The Angosat-1 communications satellite The Angolan satellite or Angosat-1 was designed to be the first national communications spacecraft for the African country of Angola. In part thanks to extensive political, economic and military ties between Russia and Angola dating back to the Soviet period, the Russian firm RKK Energia won the contract for the development of the Angosat-1 satellite. Previous chapter: Sea Launch venture The Angosat-1 mission at a glance: Operational orbital position in the geostationary orbit 13 degrees East Spacecraft mass 1,647 kilograms Communications payload mass 262.4 kilograms Power supply capability 3,753 Watts Transponders 16 C-band and 6 Ku-band Guaranteed life span in orbit 15 years Launch vehicle Zenit-3SLBF No. SLB80.5/Fregat Launch site Baikonur, Site 45 Launch date and time 2017 Dec. 26, 22:00:03.435 Moscow Time Project cost $327.6 million From the publisher: Pace of our development depends primarily on the level of support from our readers! At the beginning of the 21st century, the Angolan government embarked on a major effort to revamp the nation's telecommunications infrastructure and switch local TV channels from analog to digital format. In order to improve and expand communications across all 117 municipalities and to link the nation to the rest of the African continent, the Angolan Ministry of Telecommunications and Informational Technologies planned to launch the first Angolan communications satellite, Angosat-1. The spacecraft, which was expected to carry up to 40 C- and Ku-band transponders, could be used for all forms of modern communications including TV broadcasts, telephone service, the Internet and secure electronic services for the government. According to the African press, the Angolan government gave high priority to the project, estimated to cost around $300 million, despite limited financial resources. In June 2009, Rosoboroneksport, a Moscow-based entity specialized in sales of Russian defense-related technologies reached an agreement with the Angolan government to build and launch the Angosat-1 satellite. The deal was probably sweetened by the fact that Russian banks had agreed to lend the money for the venture. The actual job of building the spacecraft was delegated to RKK Energia, which had pioneered satellite communications in the USSR in the 1960s and returned to this line of work in the 1990s. After preliminary studies, the practical implementation of the project started in December 2012. RKK Energia based the design of the Angosat satellite on a standard platform, which had previously served as a basis for the Yamal communications satellite series and the military EKS Tundra early-warning spacecraft. By the standards of modern commercial communications satellites, which reach up to six tons in mass, Angosat was a relatively small spacecraft. The initial mass of the satellite was reported to be around 1,550 kilograms, but shortly before the completion of the project, RKK Energia quoted its mass as 1,647 kilograms, which is a modest increase likely resulting from various design changes during the course of the development. The company reported that the service module of the Angosat satellite could provide an onboard communications payload with up to seven kilowatts of power with electric current available at 28, 50 and 100 volts. RKK Energia also said that the platform had consisted of Russian-made components and the company's newest virtual reality design center assisted in the development of the satellite, however, the spacecraft's communications payload was apparently supplied by the European consortium Airbus Defense and Space. The communications payload aboard Angosat included 16 C-band and 6 Ku-band transponders, whose antennas could provide communications across Angola, but also cover the entire African continent. Like other satellites in the Yamal series, the Angosat was equipped with electric thrusters which could be used to maneuver the satellite to its operational orbit after launch and then maintain the correct orbital parameters. In addition to the spacecraft itself, Russia also agreed to help Angola build the primary ground control station for Angosat near the Angolan capital of Luanda and a backup facility in Korolev, Russia, as well as train local engineers to operate the satellite in orbit. In 2017, the total cost of the Angosat project, including ground infrastructure, was reported to be $327.6 million. RKK Energia's Yamal platform, which served as a basis for the Angosat satellite. Building Angosat-1 In 2011, Moscow-based banks, including Vneshekonombank, VTB and Roseksimbank, extended a $278.46-million credit to the Angolan Finance Ministry for 13 years to fund the Angosat project. The full-scale development of the Angosat satellite officially started in November 2013 and was expected to last 36 months. Around that time, RKK Energia began work on the design documentation and it was also preparing for a formal approval of the preliminary design of the spacecraft and its ground complex. That phase was followed with the development of the production documentation and, finally, the production of components for the spacecraft. In the middle of 2014, RKK Energia said that the planned work for building the satellite and its ground infrastructure was underway. By 2015, the company reported that the development of the Angosat-1 had passed the critical design review and the design of the ground segment had been submitted to the customer. The project officials were also working on securing necessary communications frequencies for the operation of the satellite. At the end of June 2015, the Angolan Ministry of Communications announced laying the foundation for the satellite control center in Funda, municipality Cacuaco, near Luanda. According to the Interministerial Commission Coordinating the National Space Program, GGPEN, the prime factor for choosing that particular location was the low level of electromagnetic interference in this largely rural area. The center's communications equipment included a 7.6-meter ZS SKU flight control antenna and a 4.9-meter support antenna. The facility also included two power generators, two electric transformers and a fuel storage, enabling its operation in case of a power outage. A water-treatment plant located five kilometers away on the Bengo river also supported the center. The futuristic three-story building of the satellite control center, designed by Moscow-based 2K Engineering Company, was completed by September 2016. Angosat-1 declared dead, Angosat-2 promised In April 2016, the Minister of Telecommunication and Information Technologies of Angola José Carvalho de Rocha announced that the Angosat-1 satellite would be launched in the first quarter of 2017. However in September of the same year, the Izvestiya daily reported that the completion of the Angosat satellite was still two months away. (828) As of October 2016, the Angosat-1 was not expected to be ready before July 2017. The satellite finally reached the launch pad in 2017 and was delivered into orbit by a Zenit rocket on December 26. Although the launch vehicle performed by the book, the satellite exhibited fatal problems with its power supply system practically immediately after entering autonomous flight, resulting in the loss of communications with the spacecraft. Despite all the hopes to restore communications, on April 23, 2018, the Angolan government officially declared the satellite a total loss. Known contractors in the Angosat-1 project: RKK Energia/ZAO ZEM - Prime contractor and system integrator;jan. 5

Airbus Defense and Space - Transponder payload;

AO NII Argon;

FGUP NII of Command Instruments - Reaction wheels for the flight control system;

AO AVEKS - Power supply system;

PAO Saturn;

ZAO TsSKT;

OOO NPO Rubikon-Innovatsiya;

AO NPP Geophysika-Kosmos;

OOO NPP TAIS;

OOO S7 Space Systems;

FGUP TsNIIMash. Angosat-1 frequencies: Beacon frequencies:

C-band - 3830 MHz

Ku-band - 10951 MHz SCCS frequency:

Command receivers - 5741.525 and 5745.495 MHz

Telemetric transmitters - 3401.125 and 3404.125 MHz EIRP of SCCS:

0 dBW (omnidirect. mode)

4.3 dBW (via PL antennas) Angosat-1 costs: Spacecraft $252 million Orbital position $20.8 million Ground infrastructure $54.3 million Project total $327.6 million

Angosat satellite during vacuum testing. Click to enlarge. Credit: RKK Energia A fully assembled Angosat satellite shortly before its shipment to the launch site. Click to enlarge. Credit: RKK Energia A traditional meeting of the Chief Designers' Council dedicated to the Angosat mission took place at RKK Energia on Nov. 14, 2017. Click to enlarge. Credit: RKK Energia Artist rendering of the Angosat ground control station in Angola circa 2014, which was expected to occupy 6,617 square meters. The main 1,978-square-meter building was designed to accommodate 45 technicians and featured an underground parking lot for 50 vehicles. Credit: 2K The ground control station for the Angosat satellite was completed in Angola in 2016. Map of Ku-band coverage of the Angosat-1 satellite over Africa. Map of C-band coverage of the Angosat-1 satellite over Africa.