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Potentially serious problem on BepiColombo Mercury mission

According to the European Space Agency (ESA), engineers have discovered what could be a potentially serious problem on BepiColombo mission that is presently on its way to Mercury.

The solar arrays and electric propulsion system on the Mercury Transfer Module are used to generate thrust during the spacecraft’s complex journey from Earth to Mercury.

However, on 26 April, as BepiColombo was scheduled to begin its next manoeuvre, the Transfer Module failed to deliver enough electrical power to the spacecraft’s thrusters.

A combined team from ESA and the mission’s industrial partners set to work the moment the issue was identified. By 7 May, they had restored BepiColombo’s thrust to approximately 90% of its previous level. However, the Transfer Module’s available power is still lower than it should be, and so full thrust cannot yet be restored.

The press release implies that this issue won’t prevent the spacecraft from entering orbit around Mercury as scheduled in December 2025, but one wonders how that could be if it doesn’t have sufficient power to do the proper course correction during its last major flyby of Mercury in September 2024. If it misses its precise route in ’24 it could miss Mercury entirely in ’25.

Engineers are analyzing the situation to see what can be done to get it to Mercury, while also trying to figure out what caused this power problem in the first place in order to fix it.

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  • Max

    The sun is very active, probably the leading cause of its problems.

    “A worst-case event could lead to significant losses in power generating capability—up to almost 8%—and cause up to four years’ worth of ionizing dose degradation, leading to component damage and a life-shortening effect on satellites.”
    Radiation Effects on Satellites During Extreme Space Weather Events

  • Max: Interesting, but I don’t think this particular paper applies. It specifically looks at the impact solar activity has on the Van Allen belts, which in turn could damage satellites in nearby orbits.

    BepiColombo has been traveling mostly in the inner solar system, far from the Van Allen belts. It was supposedly built for such travel, as were the Parker Solar Probe and Europe’s Solar Orbiter, both of which have been functioning without problems.

    At the same time, your point about the high solar activity is valid. It could be a factor that needs consideration. It could also be telling us that BepiColombo might not have been engineered properly for that activity.

  • Edward

    Another factor to consider is that these mass ejections are directed rather than omnidirectional. Not all solar flares hit the Earth, and not all hit Mercury. It depends upon which way they fly away from the Sun.

    Robert wrote: “At the same time, your point about the high solar activity is valid. It could be a factor that needs consideration. It could also be telling us that BepiColombo might not have been engineered properly for that activity.

    It shows the importance of radiation shielding for manned spacecraft that will travel outside the Earth’s magnetic field’s influence. Not only do the people have to be protected, but the sensitive parts of critical hardware also must be protected.

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