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
