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H-IIA rocket soars into the sky with IGS-Optical 6 reconnaissance satellite

A file photo of a previous H-IIA rocket launch. The Feb. 27, 2018 flight, number 38, sent the IGS-Optical 6 satellite into a Sun-synchronous orbit. Photo Credit: JAXA

A file photo of a previous H-IIA rocket launch. The Feb. 27, 2018 flight, number 38, sent the IGS-Optical 6 satellite into a Sun-synchronous orbit. Photo Credit: JAXA

An H-IIA rocket soared into the skies above Japan carrying the country’s IGS-Optical 6 reconnaissance satellite aloft. The booster thundered off the pad at 11:34 p.m. EST Feb. 26 (04:34 GMT Feb. 27), 2018, from the Yoshinobu Launch Complex at the Tanegashima Space Center.

The mission was initially scheduled for Feb. 25. However, it was delayed two times due to unfavorable weather conditions. Finally, some 13 hours before the Feb. 27 launch attempt, the rocket rolled out to the launch pad, marking the beginning of the countdown campaign.

H-IIA (F37) launch at 01:26 UTC on Dec. 23, 2017.

A file photo of a previous H-IIA launch. Photo Credit: Mitsubishi Heavy Industries / JAXA

The H-IIA launch vehicle took to the skies some five seconds after its core stage was ignited. At that moment, the rocket’s two SRB-A solid rocket boosters came to life to deliver additional thrust for the initial phase of the flight.

After completing a brief vertical ascent, the launch vehicle started heading south over the Pacific Ocean. The two SRB-A boosters accompanied the rocket until they burned out at approximately 1 minute, 48 seconds into the flight. As they were no longer needed, they detached and fell away about 20 seconds later. Meanwhile, the rocket continued its journey spaceward being powered by its core stage alone.

At around 3 minutes, 45 seconds into the flight, the payload fairing protecting the satellite from Earth’s atmosphere was jettisoned. With the mission’s sole passenger unveiled, the core stage accelerated the rocket for another three minutes until it too was detached.

After separation, some seven minutes into flight, the second stage took control. Its LE-5B engine started the longest phase of the flight, which concluded some 20 minutes after liftoff with the deployment of the IGS-Optical 6 spacecraft into a Sun-synchronous orbit (SSO) at an altitude of approximately 310 miles (500-kilometers), inclined 97.4 degrees.

IGS-Optical 6 was manufactured by Mitsubishi Electric Corporation (MELCO) and is the third generation of optical imaging satellites for the Information Gathering Satellite (IGS) program. It will be operated by Japan’s Cabinet Satellite Intelligence Center. Besides serving the country’s defense needs, it will also be used for civil natural disaster monitoring purposes.

However, due to the military nature of the payload, very little is known about the spacecraft’s specifications. In general, IGS satellites are equipped with an optical reconnaissance payload or a Synthetic Aperture Radar for remote sensing. These instruments allow the satellite to obtain optical imagery and high-resolution radar data reconnaissance for military and intelligence services.

The IGS project was initiated as a response to a 1998 North Korean missile test, which saw a Taepodong-1 medium-range ballistic missile launched over Japan and showcased the rogue nation’s ability to potentially strike anywhere on the archipelago. The program’s main goal is to provide an early warning of impending hostile launches in the region.

In 2003, the first two spacecraft of the program were launched: IGS-Optical 1 and IGS-Radar 1. To date, 14 IGS satellites have been successfully orbited. One pair was lost in November 2003 due to an H-IIA launch failure. All were launched by H-IIA rockets from the Tanegashima Space Center.

In a document released in May 2016, the government of Japan revealed that it “…will continue to strengthen the Information Gathering Satellite operating regime by increasing the number of satellites.”

While the earliest satellites launched have since been retired, there are currently six operational spacecraft being utilized for the program. Once health checks are performed and it is deemed operational, IGS-Optical 6 will be the seventh. The most recent to be sent aloft, IGS-Radar 5, was delivered into orbit on March 17, 2017.

The H-IIA rocket is a 174-foot (53-meter) tall two-stage booster operated by Mitsubishi Heavy Industries for the Japan Aerospace Exploration Agency (JAXA). With a mass of about 285 metric tons, the “202” variant that was used for Tuesday’s flight is capable of launching up to 10 metric tons to low-Earth orbit and 4.1 metric tons to a geostationary transfer orbit. The rocket’s maiden flight took place in August 2001. Since then, it has flown 38 times (including the Feb. 27 flight) with only one failure.

Additionally, Tuesday’s launch was the third orbital mission for Japan in 2018 and the first flight of an H-IIA booster this year.

Video courtesy of NVS



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.

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