Model of Glonass-K satellite at CeBIT 2011 |
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| General Information | |
|---|---|
| Manufacturer | ISS Reshetnev |
| Country of Origin | Russia |
| Bus | Express-1000 |
| Applications | Navigation |
| Orbit regimes | MEO |
| Operator | JSC «Navigation-Information systems» |
| Lifetime | 10 years |
| Production | |
| Status | In Production |
| Built | 1 |
| Launched | 1 |
| First launch | 2011-02-26 |
| Typical spacecraft | |
| Average mass | 935 kg (2,060 lb) |
| Power | 1.6 kW |
| Batteries | NiH2 |
GLONASS-K is the latest satellite design intended as a part of the Russian GLONASS radio-based satellite navigation system. Developed by Reshetnev Information Satellite Systems and first launched on 26 February 2011, it is a substantial improvement of the previous GLONASS-M second-generation satellites, having a longer lifespan and better accuracy.
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The Federal Targeted Program "Global Navigation System" 2002–2011, introduced in 2001, stipulated the development of a third-generation navigation satellite design, called GLONASS-K, as part of the overall GLONASS upgrade program in the time frame 2005–2011. The new satellite followed the second generation GLONASS-M, introduced in 2003.[1] The Russian Federal Space Agency (Roscosmos) initially ordered 27 GLONASS-K satellites from Reshetnev Information Satellite Systems, the developer of all the previous GLONASS satellites.[2] On 7 December 2010, the company announced it had completed ground tests of the first GLONASS-K satellite.[3] The satellite was launched to orbit on 26 February 2011.[4]
GLONASS-K is the first unpressurised GLONASS satellite—all of its equipment is able to operate in a vacuum. Due to this, the satellite's mass has been substantially reduced: GLONASS-K has a mass of just 750 kg compared to its predecessor GLONASS-M, which had a mass of 1,450 kg. The new satellite has an operational lifetime of 10 years, three years longer than that of GLONASS-M and seven years longer than the lifetime of the original GLONASS satellite. GLONASS-K will transmit additional navigation signals to improve the system's accuracy.[1] Existing FDMA signals, 2 military and 2 civilian, will be transmitted on the L1 and L2 bands, and additional civilian CDMA signal will be transmitted in the L1, L2, L3 and L5 bands.[5][6]. The new satellite's advanced equipment—made solely from Russian components—will allow the doubling of GLONASS' accuracy.[7]
| Roadmap of GLONASS modernization | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Satellite series | Launch | Current status | 1602 + n×0.5625 MHz (L1, FDMA) |
1575.42 MHz (L1, CDMA) |
1246 + n×0.4375 MHz (L2, FDMA) |
1242 MHz (L2, CDMA) |
1207.14 MHz (L3, CDMA) |
1176.45 MHz (L5, CDMA) |
Clock error |
| GLONASS | 1982 | Out of service | L1OF, L1SF | L2SF | 5×10−13 | ||||
| GLONASS-M | 2003 | In service | L1OF, L1SF | L2OF, L2SF | 1×10−13 | ||||
| GLONASS-K1 | 2011 | In service | L1OF, L1SF | L2OF, L2SF | L3OС † | 5×10−14-1×10−13 | |||
| GLONASS-K2 | 2013 | Design phase | L1OF, L1SF | L1OC, L1SC | L2OF, L2SF | L2SC | L3OC | 5×10−14 | |
| GLONASS-KМ | 2015 | Research phase | L1OF, L1SF | L1OC, L1OCM, L1SC | L2OF, L2SF | L2OC, L2SC | L3OC | L5OC | |
| "O": open signal (standard precision), "S": obfuscated signal (high precision); "F":FDMA , "С":CDMA; n=−7,−6,−5,...,6 †Glonass-K1 series use 1202.025 MHz for the L3OC signal |
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For launching the satellites, two options are planned: six satellites simultaneously from Baikonur Cosmodrome on the heavy-lift Proton-M, or two simultaneously from Plesetsk Cosmodrome on a Soyuz-2 with a Fregat upper stage.[8] In comparison, the previous GLONASS-M satellites could only be launched three at a time on a Proton-M. The new launch scheme is expected to cut orbiting costs by 50%.[7] The launch of the first GLONASS-K satellite did however not conform to the general plan, as it was launched alone on a Soyuz-2.1b instead of in a pair.
At 06:07 Moscow Time on 26 February 2011, the first GLONASS-K satellite was launched. The launch took place from Plesetsk Cosmodrome on a Soyuz-2.1b rocket with a Fregat upper stage.[9] The satellite reached the correct orbit at 09:39.[4] At 09:44, ground stations established control over the satellite.[10] A Space Forces spokesman told Interfax: "we have established and are maintaining steady telemetry communications with the spacecraft... the on-board systems of the Glonass-K satellite are functioning normally."[9] Successful reception of the CDMA signal in L3 band has been reported by independent researchers[11][12].
Russia has exhibited the Glonass-K spacecraft during the CeBIT 2011 fair, that took place in Hannover from 1st to 5 March.