Astrodynamical Space Test of Relativity using Optical Devices I (ASTROD I) - A class-M fundamental physics mission proposal for Cosmic Vision 2015-2025

Authors: Thierry Appourchaux, Raymond Burston, Yanbei Chen, Michael Cruise, Hansjoerg Dittus, Bernard Foulon, Patrick Gill, Laurent Gizon, Hugh Klein, Sergei Klioner, Sergei Kopeikin, Hans Krueger, Claus Laemmerzahl, Alberto Lobo, Xinlian Luo, Helen Margolis, Wei-Tou Ni, Antonio Pulido Paton, Qiuhe Peng, Achim Peters, Ernst Rasel, Albrecht Ruediger, Etienne Samain, Hanns Selig, Diana Shaul, Timothy Sumner, Stephan Theil, Pierre Touboul, Slava Turyshev, Haitao Wang, Li Wang, Linqing Wen, Andreas Wicht, Ji Wu, Xiaomin Zhang, Cheng Zhao

(Submitted on 5 Feb 2008)

Abstract: ASTROD I is a planned interplanetary space mission with multiple goals. The primary aims are: to test General Relativity with an improvement in sensitivity of over 3 orders of magnitude, improving our understanding of gravity and aiding the development of a new quantum gravity theory; to measure key solar system parameters with increased accuracy, advancing solar physics and our knowledge of the solar system and to measure the time rate of change of the gravitational constant with an order of magnitude improvement and the anomalous Pioneer acceleration, thereby probing dark matter and dark energy gravitationally. It is an international project, with major contributions from Europe and China and is envisaged as the first in a series of ASTROD missions.

ASTROD I will consist of one spacecraft carrying a telescope, four lasers, two event timers and a clock. Two-way, two-wavelength laser pulse ranging will be used between the spacecraft in a solar orbit and deep space laser stations on Earth, to achieve the ASTROD I goals. A second mission,

ASTROD II is envisaged as a three-spacecraft mission which would test General Relativity to one part per billion, enable detection of solar g-modes, measure the solar Lense-Thirring effect to 10 parts per million, and probe gravitational waves at frequencies below the LISA bandwidth. In the third phase (ASTROD III or Super-ASTROD), larger orbits could be implemented to map the outer solar system and to probe primordial gravitational-waves at frequencies below the ASTROD II bandwidth.

Comments: 26 pages, 11 figures, shortened from the original cosmic vision proposal, submitted to Experimental Astronomy

Subjects: Astrophysics (astro-ph)

Cite as: arXiv:0802.0582v1 [astro-ph]

Submission history

From: Wei-Tou Ni [view email]

[v1] Tue, 5 Feb 2008 10:22:20 GMT (749kb)

http://arxiv.org/abs/0802.0582

And for those who might prefer using more stay-at-home methods:

Testing Gravity in the Outer Solar System: Results from Trans-Neptunian Objects

Authors: John F. Wallin, David S. Dixon, Gary L. Page

(Submitted on 23 May 2007)

Abstract: The inverse square law of gravity is poorly probed by experimental tests at distances of ~ 10 AUs. Recent analysis of the trajectory of the Pioneer 10 and 11 spacecraft have shown an unmodeled acceleration directed toward the Sun which was not explained by any obvious spacecraft systematics, and occurred when at distances greater than 20 AUs from the Sun. If this acceleration represents a departure from Newtonian gravity or is indicative of an additional mass distribution in the outer solar system, it should be detectable in the orbits of Trans-Neptunian Objects (TNOs). To place limits on deviations from Newtonian gravity, we have selected a well observed sample of TNOs found orbiting between 20 and 100 AU from the Sun. By examining their orbits with modified orbital fitting software, we place tight limits on the perturbations of gravity that could exist in this region of the solar system.

Comments:

20 pages, 4 figures, 2 tables, uses AASTex v5.x macros

Subjects:

Astrophysics (astro-ph)

Cite as:

arXiv:0705.3408v1 [astro-ph]

Submission history

From: John Wallin [view email]

[v1] Wed, 23 May 2007 16:03:08 GMT (28kb)

http://arxiv.org/abs/0705.3408

Jupiter, Saturn and the Pioneer anomaly: a planetary-based independent test

Authors: Lorenzo Iorio

(Submitted on 8 Dec 2007)

Abstract: In this paper we use the ratio of the corrections to the standard Newtonian/Einsteinian secular precessions of the longitudes of perihelia of Jupiter and Saturn, recently estimated by the Russian astronomer E.V. Pitjeva by fitting almost one century of data with the EPM ephemerides, to make an independent, planetary-based test of the hypothesis that the Pioneer anomaly (PA), as it is presently known in the 5-10 AU region, is of gravitational origin. Accounting for the errors in the determined apsidal extra-rates and in the values of the PA acceleration at the orbits of Jupiter and Saturn the answer is negative.

If and when the re-analysis of the entire Pioneer 10/11 will be completed more firm conclusions could be reached. Moreover, it would also be important that other teams of astronomers estimate independently their own corrections to the perihelion precessions.

Comments: Latex, 6 pages, no figures, no tables, 22 references. To appear in JGP (Journal of Gravitational Physics)

Subjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics (astro-ph); High Energy Physics - Phenomenology (hep-ph); Space Physics (physics.space-ph)

Cite as: arXiv:0712.1273v1 [gr-qc]

Submission history

From: Lorenzo Iorio [view email]

[v1] Sat, 8 Dec 2007 10:31:43 GMT (6kb)

http://arxiv.org/abs/0712.1273