Editor’s note: The EST (1000 GMT) was updated at 5 a.m. after confirming a successful launch.
A Japanese satellite designed to transmit data and images from a civilian and military Earth observation spacecraft was launched on an H-2A rocket on Sunday.
The dual-use communications satellite launched an H-2A rocket into orbit at 2:25 AM EST (0725 GMT; 4:25 PM Japan Standard Time) from the Thane Kashima Space Center in southern Japan.
A live video feed from media viewers in Thane Kashima as the 174-foot (53 m) H-2A rocket rises into broken clouds in space.
The Japan Aerospace Exploration Agency did not provide a live webcast of the launch site on Sunday, which may be due to significant military interaction with the data relay payload. Japanese authorities have not released specifications on the exact orbit of the new satellite in geostationary or its mass and size.
Powered by a hydrogen-fueled LE-7A main engine and two strap-on solid rocket boosters, the H-2A launcher climbed into the stratosphere with a thrust of 1.4 million pounds, and the rocket flew eastward from Thanekashima into the Pacific Ocean.
Double strap-on boosters were fired from the H-2A launcher two minutes after the liftoff was completed.
The H-2A’s core engine was shut down, and the first phase took about six and a half minutes to complete, triggering the cryogenic upper phase to place the data relay satellite in its target egg-shaped transmission orbit.
Mitsubishi Heavy Industries, builder and launcher operator of the H-2A rocket, said the rocket’s top-level data relay satellite was successfully placed in orbit.
Sunday’s launch is the 43rd flight of the H – 2A rocket since 2001, and Japan’s fourth space launch this year.
The H-2A rocket was expected to launch its payload – part of the Japan Data Relay System, or JDRS – into an elliptical geostationary transmission orbit. The satellite will use its own propulsion system to reach a circular geostationary orbit 22,000 miles (approximately 36,000 kilometers) above the equator, where it will enter service and begin a 10-year journey.
At that altitude, the satellite will orbit at the same rate as the Earth’s rotation, giving a continuous view of the Asia-Pacific region.
The new satellite features a laser application communication system, or Lucas, payload, developed by the Japan Aerospace Exploration Agency. From its perch in geographical orbit, the optical communication payload connects with satellites flying several hundred miles from the Earth to a nearby infrared laser beam, and allows data to be transmitted at a higher rate.
A single data relay satellite can communicate with the spacecraft for approximately 40 minutes in each orbit, transmitting images, scientific data and other information between the Earth observation satellite and a ground station. This connection allows image analysts to retrieve data faster than they would have expected an observation satellite to pass an antenna on the ground.
The new optical data relay satellite replaces Jaxa’s Kodama spacecraft, which had S-band and Ka-band inter-satellite connections, delivering a transmission speed of about 240 megabytes per second. Jaxa removed the Kodama satellite in 2017 after 15 years of work.
The laser-equipped relay will allow satellite data transfer speeds of up to 1.8 gigabits per second, which is seven times faster than with a Kodama. Kodama’s antenna for radio frequency transmissions is 11.8 feet or 3.6 meters in diameter, while the laser terminal of an optical relay satellite is 5.5 inches or 14 centimeters in diameter.
In 2005, Jaxa launched the experimental Girari satellite to demonstrate inter-satellite laser communications.
“Using this as a foundation, Lucas was developed to achieve greater reliability, miniaturization and significant improvement in communication skills for practical use,” Jaxa said.
Designed for a 10-year mission, the new optical data relay satellite will be used by Japanese citizen-operated Earth Surveillance Satellites and Japan Naval Intelligence Surveillance Spacecraft to spy on North Korea and other strategic areas.
Prototype public satellites using the new laser data relay station include Japan’s ALOS 3 and ALOS 4 land imaging laboratories. Once launched, ALOS 3 and ALOS 4 will collect images that will help with disaster response, environmental monitoring, agriculture and forestry management, and urban infrastructure planning.
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