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|Placed by: Modelraketten.NL on 15-06-17 13:15 | E-mail: info(at)modelraketten.nl|
Successful Launch of H-IIA Launch Vehicle No. 34 Encapsulating MICHIBIKI No. 2
June 1, 2017 (JST)
Mitsubishi Heavy Industries, Ltd.
National Research and Development Agency Japan Aerospace Exploration Agency (JAXA)
Mitsubishi Heavy Industries, Ltd. and JAXA successfully launched H-IIA Launch Vehicle No. 34 (H-IIA F34) which encapsulates MICHIBIKI No. 2, Quasi-Zenith Satellite System at 9:17:46 a.m. on June 1, 2017 (JST) from JAXA’s Tanegashima Space Center. The launch and flight of H-IIA Launch Vehicle No. 34 proceeded as planned and the separation of the satellite was done 28 minutes 21 seconds after the launch time.
Overview of the Quasi-Zenith Satellite System (QZSS)
QZSS is a Japanese satellite positioning system composed mainly of satellites in quasi-zenith orbits (QZO). However, the term “Quasi-Zenith Satellite (QZS)” can refer to both satellites in QZO and geostationary orbits (GEO). For that reason, the name “QZO satellite” is used when it is necessary to specifically refer to satellites in QZO.
Satellite positioning systems use satellite signals to calculate position information. One famous example is the American Global Positioning System (GPS); the QZSS is sometimes called the Japanese GPS.
Complements GPS for a satellite positioning service that is more precise and stable
Satellite positioning is possible with four or more satellites, but eight or more satellites are regarded as necessary for stable position information. But since GPS satellites are stationed across the globe, some of these satellites cannot be seen on the reverse side, and in general only six satellites are constantly visible at a given location.
When QZSS (Michibiki) becomes a four-satellite constellation in 2018, three satellites will be visible at all times from locations in the Asia-Oceania regions. QZSS can be used in an integrated way with GPS, bringing the number of satellites to eight or more (six GPS satellites and three QZS) and making stable, high-precision positioning possible. QZS are compatible with GPS and receivers can be procured at a low cost, so it is expected that position information businesses utilizing geographical and spatial information will be developed.
Even when the QZSS is a four-satellite constellation, stable positioning will not be available at some times in urban areas and mountainous regions due to the reduced number of satellites that can be seen behind buildings and mountains. Accordingly, efforts will be made to establish a seven-satellite constellation in the future and to obtain accurate position information even in urban areas and mountainous regions.
|H-IIA rocket launches GCOM-C | Reaction of: DRRA-KJvTil on 25-12-17 14:40 | E-mail: info(at)drra.nl|
|Japan launched the second satellite of its Global Change Observation Mission Saturday. The GCOM-C satellite lifted off from the Tanegashima Space Centre atop an H-IIA rocket at the start of a 22-minute window that opened at 10:26:22 local time (01:26 UTC).
Saturdays launch, also lofting the Super-Low Altitude Test Satellite (SLATS), was Japans seventh of the year. It came two and a half months after the rockets previous mission delivered the fourth QZSS navigation satellite into orbit.
Saturdays launch marked the fiftieth flight of Japans H-II family of rockets. Japans first fully-indigenously-developed liquid-fuelled rocket, the H-II first flew in February 1994. It replaced the H-I, which used a license-built version of the American Thor rocket as its first stage and Japanese upper stages. It was Japans fourth liquid-fuelled orbital launch system overall, but the N-I and N-II that preceded H-I also used license-built components from the American Thor and Delta rockets.
The original H-II made seven flights between 1994 and 1999. Its core vehicle consisted of two stages burning cryogenic propellant, with two large solid rocket motors attached to the first stage. For the rockets third flight, which orbited the Himawari 5 weather satellite and the recoverable Space Flyer Unit (SFU) – which was returned to Earth by Space Shuttle Endeavour during the STS-72 mission – H-II also flew with two additional, smaller, solids.
The H-II's last two launches both failed. Its penultimate launch, which carried an experimental communications satellite – COMETS – reached a lower-than-planned orbit due to a second stage malfunction. The final flight – the only one to use the H-IIS configuration which included an upgraded second stage with an LE-5B engine instead of the earlier LE-5A – failed to achieve orbit resulting in the loss of the MTSAT-1 spacecraft. An investigation discovered that a blade in one of the first stage turbopumps, responsible for feeding liquid hydrogen into the LE-7 engines combustion chamber, had fractured – causing the pump to fail and the engine to shut down prematurely.
Citing cost and reliability, Japan abandoned the H-II in favor of an upgraded rocket, the H-IIA. A launch that had been planned for 2001 was canceled – its payloads were eventually flown aboard H-IIA rockets and the final rocket was placed into storage at Tanegashima.
The H-IIA first flew in August 2001, introducing an upgraded first stage powered by an LE-7A engine, and a second stage powered by the LE-5B. Like the H-II, solid rocket motors would be used to provide additional thrust at liftoff, although the H-IIA's SRB-A motors are smaller than the H-II's. Depending on mission requirements, H-IIA can fly with two or four SRB-A motors – the 202 and 204 configurations. Two earlier configurations that used two SRB-A motors alongside two or four US-built Castor-4AXL boosters – the H-IIA 2022 and 2024 – have since been phased out.
H-IIA Launch – Photo By JAXA
During thirty-six flights before Saturdays launch, the H-IIA has achieved thirty-five successes. Its only failure came in 2003 during the rockets sixth flight, which was aiming to deploy a pair of IGS reconnaissance satellites for the Japanese government. One of the SRB-A boosters failed to separate from the rocket, which was later destroyed by range safety after it became clear that it was not going to achieve orbit.
Since its introduction the H-IIA has carried critical missions for JAXA and the Japanese government, including reconnaissance satellites, scientific, technology demonstration, communication and weather satellites. H-IIA rockets launched the SELENE (Kaguya), PLANET-C (Akatsuki) and Hayabusa 2 missions to the Moon, Venus and asteroid (162173) Ryugu. In recent years the rocket has also begun to attract interest from commercial satellite operators, making its first dedicated commercial launch in late 2015 with the Telstar 12V communications satellite aboard.
The H-IIA has been upgraded continually, with changes including more powerful SRB-A3 boosters that were introduced in place of the earlier SRB-As and enhancements to the second stage that allow it to perform missions involving extended coast periods and multiple restarts. During Saturdays launch the stage will be called upon to make three burns.
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