[ad_1]
A Japanese satellite designed to transmit data and images from civilian and military Earth observation spacecraft is ready for takeoff on Sunday aboard an H-2A rocket.
According to Mitsubishi Heavy Industries, the dual-use communications satellite is expected to drive an H-2A rocket into orbit at 2:25 am EST (0725 GMT; 16:25 Japanese solar time) from the Tanegashima space center in southern Japan, builder of the H-2A rocket and launch operator.
The H-2A rocket will deploy the spacecraft – part of the Japan Data Relay System, or JDRS – into an elliptical geostationary transfer orbit about half an hour after takeoff. The satellite will use its propulsion system to reach a circular geostationary orbit more than 22,000 miles (nearly 36,000 kilometers) above the equator, where it will enter service and begin a 10-year mission.
At that altitude, the satellite will orbit at the same rate of Earth’s rotation, giving it a continuous view of the Asia-Pacific region.
The new satellite carries the laser-use communication system, or LUCAS, payload developed by the Japan Aerospace Exploration Agency. From its perch in geostationary orbit, the payload of optical communication will connect to satellites flying several hundred miles above the Earth with a near-infrared laser beam, enabling high-speed data transmission.
A single data transmission satellite can communicate with a user spacecraft for about 40 minutes on each orbit, transmitting images, scientific data and other information between the Earth observation satellite and a ground station. The connection allows image analysts to receive data faster than when waiting for the observation satellite to pass over a ground antenna.
The new satellite with optical data transmission replaces JAXA’s Kodama spacecraft, which had S- and Ka-band inter-satellite links that provided communication speeds of approximately 240 megabits per second. JAXA deactivated the Kodama satellite in 2017 after a 15-year mission.
The laser-equipped relay satellite will enable data rates of up to 1.8 gigabits per second, more than seven times faster than the speeds possible with Kodama. Kodama’s radio frequency antenna was 11.8 feet or 3.6 meters in diameter, while the laser terminal for the optical relay satellite was 5.5 inches or 14 centimeters in diameter.
JAXA launched an experimental test satellite called Kirari in 2005 to demonstrate inter-satellite laser communication links.
“Using this as a foothold, LUCAS has been developed to achieve high reliability, miniaturization and significant improvement in communication skills for practical use,” said JAXA.
Designed for a 10-year mission, the new optical data transmission satellite will serve Japanese civilian-operated Earth observation satellites and Japanese intelligence-gathering fleet surveillance spacecraft spying on North Korea and other locations. of strategic interest.
JAXA is not expected to provide a live webcast of Sunday’s launch, possibly due to the delicate military connection with the data transfer payload. Japanese officials also did not disclose the new satellite’s exact operational location in geostationary orbit, or the specifics of its mass and size.
Civilian satellites under development that are ready to use the new laser data transmission station include the Japanese terrestrial image observatories ALOS 3 and ALOS 4. Once launched, ALOS 3 and ALOS 4 will collect images to assist in disaster response. in environmental monitoring, in agriculture and forestry management and in urban infrastructure planning.
Sunday’s launch will mark the 43rd flight of an H-2A rocket since 2001 and the fourth Japanese space launch of the year.
Powered by a hydrogen-powered LE-7A main engine and two strap-on solid rocket boosters, the H-2A launcher will depart from the Tanegashima Space Center with 1.4 million pounds of thrust and head east over the Pacific Ocean.
The double strap-on boosters will burn out and launch off the 174-foot (53-meter) rocket less than two minutes after takeoff. The main engine of the H-2A will shut down and the first stage will separate approximately six and a half minutes from the mission, leaving the cryogenic upper stage to perform a couple of shots to place the data transmission satellite in its targeted egg-shaped transfer orbit. .
Email the author.
Follow Stephen Clark on Twitter: @ StephenClark1.
[ad_2]
Source link
