Sunday, September 13, 2015

Proton-M Rocket Set to Launch Russian Ekspress-AM8 Satellite into Orbit

A Proton-M rocket being placed at the Baikonur Cosmodrome's launch pad for the Sept. 14 launch. Credit: Roscosmos

A Proton-M rocket stands tall at the Baikonur Cosmodrome in Kazakhstan, ready to blast off into space with Russian Ekspress-AM8 communications satellite. The lift-off is scheduled to take place from the Complex 81 at 3:00 p.m. EDT (19:00 GMT) on Monday, Sept. 14. It will be the second Proton-M launch since the May 16 accident, when it failed to deliver the MexSat-1 satellite into orbit.

Monday’s mission will see the rocket in configuration with the Blok DM-03 upper stage, instead of predominantly used Briz-M in Proton launches. It will be the third flight for Blok DM-03 and it may be the first successful mission for this upper stage as the two previous launches ended in failure. The first launch of the Block DM-03 in December 2010 was tasked with the delivery of three Uragan-M satellites for the GLONASS navigation system. However, the Proton-M rocket failed to reach the intended orbit causing the upper stage and payloads to re-enter over the Pacific Ocean. The second Block DM-03 was destroyed in July 2013, within seconds after the lift-off. The Block DM-03 upper stage measures 18.4 ft. in length and 12.1 ft. in diameter.

The Ekspress-AM8 satellite is a communications satellite operated by the Russian Satellite Communications Company (RSCC), a state-owned satellite operator. RSCC provides mobile communications for the Russian president and the government, federal TV and radio broadcasting, builds departmental satellite communications networks for the Russian government bodies. ISS Reshetnev built the satellite platform, based on the Ekspress-1000NTB satellite bus, while Thales Alenia Space provided the multi-band communications payload. ISS Reshetnev owns technologies of a full development cycle from satellite design to satellite control in all types of orbits, from low circular to geostationary. Thales Alenia Space is the leading European supplier of satellite-based solutions for Defense and Security, with strong positions in both satellite and space and ground segments.

The partnership with the Russian industry began in the early 2000's when Thales Alenia Space and ISS Reshetnev started joint marketing of satellites based on the Ekspress-1000 platform. Thales Alenia Space has provided payloads, which were integrated with Russian platforms: Ekspress-A1, Ekspress-A2, Ekspress-A3, Ekspress-A4, Ekspress-AM11, Ekspress-AM22, Ekspress-AM2, Ekspress-AM3, Ekspress-AM33, Ekspress-AM44 (all with ISS Reshetnev), plus Ekspress-MD1 and Ekspress-MD2 (with Khrunichev State Research and Production Space Center).

The Ekspress-1000NTB bus is capable of hosting mid-sized communication payloads providing propulsion, power generation, power storage and distribution, precise navigation and accurate Earth pointing and stationkeeping capabilities. The platform has an isogrid core with honeycomb panels holding the service systems, powered by solar arrays of triplejunction gallium arsenide cells, Saft VES 180 Li-ion batteries, and SPD-100 stationary plasma thrusters for longitude/latitude corrections. It has also a hybrid thermal control system with a redundant coolant loop.

Weighing 2.1 tons, the satellite will carry a payload of about 1,400 lbs. Two deployable solar arrays will deliver a total of 5.9 kilowatts of end-of-life power to a payload consisting of 24 C-band, 12 Ka-band and 2 L-band transponders. The spacecraft will cover Europe, Africa, the Middle East and South America, delivering a variety of communications services. The Ekspress-AM8 mission is part of a largescale national program to upgrade the Russian orbital communications constellation that was initiated with the launch of Ekspress-AM5 in December 2013.

The Ekspress-AM8 satellite will be put into a geostationary orbit (GEO) of 14 degrees west. It is designed to operate for at least 15 years. It will replace the Ekspress-A4 spacecraft launched in June 2002.

The launch of Ekspress-AM8 was initially planned for early April, but it was delayed when metal dust was found in Proton's second stage propellant system, requiring decontamination of the stage and additional inspections. After the May 16 Proton failure, the satellite was put in a storage mode because the grounding of the rocket was expected to last several months. The launch campaign was restarted when the Inmarsat 5-F3 satellite was successfully sent into orbit by the Proton-M rocket on Aug. 28. When the campaign resumed, testing on the satellite was performed and the spacecraft underwent propellant loading for the flight.

Two first generation Ekspress satellites and four improved Ekspress-A satellites were launched between 1994 and 2001. The First launch of an Ekspress-AM satellite was conducted in 2003. The last Ekspress satellite (AM7) was launched on Mar. 18, 2015 to deliver internet, radio and TV services to Europe, Asia and Africa.

The Ekspress satellites are the most powerful commercial commsats under Russian operation to expand services on a global scale. The Ekspress-AM8 satellite is part of the 2006-2015 Russian Federal Space Program and the 2009-2015 Television and Radio Broadcasting Development Program.

New Ekspress versions will be inaugurated over the coming years, including the AMU and RV series.

The assembled Blok DM-03 upper stage was installed atop the Proton-M rocket earlier this week to finish the integration of the launch vehicle. The rollout of the launch vehicle was conducted in the early hours on Friday, Sept. 12. Then, the rocket was placed in its vertical launch position at the launch pad. Later on Friday, teams performed a detailed integrated test involving all stages of the rocket to confirm all electronics on the launcher were functioning to specification.

Manufactured by Khrunichev, the 190 ft. tall, four-stage Russian Proton-M launch vehicle will use its six RD-275M engines to lift the satellite into space. Nine minutes and 42 seconds after liftoff, the rocket will separate the Block DM-03 upper stage. The deployment of the satellite is planned to occur six hours and 37 minutes after the launch. Proton-M is designed to launch payloads into various earth orbits and escape trajectories.

The next Proton-M launch is scheduled for Oct. 9 and will loft T├╝rksat 4B communications satellite into orbit. For this launch the rocket will employ the Briz-M upper stage.

Monday’s mission will be the fifth Proton launch of the year and the 406th Proton flight overall since its debut in 1965. The launch will be conducted under the auspices of the Russian government’s federal space program.

No comments:

Post a Comment