APOLLO: A NEW PUSH IN LUNAR LASER RANGING

2007 ◽  
Vol 16 (12a) ◽  
pp. 2127-2135 ◽  
Author(s):  
T. W. MURPHY ◽  
E. L. MICHELSON ◽  
A. E. ORIN ◽  
E. G. ADELBERGER ◽  
C. D. HOYLE ◽  
...  
Keyword(s):  
Gravitational Constant ◽  
Rate Of Change ◽  
Laser Ranging ◽  
Lunar Laser Ranging ◽  
Time Rate ◽  
Strong Signal ◽  
Minute Period ◽  
Lunar Laser ◽  
Future Space ◽  
Order Of Magnitude

APOLLO (the Apache Point Observatory Lunar Laser-ranging Operation) is a new effort in lunar laser ranging that uses the Apollo-landed retroreflector arrays to perform tests of gravitational physics. It achieved its first range return in October 2005, and began its science campaign the following spring. The strong signal (> 2500 photons in a ten-minute period) translates to one-millimeter random range uncertainty, constituting at least an order-of-magnitude gain over previous stations. One-millimeter range precision will translate into order-of-magnitude gains in our ability to test the weak and strong equivalence principles, the time rate of change of Newton's gravitational constant, the phenomenon of gravitomagnetism, the inverse-square law, and the possible presence of extra dimensions. An outline of the APOLLO apparatus and its initial performance is presented, as well as a brief discussion on future space technologies that can extend our knowledge of gravity by orders of magnitude.

scholarly journals APOLLO: A new push in solar-system tests of gravity

2009 ◽  
Vol 5 (S261) ◽  
pp. 200-203
Author(s):  
T. W. Murphy ◽  
E. G. Adelberger ◽  
J. B. R. Battat ◽  
C. D. Hoyle ◽  
R. J. McMillan ◽  
...  
Keyword(s):  
Equivalence Principle ◽  
Gravitational Constant ◽  
Rate Of Change ◽  
Laser Ranging ◽  
Lunar Laser Ranging ◽  
Time Rate ◽  
Geodetic Precession ◽  
Lunar Laser ◽  
Tests Of Gravity ◽  
Strong Equivalence Principle

AbstractLunar laser ranging (LLR) has long provided many of our best measurements on the fundamental nature of gravity, including the strong equivalence principle, time -rate-of-change of the gravitational constant, the inverse square law, geodetic precession, and gravitomagnetism. This paper serves as a brief overview of APOLLO: a recently operational LLR experiment capable of millimeter-level range precision.

scholarly journals CONSTRAINT ON INTERMEDIATE-RANGE GRAVITY FROM EARTH–SATELLITE AND LUNAR ORBITER MEASUREMENTS, AND LUNAR LASER RANGING

2005 ◽  
Vol 14 (10) ◽  
pp. 1657-1666 ◽  
Author(s):  
GUANGYU LI ◽  
HAIBIN ZHAO
Keyword(s):  
Experimental Tests ◽  
Earth Satellite ◽  
Laser Ranging ◽  
Satellite Measurement ◽  
Lunar Orbiter ◽  
Lunar Laser Ranging ◽  
Intermediate Range ◽  
Earth Gravity ◽  
Lunar Laser ◽  
Order Of Magnitude

In the experimental tests of gravity, there have been considerable interests in the possibility of intermediate-range gravity. In this paper, we use the earth–satellite measurement of earth gravity, the lunar orbiter measurement of lunar gravity, and lunar laser ranging measurement to constrain the intermediate-range gravity from λ = 1.2 × 107 m –3.8 × 108 m . The limits for this range are α = 10-8–5 × 10-8, which improve previous limits by about one order of magnitude in the range λ = 1.2 × 107 m –3.8 × 108 m .

scholarly journals Constraining a Possible Variation of G with Type Ia Supernovae

2014 ◽  
Vol 31 ◽  
Author(s):  
Jeremy Mould ◽  
Syed A. Uddin
Keyword(s):  
Dark Energy ◽  
Task Force ◽  
Rate Of Change ◽  
Laser Ranging ◽  
Lunar Laser Ranging ◽  
Data Set ◽  
Lunar Laser ◽  
Standard Candle ◽  
Type Ia ◽  
Ia Supernovae

AbstractAstrophysical cosmology constrains the variation of Newton’s Constant in a manner complementary to laboratory experiments, such as the celebrated lunar laser ranging campaign. Supernova cosmology is an example of the former and has attained campaign status, following planning by a Dark Energy Task Force in 2005. In this paper, we employ the full SNIa data set to the end of 2013 to set a limit on G variation. In our approach, we adopt the standard candle delineation of the redshift distance relation. We set an upper limit on its rate of change $|\dot{G}/G|$ of 0.1 parts per billion per year over 9 Gyrs. By contrast, lunar laser ranging tests variation of G over the last few decades. Conversely, one may adopt the laboratory result as a prior and constrain the effect of variable G in dark energy equation of state experiments to δw < 0.02. We also examine the parameterisation G ~ 1 + z. Its short expansion age conflicts with the measured values of the expansion rate and the density in a flat Universe. In conclusion, supernova cosmology complements other experiments in limiting G variation. An important caveat is that it rests on the assumption that the same mass of 56Ni is burned to create the standard candle regardless of redshift. These two quantities, f and G, where f is the Chandrasekhar mass fraction burned, are degenerate. Constraining f variation alone requires more understanding of the SNIa mechanism.

scholarly journals Benefit of New High-Precision LLR Data for the Determination of Relativistic Parameters

Universe ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 34
Author(s):  
Liliane Biskupek ◽  
Jürgen Müller ◽  
Jean-Marie Torre
Keyword(s):  
Equivalence Principle ◽  
Gravitational Constant ◽  
Lunar Orbit ◽  
Laser Ranging ◽  
The Moon ◽  
Lunar Laser Ranging ◽  
Lunar Laser ◽  
Infra Red ◽  
Ppn Parameters

Since 1969, Lunar Laser Ranging (LLR) data have been collected by various observatories and analysed by different analysis groups. In the recent years, observations with bigger telescopes (APOLLO) and at infra-red wavelength (OCA) are carried out, resulting in a better distribution of precise LLR data over the lunar orbit and the observed retro-reflectors on the Moon. This is a great advantage for various investigations in the LLR analysis. The aim of this study is to evaluate the benefit of the new LLR data for the determination of relativistic parameters. Here, we show current results for relativistic parameters like a possible temporal variation of the gravitational constant G˙/G0=(−5.0±9.6)×10−15yr−1, the equivalence principle with Δmg/miEM=(−2.1±2.4)×10−14, and the PPN parameters β−1=(6.2±7.2)×10−5 and γ−1=(1.7±1.6)×10−4. The results show a significant improvement in the accuracy of the various parameters, mainly due to better coverage of the lunar orbit, better distribution of measurements over the lunar retro-reflectors, and last but not least, higher accuracy of the data. Within the estimated accuracies, no violation of Einstein’s theory is found and the results set improved limits for the different effects.

Lunar Laser Ranging at CERGA for the ruby period (1981–1986)

1993 ◽  
pp. 189-193 ◽  
Author(s):  
C. Veillet ◽  
J. F. Mangin ◽  
J. E. Chabaubie ◽  
C. Dumolin ◽  
D. Feraudy ◽  
...  
Keyword(s):  
Laser Ranging ◽  
Lunar Laser Ranging ◽  
Lunar Laser
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