scholarly journals CAN CONVENTIONAL FORCES REALLY EXPLAIN THE ANOMALOUS ACCELERATION OF PIONEER 10/11?

2004 ◽  
Vol 13 (05) ◽  
pp. 865-870 ◽  
Author(s):  
J. P. MBELEK ◽  
M. MICHALSKI
Keyword(s):  
Observational Data ◽  
Doppler Shift ◽  
Reaction Force ◽  
Rate Change ◽  
Shift Analysis ◽  
Pioneer Anomaly ◽  
Anomalous Acceleration ◽  
Pioneer 10 ◽  
Good Agreement

A conventional explanation of the correlation between the linear and the angular accelerations of Pioneer 10/11 spacecraft is given. First, the rotational Doppler shift analysis is improved. Finally, a relation between the radio beam reaction force and the spin-rate change is established. Computations are found in good agreement with observational data. Our analysis leads us to the conclusion that the Pioneer anomaly may not necessarily be due to systematics.

PRESENT STATUS OF THE STUDY OF THE ANOMALOUS ACCELERATION OF THE PIONEER 10/11 SPACECRAFT

2005 ◽  
Vol 20 (11) ◽  
pp. 2304-2308 ◽  
Author(s):  
J. P. MBELEK
Keyword(s):  
Weak Field ◽  
Low Velocity ◽  
Pioneer Anomaly ◽  
Real Change ◽  
Local Manifestation ◽  
Anomalous Acceleration ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Pioneer 10 ◽  
Radiometric Data

Results from an almost twenty years study of radiometric data from Pioneer 10/11, Galileo and Ulysses spacecraft indicate an anomalous time depending blueshift1, 2 which bares hardly prosaic explanations. Local manifestation of the expansion of the universe or new force terms are not favored either by the observational data. So, we explore the possibility that the reported anomaly, referred to as the "Pioneer anomaly", does not result from a real change in velocity. It turns out that the main Pioneer anomaly may be looked at as a new validation of general relativity (GR) in the weak field and low velocity limit on account of the "machian" behavior of quintessence like dark energy.

scholarly journals A STUDY OF THE PIONEER ANOMALY: NEW DATA AND OBJECTIVES FOR NEW INVESTIGATION

2006 ◽  
Vol 15 (01) ◽  
pp. 1-55 ◽  
Author(s):  
SLAVA G. TURYSHEV ◽  
VIKTOR T. TOTH ◽  
LARRY R. KELLOGG ◽  
EUNICE L. LAU ◽  
KYONG J. LEE
Keyword(s):  
Current Knowledge ◽  
Doppler Frequency ◽  
Blue Shift ◽  
Data Sets ◽  
Pioneer Anomaly ◽  
Doppler Data ◽  
History Of ◽  
Anomalous Acceleration ◽  
Pioneer 10

The Pioneer 10/11 spacecraft yielded the most precise navigation in deep space to date. However, their radiometric tracking data has consistently indicated the presence of a small, anomalous, Doppler frequency drift. The drift is a blue shift, uniformly changing with a rate of ~6 × 10-9 Hz/s and can be interpreted as a constant sunward acceleration of each particular spacecraft of aP = (8.74±1.33) × 10-10 m/s 2 (or, alternatively, a time acceleration of at = (2.92±0.44) × 10-18 s/s 2). This signal has become known as the Pioneer anomaly; the nature of this anomaly remains unexplained. We discuss the current state of the efforts to retrieve the entire data sets of the Pioneer 10 and 11 radiometric Doppler data. We also report on the availability of recently recovered telemetry files that may be used to reconstruct the engineering history of both spacecraft using original project documentation and newly developed software tools. We discuss possible ways to further investigate the discovered effect using these telemetry files in conjunction with the analysis of the much extended Pioneer Doppler data. In preparation for this new upcoming investigation, we summarize the current knowledge of the Pioneer anomaly and review some of the mechanisms proposed for its explanation. We emphasize the main objectives of this new study, namely (i) analysis of the early data that could yield the true direction of the anomaly and thus, its origin, (ii) analysis of planetary encounters, which should say more about the onset of the anomaly (e.g. Pioneer 11's Saturn flyby), (iii) analysis of the entire dataset, which should lead to a better determination of the temporal behavior of the anomaly, (iv) comparative analysis of individual anomalous accelerations for the two Pioneers with the data taken from similar heliocentric distances, (v) the detailed study of on-board systematics, and (vi) development of a thermal-electric-dynamical model using on-board telemetry. The outlined strategy may allow for a higher accuracy solution for the anomalous acceleration of the Pioneer spacecraft and, possibly, will lead to an unambiguous determination of the origin of the Pioneer anomaly.

scholarly journals Conformal Cosmology and the Pioneer Anomaly

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Gabriele U. Varieschi
Keyword(s):  
Cosmological Parameters ◽  
Hubble Constant ◽  
Conformal Gravity ◽  
Conformal Cosmology ◽  
Pioneer Anomaly ◽  
Radio Signals ◽  
Anomalous Acceleration ◽  
Near Future ◽  
Pioneer 10

We review the fundamental results of a new cosmological model, based on conformal gravity, and apply them to the analysis of the early data of the Pioneer anomaly. We show that our conformal cosmology can naturally explain the anomalous acceleration of the Pioneer 10 and 11 spacecrafts, in terms of a local blueshift region extending around the solar system and therefore affecting the frequencies of the navigational radio signals exchanged between Earth and the spacecraft. By using our model, we explain the numerical coincidence between the value of the anomalous acceleration and the Hubble constant at the present epoch and also confirm our previous determination of the cosmological parameters γ∼10−28 cm−1 and δ~10-4–10-5. New Pioneer data are expected to be publicly available in the near future, which might enable more precise evaluations of these parameters.

A model for the pioneer anomaly

2009 ◽  
Vol 87 (10) ◽  
pp. 1089-1093 ◽  
Author(s):  
Ivan G. Avramidi ◽  
Guglielmo Fucci
Keyword(s):  
General Relativity ◽  
Test Particles ◽  
Pioneer Anomaly ◽  
Modified Theory Of Gravity ◽  
Anomalous Acceleration ◽  
Theory Of Gravity ◽  
Modified Theory ◽  
Pioneer 10

In a previous work, we showed that massive test particles exhibit a nongeodesic acceleration in a modified theory of gravity obtained by a noncommutative deformation of General Relativity (so-called Matrix Gravity). We propose that this nongeodesic acceleration might be the origin of the anomalous acceleration experienced by the Pioneer 10 and Pioneer 11 spacecrafts.

scholarly journals On the possible onset of the Pioneer anomaly

2015 ◽  
Vol 24 (08) ◽  
pp. 1550066 ◽  
Author(s):  
Michael R. Feldman ◽  
John D. Anderson
Keyword(s):  
Solar Radiation Pressure ◽  
Sudden Onset ◽  
Oscillatory Behavior ◽  
Pioneer Anomaly ◽  
Order Of Magnitude ◽  
Anomalous Acceleration ◽  
The Difference ◽  
Definition Of ◽  
Yearly Period ◽  
Pioneer 10

We explore the possibility that the observed onset of the Pioneer anomaly after Saturn encounter by Pioneer 11 is not necessarily due to mismodeling of solar radiation pressure but instead reflects a physically relevant characteristic of the anomaly itself. We employ the principles of a recently proposed cosmological model termed "the theory of inertial centers" along with an understanding of the fundamental assumptions taken by the Deep Space Network (DSN) to attempt to model this sudden onset. Due to an ambiguity that arises from the difference in the DSN definition of expected light-time with light-time according to the theory of inertial centers, we are forced to adopt a seemingly arbitrary convention to relate DSN-assumed clock-rates to physical clock-rates for this model. We offer a possible reason for adopting the convention employed in our analysis; however, we remain skeptical. Nevertheless, with this convention, one finds that this theory is able to replicate the previously reported Hubble-like behavior of the "clock acceleration" for the Pioneer anomaly as well as the sudden onset of the anomalous acceleration after Pioneer 11 Saturn encounter. While oscillatory behavior with a yearly period is also predicted for the anomalous clock accelerations of both Pioneer 10 and Pioneer 11, the predicted amplitude is an order of magnitude too small when compared with that reported for Pioneer 10.

scholarly journals <i>Letter to the Editor</i> Why do ultra-low-frequency MHD oscillations with a discrete spectrum exist in the magnetosphere?

2005 ◽  
Vol 23 (3) ◽  
pp. 1075-1079 ◽  
Author(s):  
A. S. Leonovich ◽  
V. A. Mazur
Keyword(s):  
Discrete Spectrum ◽  
Observational Data ◽  
High Latitude ◽  
Plasma Sheet ◽  
Low Frequency ◽  
Magnetosonic Wave ◽  
Letter To The Editor ◽  
Morning Sector ◽  
Good Agreement

Abstract. A new concept of the global magnetospheric resonator is suggested for fast magnetosonic waves in which the role of the resonator is played by the near-Earth part of the plasma sheet. It is shown that the magnetosonic wave is confined in this region of the magnetosphere within its boundaries. The representative value of the resonator's eigenfrequency estimated at f~1MHz is in good agreement with observational data of ultra-low-frequency MHD oscillations of the magnetosphere with a discrete spectrum (f~0.8, 1.3, 1.9, 2.6...MHz). The theory explains the ground-based localization of the oscillations observed in the midnight-morning sector of the high-latitude magnetosphere.

scholarly journals A Search for an Excited Kp=0+ Rotational Band in 24Mg

1976 ◽  
Vol 29 (3) ◽  
pp. 139 ◽  
Author(s):  
D Branford ◽  
LE Carlson ◽  
FCP Huang ◽  
N Gardner ◽  
TR Ophel ◽  
...  
Keyword(s):  
Shell Model ◽  
Quadrupole Moment ◽  
Rotational Band ◽  
Doppler Shift ◽  
Transition Rates ◽  
Model Calculations ◽  
Doppler Shift Attenuation ◽  
Doppler Shift Attenuation Method ◽  
Absolute Transition ◽  
Good Agreement

A search is described for an excited Kn = 0+ rotational band based on the 6� 44 MeV level of 24Mg. Mean nuclear lifetimes have been measured by the Doppler shift attenuation method using the 12C('60,a)24Mg reaction and the results are 't'm = 66�29, 28�7 and 13�3 fs for levels at 6'44, 8�65 and 10� 58 MeV respectively. The absolute transition rates found for the y decays from the 6�44 and 8�65 MeV levels are in good agreement with the results of shell model calculations if it is assumed that these levels are the 0+ and 2 + members respectively of the excited Kn = 0+ rotational band. Based on this assumption, a result Qoo = 0�48 �0�08b is obtained for the intraband quadrupole moment. From a study of the 23Na(p, y) reaction, it is established that the J = 4 levels at 12� 63 and 13�05 MeV do not decay by enhanced E2 transitions to the 8� 65 MeV level. This suggests that neither of these levels is the 4 + member of the excited Kn = 0+ rotational band. An assignment of J" = 4+ is made to one member of the doublet at 10�58 MeV.

scholarly journals Study of the anomalous acceleration of Pioneer 10 and 11

2002 ◽  
Vol 65 (8) ◽  
Author(s):  
John D. Anderson ◽  
Philip A. Laing ◽  
Eunice L. Lau ◽  
Anthony S. Liu ◽  
Michael Martin Nieto ◽  
...  
Keyword(s):  
Anomalous Acceleration ◽  
Pioneer 10

scholarly journals SEARCH FOR A STANDARD EXPLANATION OF THE PIONEER ANOMALY

2002 ◽  
Vol 17 (14) ◽  
pp. 875-885 ◽  
Author(s):  
JOHN D. ANDERSON ◽  
EUNICE L. LAU ◽  
SLAVA G. TURYSHEV ◽  
PHILIP A. LAING ◽  
MICHAEL MARTIN NIETO
Keyword(s):  
Doppler Frequency ◽  
Frequency Drift ◽  
The Sun ◽  
Physical Origin ◽  
Thermal Models ◽  
Pioneer Anomaly ◽  
Pioneer 10

The data from Pioneer 10 and 11 shows an anomalous, constant, Doppler frequency drift that can be interpreted as an acceleration directed towards the Sun of aP = (8.74 ± 1.33) × 10-8 cm / s 2. Although one can consider a new physical origin for the anomaly, one must first investigate the contributions of the prime candidates, which are systematics generated on board. Here we expand upon previous analyses of thermal systematics. We demonstrate that thermal models put forth so far are not supported by the analyzed data. Possible ways to further investigate the nature of the anomaly are proposed.

Experimental Characterization of a T-Shaped Programmable Multistable Mechanism

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Mohamed Zanaty ◽  
Simon Henein
Keyword(s):  
Numerical Simulations ◽  
Reaction Force ◽  
Experimental Measurements ◽  
Experimental Characterization ◽  
Stable States ◽  
Stability Behavior ◽  
The Stability ◽  
Force Characteristics ◽  
Good Agreement

Programmable multistable mechanisms (PMM) exhibit a modifiable stability behavior in which the number of stable states, stiffness, and reaction force characteristics are controlled via their programming inputs. In this paper, we present experimental characterization for the concept of stability programing introduced in our previous work (Zanaty et al., 2018, “Programmable Multistable Mechanisms: Synthesis and Modeling,” ASME J. Mech. Des., 140(4), p. 042301.) A prototype of the T-combined axially loaded double parallelogram mechanisms (DPM) with rectangular hinges is manufactured using electrodischarge machining (EDM). An analytical model based on Euler–Bernoulli equations of the T-mechanism is derived from which the stability behavior is extracted. Numerical simulations and experimental measurements are conducted on programming the mechanism as monostable, bistable, tristable, and quadrastable, and show good agreement with our analytical derivations within 10%.

Sign in / Sign up

Export Citation Format

Share Document