scholarly journals MICROSCOPE Mission scenario, ground segment and data processing

Author(s):  
Manuel Rodrigues ◽  
Gilles Metris ◽  
Judicael Bedouet ◽  
Joel Bergé ◽  
Patrice Carle ◽  
...  

Abstract Testing the Weak Equivalence Principle (WEP) to a precision of 10-15 requires a quantity of data that give enough confidence on the final result: ideally, the longer the measurement the better the rejection of the statistical noise. The science sessions had a duration of 120 orbits maximum and were regularly repeated and spaced out to accommodate operational constraints but also in order to repeat the experiment in different conditions and to allow time to calibrate the instrument. Several science sessions were performed over the 2.5 year duration of the experiment. This paper aims to describe how the data have been produced on the basis of a mission scenario and a data flow process, driven by a tradeoff between the science objectives and the operational constraints. The mission was led by the Centre National d’Etudes Spatiales (CNES) which provided the satellite, the launch and the ground operations. The ground segment was distributed between CNES and Office National d’Etudes et de Recherches Aerospatiales (ONERA). CNES provided the raw data through the Centre d’Expertise de Compensation de Trainee (CECT: Drag-free expertise centre). The science was led by the Observatoire de la Coote d’Azur (OCA) and ONERA was in charge of the data process. The latter also provided the instrument and the Science Mission Centre of MICROSCOPE (CMSM).

2018 ◽  
Vol 861 (1) ◽  
pp. 66 ◽  
Author(s):  
Calvin Leung ◽  
Beili Hu ◽  
Sophia Harris ◽  
Amy Brown ◽  
Jason Gallicchio ◽  
...  

2020 ◽  
Vol 499 (1) ◽  
pp. L53-L57
Author(s):  
Shu-Cheng Yang ◽  
Wen-Biao Han ◽  
Gang Wang

ABSTRACT The weak equivalence principle (WEP) is the cornerstone of gravitational theories. At the local scale, WEP has been tested to high accuracy by various experiments. On the intergalactic distance scale, WEP could be tested by comparing the arrival time of different messengers emitted from the same source. The gravitational time delay caused by massive galaxies is proportional to γ + 1, where the parameter γ is unity in general relativity. The values of γ for different massless particles should be different if WEP is violated, i.e. Δγ is used to indicate the deviation from WEP. So far, |Δγ| has been constrained with gamma-ray bursts, fast radio bursts, etc. Here, we report a new constraint of |Δγ| by using the gravitational wave data of binary black hole coalescences in the LIGO–Virgo catalogue GWTC-1. The best constraints imply that |Δγ| ≲ 10−15 at 90 per cent confidence level.


2000 ◽  
Vol 25 (6) ◽  
pp. 1245-1249 ◽  
Author(s):  
F.M. Huber ◽  
R.A. Lewis ◽  
E.W. Messerschmid ◽  
G.A. Smith

2014 ◽  
Vol 30 ◽  
pp. 1460267 ◽  
Author(s):  
C. S. Unnikrishnan

After a brief review of the evidence for the validity of the Weak Equivalence principle for anti-matter, I show that, contrary to general belief, the near equality of the Shapiro delay for photons, neutrinos and anti-neutrinos in the galactic gravitational potential is not a true test of the WEP for their intrinsic properties and quantum numbers due to the overwhelming contribution to the gravitational mass from the relativistic kinetic energy. Then I prove the remarkable result that particles that obey the Newtonian law of dynamics automatically respect the WEP due to the firm equivalence between the law of motion and the WEP in any relativistic scenario, through gravity of all the matter in the Universe. Thus a test of the validity of Newtons's law in any force field is a true test of the WEP and provides strong direct tests of WEP for anti-particles. This result opens up an entire new insight of conceptual and practical importance for the tests of WEP.


2012 ◽  
Vol 21 (11) ◽  
pp. 1242016
Author(s):  
C. S. UNNIKRISHNAN ◽  
G. T. GILLIES

A significant question in experimental gravity is the nature of free fall of antiparticles under gravity and elaborate preparations are underway to directly test this with cold antihydrogen. Earlier, the Shapiro delay of supernova 1987A neutrinos was interpreted as testing the weak equivalence principle (WEP). We establish the surprising result that the Shapiro delay of relativistic particles does not test WEP for intrinsic properties or quantum numbers of particles or antiparticles. This is because essentially the entire gravitational mass of the relativistic neutrinos is contributed by kinetic energy, diluting to insignificance any EP violating contribution from intrinsic properties, by the relativistic factor. The crucial message here is that a true test of the WEP involving intrinsic properties of matter or antimatter — the foundation of relativistic gravity — necessarily requires nonrelativistic "cold" matter and antimatter.


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