Wednesday , June 16 2021

Japan's Epsilon leads the launch of RAPIS-1 –

Japan made its first launch in 2019 on Friday, using the small Epsilon rocket to launch seven satellites, including the RAPIS-1 technology demonstration mission, into orbit. Epsilon took off from the Uchinoura Space Center at the start of a nine-minute, 17-second window that opened at 09:50:20 local time (00:50 UTC).

The main charge for Friday's launch was the Rapid Rapid Demo Demonstration Satellite for Rapid Innovation, RAPIS-1, for Japan's Aerospace Exploration Agency (JAXA). Also known as the innovative technology demonstration satellite, this spacecraft aims to test components in orbit for potential use in future missions.

The 200-kilo satellite is cube-shaped, with one-meter sides, and was built by Axelspace in conjunction with JAXA. RAPIS-1 will operate in orbit synchronized with the sun.
RAPIS-1 will run for at least one year. At that time, it will test various technologies in orbit. These include a nanobridge field-programmable gate array (NBFPGA) that will be evaluated for use in future integrated circuit chips, an X-band communications payload incorporating a high data rate transmitter and medium gain antenna, and a reaction control. maneuvering the satellite using greener propellers.

Other experiments include a particle monitor and star trackers that incorporate a deep machine learning to determine the attitude of the satellite.

The Fireant is a miniaturized low-power receiver that will use navigation satellite signals to track the position of RAPIS-1 in orbit.

Finally, the satellite will be powered by lightweight solar panel prototypes, consisting of five lightweight panels mounted on a movable plate that will be extended as soon as the RAPIS is in orbit to generate about 100 watts.
Six small satellites accompanied RAPIS-1 during its ascent on Friday.

These include Astro Live Experiences 1 (ALE-1), a 150-kilogram (68 kilogram) spacecraft for the Japanese company Astro Live Experiences, which will be used to generate artificial meteor showers. The satellite will eject small pellets into the atmosphere – each measuring about one centimeter (0.4 inches) in diameter – that will burn in an area designated for the enjoyment of viewers. ALE-1 is a prototype designed to demonstrate the concept before larger satellites are launched to offer this service in the future.

Hodoyoshi-2, also known as Rapid International Scientific Experiment Satellite (RISESAT), is a 50 kilogram satellite for an international research consortium led by the University of Tokyo. It carries a high-precision telescope to study how Earth reflects sunlight, two cameras to record transient light events (TLEs) – a phenomenon in the upper atmosphere of Earth – and study the surface of the oceans. The Hodoyoshi-2 also incorporates a magnetometer, radiation detectors, a dosimeter and an optical communication experiment. In addition, the satellite will be used to collect and transmit data from environmental monitoring stations.

The MicroDragon of Vietnam's National Satellite Center is a 50-kilogram satellite built to study the coastal regions of Vietnam, collecting data to help determine water quality, locate regions for fishing and monitor changes in the country's coastline.

The other three satellites aboard the Epsilon were CubeSats. OrigamiSat-1 was built for the CubeSat standard of three units, measuring 10 by 10 by 34 centimeters (3.94 by 3.94 by 13.39 inches). The satellite will be operated by the Tokyo Institute of Technology. Once in orbit, the OrigamiSat will test the implantation of a membrane structure, observing its behavior according to the implantation and its final form. The satellite is also equipped with an amateur radio charge.

The NEXUS satellite from Nihon University is a single unit CubeSat that is equipped with a camera and an amateur radio transponder. The purpose of the satellite is to demonstrate its amateur radio system, which should allow for faster data re-routing than comparable existing satellites. The Aoba VELOX IV satellite is a two-unit CubeSat that was developed jointly by Japan's Kyushu Institute of Technology and Singapore's Nanyang Technological University.

Aoba VELOX IV will test in Earth's orbit a camera designed to study the brightness of the lunar horizon – a phenomenon in which a bright light was observed just after sunset on the surface of the Moon. Once demonstrated, a similar camera could be sent on a future mission to study this brightness of the lunar orbit. The Aoba VELOX IV will also test pulsed plasma propellers and transmit the telemetry in its subsystems to the ground for evaluation.

Friday's launch was the fourth Epsilon flight from Japan, launched in 2013. The launch came one year after the third rocket flight, which used the experimental ASNARO-2 radar imaging satellite on January 18, 2018 ( January 17 in UTC). ).

Epsilon was developed as a successor to the previous series of Mu rockets, which Japan used to launch its smaller science and technology satellites. The last member of the Mu family, the M-V, was retired in 2006 with foreign launches and opportunity sharing on the H-IIA rocket, used to bridge the gap before the Epsilon debut. Epsilon is designed to leverage existing components by combining the upper stages of the M-V with a first stage derived from the SRB-A3 propellers used in the H-IIA, although from the second flight the updated versions of the M-V stages have been used.

At its core, the Epsilon rocket is a solid three-stage vehicle, yet it can also fly in a four-stage configuration with the Compact Liquid Propulsion System (CLPS). This liquid-fueled upper refreshed stage can provide an extra boost to the rocket payload and ensure delivery to an accurate orbit. The CLPS will be used in conjunction with Epsilon for Friday's launch.

Epsilon launches take place at Mu Center, a launch complex of the Uchinoura Space Center that was originally built as a rake launcher for the Mu rocket series. After the M-V was removed, the block was converted to allow the Epsilon to be launched vertically, with the old launch rail remaining in place to serve as an umbilical tower.

Uchinoura Space Center – via JAXA

At the zero mark on Friday's countdown, the first stage of Epsilon was fired and the rocket took off to start climbing toward orbit. Its SRB-A3 engine burned for 108 seconds, accelerating the Epsilon at a speed of 2.3 kilometers per second. After it was exhausted, the rocket stopped – 43 seconds later, at an altitude of 151 kilometers (76 miles, 66 nautical miles). Ten seconds after the fairing split, the first Epsilon spent stage was discarded, with the ignition of the second stage occurring four seconds thereafter.

The second stage of the Epsilon is an M-35, derived from the M-34 that makes up the third stage of the previous M-V rocket. The M-35 fed the Epsilon flight for 129 seconds, before another coast of 96 seconds until separation. The third stage, the KM-V2c, began to burn four seconds after separating the second stage, firing for 88 seconds. KM-V2c is derived from the upper stages of KM-V that were used in conjunction with M-V.

The third stage and the CLPS separated 112 seconds after the burnout, but the upper stage did not come on for another 285 seconds. The CLPS performed a complex seven-burn mission to deploy each Epsilon payload into its prescribed orbits, ensuring adequate separation between them. The first burn lasted five minutes, and after a coast of 23 minutes and 38 seconds, a burn of six minutes and 32 seconds set the stage in the correct orbit for RAPIS-1. The separation of the spacecraft came 126 seconds after the end of the second firing.

With RAPIS-1 successfully deployed, the CLPS waited nine minutes and 16 seconds before performing a 17-second recording. Hodoyoshi-2 was implanted 112 seconds after completion of the burn. Twenty-three seconds later, the fourth stage performed a three-second, 74-second firing before the MicroDragon was deployed.

After another 24 seconds, a two-second firing followed by a seventy-four second coast to provide spacing to deploy the OrigamiSat. The twenty-four-second coastline cycle, two seconds of burning and seventy-four seconds of coastline was repeated for the next unfolding, which made NEXUS and Aoba VELOX IV separate. Twenty-three seconds later, the CLPS started burning last, firing for four seconds and placing ALE-1 seventy-three seconds after the burn was completed.

Friday's launch was the first of 2019 in Japan, after a year in which the country made six successful orbital launches. It is Epsilon's first launch in exactly one year and is currently expected to be the only rocket flight in 2019 – with its next mission scheduled for 2020 with yet another demonstration satellite.

Japan has not yet announced a date for the country's next satellite launch. However, several are expected by the end of this year, including data transfer and the Information Rechar Satellite (IGS) reconnaissance spacecraft via H-IIA vehicles and HTV-8 (Kounotori 8) to the International Space Station on board an H-IIB.

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