Update on the Anomaly of “GRUS-3” Microsatellites in the AxelGlobe Business and Establishment of the “GRUS-3 Anomaly Review Advisory Board”

Axelspace Corporation (“Axelspace”) hereby announces an update regarding the anomaly of the “GRUS-3” microsatellites and the establishment of the “GRUS-3 Anomaly Review Advisory Board.”

As announced in the “Notice Regarding a Malfunction of ‘GRUS-3’ Microsatellites for the AxelGlobe Business” dated September 29, 2026, Axelspace confirmed an anomaly in the high-speed communication systems of four of the seven “GRUS-3” microsatellites launched on July 7, 2026 (JST), and subsequently reported its conclusion that restoring the high-speed communication systems and commencing commercial operations as originally planned would be difficult.

Axelspace has continued its investigation into the cause of the anomaly and has determined that the anomaly in the high-speed communication systems constitute a permanent failure and that, for the four affected satellites, commercial operations involving the downlink of image data through the high-speed communication systems as originally planned would be difficult.

In addition, in order to obtain an objective assessment of the presumed cause of the anomaly and the appropriateness of the measures to be applied to satellites scheduled for future launches, Axelspace announces that its parent company, Axelspace Holdings Corporation has decided to establish the “GRUS-3 Anomaly Review Advisory Board” (the “Advisory Board”), comprising external experts.

Update on the Anomaly of “GRUS-3”
Background Leading Up to the Disclosure of the Anomaly

Axelspace completed critical operations to verify the in-orbit health of the seven “GRUS-3” satellites on July 10, following their launch on July 7. Axelspace subsequently commenced initial operations, including attitude control checks, verification of onboard equipment functionality, and integrated system testing, to prepare the satellites for the provision of the planned image data services.

During the initial operations phase of a satellite, temporary anomalies may occur due to factors such as the space environment or inappropriate system settings. In such cases, recovery operations are conducted to restore normal functionality, including restarting or reconfiguring equipment and, where necessary, reprogramming software.

With respect to the anomaly in the high-speed communication systems, Axelspace investigated the issue in parallel with verification and recovery efforts aimed at restoring normal functionality as part of the initial operations. However, it became apparent that the issue was not a temporary anomaly but potentially a permanent failure of the high-speed communication systems, and because Axelspace reported its conclusion that recovery and the planned commercial operations would be difficult, Axelspace made the announcement on September 29.

Axelspace’s Assessment of the Cause

Axelspace presumes damage to the power amplifier within the high-speed transmitter used to downlink captured image data to be the most likely cause of the anomaly.

The satellites are generally equipped with two separate communication systems. One is a communication system used for satellite control operations (the “low-speed communication system”), which transmits and receives relatively small amounts of data used to monitor the health of the satellites from the ground and to receive commands from the ground, including information on satellite voltage, temperature, position and attitude, and the operational status of onboard equipment (collectively, “telemetry data”). The other is a communication system used to transmit large volumes of mission data, such as captured images, to ground stations at high speed (the “high-speed communication system”).

Both the high-speed and low-speed communication systems transmit data over long distances from space to the ground. However, the high-speed communication system must transmit data at a higher speed and therefore uses higher-frequency radio waves and a higher-power amplifier than the low-speed communication system to amplify radio-frequency signals before transmitting them to ground stations via an antenna.
Based on the analysis of the telemetry data from the four affected satellites and the verification test on ground, Axelspace presumes that insufficient thermal dissipation from the power amplifier caused the internal amplifier IC (an electronic component within the power amplifier that amplifies electrical power) to reach abnormally high temperatures and sustain damage.

Outlook for Operations

The amplifier ICs used in the affected power amplifiers are also installed on Axelspace’s “GRUS-1” satellites and have a track record of normal operation to date. Axelspace’s findings suggest that there was likely an issue with the thermal design associated with the design changes made to the high-speed communication systems installed on “GRUS-3.”

The three satellites that have not experienced the anomaly use the same design. For these satellites, Axelspace will seek to downlink data for commercial operations while preventing excessive temperature increases in the power amplifiers in the vacuum environment of space by reducing the power consumption and shortening communication durations.

As Axelspace has decided to conduct these operations carefully on a satellite-by-satellite basis, the planned commencement of commercial operations for these three satellites will also be postponed by two months from the previous target of commencing operations by the end of 2026, with commercial operations now targeted to commence in February 2027.

With respect to the four affected satellites, onboard systems other than the high-speed communication systems are operating normally. Accordingly, Axelspace does not intend to immediately deorbit these satellites and will consider potential commercial uses, including the possibility of providing images that can be obtained through the low-speed communication systems and utilizing telemetry data obtained from the satellites.

In response to these issues, Axelspace will implement modifications to the high-speed communication systems for satellites to be developed in the future.

The “GRUS-3” microsatellites are designed to be used for Earth observation for five years in low Earth orbit. In light of this incident, Axelspace will review its development processes and continue building its microsatellite optical constellation while pursuing the best measures currently available to improve the quality and reliability of satellites scheduled for future launches.

Purpose and Background of Establishing the Advisory Board

Axelspace takes seriously the anomaly in the high-speed communication systems of four of the seven “GRUS-3” satellites, as well as the postponement of the commencement of commercial operations using the three satellites that have not experienced the anomaly.

Axelspace has therefore determined that it is necessary to obtain opinions from independent third-party perspectives regarding its cause analysis, countermeasures, and other related matters, and has decided to establish the Advisory Board.

The main objectives of the Advisory Board are as follows:

・To review, from a third-party perspective, Axelspace’s internal technical analysis of the factors behind the high-speed communication systems anomaly affecting four “GRUS-3” satellites, as well as the validity of the countermeasures to be applied to satellites scheduled for future launches, and to obtain additional insights regarding relevant technical and systemic factors; and

・To obtain opinions from a third-party perspective regarding Axelspace’s satellite project management structure in connection with this incident and, by disclosing such opinions transparently, maintain relationships of trust with all stakeholders, including shareholders, customers, and government organizations.

Planned Activities of the Advisory Board

Axelspace will compile a report covering the technical information concerning the anomaly, its cause analysis, and future countermeasures, and will submit the report to the Advisory Board.

Based on the report, the Advisory Board will provide recommendations from a third-party perspective. In response to these recommendations, Axelspace will conduct additional investigations and testing as necessary and update its future countermeasures accordingly.

The final report is expected to be completed approximately one and a half months after the members of the Advisory Board have been finalized.

The members of the Advisory Board will be announced promptly once they have been confirmed.