_ MSG-3 or Meteosat Second Generation 3 Satellite, is a meteorological satellite that is the third of the MSG Satellite Fleet. The first two new-generation satellites were launched in 2002 and 2005. This satellite constellation builds on the original Meteosat Fleet of spacecraft dating back to 1977. The European Space Agency has developed the satellites in close cooperation with Eumetsat – the European Organisation for the Exploitation of Meteorological Satellites. Eumetsat will be the primary satellite operator. MSG-3 will examine cloud development and temperature to improve weather forecasting accuracy and serve two secondary objectives. Its Radiation Budget Payload measures energy that is radiated by Earth and determines Earth radiation balance to gain insight in atmospheric circulation and energy distribution. A Search and Rescue Transponder will receive and relay emergency signals from beacons that are in its field of view. MSG-3 was built by Thales Alenia Space. The Spacecraft is 2.4 meters in length and 3.2 meters in diameter; it has a liftoff mass of around 2,000 Kilograms. The vehicle is spin-stabilized spinning counter-clockwise a 100 RPM. The Satellite carries two main instruments, the Spinning Enhanced Visible and Infrared Imager (SEVIRI), that observes Earth in 12 spectral channels and provides image data which is required for operational weather forecasting, and the Geostationary Earth Radiation Budget (GERB) instrument that is supporting climate studies. Eight of SEVIRI’s channels are measuring infrared thermal radiation to obtain information on cloud, sea and land temperature. A three dimensional image of the atmosphere is obtained by channels that gather information on ozone, water vapour and carbon dioxide dispersion as well as properties of atmospheric air masses. One of the channels is called the High Resolution Visible (HRV) channel and has a sampling distance on its Earth-Facing side of 1 km. GERB is a visible-infrared radiometer that is used for for Earth radiation budget studies by making precise measurements of short and long wave components of the radiation budget at the top of the atmosphere. The third major element of the vehicle is the Mission Communication Payload that includes all antennas and transponders for telemetry, command uplink and data transmission. Eight curved solar panels are mounted on the exterior of the vehicle. MSG-3 will operate from Geostationary Orbit. It will make orbit adjustments after being delivered to its desired Transfer Orbit by the Ariane 5 Launch Vehicle. Once operational, MSG-3 will enter its spot as part of the Meteosat Constellation that provides frequent and real-time imagery and data.
Echo Star XVII
_ Echo Star XVII is a commercial communications satellite that was built by Space Systems Loral of Palo Alto, California, and will be operated by Hughes Network Systems, LLC – a Echostar company – based in Germantown, Maryland (USA). The Spacecraft is based on the flight-proven LS-1300 Satellite platform. The Satellite features a Ka-Band Payload and will be the first vehicle to fly the Jupiter high-throughput technology provided by Hughes. The spacecraft will feature multi-spot beams with bent-pipe architecture providing additional capacity. Echo Star XVII will bring high-speed internet to consumers and business customers. Echo Star has a liftoff mass of about 6,100 Kilograms and features two deployable solar arrays and batteries for power supply. Total data throughput of the Ka-Band payload is planned to be over 100Gbps. The satellite will use its bi-propellant propulsion system for orbit maintenance and adjustments as well as apogee burns after insertion into Geostationary Transfer Orbit. Echo Star XVII will be operational for at least 15 years.
Mission Preview and Timeline
The Countdown for a Launch of the Ariane 5 Rocket begins 11 hours and 30 minutes before the launch window opens. At L-7:30 final electrical checks will be made before Fueling starts just under 5 hours to liftoff. 90 Minutes into LOX and LH2 Tanking, the Vulcain Main Engine is being chilled down by the supercold propellants. 1 hour and 10 minutes prior to launch, final checks of all communication connections and telemetry links are conducted to ensure all Ground Tracking Stations are ready to support the mission. The Vehicle will be placed in a stable configuration for T-7 Minutes and Holding. The Launcher can remain in this configuration throughout the launch window. At T-7 Minutes and Counting, the Synchronized Sequence begins. Computers are watching all parameters of the vehicle and ground support equipment as final reconfigurations are made to put the Ariane in a launch configuration. Should any system show an off-nominal performance, the Computers will automatically recycle all systems to their T-7-Configuration to back out of the automated sequence. 4 Minutes prior to launch, all tanks of the first and second stage are being pressurized for flight. 1 Minute before T-0, the vehicle switches to onboard power. 30 Seconds before Ignition, Water begins flowing into the Flame Trenches. Hydrogen aspiration of the Vulcain engine starts 18 seconds before it is ignited. The Cryogenic arms that are used for critical connections including fuel lines are retracted. 4 seconds before the Ignition Sequence commences, the Handoff to Ariane’s onboard computers occurs and the Guidance System enters its flight mode one second later.
At T-0, the Vulcain Engine Ignition Sequence begins. Three pyrotechnic devices are used to ignite the main engine which reaches flight thrust at T+4.5 seconds. Engine performance is being monitored before the Solid Rocket Boosters are ignited at T+7.05 seconds. Liftoff occurs just a quarter of a second later. The two Solid Rocket Boosters provide 92% of total thrust at blastoff. The launcher climbs vertically for 6 seconds before the pitch maneuver begins which puts the rocket into the proper trajectory that is required to reach the targeted Main Engine Cutoff point.
_After 2 minutes and 21 seconds of powered flight, the SRBs burn out and are jettisoned to fall back to Earth and into the Atlantic Ocean. Immediately after SRB jettison, the onboard computers calculate the precise trajectory that is required to recover from minimal transients that are nominal for the SRB Phase. That course correction is conducted in real time by swivalling the main engine. The next Event is Payload Fairing Jettison. The Fairing is used to protect the Payloads from thermal loads during atmospheric flight. When heat levels are at an acceptable level, the fairing is jettisoned by pyrotechnically initiated separation tubes. Separating the fairing as early as possible increases ascent performance. At 9 minutes into the flight, the Vulcain Engine shuts down for first stage cutoff. Stages #1 and #2 separate from each other and the second stage with its HM-7B engine continue powered flight after the engine ignites. The first stage falls back to Earth and impacts off the coast of Africa in the Gulf of Guinea. The second stage will make its first burn before final engine cutoff. Afterwards, the stage re-orients itself to the proper attitude to release the first payload. When the first Spacecraft Separation is successful, the coast phase continues with more orientation maneuvers and the separation of the Sylda 5. This is a fairing like object that is used to install two payloads on top of the rocket. The first payload is mounted atop the Sylda and the second satellite is hidden beneath it until the first payload is released. With Sylda Separation, the path is clear to jettison the second and final payload into its targeted orbit. The second stage continues its mission for several minutes during which it performs reorientation maneuvers and avoidance firings. After second stage passivation, Ariane’s mission is complete. The two satellites will then be in a geostationary transfer orbit that will be optimized when the spacecraft fire their individual engines to reach a precise position.
|Time||Event||Altitude (km)||Velocity (m/s)|
|0:00:00.00||Vulcain Engine Ignition Sequence||0||0|
|0:00:07.05||Solid Rocket Booster Ignition||0||0|
|0:02:22.00||SRB Burnout and Jettison||67.500||2013.0|
|0:03:17.00||Payload Fairing Jettison||107.400||2260.0|
|0:08:07:00||Acquisition by Natal Tracking Station||172.500||5585.0|
|0:08:59.00||Core Stage shutdown||171.900||6884.0|
|0:09:09.00||2nd Stage Ignition||172.100||6912.0|
|0:13:39.00||Acquisition by Ascension Tracking Station||161.100||7544.0|
|0:18:25.00||Acquisition by Libreville Tracking Station||196.000||8354.0|
|0:23:09.00||Acquisition by Malindi Tracking Station||433.000||9062.0|
|0:24:59.00||Second Stage Shutdown||648.400||9361.0|
|0:27:34.00||Echo Star XVII Release||1040.000||9037.0|
|0:48:59.00||Ariane 5 - End of Mission||6153.000||6188.0|