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![]() ![]() BY JUSTIN RAY ![]() February 18, 2000 -- Follow the launch of the Superbird 4 communications satellite aboard an Ariane 4 rocket. Reload this page for the very latest on the mission.
0219 GMT (9:19 p.m. EST) Over the next few weeks, Superbird 4 will fire its onboard rocket engine to achieve a final operational orbit 22,300 miles above the Earth's equator, ultimately arriving at 162 degrees East. The Ariane rocket deployed the satellite into a highly elliptical geosynchronous transfer orbit with a low point of 124 miles and high point of 22,369 miles. In addition, the spacecraft's twin solar panels and communications antennas will be deployed. Following a period of on-orbit tests, Hughes will hand control of Superbird 4 to owner Space Communications Corporation (SCC) of Tokyo in about a month. Commercial service for the satellite should start in early April. We have posted our launch story with a complete summary of the Arianespace Flight 127 mission.
0125 GMT (8:25 p.m. EST) Check back later tonight for a wrap-up story on this launch and confirmation first contact with Superbird 4 by ground controllers.
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0115 GMT (8:15 p.m. EST) Also, the rocket is now passed out of range from the tracking station in Kourou.
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0103 GMT (8:03 p.m. EST) In the final seconds of the countdown, activities will include releasing the inertial platform at minus 9 seconds, and the release command to the retraction system for the two cryogenic arms will be given at minus 5 seconds.
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0058 GMT (7:58 p.m. EST) During the last six minutes, the Ariane 44LP rocket, satellite payload and ground systems will be configured for launch. There are two master computers running the countdown. One is responsible for fluids and propellants and the other for final preparation of the electrical systems such as initiating the flight program, activation of the engine steering systems and power transfer from ground supplies to onboard batteries. The computers will control until minus 5 seconds when a majority logic sequencer takes over for first stage engine start at zero seconds. Engine performance checks are done in parallel by the two computers starting at plus 2.8 seconds. Finally, the command will be issued to open the launch table clamps for liftoff.
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THURSDAY, FEBRUARY 17, 2000
1630 GMT (11:30 a.m. EST) The launch, Arianespace's second of 2000, was postponed 24 hours due to thick layered clouds that could have caused the rocket to generate triggered lightning during liftoff.
0145 GMT (8:45 p.m. EST) The countdown was stopped at Minus-6 minutes, the last moment before entering the computer-controlled Synchronized Launch Sequence. After passing Minus-6 minutes, computers would be running the countdown. An unplanned hold due to the weather or any other problem inside the sequence would have resulted in the countdown being recycled back to Minus-6 minutes.
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0127 GMT (8:27 p.m. EST) At the ELA-2 launch complex, the rocket's third stage cryogenic propellants -- liquid oxygen and liquid hydrogen -- are being topped off to keep the tanks full for launch. Given the super-cold nature of the cryos, the fuels naturally boil away during the countdown. Also, the battery trickle charge to the Superbird 4 spacecraft is continuing, Arianespace says.
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0054 GMT (7:54 p.m. EST) A network of tracking stations are standing ready to relay data from the Ariane 4 rocket to engineers in Kourou. The early portion of flight will be monitored through the Kourou and Cayenne stations in French Guiana. About 6 minutes, 50 seconds into flight the Natal station in Brazil will pick up the rocket's signal as the third stage burn gets underway. At plus 12 minutes, 50 seconds the site on Ascension Island in the Atlantic Ocean will begin coverage. Libreville in Gabon will provide services for spacecraft separation and the conclusion of Arianespace Flight 127.
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0039 GMT (7:39 p.m. EST) The craft will join three other Superbird satellites in space to provide communications services to the Asia-Pacific Region. SCC ordered Superbird 4 to expand its capability throughout Japan and surrounding area. Superbird 4 currently weighs 8,925 pounds on the launch pad. It carries 23 Ku-band and six Ka-band transponders and will have 5.3 kilowatts of power at the end of its 15-year life. The craft will be positioned at 162 degrees East along the Equator some 22,300 miles above the planet. Superbird 4 arrived in Kourou on January 24. It underwent final testing and fueling before being encapsulation into the payload fairing. The craft was then transferred to the launch pad on February 9 and mated to the Ariane the following day. Read about Superbird 4's planned uses and about the HS601 HP satellite from Hughes.
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WEDNESDAY, FEBRUARY 16, 2000
TUESDAY, FEBRUARY 15, 2000 Arianespace Flight 127 was cleared for launch following the final readiness review on Monday when officials discussed the status of the rocket, Superbird 4 communications satellite payload and ground support systems. Liftoff from the Guiana Space Center in Kourou, French Guiana, South America, is planned for 8:04 p.m. EST Wednesday (0104 GMT Thursday). The available launch window extends 51 minutes to 8:55 p.m. EST (0155 GMT). With Monday's management review completed, workers began arming the Ariane rocket. This launch will feature an Ariane 44LP vehicle featuring two liquid-fueled boosters and two solid-fueled boosters strapped to the first stage to provide additional thrust at liftoff. Today will be spent loading storable propellants into the rocket's first and second stages and the two strap-on liquid-fueled boosters. The final countdown to launch of Arianespace Flight 126 will start at 5:34 a.m. EST on Wednesday (1034 GMT). The 321-foot tall gantry enclosing the rocket at the ELA-2 launch complex will be retracted beginning at 2:09 p.m. EST (1909 GMT). Loading of super-cold liquid oxygen and liquid hydrogen into the Ariane's third stage will commence at 4:29 p.m. EST (2129 GMT). The launch team will activate the rocket's telemetry, radar transponders and telecommand systems just over an hour before launch at 6:59 p.m. EST (2359 GMT). If there are no problems standing in the way of an on-time liftoff, officials will allow the Synchronized Launch Sequence to begin at Launch Minus-6 minutes. This computer-controlled process performs the final tasks to prepare the rocket for liftoff. The Superbird 4 spacecraft is designed to bolster telecommunications services in the Asia-Pacific region. The satellite was built for Space Communications Corp. (SCC) of Tokyo by U.S. manufacturer Hughes Space and Communications. The satellite will be delivered into a highly elliptical geosynchronous transfer orbit by the Ariane 4 rocket. Superbird 4 will then perform orbit raising maneuvers using its onboard kick motor, achieving a circular geostationary orbit around the Earth's equator. Controllers plan to park the satellite at 162 degrees East longitude to join the fleet of three other Superbird spacecraft already operating. A Hughes HS 601HP model satellite, Superbird 4 carries 23 Ku-band transponders and a steerable Ku-band spot beam for digitial TV transmissions and other telecommunications services. In addition, the satellite's six Ka-band transponders will allow high-speed data relay capability.
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Flight data file Vehicle: Ariane 44LP Payload: Superbird 4 Launch date: Feb. 18, 2000 Launch window: 0104-0155 (8:04-8:55 p.m. EST on 17th) Launch site: ELA-2, Kourou, French Guina ![]() Pre-launch Briefing Ariane 44LP - Overview of the rocket to launch Superbird 4. ![]() Launch timeline - Chart with times and descriptions of the events to occur during launch. ![]() Purpose of Superbird 4 - Satellite to meet growing communications needs of Asia-Pacific. ![]() The Superbird 4 satellite - Overview of the Hughes-built HS601 HP model spacecraft. ![]() Explore the Net Arianespace - European launch services provider that uses Ariane 4 and 5 rockets to carry satellites into space. ![]() Space Communications Corp. - Tokyo-based company that will operate Superbird 4 once in space. ![]() Hughes Space and Communications - U.S. manufacturer of Galaxy 10R satellite. ![]() NewsAlert Sign up for Astronomy Now's NewsAlert service and have the latest news in astronomy and space e-mailed directly to your desktop (free of charge). ![]() ![]() |