Arianespace successfully launches Star One C4 and MSG-4 satellites
European weather satellite MSG-4 and Brazilian communications satellite Star One C4 lifted off on an Ariane 5 launcher at 21:42 GMT on July 15, 2015, from Europe’s Spaceport in Kourou, French Guiana. Photo Credit: ESA/CNES/Arianespace
On Wednesday, July 15, Arianespace successfully launched a Brazilian communications satellite Star One C4 and a European weather satellite MSG-4 into a geostationary transfer orbit (GTO). The satellites were lifted off at 6:42 p.m. local time (5:42 p.m. EDT; 21:42 GMT) from the Kourou Spaceport located in Kourou, French Guiana, using the company’s powerful Ariane 5 launcher.
The mission had previously been set for July 8, but it was delayed by Arianespace due to last-minute precautionary checks on the rocket and spacecraft.
The countdown for the start of the Arianespace’s 224th mission commenced 11 hours and 30 minutes ahead of the launch. Next, the electrical systems were checked and filling of the main cryogenic stage with liquid oxygen and hydrogen began. About 1 hour before the scheduled lift-off, connections between launcher and telemetry, tracking and command systems were examined.
The computers commanded the final electrical operations and associated checks. They also placed the propellant and fluid systems in flight configuration and performed associated checks.
The launch went smoothly with the ignition of the cryogenic main stage engine (EPC) and solid boosters. The boosters separated about 2 minutes and 22 seconds after the lift-off, and the fairing was jettisoned nearly 4 minutes into the launch. The EPC thrust phase ended at T+8:49 minutes and the main engine was cut off. The first stage of the rocket separated 6 seconds later.
Engineers prepare the Star One C4 satellite for the July 15 launch. Photo Credit: ESA/CNES/Arianespace
The second stage ignition started shortly after, and the flight continued flawlessly for about 14 minutes. Then, the second stage engine cutoff occurred and the rocket was injected into orbit. Star One C4 separated first at T+28:15 and the MSG-4 was released 12 minutes later.
Star One C4, designed and built by Space Systems Loral (SSL) for the private Brazilian operator Embratel Star One, will be located at 70 degrees West longitude, which is the most important one for the Broadcasters market in Brazil. This is considered a “hot” position for transmitting signals of major TV stations in Brazil and for having 22-25 million parabolic antennas pointed in that direction.
The satellite was built based on the SSL’s 1300 platform and has 15,600 W of power, a total mass of 12,423 lbs. (5,635 kg), and an expected service life of 15 years. The Wednesday launch of Star One C4 is the 50th SSL mission with Arianespace. The latest launch for this company was the Star One C3 satellite in November 2012.
Star One C4 will ensure the continuity of telephone, television, radio, data transmission, and Internet services in Brazil, in addition to expanding these services to Latin American countries and mainland United States.
The satellite will feature 48 transponders (signal receivers and transmitters) in Ku-Band, increasing the current capacity of the 70 degrees West orbital position at this frequency band by threefold.
Embratel Star One is the largest satellite operator in Latin America. Founded in December 2000 as a subsidiary from Embratel, Embratel Star One has a fleet of seven satellites. It operates four GEO satellites (Star One C1, C2, C3, and BRASILSAT B4), and two in inclined orbit (BRASILSAT B2 and B3), with the central ground station located in Guaratiba (Rio de Janeiro – Brazil). The Star One C4 together with the C1, C2, C3, and C12 are part of the third generation of satellites now.
The Meteosat Second Generation (MSG-4) satellite, built by Thales Alenia Space using an MSG FM4 platform, is designed to help detect and forecast rapidly developing high impact weather, such as thunderstorms or fog. Nowcasting and very short range forecasts — up to six hours — are vital for the safety of life, property, and infrastructure and rely on very frequent, detailed images of the atmosphere.
The rapid 15 minute, or even five minute, image updates from Meteosat satellites are an important tool for meteorologists to monitor the often rapid development of convective storms and help them issue timely warnings. MSG satellites can also detect ash in the atmosphere. Because of this capability, the satellites are the primary satellites used for monitoring volcanic ash plumes.
The MSG-4 satellite being prepared for the July 15 launch. Photo Credit: ESA/CNES/Arianespace
MSG-4 is the last of the MSG satellites resulting from the cooperation between the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) and the European Space Agency (ESA). All MSG satellites are manufactured by a European industry consortium led by Thales Alenia Space (TAS).
“This contract was awarded many years ago; it was following the first generation of Meteosat contracts also under prime contractorship of TAS. The company has more than 30 years of expertise and is a worldwide leader for meteorology from the geostationary orbit,” Sandrine Bielecki, the Head of Media Relations at Thales Alenia Space, told SpaceFlight Insider.
Weighing 2 tons, the MSG-4 is the 142nd satellite built by Thales Alenia Space to be launched by Arianespace.
A team at the European Space Agency’s (ESA) European Space Operations Centre (ESOC) in Darmstadt, Germany, will assume control of MSG-4 immediately after separation and oversee its first 12 days in space – the critical launch and early orbit phase (LEOP) – before handing control over to EUMETSAT.
During LEOP, two teams will work on a shift in the Main Control Room 24 hours/day, using ESA’s global ground station network to conduct the well-rehearsed operations.
If all goes as planned, by 26 July, the LEOP activities will come to an end with the satellite fully functional and located in its projected geosynchronous orbital slot above Europe. It will then be handed over to EUMETSAT for payload commissioning, preparing MSG-4 to serve as the in-orbit ‘hot backup’ to its three sibling satellites, which were all shepherded into orbit by ESOC.
As Meteosat-11, MSG-4 will ultimately bridge the gap between Meteosat-10 (launched in 2012) and the first Meteosat Third Generation (MTG) satellites, expected to be launched in 2019 and 2021. MGS-4 is planned to be in service for seven years.
Ariane 5 in ECA configuration that was used in the launch is the heavy-lift rocket for missions to GTO. It is powered during the initial flight phase by a cryogenic core stage and two solid rocket boosters, followed by the use of a cryogenic upper stage for orbital injection of the payload.
The 180 ft. (54.8 m) tall ECA is an improved version of the Ariane 5 launcher, designed to deliver payloads, mainly communications satellites, weighing up to 10 metric tons. Although it has the same general architecture, some major changes were made to the basic structure of the generic version to increase thrust and enable it to carry heavier payloads.
Wednesday’s launch was the 80th for the Ariane 5 rocket.
Tomasz Nowakowski
Tomasz Nowakowski is the owner of Astro Watch, one of the premier astronomy and science-related blogs on the internet. Nowakowski reached out to SpaceFlight Insider in an effort to have the two space-related websites collaborate. Nowakowski's generous offer was gratefully received with the two organizations now working to better relay important developments as they pertain to space exploration.
Excellent and in-depth article.