"抢险救援任务" can be translated into English as "emergency rescue and relief mission" or "emergency rescue and disaster relief operation".
Both translations are commonly used to describe tasks or operations aimed at responding to and mitigating the effects of emergencies, disasters, or other urgent situations. The choice between them may depend on the specific context or the emphasis you wish to place on the task (e.g., whether it's more focused on rescue or on broader disaster relief efforts).