Swarm Alpha and Charlie orbit raise campaign starting on 3 May 2022 - Potential impact on data quality

29 Apr 2022

After more than eight years of operations, the Swarm constellation is continuing to provide multi-point measurements of the Earth’s magnetic field and ionospheric parameters with unprecedented accuracy.

A mission extension through to 2025 has recently been endorsed, and there are plans for further extensions to bring Swarm through Solar Cycle 25. To allow for this, it has been decided to perform a series of orbital manoeuvres to raise the orbit of the lower pair (Alpha and Charlie) to allow them to survive the enhanced drag expected during the upcoming solar maximum and hence prevent early re-entry.

This orbital raise is envisaged in multiple steps, with the first one starting on third of May, raising the altitude of Swarm Alpha and Charlie by about 45 km. According to the current planning, this first orbit raise campaign will be completed on 8 July 2022. The subsequent raise steps will be planned in the next years and will adjust the altitude of the Swarm spacecraft according to the evolution of the solar activity.

In this 10-week period, up to two manoeuvres per spacecraft will be performed per week, each lasting for up to two full revolutions. During these periods, attitude errors may affect the quality of Swarm L1b and L2 data.

Moreover, a substantial increase of Swarm Alpha and Charlie along track separation during the entire 3 May to 8 July interval, with a delay up to minutes instead of the usual 4-10 seconds, could result in degraded quality of a number of L1b and L2 Swarm data products. The Swarm data quality team will monitor these issues, and provide further details in the upcoming months.