scholarly journals The Laser Astrometric Test of Relativity Mission

2004 ◽  
Vol 134 ◽  
pp. 171-178 ◽  
Author(s):  
Slava G. Turyshev ◽  
Michael Shao ◽  
Kenneth L. Nordtvedt
Keyword(s):  
Relativity Mission

Gyroscopes and charge control for the Relativity Mission Gravity Probe B

2000 ◽  
Vol 25 (6) ◽  
pp. 1181-1184 ◽  
Author(s):  
Saps Buchman ◽  
C.W.F. Everitt ◽  
Brad Parkinson ◽  
J.P. Turneaure ◽  
R. Brumley ◽  
...  
Keyword(s):  
Gravity Probe B ◽  
Charge Control ◽  
Gravity Probe ◽  
Relativity Mission

Spacecraft control system for the relativity mission

1995 ◽  
Vol 3 (8) ◽  
pp. 1119-1123 ◽  
Author(s):  
H. Dougherty ◽  
D. Hegel ◽  
J. Kirschenbaum ◽  
J. Vanden Beukel ◽  
W. Reeve ◽  
...  
Keyword(s):  
Control System ◽  
Spacecraft Control ◽  
Relativity Mission

Stress and its Effect on Surface Morphology in Multi-Layer Ti-Cu Films

1996 ◽  
Vol 441 ◽  
Author(s):  
Ping Zhou ◽  
Saps Buchman ◽  
Chris Gray ◽  
John Turneaure ◽  
James E. Turlo
Keyword(s):  
Surface Morphology ◽  
Smooth Surface ◽  
Total Thickness ◽  
Full Understanding ◽  
Gravity Probe B ◽  
Cu Films ◽  
Number Of Layers ◽  
Gravity Probe ◽  
Relativity Mission ◽  
Scanning Electron

AbstractWe have characterized the stress and its effects on surface morphology for multi-layer thin films of about 3μm total thickness, consisting of three or seven layers of Ti and Cu. These films constitute the electrostatic suspension electrodes for the gyroscope housings of the Relativity Mission Gravity Probe B. Full understanding of surface morphology is critical for meeting the complex requirements of this application.The residual stresses have been measured using a laser curvature technique, while the surface morphology was studied by scanning electron microscopy (SEM). We find that the surface morphology depends strongly on the stress, which evolves with the Ti-Cu multi-layer period. Average stress and the resulting surface roughness decrease for thinner Cu layers (increased total number of layers). Seven layer Ti-Cu films with low stress and very smooth surface have been successfully used for the electrodes of the gyroscope housings.

scholarly journals Progress in VLBI Stellar Astrometry for the NASA/Stanford Relativity Mission (Gravity Probe B)

1998 ◽  
Vol 164 ◽  
pp. 385-386
Author(s):  
M. I. Ratner ◽  
D. E. Lebach ◽  
I. I. Shapiro ◽  
N. Bartel ◽  
M. F. Bietenholz ◽  
...  
Keyword(s):  
General Relativity ◽  
Standard Error ◽  
Proper Motion ◽  
Gravity Probe B ◽  
Frame Dragging ◽  
Vlbi Observations ◽  
Gravity Probe ◽  
Guide Star ◽  
Radio Stars ◽  
Relativity Mission

AbstractThe NASA/Stanford Relativity Mission (Gravity Probe B) is to test the unverified “frame-dragging” prediction of general relativity through measurements of the precessions of orbiting gyroscopes. For mission accuracy goals to be met, the proper motion of a “guide star,” whose position will be used as an inertial reference, must be determined in an extragalactic reference frame with a standard error less than 0.5 mas/yr. We discuss our VLBI observations of the current guide-star candidates (radio stars HR 1099, HR 5110, and HR 8703) and our techniques for obtaining differential astrometric positions with the needed accuracy.

RELATIVITY MISSION SPACECRAFT CONTROL SYSTEM

1995 ◽  
pp. 315-320
Author(s):  
H. DOUGHERTY ◽  
D. HEGEL ◽  
J. KIRSCHENBAUM ◽  
J. VANDEN BEUKEL ◽  
W. REEVE ◽  
...  
Keyword(s):  
Control System ◽  
Spacecraft Control ◽  
Relativity Mission

Experimental techniques for gyroscope performance enhancement for the Gravity Probe B relativity mission

1996 ◽  
Vol 13 (11A) ◽  
pp. A185-A191 ◽  
Author(s):  
Saps Buchman ◽  
Francis Everitt ◽  
Brad Parkinson ◽  
John Turneaure ◽  
Mac Keiser ◽  
...  
Keyword(s):  
Performance Enhancement ◽  
Experimental Techniques ◽  
Gravity Probe B ◽  
Gravity Probe ◽  
Relativity Mission

Performance of the relativity mission superfluid helium flight dewar

2003 ◽  
Vol 32 (7) ◽  
pp. 1407-1416 ◽  
Author(s):  
R.T. Parmley ◽  
G.A. Bell ◽  
D.J. Frank ◽  
D.O. Murray ◽  
R.A. Whelan
Keyword(s):  
Superfluid Helium ◽  
Relativity Mission
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