H-IIA rocket launches 3rd Japanese navigation satellite
Lifting off from the sea-side Tanegashima Space Center, Japan’s H-IIA rocket launched the Asian country’s latest GPS augmentation satellite for the Quasi-Zenith Satellite System (QZSS). The launch took place at 1:29 a.m. EDT (5:29 GMT) on August 19, 2017.
Originally, the rocket was supposed to launch on August 12, 2017. However, technical difficulties related to the vehicle’s propulsion system cropped up, prompting a delay. Once the issues were resolved, the new date was confirmed.
The Michibiki-3 spacecraft that was launched is a satellite designed to work with the GPS constellation to increase the accuracy of positioning and timing services over East Asia in areas with rough terrain or crowded urban areas that can diminish or block GPS signals.
Requiring four satellites for initial operation, three are now in orbit, including Michibiki-3. The first launch, which doubled as a test platform, occurred in Sept. 2010. The second was on June 1, 2017. The fourth is expected to launch by the end of this year.
While vehicles No. 1, 2, and eventually 4 will operate in a highly elliptical geosynchronous orbit called a Tundra orbit, Michibiki-3 will reside in geostationary orbit some 22,300 miles (35,800 kilometers) over the equator.
Michibiki-3 weighed some 10,400 pounds (4,700 kilograms) at launch. The Mitsubishi Electric-built spacecraft has two solar panels along with numerous navigation transponders as well as S-, Ku-, and L-band antennas. It is expected to have a 15-year service life.
The H-IIA rocket that carried Michibiki-3 into orbit was in the 204 configuration, meaning it was a two-stage rocket with four solid rocket boosters attached. Overall, the launch vehicle was 174 feet (53 meters) tall.
As the countdown neared zero, the first stage’s liquid oxygen and liquid hydrogen consuming LE-7 engine ignited. Once the four strap-on boosters ignited, the rocket was released to begin its climb uphill to deposit Michibiki-3 into a geostationary transfer orbit.
About a minute into flight, the stack surpassed the speed of sound. A minute later, the four solid rocket boosters burned out and fell away.
Four minutes, 5 seconds into flight, the payload fairing protecting Michibiki-3 fell away as planned. The LE-7 engine continued to burn spaceward for another three minutes before cutting off just after seven minutes into the mission.
After stage separation, the upper stage’s LE-5B engine fired for about 4.5 minutes to place it and the satellite payload into a parking orbit.
Almost 24 minutes into the flight, the second stage engine ignited again to place Michibiki-3 into a geostationary transfer orbit. That burn lasted for 4 minutes, 10 seconds.
One minute after the second stage finished its job, Michibiki-3 separated. It will use its onboard thrusters to gradually circularize its orbit at 22,300 miles (35,800 kilometers).
This was the 35th H-IIA flight since 2001 and the fourth in the 204 configuration. So far in 2017, four H-IIA rockets have launched from Tanegashima.
Michibiki-3’s launch marks the 50th space launch attempt worldwide in 2017, with just as many planned before the end of the year. Should all of these missions launch this year, it would be the first time worldwide that launch attempts have crossed the 100 mark in nearly 30 years.
Video courtesy of SciNews
Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity. You can find him on twitter @TheSpaceWriter.