GLONASS-K
Class of GLONASS satellites
From Wikipedia, the free encyclopedia
GLONASS-K is the latest satellite design intended as a part of the Russian GLONASS radio-based satellite navigation system. Developed by ISS Reshetnev (Information Satellite Systems Reshetnev) 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.
Model of Glonass-K satellite at CeBIT 2011 | |||
| Manufacturer | ISS Reshetnev | ||
|---|---|---|---|
| Country of origin | Russia | ||
| Operator | JSC «Navigation-Information systems» | ||
| Applications | Navigation | ||
| Specifications | |||
| Bus | Ekspress-1000K | ||
| Launch mass | 935 kg | ||
| Power | 1600 watts | ||
| Batteries | NiH2 | ||
| Equipment | FDMA signals: L1OF, L1SF, L2OF and L2SF CDMA signals: L3OC | ||
| Regime | Medium Earth orbit (MEO) | ||
| Design life | 10 years (planned) | ||
| Production | |||
| Status | In production | ||
| On order | 7[1] | ||
| Built | 5 | ||
| Launched | 5 | ||
| Operational | 3 | ||
| Retired | 1 | ||
| Maiden launch | 26 February 2011 | ||
| Last launch | 10 October 2022 | ||
| Related spacecraft | |||
| Derived from | GLONASS-M | ||
| |||
History
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.[2] The Roscosmos initially ordered 27 GLONASS-K satellites from ISS Reshetnev, the developer of all the previous GLONASS satellites.[3] On 7 December 2010, the company announced it had completed ground tests of the first GLONASS-K satellite.[4] The satellite was launched to orbit on 26 February 2011.[5] On 30 November 2014, the second and supposedly last GLONASS-K1 development satellite was put to orbit as Kosmos 2501.[6]
On 28 May 2014, interview, Nikolay Testoyedov (president of ISS Reshetnev) stated that production of GLONASS-M would end in 2015, with GLONASS-K being exclusively produced after that final batch.[7] On 14 December 2014, an interview with GPS World, he stated that because of international sanctions that limited the supply of radiation resistant electronics, they had decided to launch nine additional GLONASS-K1 as fleet replacement while they finished the GLONASS-K2 design.[8] In May 2015 presentation, Mr. Testoyedov expected the serial production of GLONASS-K1 to start flying in early 2018, just after the launch of the first GLONASS-K2 prototype. The presentation showed at least eleven additional GLONASS-K1 satellites flying until 2020.[9]
Satellites
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 935 kg compared to its predecessor GLONASS-M, which had a mass of 1450 kg.[10] 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. It also increased the power supply from GLONASS-M's 1400 watts to 1600 watts.[10]
GLONASS-K will transmit additional navigation signals to improve the system's accuracy.[2] Existing FDMA signals, 2 military and 2 civilian, will be transmitted on the L1 and L2 bands, and additional civilian CDMA signals will be transmitted in the L1, L2, L3 and L5 bands.[11][12]
GLONASS-V
GLONASS-V, also known as GLONASS-VKK, is a planned modification of GLONASS-K for use in highly elliptical orbit.[13][14] Roscosmos plans to launch six GLONASS-V satellites in three orbital planes starting in 2028.[15][16] The new satellites will improve location accuracy in urban canyons and increase redundancy in longitudes between 20° and 160° East covering most of Russia.
Launches
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.[17] 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%. The new satellite's advanced equipment — made solely from Russian components — was expected to allow doubling the accuracy.[12] 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 03:07 UTC on 26 February 2011, the first GLONASS-K satellite, Kosmos 2471, was launched. The launch took place from Plesetsk Cosmodrome on a Soyuz-2.1b rocket with a Fregat upper stage.[18] The satellite reached the correct orbit at 06:39 UTC.[5] At 06:44, ground stations established control over the satellite.[19] 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".[18] Successful reception of the CDMA signal in L3 band has been reported by independent researchers.[20][21]
At 21:52:26 UTC on 30 November 2014, the second GLONASS-K satellite, Kosmos 2501 was launched. The launch took place from Plesetsk Cosmodrome on a Soyuz-2.1b rocket with a Fregat upper stage.[22][19] The spacecraft separated from the launch vehicle at 01:25 UTC of 1 December 2014.[23]
A third GLONASS-K satellite, Kosmos-2547 was launched on 25 October 2020 at 19:08:42 UTC by a Soyuz-2.1b launcher from the Plesetsk Cosmodrome.[24]
The fourth GLONASS-K satellite Kosmos-2557 was launched on 7 July 2022 at 09:18:06 UTC by a Soyuz-2.1b launcher with a Fregat upper stage from the Plesetsk Cosmodrome.[25]
The fifth GLONASS-K satellite Kosmos 2559 was launched on 10 October 2022 at 02:52:32 UTC by a Soyuz-2.1b launcher with a Fregat upper stage from the Plesetsk Cosmodrome.[26]
