ESA Document - Emits - ESA

s
HMM
Assessment Study
Report: CDF-20(A)
February 2004
page 105 of 422
Risk
acceptability
Risk domain & scenario (indicative nature) Reason-status
Unacceptable 1. Maximum likelihood with catastrophic 3. Numerous critical areas
consequences:
with uncertain
1. Human factors inadequate to mission.
environment definition.
2. EVA Suits inadequate to environment. 4. Research level only.
3. Inadequacy to radiation environment. 5. New project beyond the
4. Landing on Mars failure.
status of the art.
5. ECLSS failure.
6. High level of autonomy
2. Maximum likelihood with critical consequences. required for operations.
Failures during AIV activities
Highly complex Program.
Acceptable if 7. Medium likelihood with critical consequences. 8. Qualified technologies but
reduction Communications loss.
never applied in projects.
impossible
Numerous modifications of
qualified product.
Acceptable Others Defined environmental
conditions, qualified products,
existing processes & facilities.
2.9.8 Risk assessment process example
Table 2-40: Risk acceptability
Figure 2-59 shows how the analysis is done, following the sequence of steps already mentioned
at section 2.9.5.
Loss of
ECLSS
Analysis performed per Mission
Phase
Loss of
Propulsion
Loss of
DHS
Scenario
Loss of
THM
OR
Loss of
Comms
OR
Loss of
MEV
Loss of
TCS
Loss of mission
Mission Objectives NOT met
Loss of
PWR
Loss of
ERC
OR
Loss of
crew
Crew
Sickness
Loss of
Structure
Figure 2-59: Risk assessment process
Loss of life
OR
Likelihood depends on:
•Technology readiness
status;
•Redundancy;
•Abort capabilities, etc
Loss of
Mech.
Crash at
landing
Illness
…
…