scholarly journals Drag-free deep-space laser ranging missions for fundamental physics

2019 ◽  
Author(s):  
H. Dittus ◽  
C. Lämmerzahl ◽  
H. Araújo
Keyword(s):  
Laser Ranging ◽  
Deep Space ◽  
Fundamental Physics

scholarly journals Development of a space cold atom clock

2020 ◽  
Vol 7 (12) ◽  
pp. 1828-1836
Author(s):  
Wei Ren ◽  
Tang Li ◽  
Qiuzhi Qu ◽  
Bin Wang ◽  
Lin Li ◽  
...  
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Cold Atoms ◽  
Cold Atom ◽  
Deep Space ◽  
Fundamental Physics ◽  
Time Frequency ◽  
Frequency Standards ◽  
Scientific Experiments ◽  
Primary Frequency

Abstract Atomic clocks with cold atoms play important roles in the field of fundamental physics as well as primary frequency standards. Operating such cold atom clocks in space paves the way for further exploration in fundamental physics, for example dark matter and general relativity. We developed a space cold atom clock (SCAC), which was launched into orbit with the Space Lab TG-2 in 2016. Before it deorbited with TG-2 in 2019, the SCAC had been working continuously for almost 3 years. During the period in orbit, many scientific experiments and engineering tests were performed. In this article, we summarize the principle, development and in-orbit results. These works provide the basis for construction of a space-borne time-frequency system in deep space.

scholarly journals Second post-Newtonian approximation of light propagation in Einstein-Aether theory

2007 ◽  
Vol 3 (S248) ◽  
pp. 405-406
Author(s):  
Y. Xie ◽  
T. Y. Huang
Keyword(s):  
Light Propagation ◽  
Laser Ranging ◽  
Deep Space ◽  
Newtonian Approximation ◽  
Theories Of Gravity ◽  
Theory Of Gravity

AbstractFuture deep space laser ranging missions together with astrometry missions will be able to test relativistic gravity to an unprecedented level of accuracy and will require second post-Newtonian approximation of relevant theories of gravity. Einstein-aether theory is adopted as the theory of gravity and the second post-Newtonian approximation of light propagation is studied.

scholarly journals SPACE-BASED TESTS OF GRAVITY WITH LASER RANGING

2007 ◽  
Vol 16 (12a) ◽  
pp. 2165-2179 ◽  
Author(s):  
SLAVA G. TURYSHEV ◽  
JAMES G. WILLIAMS
Keyword(s):  
Laser Ranging ◽  
Lunar Laser Ranging ◽  
Fundamental Physics ◽  
Entire Area ◽  
Geodetic Precession ◽  
Frequency Standards ◽  
Lunar Laser ◽  
Ppn Parameters ◽  
Precision Frequency ◽  
Tests Of Gravity

Existing capabilities of laser ranging, optical interferometry, and metrology, in combination with precision frequency standards, atom-based quantum sensors, and drag-free technologies, are critical for space-based tests of fundamental physics; as a result of the recent progress in these disciplines, the entire area is poised for major advances. Thus, accurate ranging to the Moon and Mars will provide significant improvements in several gravity tests, namely the equivalence principle, geodetic precession, PPN parameters β and γ, and possible variation of the gravitational constant G. Other tests will become possible with the development of an optical architecture that allows one to proceed from meter to centimeter to millimeter range accuracies on interplanetary distances. Motivated by anticipated accuracy gains, we discuss the recent renaissance in lunar laser ranging and consider future relativistic gravity experiments with precision laser ranging over interplanetary distances.

CONCEPT CONSIDERATIONS FOR A DEEP SPACE GRAVITY PROBE BASED ON LASER-CONTROLLED FREE-FLYING REFERENCE MASSES

2007 ◽  
Vol 16 (12a) ◽  
pp. 2297-2307
Author(s):  
ULRICH A. JOHANN
Keyword(s):  
State Of The Art ◽  
Space Mission ◽  
Laser Ranging ◽  
Communication Link ◽  
Deep Space ◽  
Radio Communication ◽  
Light Pressure ◽  
Small Test ◽  
Gravity Probe ◽  
Mission Operation

Concept considerations for a space mission with the objective of precisely testing the gravitational motion of a small test mass in the solar system environment are presented. In particular, the mission goal is an unambiguous experimental verification or falsification of the Pioneer anomaly effect. A promising concept is featuring a passive reference mass, shielded or well modeled with respect to nongravitational accelerations and formation flying with a rather standard deep space probe. The probe provides laser ranging and angular tracking to the reference mass, ranging to Earth via the radio-communication link and shielding from light pressure in the early parts of the mission. State-of-the-art ranging equipment can be used throughout, but requires in part optimization to meet the stringent physical budget constraints of a deep space mission. Mission operation aspects are briefly addressed.

scholarly journals Deep-space laser-ranging missions ASTROD and ASTROD I for astrodynamics and astrometry

2007 ◽  
Vol 3 (S248) ◽  
pp. 379-382
Author(s):  
W. T. Ni ◽  
Keyword(s):  
Solar System ◽  
Reference Frame ◽  
Optical Devices ◽  
Laser Ranging ◽  
Deep Space

AbstractDeep-space laser ranging will be ideal for testing relativistic gravity, and mapping the solar-system to an unprecedented accuracy. ASTROD (Astrodynamical Space Test of Relativity using Optical Devices) and ASTROD I are such missions. ASTROD I is a mission with a single spacecraft; it is the first step of ASTROD with 3 spacecraft. In this talk, after a brief review of ASTROD and ASTROD I, we concentrate on the precision of solar astrodynamics that can be achieved together with implications on astrometry and reference frame ties. The precise planetary ephemeris derived from these missions together with second post-Newtonian test of relativistic gravity will serve as a foundation for future precise astrometry observations. Relativistic frameworks are discussed from these considerations.

scholarly journals Satellite Laser-Ranging as a Probe of Fundamental Physics

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ignazio Ciufolini ◽  
Richard Matzner ◽  
Antonio Paolozzi ◽  
Erricos C. Pavlis ◽  
Giampiero Sindoni ◽  
...  
Keyword(s):  
General Relativity ◽  
Gravitational Field ◽  
Equivalence Principle ◽  
Free Fall ◽  
Satellite Laser Ranging ◽  
Laser Ranging ◽  
Weak Equivalence ◽  
Fundamental Physics ◽  
Weak Equivalence Principle ◽  
Gravitational Theories

Abstract Satellite laser-ranging is successfully used in space geodesy, geodynamics and Earth sciences; and to test fundamental physics and specific features of General Relativity. We present a confirmation to approximately one part in a billion of the fundamental weak equivalence principle (“uniqueness of free fall”) in the Earth’s gravitational field, obtained with three laser-ranged satellites, at previously untested range and with previously untested materials. The weak equivalence principle is at the foundation of General Relativity and of most gravitational theories.

SPACECRAFT GRAVITATIONAL WAVE DETECTORS

2011 ◽  
Vol 20 (10) ◽  
pp. 2057-2062 ◽  
Author(s):  
PENG DONG ◽  
WEI-TOU NI
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Space Missions ◽  
Common Method ◽  
Integration Time ◽  
Laser Ranging ◽  
Deep Space ◽  
Measurement Sensitivity ◽  
Laser Technology ◽  
Gravitational Wave Detectors

For detecting gravitational waves in space, deep-space laser ranging using drag-free spacecraft is a common method. Deep space provides a large arena and a long integration time. Laser technology provides measurement sensitivity, while drag-free technology ensures gravitational phenomenon to be measured with least spurious noises. In this talk, we give an overview of motivations and methods of various space missions/proposals for detecting gravitational waves, and refer them to various references.

Clock comparison based on laser ranging technologies

2015 ◽  
Vol 24 (08) ◽  
pp. 1530021 ◽  
Author(s):  
Etienne Samain
Keyword(s):  
Recent Progress ◽  
Laser Ranging ◽  
The Moon ◽  
Time Transfer ◽  
Transfer Experiment ◽  
Fundamental Physics ◽  
Frequency Standards ◽  
Future Space ◽  
Lunar Reconnaissance Orbiter ◽  
Clock Comparison

Recent progress in the domain of time and frequency standards has required some important improvements of existing time transfer links. Several time transfer by laser link (T2L2) projects have been carried out since 1972 with numerous scientific or technological objectives. There are two projects currently under exploitation: T2L2 and Lunar Reconnaissance Orbiter (LRO). The former is a dedicated two-way time transfer experiment embedded on the satellite Jason-2 allowing for the synchronization of remote clocks with an uncertainty of 100 ps and the latter is a one-way link devoted for ranging a spacecraft orbiting around the Moon. There is also the Laser Time Transfer (LTT) project, exploited until 2012 and designed in the frame of the Chinese navigation constellation. In the context of future space missions for fundamental physics, solar system science or navigation, laser links are of prime importance and many missions based on that technology have been proposed for these purposes.

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