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<\/p>\nJapan\u2019s experimental radar imaging satellite ASNARO-2 was launched Thursday aboard the third flight of the Epsilon rocket. Liftoff \u2013 from the Uchinoura Space Centre \u2013 occurred at the opening of a twenty-four-minute, two-second window opening at 06:06:11 local time (21:06 UTC on Wednesday).\n<\/p>\n
Japan\u2019s first launch of 2018, Wednesday\u2019s mission was originally scheduled towards the end of last year, before an electrical issue with the rocket delayed its liftoff. Epsilon was tasked with deploying the ASNARO-2 satellite into a sun-synchronous low Earth orbit.<\/p>\n
Advanced Satellite with New System Architecture for Observation 2 \u2013 or ASNARO-2 \u2013 is the second in a series of experimental Earth imaging satellites operated by Japan Space Systems, formerly the Institute for Unmanned Space Experiment Free Flyer (USEF).<\/p>\n
A radar imaging mission, it follows the ASNARO-1 optical satellite that launched aboard Russia\u2019s Dnepr rocket in November 2014. The mission is funded by Japan\u2019s Ministry of Economy, Trade and Industry through its New Energy and Industrial Technology Development Organisation (NEDO).<\/p>\n
ASNARO-2 was constructed by NEC, and is based on the modular NEXTAR NX-300L platform. It measures 3.9 meters (12.8 feet) in length and 1.5 meters (4.9 feet) in height and width, excluding its solar panels and radar antenna. The satellite has a mass of 570 kilograms (1,257 lb) \u2013 including its 220-kilogram (485 lb) payload and 45 kilograms (99 lb) of propellant.<\/p>\n
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ASNARO-2 \u2013 via JAXA<\/p>\n
Two deployable solar arrays will generate electrical power for the satellite. At the end of the spacecraft\u2019s five-year design life, these are still expected to be generating at least 1,300 watts of power.<\/p>\n
ASNARO-2 will be operated in a near-circular sun-synchronous orbit, at an altitude of 505 kilometers (314 miles, 273 nautical miles) and an inclination of 97.4 degrees. It will orbit the Earth about once every 95 minutes.<\/p>\n
The spacecraft carries XSAR, a synthetic aperture radar (SAR) payload operating in the X band. This can be operated in three different observation modes: spotlight, strip mapping and scanning.<\/p>\n
Space Shuttle (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n The spotlight mode, where the instrument focusses on a small area of the Earth\u2019s surface, offers the highest resolution \u2013 one meter (3 feet) or better \u2013 with a swath width of 10 kilometers (6.2 miles, 5.4 nautical miles). In strip mapping mode, the satellite can image a longer strip of the Earth\u2019s surface in the direction of travel.<\/p>\n ASNARO-2 \u2013 via JAXA<\/p>\n This offers a resolution of better than 2 meters (7 feet) over a swath width of 12 kilometers (7.5 miles, 6.5 nautical miles). Scanning mode allows the satellite to image a wider area \u2013 with a swath width of at least 50 kilometers (31 miles, 27 nautical miles) \u2013 at a resolution of at least 16 meters (52 feet).<\/p>\n Japan\u2019s Epsilon rocket will undertake the ASNARO-2 launch. Epsilon, which made its debut in September 2013 with the Hisaki \u2013 formerly SPRINT-A \u2013 satellite. In its standard configuration, Epsilon is a three-stage all-solid rocket, however it can also fly with an optional liquid-fuelled fourth stage. Thursday\u2019s launch \u2013 designated Epsilon-3 \u2013 will use this four-stage configuration.<\/p>\n Epsilon (F3)<\/p>\n JAXA developed Epsilon to provide Japan a rocket capable of placing small satellites into orbit. It draws heavily on pre-existing components, with its first stage based on the SRB-A3 boosters used by the larger H-IIA rocket, and its upper stages derived from the older M-V vehicle. M-V, which Epsilon replaced, was retired in 2006 as its high cost-to-payload ratio made it uneconomical to operate.<\/p>\n During the gap between the M-V\u2019s retirement and Epsilon\u2019s introduction, JAXA relied on foreign rockets such as Dnepr to launch its small satellites.<\/p>\n The Epsilon launches from the same launch complex at the Uchinoura Space Centre that was used by the M-V \u2013 and earlier members of the Mu family of rockets. The Uchinoura Space Centre is one of Japan\u2019s two operational orbital launch sites. The facility was originally used by Japan\u2019s Institute for Space and Astronautical Science, or ISAS, one of three Japanese space agencies that merged in 2003 to form JAXA.<\/p>\n Before the merger, ISAS operated Japan\u2019s smaller rockets \u2013 Mu, Lambda and the country\u2019s sounding rockets \u2013 while the National Space Development Agency (NASDA) flew larger liquid-fuelled rockets from the Tanegashima Space Centre. While operated by ISAS, what is now Uchinoura was named the Kagoshima Space Centre.<\/p>\n The Mu rockets were rail-launched, so Uchinoura\u2019s Mu Centre launch complex was originally designed as a rail launcher. Now that the complex is used by the vertically-launched Epsilon, it has been modified and the former launch rail now serves as an umbilical tower.<\/p>\n Although it is Epsilon\u2019s third flight, Thursday\u2019s launch was the first to combine both the operational version of the rocket and the CLPS upper stage. The operational form of Epsilon, described by JAXA as \u201cEnhanced Epsilon\u201d at the time of its last launch \u2013 although this name seems to have been dropped \u2013 incorporates enhanced second and third stages over the original design that flew the vehicle\u2019s maiden flight. The second Epsilon used this \u201cEnhanced\u201d configuration, which is now the standard for all launches, while the CLPS was used on the first Epsilon launch.<\/p>\n Thursday\u2019s launch began with ignition of Epsilon\u2019s SRB-A3 first stage at the zero mark in the countdown. Epsilon lifted off and climbed quickly away from Uchinoura. The SRB-A3 burned for 108 seconds, propelling the rocket to a speed of 2.3 kilometers per second (1.4 miles per second). Following first stage burnout, the mission entered a brief coast phase as the vehicle continues to ascend.<\/p>\n<\/p>\n![\"\"](\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2018\/01\/2018-01-17-134634.jpg\")
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<\/p>\nSee Also<\/h4>\n
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