Japan launched its third mission of the year on Tuesday by lofting the Himawari 8 weather satellite atop an H-IIA carrier rocket. Liftoff from pad 1 of the Yoshinobu Launch Complex at the picturesque Tanegashima Space Centre occurred on schedule at 14:16 local time (05:16 UTC).
The eighth satellite in Japan’s Himawari series of geosynchronous weather satellites, Himawari 8 marks the beginning of the constellation’s third generation of spacecraft.
The satellite was constructed by the Mitsubishi Electric Corporation with assistance from Boeing, and is based around the DS-2000 satellite bus.
The DS-2000 bus gives the spacecraft a design life of fifteen years, however its operational lifespan may be limited by its instruments, which are only designed for eight years of service.
Tuesday’s launch placed the 3,500 kilogram (7,700 lb) satellite into a geosynchronous transfer orbit.
A series of burns from the spacecraft’s onboard propulsion system will raise it into geostationary orbit, where it will take up position at a longitude of 140 degrees East.
The spacecraft will replace Himawari 7, which has been in orbit since 2006.
Himawari 8 carries three payloads; the Advanced Himawari Imager (AHI), Space Environment Data Acquisition Monitor (SEDA) and the Data Collection Subsystem (DCS).
The Advanced Himawari Imager is the spacecraft’s main instrument. A sixteen-channel multispectral imager operating at visible-light and infrared wavelengths, it will produce full-disc and area images.
It can produce images at a resolution of up to 500 metres (1,640 feet), with each spectral band being of use for different observations; allowing the satellite to collect data on various factors including cloud cover, temperatures, winds, precipitation and aerosol distribution.
The Space Environmental Data Acquisition Monitor will collect space radiation data; studying protons and electrons incident upon the spacecraft. The Data Collection Subsystem is a communications payload which will be used to collect and relay data from ground weather stations for analysis.
The Himawari series of satellites began with the launch of Japan’s Geostationary Meteorological Satellite (GMS) atop a Delta 2914 rocket in July 1977. Built and launched in the United States, GMS – which was renamed Himawari, meaning Sunflower, after launch – was Japan’s first weather satellite.
Four more GMS spacecraft were constructed by Hughes in the United States, however unlike the first spacecraft they were shipped to Japan for launch.
Himawari 2 and 3 were launched by N-II rockets – license-built copies of the American Delta series – in 1981 and 1984. Himawari 4 followed them into orbit in September 1989, riding an H-I rocket – a Thor first stage topped by a Japanese-built cryogenic second stage. The final first-generation satellite, Himawari 5, was launched by the all-Japanese H-II rocket in March 1995.
Space Systems/Loral were contracted to build a new-generation weather satellite for Japan, which became the Multi-functional Transport Satellite (MTSAT).
Intended to replace the ageing GMS spacecraft, Japan launched MTSAT atop an H-II F-8 rocket in 1999.
Used for only the one launch, the H-II F-8 consisted of the first stage and boosters of the H-II, with an enhanced upper stage which would later be used by the H-IIA.
During the MTSAT launch a turbopump malfunction late in first stage flight resulted in the vehicle failing to reach orbit, with the loss of the satellite.
After the loss of MTSAT, the MTSAT-1R spacecraft was ordered as an identical replacement and successfully launched atop an H-IIA in February 2005, becoming Himawari 6 upon its arrival in orbit. In the meantime the Japan Meteorological Agency were forced to lease an American satellite to cover its weather monitoring, with the NOAA’s GOES 9 spacecraft operating over the Pacific between 2003 and 2005.
A further MTSAT spacecraft, MTSAT-2 or Himawari 7, was launched in 2006 as a backup to Himawari 6.
Both spacecraft’s instruments were designed for five years’ operations; in 2010 when Himawari 6 reached five years in orbit, the roles of the satellites were swapped with Himawari 7 becoming the operational satellite and Himawari 6 its backup.
By the time Himawari 8 has been commissioned and completed its testing in mid-2015, Himawari 7 will be approaching the end of its five year service life. It will become Himawari 8’s backup, allowing Himawari 6 to be decommissioned.
Himawari 9, scheduled for launch in 2016, is identical to Himawari 8 and will take over as the on-orbit backup before replacing Himawari 8 around 2022. Himawari 8 will then become the backup satellite until the introduction of a new generation of satellites in the late 2020s.
Tuesday’s launch was the twenty-fifth flight of the H-IIA rocket, which Japan introduced in 2001 to replace the earlier H-II. A two-stage rocket, the H-IIA consists of two cryogenically-fuelled stages, using liquid hydrogen propellant oxidised by liquid oxygen.
The first stage is powered by an LE-7A engine, with an LE-5B propelling the second stage.
For Tuesday’s launch the H-IIA flew in the 202 configuration; the smallest variant which is used for most of its flights. In this form, a pair of SRB-A3 solid rocket motors were used to augment the first stage’s thrust during the early stages of flight.
The only other configuration currently in use is the H-IIA 204, which has four solid rocket motors instead of two, however this has only flown once.
Until 2008 two intermediate configurations were also offered; the H-IIA 2022 and 2024; which added two or four Castor-4AXL motors to a pair of SRB-As, however these variants are no longer available.
The H-IIA made its first flight in August 2001, carrying a Vehicle Evaluation Payload and Laser Ranging Equipment (LRE), a small passive satellite. In the twenty four flights it has made to date, the H-IIA has achieved twenty three successful missions.
Its sole failure came during a November 2003 launch with a pair of IGS reconnaissance satellites, when one of the SRB-A boosters failed to separate from the first stage. The rocket was destroyed by range safety after it was determined that it would not be able to achieve orbit.
During its time in service, the H-IIA has undergone two minor booster upgrades; the first being the introduction of enhanced SRB-A boosters in 2005, and the second being the replacement of the SRB-A with SRB-A3 motors from 2008 onwards. Further upgrades are planned, with next year’s launch of Telstar 12V expected to introduce an upgraded second stage.
The launch of H-IIA No.25 began with the ignition of its LE-7A first stage engine, with ignition of the solids and liftoff timed to occur when the countdown reaches zero. The rocket flew East from Tanegashima, along an azimuth of 96 degrees towards a near-equatorial orbit.
The solid rocket motors burned for 98 seconds, burning out at an altitude of around 45 kilometres (28 miles). The spent boosters will separated ten seconds after burnout.
Separation of the payload fairing occurred four minutes and five seconds after liftoff, at which point the rocket was at an altitude of 142 kilometres (88.2 miles), well above the dense parts of the atmosphere which the fairing is designed to protect its payload from.
The first stage continued to burn until the six minute, thirty six second mark in the flight, at which point its engine shut down. The first stage was jettisoned eight seconds later, with second stage ignition timed to occur after a further six seconds’ coast.
During Tuesday’s mission the second stage made two burns. The first, lasting five minutes and twenty-two seconds, followed by an eleven minute, 38-second coast phase. The second burn then lasted three minutes and seventeen seconds, to inject Himawari 8 into its planned geosynchronous transfer orbit.
The target orbit for the launch is 250 by 35976 kilometres (155 x 16,141 statute miles, 135 x 14,026 nautical miles), at an inclination of 22.4 degrees. The spacecraft will use its own propulsion system to reach an equatorial geostationary orbit.
Tuesday’s launch took place from pad 1 of the Yoshinobu Launch Complex at Japan’s Tanegashima Space Centre.
Built for the H-II in the early 1990s, this pad has been used for all H-II and H-IIA launches, while the second pad of the complex – which was built as a backup for the H-IIA in 2000 – is used by the larger H-IIB.
The Himawari 8 launch was the thirty-sixth from the Yoshinobu Launch Complex and the thirty-second from pad 1.
The launch of Himawari 8 was the sixty-first orbital launch of 2014 and the third conducted by Japan. The two previous Japanese launches both used H-IIA rockets, the first carrying the GPM Core Observatory mission in February, and the second carrying the Daichi 2 Earth observation satellite in May.
Another H-IIA launch is planned for late next month, carrying the Hayabusa 2 asteroid probe. This is expected to be Japan’s last launch of the year.