Proton launches Angosat-2 communications satellite
Specialists in Baikonur cosmodrome successfully launched the second Russian-built spacecraft for the government of Angola, meant to replace its predecessor that failed immediately upon reaching orbit in 2017.
Angosat-2 satellite at a glance:
On April 28, 2019, after more than two years of negotiations between Russian and Angolan officials over the fate of Angosat-1, the satellite was pronounced a total loss. At the same time, the Minister of Telecommunication and Information Technologies of Angola José Carvalho de Rocha told the Jornal de Angola newspaper that his government had accepted a proposal from Roskosmos to built a replacement spacecraft. The Russian side reportedly promised that the construction of the Angosat-2 satellite would take no longer than 18 months and that the replacement vehicle would have better technical capabilities than its predecessor. For example, the new satellite would be able to provide specialized services for the "Internet of things." In the meantime, Vladimir Solntsev, the head of RKK Energia, which developed Angosat-1, was quoted as saying that the new spacecraft would be built in 30 months, beginning on April 24, 2018.
According to Angolan and Russian officials, part of the cost for the construction of Anogsat-2 would be covered with a $121-million insurance payment for the loss of Angosat-1 and the rest would be paid by the Russian government. In addition, Russia's State Enterprise for Satellite Communications, GPKS, committed to provide Angola with capacity in C- and Ku-band on already operating communications satellites, such as Ekspress-AM7 and Eutelsat-3B, while the replacement for the Angosat-1 was in the works. Finally, Russia promised to support operations of the ground control center for Angosat in Funda, Angola.
Artist depiction of the Anogsat-2 satellite developed at ISS Reshetnev.
Despite claims in the official Russian press as late as January 2020 about the ongoing development of the Angosat-2 satellite at RKK Energia, industry sources told RussianSpaceWeb.com that, in fact, Roskosmos had transferred the project to ISS Reshetnev in the fourth quarter of 2019, and that the company had already begun full-scale work on the spacecraft in early 2020. The agreement called for the delivery of the satellite in 24 months, according to industry sources.
The communications payload for Angosat-2 had been sub-contracted to the European consortium Airbus Defense and Space and the same company was apparently bidding for the development of the power-supply system for the project to replace the hardware from RKK Energia which doomed Angosat-1.
On January 21, 2020, the TASS news agency reported that the Angolan government was choosing the prime contractor for the Angosat-2 project between RKK Energia and ISS Reshetnev. However, on the same day, the TASS also quoted Sergei Dubik, Deputy Director at Roskosmos, as saying that the Angosat-2 satellite was in production and that, according to the Head of RKK Energia Nikolai Sevastyanov, the spacecraft would be ready by the end of 2021. Around the same time, reports in the Angolan press reported the readiness of the satellite at 50 percent.
The switch of prime contractor in the Angosat-2 project could mark the end of communications satellite development at RKK Energia, leaving ISS Reshetnev as the only Russian company in the nation producing that type of spacecraft. After pioneering the development of communications satellites in the USSR in the 1960s, RKK Energia re-entered the field in the 1990s with its Yamal series, however, the project had experienced a number of major setbacks.
In turn, ISS Reshetnev planned to rely on its Ekspress-1000 satellite bus or one of its derivatives which had previously served as the basis for several Russian and foreign commercial projects. To accelerate the development of Angosat-2 even further, the company also hoped to emulate as closely as possible the Ekspress-80 and -103 satellites, which came off its assembly line in 2019.
As of mid-2020, the launch of Angosat-2 was expected on a Proton rocket. In October 2020, ISS Reshetnev said that it had shipped the payload platform for Angosat-2 to an Airbus facility in Europe for installation of the communications payload. The hardware was then expected to return to Reshetnev for the integration with the service module, the company said. However, in February 2021, Airbus had postponed the delivery of the payload from April 30 to the third or fourth week of May 2021, due to problems at sub-contractors stemming from the coronavirus pandemic. Moreover, in June, the official Russian press reported that Airbus faced problem with the delivery due to US sanctions against Moscow affecting some American components on the Airbus-built payload module. Fortunately for the Angosat-2 project, the export problems were eventually resolved and the payload module for the satellite was delivered to ISS Reshetnev by October 2021.
Still, in the wake of the Russian escalation of war against Ukraine on Feb. 24, 2022, Airbus stopped the delivery of 57 waveguides and related documentation for the deployable antennas operating in Ku- and C-band. The replacement of the banned hardware with indigenously built equivalents delayed the launch of Angosat-2 from March to October 2022. As a result, the project failed to provide a political boost to the incumbent government in Angola on the eve of the country's general elections on August 24.
A photo taken at ISS Reshetnev likely showing handling of the Anogsat-2 satellite.
On April 5, 2022, Roskosmos announced that a pair of Proton rockets along with Briz-M and DM upper stages had been shipped to Baikonur for upcoming missions, including "one for a foreign customer." According to industry sources, the launch of the Angosat-2 satellite was planned for July 2022 at the time. In early June 2022, the Russian TASS news agency, citing an unnamed source said that the launch had been scheduled for the first 10 days of September 2022. However, by early August, the launch slipped to Oct. 12, 2022.
According to ISS Reshetnev, Angosat-2 was delivered to Baikonur on July 26, 2022, where it underwent initial checks and fueling. After the satellite's integration with the Block DM-03 space tug, the upper composite was connected to a Proton rocket on Oct. 7, 2022, completing the integration of the vehicle inside processing building 92A-50.
The rocket was rolled out to Pad 24 at Site 81 on the morning of Oct. 9, 2022. The State Commission overseeing the launch campaign gathered at 11:20 Moscow Time on October 12, clearing the mission for liftoff.
Angosat-2 lifts off
According to Roskosmos, the separation of the first stage took place at T+123.79 seconds into the flight. Moments before separation, the four-engine cluster of the second stage took over the powered flight, initially firing through a lattice structure connecting the two stages.
The second stage then separated at T+335.77 seconds in flight and the third stage took over the powered ascent. Just seconds later, at T+348.68 seconds into the flight, the payload fairing protecting the satellite from aerodynamic loads in the lower atmosphere split into two halves and dropped away.
The third stage fired its main RD-0213 engine until T+584.06 seconds into the flight. Still, the four-nozzle steering engine of the stage continued firing for another 12 seconds to refine the velocity to an exactly precise parameter. A fraction of a second later, the payload section, including the Block DM-03 upper stage and the Anogsat-2 satellite, separated from the third stage at T+585.40 seconds into the flight into a suborbital trajectory. The third stage would then reenter the atmosphere and any of its surviving debris were to fall into the Pacific Ocean.
The subsequent insertion into the initial parking orbit, as well as the ascent to the transfer orbit and the target orbit was to be performed with three firings of the Block DM-03 upper stage over a nearly seven-hour period. The release of the satellite into its planned orbit was scheduled around 00:44 Moscow Time on Oct. 13, 2022 (5:44 p.m. EDT on October 12).
According to industry sources, the active phase of the ascent to the initial parking orbit went as scheduled. After around one revolution around the Earth in the initial orbit, Block DM-03 re-started the engine, boosting itself and its cargo to a highly elliptical (egg-shaped) transfer orbit with a apogee (highest point) roughly matching the altitude of the circular target orbit.
The upper stage/satellite stack was expected to passively climb toward the apogee of the transfer orbit, before the final maneuver to circularize the orbit at the planned altitude. Initial measurements showed good parameters of the transfer orbit. According to the US Space Force, Object No. 54033/2022-131A, associated with the Angosat-2 mission, was at the time in the 36,201 by 233-kilometer orbit within an inclination 48.87 degrees toward the Equator.
The target orbit for Anogsat-2 was designed to be around 540 kilometers higher than the geostationary altitude of 36,000 kilometers from Earth to enable a gradual westerly drift of the spacecraft relative to the Earth surface toward its stationary position at 23 degrees East longitude over the Equator.
Soon after midnight Moscow Time on Oct. 13, 2022, Roskosmos announced that the Angosat-2 satellite had successfully delivered into its planned orbit.
At a post-launch press-conference, Head of Roskosmos Yuri Borisov said that Angosat-2 had established communications with ground control, deployed its solar panels and began establishing three-axis orientation in space. According to Angolan officials, the routine operation of Angosat-2 was scheduled to begin 90 days after launch.
Angosat-2 reached its operational position at 23 degrees East longitude by Nov. 4, 2022. On Dec. 2, 2022, the satellite was declared fully operational.
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
Angosat-2 under assembly at ISS Reshetnev circa October 2020.
Angosat-2 at the completion of assembly. Click to enlarge. Credit: Roskosmos
Integration of the payload fairing with the Proton rocket for the Angosat-2 mission insider facility 92A-50 in Baikonur. Click to enlarge. Credit: Roskosmos
Rollout of the Proton rocket with the Angosat satellite on Oct. 9, 2022. Click to enlarge. Credit: Roskosmos
Proton rocket with Angosat-2 satellite shortly after installation on the launch pad on Oct. 9, 2022. Click to enlarge. Credit: Roskosmos
Proton lifts off with Anogsat-2 on Oct. 12, 2022. Click to enlarge. Credit: Roskosmos