# GEOStar-2

The STAR-2 Bus is a fully redundant, flight-proven, spacecraft bus designed for geosynchronous missions.
It is a satellite platform, designed and developed by Thomas van der Heyden for the Indonesian Cakrawarta satellite program in the early 1990s, now manufactured by Northrop Grumman Innovation Systems with an apogee kick motor to place a communications satellite into geostationary orbit, a thruster to provide the satellite with orbital station-keeping for a 15-year mission, and solar arrays to provide the satellite payload with 5 kW of electrical power.

## Advantages

NGIS's GEOStar-2 bus design is unique within the satellite industry. NGIS's GEOStar-2 bus provides an affordable low-to-medium power satellite platform that is ideal for missions of this size. Rather than being a less efficient version of a larger, heavier product, NGIS's GEOStar-2 bus is designed specifically for the 1000 to 5550 watts payload class.

## Design

The GEOStar-2 bus satellite is a modular, mass efficient structure, designed for simplified integration to reduce manufacturing cycle times. The structure is supported by a composite thrust cylinder, to which the bus, payload, nadir and base panels are connected. Energy from two multi-panel solar wings and lithium-ion batteries is electronically processed to provide 36 volts regulated power to the satellite throughout the mission. All active units aboard the satellite are connected through a 1553 data bus. Commands and telemetry are processed through the flight software resident on the flight processor, which provides robust autonomous control to all GEOStar-2 satellites. The modularity of the structure and the standard 1553 interfaces allow parallel assembly and test of the bus and payload systems, reducing manufacturing schedule risk by minimizing the time spent in serial satellite integration and test flow. GEOStar-2 is designed for missions up to 15 years in duration. The propulsion system is sized for ten years of station keeping in geosynchronous orbit. Built-in radiation hardness for the severe geosynchronous environment is achieved through conservative selection of electronic parts. Several available options augment the basic bus to provide improved pointing, more payload power, secure communications, higher downlink data rates or enhanced payload computing power.

### Structure

* Bus Dimensions (H x W x L): 1.75 x 1.7 x 1.8 m
* Construction: Composite/Al

### Power subsystem

* Payload Power: Up to 5550 watts orbit average at 15 years
* Bus Voltage: 24-36 VDC (nominal)
* Solar Arrays: multi-junction GaAs cells
* Batteries: lithium-ion

### Attitude control subsystem

* Stability Mode: 3-axis; zero momentum
* Propulsion Subsystem
* Transfer Orbit System: liquid bi-propellant
* On Orbit: monopropellant (hydrazine)

### Command and data handling subsystem

* Flight Processor: MIL-STD-1750A
* Interface Architecture: MIL-STD 1553B, CCSDS

## Payload support

While primary applications are Fixed-Satellite Services (FSS) and Broadcast Satellite Services (BSS), the GEOStar-2 bus can be adapted for MSS, Earth and space science applications, as well as for technology demonstration or risk reduction programs. Depending on mission duration requirements, the GEOStar-2 bus can accommodate payloads in excess of 500 kilograms, and provide up to 5550 watts of power. Instrument data can be provided in standard format such as CCSDS or through secured encryption, as approved by the National Security Agency (NSA).

### Shared launch opportunities

Due to the size and mass envelope of the satellite, the GEOStar-2 bus is compatible with almost all commercially available launch vehicles, maximizing opportunity for launch and access to space. While dedicated or single launch services are more readily available, the GEOStar-2 bus targets shared launch opportunities, where launch cost and launch-sharing opportunities are favorable.

### Mission services

Customers can purchase the GEOStar-2 bus spacecraft bus alone, or as part of a turn-key service that includes an integrated payload, network operations center and launch vehicle. NGIS conducts spacecraft commissioning from its own ground station prior to transferring spacecraft control to the customer's operations center.

## Satellite Orders

| Satellite | Country | Operator | Type | Transponders | Launch date (UTC) | Rocket | Changes | Status |
| AMC-21 | United States | SES Americom | Television broadcasting | 24 Ku-band | 14 August 2008 | Ariane 5 ECA | | Active |
| Amazonas 4A | Spain | Hispasat | Communications | 24 Ku-band | 14 August 2008 | Ariane 5 ECA | | Active |
| Azerspace-1/Africasat-1a | Azerbaijan | Azercosmos | Communications | 24 C-band, 12 Ku-band | 7 February 2013 | Ariane 5 ECA | | Active |
| Eutelsat 5 West B | International | Eutelsat | Communications | 35 Ku-band | 9 October 2019 | Proton-M Phase 4 | | Active |
| Galaxy 12 | United States | PanAmSat | Television broadcasting | 20-24 C-band | 9 April 2003 | Ariane 5 G | | Active |
| Galaxy 14 | United States | PanAmSat | Television broadcasting | 20-24 C-band | 13 August 2005 | Soyuz-FG | | Active |
| Galaxy 15 | United States | PanAmSat | Television broadcasting | 20-24 C-band | 13 October 2005 | Ariane 5 GS | | Active |
| Galaxy 30 | United States | Intelsat | Television broadcasting | C-band, Ku-band, Ka-band, and WAAS payload | 15 August 2020 | Ariane 5 ECA | | Active |
| Horizons-2 | United States, Japan | PanAmSat, SKY Perfect JSAT | Communications | 20 Ku-band | 21 December 2007 | Ariane 5 GS | | Active |
| HYLAS 2 | United Kingdom | Avanti Communications | Satellite internet | 24 Ka-band | 2 August 2012 | Ariane 5 ECA | | Active |
| Intelsat 11 | United States | Intelsat | Communications | 16 C-band, 18 Ka-band | 5 October 2007 | Ariane 5 GS | Formerly PAS 11 | Active |
| Intelsat 15 | United States | Intelsat | Communications | 22 Ku-band | 30 November 2009 | Zenit-3SLB | | Active |
| Intelsat 16 | United States | Intelsat | Communications | 24 Ku-band | 12 February 2010 | Proton-M Phase 1 | Formerly PAS 11R | Active |
| Intelsat 18 | United States | Intelsat | Communications | 24 C-band, 12 Ku-band | 5 October 2011 | Zenit-3SLB | | Active |
| Intelsat 23 | United States | Intelsat | Communications | 24 C-band, 15 Ku-band | 14 October 2012 | Proton-M Phase 3 | | Active |
| Koreasat 6 | South Korea | KT Corporation | Television broadcasting | 30 Ku-band | 29 December 2010 | Ariane 5 ECA | | Active |
| MEASAT-3a | Malaysia | MEASAT Satellite Systems | Television broadcasting | 12 C-band, 12 Ku-band | 21 June 2009 | Zenit-3SLB | | Active |
| Mexsat-3 | Mexico | Mexican Satellite System | Mobile communications | 12 C-band, 12 Ku-band | 19 December 2012 | Ariane 5 ECA | | Active |
| N-STAR c | Japan | NTT Docomo | Mobile communications | 1 C-band, 20 S-band | 5 July 2002 | Ariane 5 G | | Retired |
| New Dawn | United States | Intelsat | Television broadcasting | 28 C-band, 24 Ku-band | 22 April 2011 | Ariane 5 ECA | Known as Intelsat 28 | Active |
| NSS-9 | Netherlands | SES World Skies | Communications | 28 C-band | 12 February 2009 | Ariane 5 ECA | | Active |
| Optus D1 | Australia | Optus | Television broadcasting | 24 Ku-band | 13 October 2006 | Ariane 5 ECA | | Active |
| Optus D2 | Australia | Optus | Television broadcasting | 24 Ku-band | 5 October 2007 | Ariane 5 GS | | Active |
| Optus D3 | Australia | Optus | Television broadcasting | 24 Ku-band | 21 August 2009 | Ariane 5 ECA | | Active |
| SES-1 | United States | SES Americom | Communications | 24 C-band, 24 Ku-band, 2 Ka-band | 24 April 2010 | Proton-M Phase 2 | Formerly AMC-4R | Active |
| SES-2 and CHIRP (Commercially Hosted InfraRed Payload) | United States | SES Americom | Communications | 24 C-band, 24 Ku-band, 2 Ka-band | 21 September 2011 | Ariane 5 ECA | Formerly AMC-5R | Active |
| SES-3 | United States | SES Americom | Communications | 24 C-band, 24 Ku-band, 2 Ka-band | 15 July 2011 | Proton-M Phase 3 | | Active |
| SES-8 | Luxembourg | SES | Television broadcasting | 33 Ku-band | 3 December 2013 | Falcon 9 | | Active |
| Sky-Mexico 1 | Mexico | DirecTV | Television broadcasting | 24 Ku-band, 2 R-band | 27 May 2015 | Ariane 5 ECA | Known as SKYM 1 | Active |
| Star One C3 | Brazil | Star One | Communications | 28 C-band, 16 Ku-band | 10 November 2012 | Ariane 5 ECA | | Active |
| Telkom-2 | Indonesia | Telkom Indonesia | Communications | 24 C-band | 16 November 2005 | Ariane 5 ECA | | Retired |
| Thaicom 6 | Thailand | Thaicom | Communications | 24 C-band, 9 Ku-band | 6 January 2014 | Falcon 9 | Known as AfriCom 1 | Active |
| Thaicom 8 | Thailand | Thaicom | Communications | 24 Ku-band | 27 May 2016 | Falcon 9 | | Active |
| Thor 5 | Norway | Telenor | Television broadcasting | 24 Ku-band | 11 February 2008 | Proton-M Phase 3 | | Active |