Ekspress (satellite bus)

The Ekspress (Russian: Экспресс) is a highly flexible satellite bus designed and manufactured by ISS Reshetnev. It is an unpressurized bus originally designed for GEO, but that has been adapted for medium Earth orbit and to highly elliptical orbit. It has different versions and has been used from civilian communications to satellite navigation.

Platform variations
The Ekspress bus has two main platforms: the 1000 light to medium version and the 2000, for heavy satellites. There was a project for a third platform, the 4000, but it has not yet been used.

Ekspress-1000 Series
The Ekspress-1000 (Russian: Экспресс-1000) in its different variations offers an platform for small to medium satellites. It is a direct to GEO bus for total spacecraft weights from 1200 kg to 2200 kg and having a power production from 3 kW to 8 kW with a life expectancy of 15 years. It is designed for directly stacking up to 3 of the smallest version (Ekspress-1000K) or 2 of the bigger ones.


 * Ekspress-1000K (Russian: Экспресс-1000K): The smallest platform. It is designed for spacecraft up to 1200 kg, with space for 250 kg of payload and up to 3 kW of power generation and 1.8 kW of heat dissipation. It can be stacked up to three Ekspress-1000K.
 * Ekspress-1000H (Russian: Экспресс-1000Н): The middle platform. It is designed for spacecraft up to 1900 kg, with space for 500 kg of payload and up to 5.6 kW of power generation and 3.5 kW of heat dissipation. It can be dual stacked with Ekspress-1000K or Ekspress-1000H.
 * Ekspress-1000SH (Russian: Экспресс-1000SH): The biggest platform. It is designed for spacecraft up to 2200 kg, with space for 700 kg of payload and up to 8 kW of power generation and 5 kW of heat dissipation. It can be dual stacked with an Ekspress-1000K.
 * Ekspress-1000HT (Russian: Экспресс-1000НТ): Evolution of the SH platform.
 * Ekspress-1000HTA (Russian: Экспресс-1000НТА): Evolution of the HT platform.
 * Ekspress-1000HTV (Russian: Экспресс 1000НТВ): Evolution of the HTA platform.

Ekspress-2000 Series
The Ekspress-2000 (Russian: Экспресс-2000)  is the fruits of the collaboration with Thales Alenia Space and their Spacebus 4000 experience with the Ekspress-1000H. It is a big platform for spacecraft massing up to 3500 kg, with space for 1000 kg of payload and up to 14 kW of power generation and 7.5 kW of heat dissipation. It is, as the rest of the family, a direct to GEO bus and given its size it is not designed to be stacked. It has an expected design life of 15 years.

Ekspress-4000 Series
The Ekspress-4000 (Russian: Экспресс-4000) is a collaboration with Thales Alenia Space to mix the best elements of the Ekspress-2000 with the Spacebus 4000. It would be a direct to GEO platform for spacecraft massing up to 3200 kg and having a power production of 14 kW with a life expectancy of 15 years. This would enable more than 60 transponders of payload.

It would lack any orbit raising propulsion, but would keep the electric propulsion thrusters (SPT-100) supplied by OKB Fakel for station keeping. It would also use the Russian solar panels and have versions designed for highly elliptical orbit like Molniya orbit so important for the northerner regions of Russia.

During 2009, the plan was to start with a series of satellites in HEO orbits for the Russian government, called Ekspress-RV Экспресс-РВ). It would be a constellation of three on orbit spacecraft with a fourth backup on Earth, but no further development have been communicated. Nor any of the expected foreign sales were closed.

List of satellites
The Ekspress bus has seen many successes, both for the commercial market and the military programs. Here is a list of all known orders as of July 2016.