This segment covers the period from 05 June 2021 to 10 September 2021 (before and including part of the long eclipse season 2021) and has 140% data volume until orbit 3336 and 130% after. For the eclipse season the payload will be off, the dates are: * C1: 08/09/2021 12:00 - 18/09/2021 12:00 * C2: 08/09/2021 12:00 - 16/09/2021 12:00 * C34: 06/09/2021 06:00 - 14/09/2021 12:00 There are no moon eclipses during this segment. There will be manoeuvres on 11th June 2021 on C123, the full list of manoeuvres for this period is included here http://jsocwiki.rl.ac.uk/attachment/wiki/WikiStart/manoeuvres_aug2020_nov2021.pdf. Cluster crosses the predicted magnetopause until: C1 - 21/06/2021, C2 - 24/06/2021, C34 - 17/06/2021. Cluster crosses the predicted neutral sheet from: C12 - 09/07/2021, C34 - 10/07/2021. The main science targets are the Cluster/MMS conjunctions at the magnetopause and inside the magnetosheath, skimming magnetopause, conjunctions in the plasmasheet between Cluster with MMS and/or THEMIS, and hiss origin. The BM1 data for the PEACE/WHISPER cross-calibration in the magnetosheath also will be collected once per month. '''Sceince planning for the last three orbits of the MSP45.1, orbits 3348-3350, was changed on 24/06/2021 to accommodate the start of the eclipse season. A number of the burst mode intervals has been changed/removed, please see new issued files *UPDATED_24062021* in the MSP45.1 attachment list. '''Science planning for orbits 3336-3338 (Planning Period 1085) was changed on 10/07/2021 to reduce the data volume to 130%. '''Science planning for orbits 3339-3350 (Planning Periods 1086-1089) was changed on 13/07/2021 to reduce the data volume to 130%.