Etalon are a Russian family (Etalon-1, Etalon-2) of passive geodetic satellites dedicated to satellite laser ranging. Etalon-1 was the first geodynamic satellite launched by the former Soviet Union. The Etalon spacecraft were launched in 1989 in conjunction with a pair of GLObal'naya NAvigatisionnay Sputnikovaya Sistema (GLONASS) satellites. The mission objectives were to determine a high accuracy terrestrial reference frame and earth rotation parameters, to improve the gravity field, and to improve the gravitational constant.

Mission Instrumentation:

The Etalon satellites are passive satellites. The only instrumentation is the retro-reflector array which consists of 2 different type of cube corners.

Mission Parameters:

Etalon-1, -2 Parameters
	Etalon-1	Etalon-2
Sponsor:	Russia	Russia
Expected Life:	hundreds of years	hundreds of years
Primary Applications:	geodesy	geodesy
COSPAR ID:	8900103	8903902
SIC Code:	0525	4146
NORAD SSC Code:	19751	20026
Launch Date:	January 10, 1989	May 31, 1989
RRA Diameter:	1.294 m	1.294 m
RRA Shape:	circular	circular
Reflectors:	2146 corner cubes	2146 corner cubes
Orbit:	Circular	Circular
Inclination:	64.9 degrees	65.5 degrees
Eccentricity:	0.00061	0.00066
Perigee:	19,120 km	19,120 km
Period:	676 minutes	675 minutes
Weight:	1415 kg	1415 kg

Additional Information:

Web sites:

Etalon array response (NERC/IPIE)
Federation of American Scientists (FAS)

Publications

Appleby, G.M., "Long-Arc analyses of SLR Observations of the Etalon Geodetic Satellites", Journal of Geodesy, Vol. 72, Issue 6, pp. 333-342, 1998.
Appleby, G.M., "Orbit determination of the Lageos and Etalon satellites - A comparison of geodetic results and orbital evolution of the Etalons", Proc. Conf. on Dynamics and Astrometry of Natural and Artificial Celestial Bodies, Poznan, Poland, pp. 333-338, 1994.
Dick, G., Gendt, G., Montag, H., Nischan, Th., and Sommerfeld, W., "Results of Etalon data analysis", Geodesy and Physics of the Earth-Geodetic Contributions to Geodynamics. Montag, H., Reigber, Ch. (Eds.), IAG No. 112, Potsdam, 1992, 315-318, Springer, London, 1993.
Mironov, N.T., Emetz. A.I., Zaharov, A.N., and Tchebotarev, V.E., "ETALON-1, -2 Center of Mass Correction and Array Reflectivity", Proc. 8th Intern. Workshop on Laser Ranging Instrumentation, Annapolis, MD, May 18-22, 1993, NASA Conference Publ. 3214, p. 6-9, 1992.
Torrence, M.H., Dunn, P.J., and Kolenkiewicz, R., "Characteristics of the LAGEOS and ETALON Satellites Orbits", Adv. Space Res., V.16, No. 12, pp. 21-24, 1995.
Wiant, J., "Tunable Etalon Usage at MLRS Mcdonald Laser Ranging Station", 5th International Workshop on Laser ranging Instrumentation, Herstmonceux, U.K., published by Geodetic Institute, Univ. Bonn, p. 185, 1984.