GLONASS Satellite Constellation

As with GLONASS’s predecessor program, Tsikada, GLONASS satellites were developed under the leadership of the Applied Mechanics NPO, with the assistance of the Institute for Space Device Engineering and the Russian Institute of Radio navigation and Time. Also following the Tsikada precedent, serial production for GLONASS satellites was accomplished primarily by the Polet PO.

Over the three decades of development, the satellites themselves have gone through numerous revisions, separated here as generations. The name of each satellite was Uragan (English: hurricane), followed either by a number for operational satellites or by an acronym GVM (English: size weight dummy) for test satellites. 

  1. Prototypes (Generation zero)

    The first GLONASS vehicles to be launched, referred to as Block I vehicles, were prototypes and GVM dummy vehicles. Three dummies and 18 prototypes were launched between 1982 and 1985. Designed to last only one year, many averaged an actual lifetime of 14 months.

     

  2. First generation 

    The true first generation of Uragan satellites were all 3-axis stabilized vehicles, generally weighing 1,250 kg and were equipped with a modest propulsion system to permit relocation within the constellation. Over time they were divided into Block IIa, IIb, and IIv vehicles, with each block containing evolutionary improvements

    Six Block IIa satellites were launched in 1985–1986 with improved time and frequency standards over the prototypes, and increased frequency stability. These spacecraft also demonstrated a 16-month average operational lifetime. Block IIb spacecraft, with a 2-year design lifetimes, appeared in 1987, of which a total of 12 were launched, but half were lost in launch vehicle accidents. The six spacecraft that made it to orbit worked well, each operating for an average of nearly 22 months.

    Block IIv was the most prolific of the first generation. Used exclusively from 1988 to 2000, and continued to be included in launches through 2005, a total of 25 satellites were launched. The design life was three years; however numerous spacecraft exceeded this, with one late model lasting 68 months.

    Block II satellites were typically launched three at a time from the Baikonur Cosmodrome using Proton-K Blok-DM-2 or Proton-K Briz-M boosters. The only exception was when, on two launches, an Etalon geodetic reflector satellite was substituted for a GLONASS satellite.

  3. Second generation 

    The second generation of satellites, known as Uragan-M (also called GLONASS-M), were developed beginning in 1990 and first launched in 2001.

    These satellites possess a substantially increased lifetime of seven years and weigh slightly more at 1,480 kg. They are approximately 2.4 m in diameter and 3.7 m high, with a solar array span of 7.2 m for an electrical power generation capability of 1600 watts at launch. Laser corner-cube reflectors are also carried to aid in precise orbit determination and geodetic research. On-board cesium clocks provide the local clock source.

    A total of fourteen second generation satellites were launched through the end of 2007. As with the previous generation, the second generation spacecraft were launched in triplets using Proton-K Blok-DM-2 or Proton-K Briz-M boosters.

  4.  Third generation 

    The third generation satellites are known as Uragan-K (GLONASS-K) spacecraft. These satellites are designed with a lifetime of 10 to 12 years, a reduced weight of only 750 kg, and offer an additional L-Band navigational signal. As with the previous satellites, these are 3-axis stabilized, nadir pointing with dual solar arrays. They will enter service in 2009.

    Due to their weight reduction, Uragan-K spacecraft can be launched in pairs from the Plesetsk Cosmodrome launch site using the substantially lower cost Soyuz-2 boosters or in six-at-once from the Baikonur Cosmodrome using Proton-K Briz-M launch vehicles.

GLONASS Satellite Development

GLONASS Satellite Development

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