JAXA launches Michibiki-4 satellite
The Japan Aerospace Exploration Agency (JAXA) launched the Michibiki-4 satellite aboard an H-IIA rocket at 7:01 a.m. Japan Standard Time on Oct. 10 (6:01 p.m. EDT / 22:01 GMT Oct. 9), 2017, from the Tanegashima Space Center. The satellite is the fourth in the Quasi-Zenith Satellite System (QZSS), which is a satellite-based positioning system similar to the U.S. operated GPS.
The H-IIA’s liquid hydrogen and liquid oxygen-consuming LE-7A main engine ignited a few seconds before the four solid rocket boosters, which quickly pushed the launch vehicle off the pad and out over the Pacific. Some 93 seconds into the flight, the pair of boosters burned out; then, at 107 seconds into the flight, the pair of boosters dropped off. The first stage continued to burn until main engine cutoff (MECO) at 396 seconds into the flight; the first stage separated eight seconds later.
Nearly seven minutes after leaving Japan, the LE-5B upper stage engine, which also consumes liquid hydrogen and liquid oxygen, ignited and burned for almost six minutes before shutting down. The upper stage and spacecraft remained in this parking orbit until a mission elapsed time of 24 minutes, 35 seconds. Then a second burn occurred, lasting for about three minutes, placing Michibiki-4 into an elliptical geosynchronous transfer orbit.
At 28 minutes and 20 seconds after liftoff, the satellite was deployed. Michibiki-4 (QZS-4) will use its onboard propellant to transfer it into its slightly elliptical geosynchronous orbit of 20,267 by 24,202 miles (32,618 by 38,950 kilometers), inclined 41 degrees.
This was the 36th H-IIA vehicle to be launched and represents the fifth launch of an H-IIA rocket in 2017. Manufactured by Mitsubishi Heavy Industries, the vehicle stands 174 feet (53 meters) tall and generates 1.7 million pounds-force (7,628 kilonewtons) of thrust at liftoff. The H-IIA rocket is the primary Japanese large-scale launch vehicle.
Michibiki-4 is the third QZSS satellite to be launched in 2017 and once operational will bring the constellation to its operating capacity of four until a planned expansion to seven satellites occurs around 2023. Once the four-satellite constellation becomes fully operational in 2018, at least 3 QZSS satellites will be visible in the Asia-Oceania regions at any given time.
QZSS can be integrated with GPS satellites to enable a higher level of precision than previously possible with fewer satellites in visible range. The QZSS constellation will trace out a figure-8 pattern over Japan, the Western Pacific, and Australia. It is expected that at least 8 satellites will be available at any given time when combining QZSS and GPS capabilities over Asia-Oceania. It will provide global positioning and timing services across frequencies ranging from 1575.42 MHz to 2 GHz.
Video courtesy of Space Videos
Bart Leahy contributed to this article
Paul is currently a graduate student in Space and Planetary Sciences at the University of Akransas in Fayetteville. He grew up in the Kansas City area and developed an interest in space at a young age at the start of the twin Mars Exploration Rover missions in 2003. He began his studies in aerospace engineering before switching over to geology at Wichita State University where he earned a Bachelor of Science in 2013. After working as an environmental geologist for a civil engineering firm, he began his graduate studies in 2016 and is actively working towards a PhD that will focus on the surficial processes of Mars. He also participated in a 2-week simluation at The Mars Society’s Mars Desert Research Station in 2014 and remains involved in analogue mission studies today. Paul has been interested in science outreach and communication over the years which in the past included maintaining a personal blog on space exploration from high school through his undergraduate career and in recent years he has given talks at schools and other organizations over the topics of geology and space. He is excited to bring his experience as a geologist and scientist to the Spaceflight Insider team writing primarily on space science topics.