‐ matter‐compensation‐constant, where this constant might be approximately sqrt((60±10)/4) * 10^‐5, based upon the Rañada effect for the Pioneer anomaly combined with the empirical validity of MOND. http://en.wikipedia.org/wiki/Pioneer_anomaly http://en.wikipedia.org/wiki/Modified_Newtonian_dynamics http://vixra.org/pdf/1203.0016v1.pdf “Anomalous Gravitational Acceleration and the OPERA Neutrino Anomaly (Updated)”. The slingshot effect in orbital mechanics uses the orbital angular momentum from a large body like a planet to increase the orbital velocity of a small body like a spacecraft.
    [Show full text]
  • Astrometric Solar-System Anomalies
    Relativity in Fundamental Astronomy Proceedings IAU Symposium No. 261, 2009 c International Astronomical Union 2010 S. A. Klioner, P. K. Seidelman & M. H. Soffel, eds. doi:10.1017/S1743921309990378 Astrometric solar-system anomalies John D. Anderson1 and Michael Martin Nieto2 1 Jet Propulsion Laboratory (Retired) 121 S. Wilson Ave., Pasadena, CA 91106-3017 U.S.A. email: [email protected] 2 Theoretical Division (MS-B285), Los Alamos National Laboratory Los Alamos, New Mexico 87645 U.S.A. email: [email protected] Abstract. There are at least four unexplained anomalies connected with astrometric data. Perhaps the most disturbing is the fact that when a spacecraft on a flyby trajectory approaches the Earth within 2000 km or less, it often experiences a change in total orbital energy per unit mass. Next, a secular change in the astronomical unit AU is definitely a concern. It is reportedly − increasing by about 15 cm yr 1 . The other two anomalies are perhaps less disturbing because of known sources of nongravitational acceleration. The first is an apparent slowing of the two Pioneer spacecraft as they exit the solar system in opposite directions. Some astronomers and physicists, including us, are convinced this effect is of concern, but many others are convinced it is produced by a nearly identical thermal emission from both spacecraft, in a direction away from the Sun, thereby producing acceleration toward the Sun. The fourth anomaly is a measured increase in the eccentricity of the Moon’s orbit. Here again, an increase is expected from tidal friction in both the Earth and Moon. However, there is a reported unexplained increase that is significant at the three-sigma level.
    [Show full text]
  • Annual Report 2014-2015
    2014 2015 Annual Report Table of Contents 2/3 The International Space Science Institute (ISSI) is an Institute of Advanced Studies where scientists from all over the world meet in a multi- and interdisciplinary setting to reach out for new scientific horizons. The main function is to contribute to the achievement of a deeper understanding of the re- sults from different space missions, ground based observations and laboratory experiments, and add- ing value to those results through multidisciplinary research. The program of ISSI covers a widespread spectrum of disciplines from the physics of the solar system and planetary sciences to astrophysics and cosmology, and from Earth sciences to astrobiology. 4 From the Board of Trustees 20 International Teams 5 From the Directors 37 International Teams approved in 2015 6 About the International Space Science Institute 39 Visiting Scientists 7 The Board of Trustees 41 International Space Science Institute Beijing 8 The Science Committee 42 Events and ISSI in the media at a glance (including centerfold) 9 ISSI Staff 44 Staff Activities 10 Facilities 48 Staff Publications 11 Financial Overview 51 Visitor Publications 12 The Association Pro ISSI 61 Space Sciences Series of ISSI (SSSI) 13 Scientific Activities: The 20th Year 66 ISSI Scientific Reports Series (SR) 14 Forum 67 Pro ISSI SPATIUM Series 15 Workshops 68 ISSI Publications in the 20th Business Year ISSI Annual Report 2014 | 2015 From the Board of Trustees One year ago the undersigned was appointed by the President as secretary of the Board, succeeding Kathrin Altwegg who had served in that capacity for six years.
    [Show full text]
  • A Solution to the Flyby Anomaly Riddle
    Issue 1 (April) PROGRESS IN PHYSICS Volume 16 (2020) A Solution to the Flyby Anomaly Riddle Eduardo D. Greaves1, Carlos Bracho2, and Imre Mikoss3 1Universidad Simon´ Bol´ıvar. Apartado 89000, Caracas, Venezuela. E-mail: [email protected] 2Facultad de Ingenier´ıa, Universidad Central de Venezuela, Caracas, Venezuela. E-mail: bracho [email protected] 3Universidad Simon´ Bol´ıvar. Apartado 89000, Caracas, Venezuela. E-mail: [email protected] The Flyby Anomaly is one of the unsolved problems of current physics in that the Doppler-shift determined speeds are inconsistent with expected values assuming the validity of Newtonian gravity. We postulate that the Flyby Anomaly is a consequence of the assumption that the speed of light is isotropic in all frames, and invariant in the method used to measure the velocity of the space probes by means of the Doppler Effect. The inconsistent anomalous values measured: positive, null or negative are simply ex- plained relaxing this assumption. During space probe energy assistance maneuvers the velocity components of the probe in the direction of the observer Vo are derived from the relative displacement ∆ f of the radiofrequency f transmitted by the probe, multiplied 0 0 by the local speed of the light c by the Doppler effect: Vo = (∆ f = f ) c . According to the Cespedes-Cur´ e´ hypothesis, the movement through variable gravitational energy density fields produces slight variations of the refractive index n0 of space and therefore of the speed of light c0 which leads to unaccounted corrections of the Doppler data that are based on an invariant c. This leads to incorrect estimates of the speed or energy change in the flyby maneuver in the Earth’s frame of reference.
    [Show full text]
  • The Flyby Anomaly in an Extended Whitehead's Theory
    Galaxies 2015, 3, 113-128; doi:10.3390/galaxies3030113 OPEN ACCESS galaxies ISSN 2075-4434 www.mdpi.com/journal/galaxies Article The Flyby Anomaly in an Extended Whitehead’s Theory Luis Acedo Instituto Universitario de Matemática Multidisciplinar, Building 8G, 2o Floor, Camino de Vera, Universitat Polit`ecnica de Val`encia, Valencia, Spain; E-Mail: [email protected]; Tel.: +34-963877007 (ext. 88285) Academic Editor: Lorenzo Iorio Received: 18 June 2015 / Accepted: 24 July 2015 / Published: 30 July 2015 Abstract: In this paper, we consider an extended version of Whitehead’s theory of gravity in connection with the flyby anomaly. Whitehead’s theory is a linear approximation defined in a background Minkowski spacetime, which gives the same solutions as standard general relativity for the Schwarzschild and Kerr metrics cast in Kerr–Schild coordinates. For a long time and because it gives the same results for the three classical tests—perihelion advance, light bending and gravitational redshift—it was considered a viable alternative to general relativity, but as it is really a linear approximation, it fails in more stringent tests. The model considered in this paper is a formal generalization of Whitehead’s theory, including all possible bilinear forms. In the resulting theory, a circulating vector field of force in the low velocities’ approximation for a rotating planet is deduced, in addition to Newtonian gravity. This extra force gives rise to small variations in the asymptotic velocities of flybys around the Earth to be compared to the recently reported flyby anomaly. Keywords: experimental tests of gravitational theories; modified theories of gravity; perihelion precession PACS classifications: 04.80.-y; 04.80.Cc; 04.50.Kd 1.
    [Show full text]
  • The RF Instrumentation for Bepicolombo
    Deep-Space Navigation: a Tool to Investigate the Laws of Gravity Luciano Iess Dipartimento di Ingegneria Meccanica e Aerospaziale Università La Sapienza Rome, Italy Outline • Laws of gravity in the solar system: observables, space probe dynamics, anomalies • Cassini, Pioneer and the Pioneer anomaly • Juno: Lense-Thirring at Jupiter • Planned tests at Mercury with BepiColombo ESA Fundamental Physics Roadmap – http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=44552 1 µm 1 mm 1 mAU 1 AU 1 kAU 1 kpc 1 Mpc 1 Gpc CMB How well do we know gravity at various scales ? poorly reasonably well well no precise data poorly poorly Theories that predict deviations from General Relativity Dark energy,IR-modified Large Scalar-Tensor Chameleon MOND gravity, f(R) gravity, Extra Extra dimen- dark energy TeVeS, dim. sions STVG branes,strings and extra dim., Experimental Approach Controlled experiments Astronomical observations Laboratory experiments Space-based experiments Astronomy Astrophysics Cosmology Techniques available to explore gravity Cosmology missions clocks, Ongoing space Precision spectroscopy LLR, GPS CMB surveys, interferometers, exploration missions Galaxy surveys, pendula pulsars Gravitational waves clocks, time links, accelerometers At what level is General Relativity violated? • In spite of the experimental success, there are strong theoretical arguments for violations of GR at some level. • Unfortunately no reliable predictive, alternative theory has been proposed yet • The theoretical uncertainties are so large that every experiment
    [Show full text]
  • Hyperbolic Orbits and the Planetary Flyby Anomaly. H.-J
    40th Lunar and Planetary Science Conference (2009) 1704.pdf HYPERBOLIC ORBITS AND THE PLANETARY FLYBY ANOMALY. H.-J. Blome 1 and T. L. Wilson 2, 1University of Applied Sciences, Hohenstaufenallee 6, 52066 Aachen, Germany, 2NASA, Johnson Space Center, Houston, Texas 77058 USA. Introduction: Space probes in the Solar System a bound state. Briefly, a stable bound-state system’s have experienced unexpected changes in velocity potential energy must equal its kinetic energy within a known as the flyby anomaly [1], as well as shifts in factor of two. acceleration referred to as the Pioneer anomaly [2-4]. The Cosmic Virial Theorem . The Layzer-Irvine In the case of Earth flybys, ESA’s Rosetta spacecraft equation [10-11] is an extension of the virial theorem experienced the flyby effect and NASA’s Galileo and to systems that interact with an expanding cosmic envi- NEAR satellites did the same, although MESSENGER ronment ( R& / R >>> 0 ). It relates the total system energy did not – possibly due to a latitudinal property of grav- E = T+U with the virial energy 2T+U as follows: ity assists. d R& Measurements indicate that both anomalies exist, T( +++U ) +++ ( 2T +++U ) === 0 , (1) and explanations have varied from the unconventional dt R to suggestions that new physics in the form of dark where R& is the expansion parameter and H = R& / R is matter might be the cause of both [5]. Although dark the Hubble parameter . Note that (1) is similar to the cos- matter has been studied for over 30 years, there is as mological perturbations of local systems found by Co- yet no strong experimental evidence supporting it [6].
    [Show full text]
  • Expected Velocity Anomaly for the Earth Flyby of Juno Spacecraft on October 9, 2013
    Expected velocity anomaly for the Earth flyby of Juno spacecraft on October 9, 2013 H. J. Busack Wulfsdorfer Weg 89, 23560 Lübeck, Germany September 25, 2013 Abstract The so-called flyby anomaly is a yet unexplainable velocity jump measured at several Earth flybys of spacecraft. Known physical effects could be excluded as source of this anomaly. In order to model a possible new physical effect, empirical equations were proposed by Busack (2007) and Anderson et al. (2007), which gave quite good description of all measured anomalies. Some theories were suggested deriving the Anderson formula or a similar one. The recent two Earth flybys of the spacecraft Rosetta showed no measurable anomaly, although the Anderson formula predicted distinct effects for both flybys. The Busack formula predicted the null results, so the notion of a possibly correct formula or of an error of the older measuring software was supported. The forthcoming Earth flyby of Juno gives a good opportunity to decide this question or give rise to enhanced theory, because the orbit parameters are very similar to earlier flybys with notable effects. In this article, the flyby anomaly according to the Busack equation will be predicted to be about -7mm/s in contrast to the value after the Anderson equation and similar ones with distinct positive value of the order of +6mm/s. 1 Introduction Several Earth flybys of diverse spacecraft have shown a distinct velocity jump past closest approach (CA) to Earth when analyzing the Doppler and range measurements with the common orbit determination programs (ODP). According to several studies [2,3,8,10], this so-called flyby anomaly cannot be declared by unconsidered known physical effects.
    [Show full text]