Post Tue Jul 19, 2011 9:47 am

Glonass reaches generation K

The first prototype of the Glonass system- the version K, has been successfully sent to orbit in the weekend confirming the decision of the Moscow authorities for establishing a global navigation system.

Since 2001 Russia spent on the Glonass system more than 4.7 billions dollars and despite this amount of money and the fact it is a strategic element for the Russian government, the system has not reached yet the maximum capacity.
In a global navigational market estimated at a value of 60-70 billions euros, Russia has targeted a niche of 15% but it succeeded to achieve only 1% far under the expectations.
For being in line with the latest technical innovations and with the competitors, the Glonass system will benefit from a 2.6 billions euros investment, hoping to reach a number of 30 operational satellites by 2011.

This launch comes at the right time and it saves the honor of the Russian space agency Roskosmos who failed twice in the past few months.
On 3rd of December 2010, SpaceAlliance was speaking about an accident on a Baikonur launched Proton Block DM3 rocket when 3 Glonass satellites were lost.
Two months latter, on 1st of February 2011 we were commenting about the incident involving the GEO-IK2 1 satellite- the first platform of a new GEO-IK satellites used for geodesic observations. That launch has been performed from Plesetsk using a Rockot Breeze KM rocket.
Both incidents were followed by very serious investigations over the Russian space agency activity and also on the collaborators from the aerospace industry and the contracts- investigations which, we were speculating, seriously threaten the position of the Roskosmos president Anatoly Perminov.

Coming back to the weekend’s event, differently from the launch of the block M satellites, which were performed from Baikonur aboard Proton rockets (typically 3 per launch), the K type platforms, due to a modern design concept and also due to the decreased weight, can be launched aboard the lighter version Soyuz2-1b/Fregate from the Plesetsk launch site. Because of this, the Russian Space Agency can save up to 50% of the launching cost by sending them in pairs of 2 satellites at a time.

The first launch of the K generation (Kosmos 2470) has been delayed initially for two days and took place finally Saturday 26th of February at 03:07 GMT, the satellite being placed in the desired orbit (19100 km x 19100 km x 64.8 degrees) a few hours latter at 06.41 GMT. The success of the mission has been confirmed shortly when the ground antennas succeeded to receive the first telemetry.

The satellite is built by ISS Reshetnev on an Ekspress-1000A spacecraft bus, is three axes stabilized and weights approximately 750 kg. Together with the classical navigation signals it will provide auxiliary emergency services for the Cospas-Sarsat program.

Despite the fact that onboard has been carried a single satellite (and not two as we mentioned it will happen in the future) the rocket flew in a complete configuration, with a fairing adapted to the volume of 2 satellites, just to give to the flight engineers the necessary exercise for the time when the Glonass flights will become a routine.
Another K type test satellite will be flown this year, but currently it is under development and the final date of the flight it is not known.
After these first two platforms will be successfully tested and will confirm their capabilities in the orbit, Russia will go to the second phase of the project, when it will try to replace all the block M with newer block K satellites. Formally to make a difference with the test platforms, these new satellites will be named generically K2.

The Glonass system has today (officially) 26 satellites in orbit (plus the one just launched now). Theoretically the number is enough for a complete coverage of the Russian Federation’s territory (a minimum of 18 satellites is required) and even for an extension to the global scale (where 24 satellites are required to operate simultaneously). It should be said however that from the 26, 4 are in technical maintenance and another 2 are kept for the moment as backup (all minimum 2 years old) – so it will only remain 20 fully operational.

The Glonass system (“Globalnaya Navigationnaya Sputnikovaya Sistema”) or “Global Orbiting Navigation Satellite System” has started first time in September 1993 with a group of 12 satellites and has reached the predicted number of 24 satellites for a global coverage in December 1995. However due to the financial problems encountered at that time and due to the lack of new investments, a part of these satellites have been retired without replacing them.

The systems consisted from three orbital planes, separated at 120 degrees and with the satellites within the same orbital plane separated by 45 degrees. Each satellite describes a circular, 19100 km height by 64.8 degrees inclination orbit, having an orbital period of 11 hours and 15 minutes. The satellites are uniquely identified by the “slot number”: the first orbital plane contains the slots 1-8, the second 9-16 and the third 17-24.
In 2007, it has been decided however a modification to the total number of satellites contained by the Glonass constellation from 24 to 30- meaning it will have 8 operational satellites plus 2 spares for each orbital plane.
This should increase the robustness and reliability of the system, lowering the risk induced by malfunctions or failures.

Each satellite transmits two types of signals: a standard one for commercial applications and an encoded high-precision one for military applications.
There are actually 25 different channels separated by 0.5625 MHz in the L1 frequency bands: 1602.5625-1615.5 MHz and respectively L2 band: 1240-1260 MHz.

When the system will be complete, it is estimated to reach an accuracy of 70 m for the position and 15 cm/s for speed (for the civil applications) and an equivalent of 10-20m for military applications.