Development of the ARICA-2 Satellite Using Spresense as an Onboard Computer

Gamma-ray bursts (GRBs) are transient astronomical phenomena that emit enormous amounts of energy in electromagnetic waves, mainly in the gamma-ray range, for several seconds to tens of seconds. GRB observations are challenging because of the difficulty in predicting the location and time of occurrence and its extremely short duration. Therefore, it is necessary to notify about the discovery in space and to conduct follow-up observations by researchers. The AGU Remote Innovative CubeSat Alert system-2 (ARICA-2) has been developed to demonstrate a new alert system using commercial satellite network services. ARICA-2 uses SONY’s Spresense as its onboard computer (OBC). We manufactured the special board to attach two Spresenses as a redundancy of the OBC system. We will present the system development of ARICA-2 using Spresense

Power System Development of the AGU Remote Innovative CubeSat Alert System -2 – ARICA-2

We present the power system development of the 2U CubeSat, AGU Remote Innovative CubeSat Alert system -2(ARICA-2). The main goal of the ARICA-2 project is to demonstrate the real-time alert system of transient astronomical sources using commercial satellite network devices. 1U CubeSat ARICA was launched in November 2021. However, we have not been able to send and receive the data at this point. Therefore, we started developing 2U CubeSat ARICA-2, which is an improved version of ARICA, in April 2022. One of the possible causes of the communication problem of ARICA is the power system, such as a negative power budget or a failure in the installation of the inhibit switches. ARICA-2 is upsized from 1U to 2U to ensure a sufficient power generation and is equipped with improved inhibit switches. The calculation of power consumption and simulation of power supply on orbit have been finished. We confirmed the performance of our Electric Power System (EPS) and the health of the installed batteries. We are currently in the EM development phase with the goal of launching in Japanese fiscal year 2024

Overview and Status of AGU Remote Innovative Cubesat Alert System-2 on 2023

We present the overview of the 2U CubeSat, AGU Remote Innovative Cubesat Alert system - 2 (ARICA-2). ARICA-2 was selected as a feasibility study phase of the JAXA-Small Satellite Rush Program (JAXA-SMASH) and the JAXA Innovative Satellite Technology Demonstration-4 project in 2022. The main goal of ARICA-2 is to demonstrate the real-time alert system of transient astronomical sources, such as gamma-ray bursts, using commercial satellite network services. The first 1U CubeSat ARICA, which had the same mission goal as ARICA-2, was successfully launched in 2021 by the JAXA’s Epsilon rocket No.5. However, communication with ARICA has yet to be established due to severe hardware issues. Therefore, ARICA-2 is the re-challenging mission of ARICA. ARICA-2 has several different features compared to ARICA. First, a transceiver using amateur radio frequency is added to the commercial satellite network devices to communicate directly from the ground. Second, ARICA-2 uses Sony’s low-power board Spresense as an onboard computer. Third, the attitude control system using magnetorquer is installed to establish better communication with the commercial network satellites. Fourth, the size of a gamma-ray detector is 70 mm x 70 mm x 10 mm, which is larger by a factor of 200 in volume compared to ARICA, to enhance the detection rate of gamma-ray bursts. We plan to develop the engineering model (EM) in 2023 and perform thermal vacuum and vibration tests on the EM. We report the current status and a prospect of ARICA-2

Development and Performance of the Engineering Model of ARICA-2

We present the status of the engineering model (EM) of 2U Cubesat, AGU Remote Innovative Cubesat Alert system-2 (ARICA-2). The main goal of ARICA-2 is to demonstrate the real-time alert system of transient astronomical sources, such as gamma-ray bursts (GRBs), using commercial satellite network services such as Iridium and Globalstar. In parallel, we have a dedicated amateur mission to provide a store and forward capability for communication among amateurs. The GRB alert and the housekeeping data are also broadcast through the amateur CW transmitter. ARICA-2 was selected as one of the JAXA Innovative Satellite Technology Demonstration-4 projects in 2022 and is scheduled to be launched in the Japanese fiscal year 2025. The communication component of ARICA-2 has two commercial satellite network devices: Inmarsat\u27s SBD9603N, Globalstar\u27s STX-3, and the UHF transmitter using 435 MHz amateur frequency. The onboard computer is Sony\u27s Spresense, low-power, and six-core microcontroller board. Thanks to its multi-core processor, Spresense can run tasks in parallel by processing in individual cores, which reduces the risk of a single failure. The gamma-ray detector comprises two layers of scintillator crystals, Csl(TI) and EJ-270. The scintillation lights of each crystal are read out by eight chips of Hamamatsu\u27s MPPC S14160-6050HS. The attitude control component consists of three-axis magnetic torques, a gyro sensor, a magnetic sensor, and infrared cameras. The infrared cameras work as the Sun\u27s and the Earth\u27s sensors. The EPS, battery, solar panels, and a 2U structure are space-qualified components of ACC-Clyde Space Inc. The development of the engineering model (EM) started in August 2023. We complete the manufacture of most of the components in February 2024. And then, the integration of the EM finished on May 2024. We report the development and various test results of the EM of ARICA-2