11.4        Establishment of radiation protection limits

a.              The project shall establish the radiation protection limits to be applied to the mission.

NOTE              These limits are established based on the policies and standards defined by the space agency for manned space flight (see ECSS-E-HB-10-12 Section 10.4, and ECSS-E-ST-10-11). Where there is more than one space agency involved, the radiation protection limits to be adopted by the project are normally agreed through consensus (e.g. through a working group of radiation effects experts from the different partner agencies).

b.              The radiation protection limits shall be defined in terms of the protection quantities in Clause 11.2.2 and the operational quantities in Clause 11.2.3.

NOTE              These limits can vary between different space agencies.

c.               Synergistic effects between radiobiological damage and other environmental stressors and the radiation protection limits specified in 11.4a shall be analysed.

NOTE 1      Example of such environmental stressors are microgravity, vibration, acceleration, and hypoxia

NOTE 2      For guidelines on the influence of spaceflight environment, see ECSS-E-HB-10-12 Section 10.5.7.

d.              The quality factors, radiation weighting factors and tissue weighting factors identified in Table 11‑1, Table 11‑2 and equation (3), shall be used to determine dose equivalent, organ equivalent dose and effective dose.

NOTE              It is the responsibility of the project manager to perform the trade-off between spacecraft and mission design and operation, and their effects on predicted crew exposure, in order to:

       achieve the defined protection limits, and

       ensure radiation protection is managed according to the ALARA (as low as reasonably achievable) principle.